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The transition from a fossil-based to a biobased chemical sector requires developing technologies to produce biobased chemicals that can replace the current market needs already supplied by fossil-based chemicals. Terephthalic acid is an important monomer for producing polyethylene terephthalate typically used to manufacture plastic bottles and textiles. Alternatively to the fossil-based route (naphtha cracking), terephthalic acid can be produced using biomass as feedstock through biochemical and thermochemical routes. The biochemical route involves the chemical and enzymatic conversion of biomass to sugars, while the thermochemical involves the thermal conversion to bio-oil. This study compares the environmental performance of both routes for terephthalic acid production using Miscanthus as feedstock. Miscanthus is a potential crop for biofuels and biochemicals due to its highly efficient use of water and resources (nitrogen, phosphorus). A life cycle assessment framework is used to quantify the environmental impact of both conversion routes using a cradle-to-gate approach. The influence of the inventory data quality and the contribution to the environmental impact is evaluated using uncertainty and hotspot analyses. The thermochemical route showed better environmental performance (higher than 50%) in most selected impact categories than the biochemical route. Energy requirements and enzyme production were the main contributors to the performance of the thermochemical and biochemical routes, respectively. | Categorize the text article into one of the two categories:
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Next-generation bioprocesses of a future bio-based economy will rely on a flexible mix of readily available feedstocks. Renewable energy can be used to generate sustainable CO2-derived substrates. Metabolic engineering already enables the functional implementation of different pathways for the assimilation of C1 substrates in various microorganisms. In addition to feedstocks, the benchmark for all future bioprocesses will be sustainability, including the avoidance of CO2 emissions. Here we review recent advances in the utilization of C1-compounds from different perspectives, considering both strain and bioprocess engineering technologies. In particular, we evaluate methanol as a co-feed for enabling the CO2 emission-free production of acetyl-CoA-derived compounds. The possible metabolic strategies are analyzed using stoichiometric modeling combined with thermodynamic analysis and prospects for industrial-scale implementation are discussed. | Categorize the text article into one of the two categories:
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The raising environmental concerns related to fossil fuel-based plastic packaging resulted in policy efforts for reducing their use and introducing bio-based materials. However, the availability of bio-based material suppliers may be currently limited. At the industrial level, Life Cycle Assessment (LCA) can provide decision support to companies willing to substitute fossil fuel-based with bio-based plastic packaging. In this context, a detailed modelling of the plastic supply chain can markedly alter the LCA results and the consequent interpretation. The present work is based on preliminary results from the Italian project “Plastic New Deal”, which aims to support small enterprises on substituting fossil fuel-based plastic with other materials. The goal of this study is to investigate the variability of LCA results related to the substitution of fossil fuel-based low-density polyethylene (LDPE) with bio-based LDPE (bio-LDPE) and polylactic acid (PLA), used as film for packaging. A total of 11 scenarios was built, modelling the country of plastic manufacturing and type of feedstock. LCA results of bio-based plastics by country vary up to +165% and -95% with respect to the average, which is much higher than the one of fossil fuel-based LDPE across all the impact categories considered in the study. This is due to the additional variability in the cultivation and conversion processes, originated from different types of feedstocks. Uncertainties on End-of-Life (EoL) treatment processes of plastic packaging and on accounting for life cycle biogenic carbon dioxide exchanges might further alter the LCA results for the climate change total category. The present paper attempts to highlight potential issues associated to a generic LCA which does not sufficiently account for the company context, empowering the accuracy of LCA as decision support tool and opening a discussion on how to improve the reliability of practical LCA recommendations. | Categorize the text article into one of the two categories:
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Microreactor studies and radiochemical tracer techniques have been used to investigate the effect of carbon dioxide on the methanol synthesis activity of catalysts derived from binary rare earth/Cu precursors and from ternary rare earth/Cu/Ti, Zr or Al precursors. In the former case, carbon dioxide causes strong irreversible deactivation. However, the inclusion of a third metal component significantly enhances poisoning resistance without undue loss of the very high activity exhibited by the binary materials. Results obtained with14CO2 indicate clearly that the methanol product is derived principally from carbonmonoxide: the catalytic mechanism which operates on this novel class of materials must therefore be quite different from that which is characteristic of conventional Cu/ZnO/Al2O3 catalysts. | Categorize the text article into one of the two categories:
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In recent decades, cleaner production has received increasing attention since it can contribute to achieving the United Nations Sustainable Development Goals (SDGs), including poverty reduction, sustainable consumption and production, and climate change mitigation. This study aims to use the Life Cycle Assessment-ReSOLVE method to find and quantify the main environmental impacts that happen along the production chain. It will also look at how each production stage contributes to these effects and then discuss ways to fix these problems using the circular economy approach and the ReSOLVE framework in the case study. Although this study used a mushroom-growing facility in the Central Highlands of Vietnam as a case study, the approach can be applied to other industries and countries worldwide. The LCA helped identify environmental hotspots, which were areas with significant environmental impact. The data on these hotspots were used to evaluate the ReSOLVE framework to determine appropriate circular practices for improving mushroom cultivation's environmental impacts. The results showed that electricity consumption and plastic baskets are the primary hotspots for environmental impacts, especially greenhouse gas emissions. Greenhouse gas emissions while growing shiitake mushrooms (Lentinula edodes) were 2.38 kg CO2e/kg mushroom, of which energy use contributes to 72.87% of the emissions. The evaluation findings obtained from the ReSOLVE framework indicate that the facility is now implementing 17 out of 42 circular practices. The facility significantly prioritizes process optimization, implementing eight practices, and places a strong emphasis on regeneration, implementing five practices. According to the study's findings, practitioners should adopt this approach to support businesses in achieving sustainable development. Practitioners should tailor the circular practices in the ReSOLVE framework to the industry in which they evaluate and implement the suggested circular economy solutions to assess the effectiveness of using both the ReSOLVE framework and CE solutions. Moreover, this study only focused on a mushroom facility as a case study. Consequently, we want to enhance the methodology and extend this approach to other sectors in future research. | Categorize the text article into one of the two categories:
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Traditional methanol production from natural gas is well-studied, but there is a lack of research on environmentally optimizing bio-based methanol production. This study focuses on optimizing the combined production of bio-methanol and power from bio-oil using a comprehensive bio-process model. The research includes a novel framework for environmental, technical, and economic optimization of bio-oil to methanol and power to determine the most eco-friendly and cost-effective approach. An organic Rankine cycle (ORC) is also integrated for waste heat recovery. The results of this study revealed that the bio-based process with ORC showed a 22.6% reduction in global warming potential impact (GWP) per kilogram of methanol, compared to the bio-based process without ORC. Also, by implementing the most environmentally friendly process, GWP will be reduced by 70.6% per kg methanol compared to base sub-optimal operation. The results showed that for the process with the addition of ORC, after performing multi-objective optimization, under the optimal conditions, the economic annual rate of return increased from 19.6% to 34.7%. Finally, it was revealed that if the considered technology is commercialized, for every percentage of the methanol market it gains, it will contribute to 2.176 million tons CO2-eq/year less emissions. | Categorize the text article into one of the two categories:
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Multilayer plastic packaging is difficult to recycle and perceived as an environmental problem, despite its valuable protective properties. This study examines environmental impacts and recyclability of six representative packaging solutions for bacon in block. Moreover, it takes into account the environmental impacts of the packaged product. The examined flexible packaging include two thermoformed films (polyamide (PA)/polyethylene (PE) & PE/ethylene vinyl alcohol (EVOH)), two vacuum bags (both PA/PE), and two shrink bags (PE/polyvinylidene dichloride (PVdC) & PA/EVOH/PE). A cradle-to-grave Life Cycle Assessment (LCA) was conducted. We assessed the recyclability of the different packagings by using the RecyClass tool, and compared the carbon footprint of the packaging with the carbon footprint of the packaged meat. The environmental impacts depend largely on the packaging weight and on the content of PA. Climate change results range from 26.64 g CO2-equivalents for the PVdC-containing shrink bag to 109.64 g CO2-equivalents for the PA-containing thermoformed film. Even if the recyclable PE/EVOH film is recycled, its climate change result (51.75 g CO2-equivalents) is considerably higher than the result for the PVdC-containing shrink bag. Only the PE/EVOH film can be recycled, however, with considerable loss of quality. Carbon footprint of the packaged bacon is on average 54 times higher than carbon footprint of packaging. Given the relatively low environmental significance of packaging compared to the packaged meat, optimal product protection should be priority for packaging designers. Weight reduction is preferable to improved recyclability. We recommend assessing recyclability and impacts of the packaged good alongside with packaging LCA to highlight potential conflict of interests and to avoid burden shifting. | Categorize the text article into one of the two categories:
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The construction industry is responsible for several environmental impacts, such as high consumption of raw materials and energy, significant contributions to global CO2 emissions, and waste production. Furthermore, concerns regarding waste and by-products valorization have been growing recently, particularly for plastic waste, whose integration into building materials components is under investigation. Different applications of polyethylene terephthalate (PET) have emerged, particularly for nonstructural purposes, with potential benefits as thermal insulation solutions, showing that further studies should be conducted for a more detailed analysis and characterization of this type of building solutions. In this context, the current study contributes to the thermal and environmental performance characterization of alternative materials composed of PET bottle panels filled with soil, water, and air. An experimental evaluation of the thermal performance and a Life Cycle Assessment (LCA) were conducted considering the horizontal and vertical positions of the bottle panels. The lowest values of the thermal transmission coefficient were observed for the PET bottles filled with soil, achieving 0.46 W/m2°C for the vertical position. Regarding LCA, the panel with empty bottles showed the best environmental performance, which was justified by the fact that no filling process was considered. Considering that filling bottles with air or soil results in similar environmental impacts, it can be concluded that PET bottles filled with soil provide the best thermal and environmental alternative. | Categorize the text article into one of the two categories:
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The accumulation of plastic waste and the increasing awareness of the environmental implications and technical challenges associated to their treatment and recycling have led to a constant increase of biopolymers market in the 90's. Polylactic acid (PLA) is one of the most promising biodegradable plastics, showing a wide range of potential applications, e.g. in the packaging industry. However, the high production costs hamper its further development. The use of PLA in multilayer (ML) films is a potential opportunity to reduce the production costs. This study tackled the ecodesign of a clam shell for packaging applications based on a novel ML film made of PLA and thermoplastic starch (TPS), evaluating the environmental performance of different design concepts through Life Cycle Assessment (LCA). In order to assure proper compatibility between PLA and TPS, the use of dielectric barrier discharge (dbd) plasma technology at atmospheric pressure to increase the hydrophilicity of PLA was investigated. The results have highlighted the significant contribution of plasma treatment to the overall environmental impact of the ML film and the need for further optimisation. Despite the contribution of the PLA end-of-life phase to the overall environmental impact of the ML clam shell is low, the methodological approach to end-of-life can have a significant influence on the LCA results. This seems to be due to the low PLA recycling and recovery rate assumed, which is nevertheless realistic. The promotion of high recovery and recycling rates should therefore be a priority in the future. At the current development stage, even the most improved ML clam shell concept obtained using atmospheric plasma technology is not an environmentally sound alternative to pure PLA clam shell, although it is likely to be a cost-effective option. A good compromise between cost and environmental constrains to be further investigated could be to increase further the proportion of PLA in the ML, by improving the water adsorption capability of TPS through, e.g., the addition of a phthalate free plasticiser. | Categorize the text article into one of the two categories:
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In this study, the life cycle assessment (LCA) has been applied to analyze the greenhouse gas (GHG) emissions and energy requirements in the post-harvest life of apples from the Trentino-South Tyrol region (Northern Italy). Data were collected over four years from two commercial apple packinghouses. The key processes in the supply chain were identified based on direct observation, and different scenarios for conservation, packaging, and transport, as well as the source of electricity were analyzed. The results showed that the packaging was the main contributor to both the global warming potential (GWP, from 68 to 98 gCO2eq per kg of apples) and to the cumulative energy demand (from 1.3 to 1.9 MJ/kg). The cooling process (i.e., initial refrigeration and maintaining the cool temperature) that the fruit undergoes before being stored was the second largest contributor to the environmental effects produced during the apple post-harvest. The use of renewable energy is an attractive option to drastically reduce the GWP of this phase. If long transportation distances need to be covered (for example for export, or distances exceeding 300 km), using rail transport or shipping could cut down substantially the environmental costs. The most favorable environmental performances during the post-harvest of the apple include the storage by controlled atmosphere (CA), the delivering of fruits in large reusable plastic bins and their transport over short distances. | Categorize the text article into one of the two categories:
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In this study, a new catalyst for heterogeneous acid based on molybdenum oxide (MoO3) supported over graphene oxide (GO) was synthesized and applied in simultaneous esterification-transesterification reactions using waste cooking oil (WCO) to obtain biodiesel. In the catalyst synthesis, the GO support was synthesized from graphite oxidation, followed by wet MoO3 impregnation. The MoO3/GO catalyst was characterized by Surface Acidity, Thermogravimetric Analysis (TG/DTG), X-ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and Energy Dispersion X-ray Spectroscopy (EDS). The application of the catalyst in the conversion of WCO into biodiesel had as parameters reaction temperature (120.0–160.0 °C), reaction time (1.0–5.0 h), catalyst loading of (2.0–10.0%) and methanol:oil molar ratio of (25:1–45:1). The results of the catalytic tests showed the best condition of biodiesel synthesis was 140.0 °C reaction temperature, 5.0 h of reaction time, 6.0% catalyst loading and 35:1 methanol:oil molar ratio, leading to a biodiesel with ester content of 95.6%. The catalyst showed good recovery and excellent catalytic performance in the reuse study, producing biodiesel with ester content above 70.0% after 5 reaction cycles. Thus, this study shows a promising new catalyst of heterogeneous acid with high catalytic activity and applicability in the biodiesel synthesis process. | Categorize the text article into one of the two categories:
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This study analysed the perceived environmental sustainability of alternative packaging systems for beverages (glass bottle, plastic bottle, and aluminium cans) from a sample of young Italian consumers with a sociological survey. In parallel, a life cycle assessment was conducted to compare the perceived and actual environmental sustainability as well as to identify any discrepancies, with comparison indicators for different environmental issues. The sample of Italian students perceived glass bottles as the most environmentally sustainable compared to aluminium cans and plastic bottles (the worst perceived option). Similar results were recorded for a sample of environmentalists from the same region with an even greater perception of environmental sustainability for single use glass bottles. Therefore, there was an overwhelming confirmation of how glass is perceived as very sustainable from an environmental point of view and of how plastic is perceived as having little or no environmental sustainability. However, the life cycle assessment study showed that the positive perception in favour of single-use glass is completely unfounded since glass packaging was clearly the worst option both in terms of midpoint impact categories as well as macro-categories of damage. The definition of indicators useful for the comparison between the perceived and actual sustainability were able to confirm that the environmental sustainability of glass bottles was widely overestimated by the respondents for both midpoint and endpoint environmental issues. There is a misperception of environmental sustainability by consumers that could be due to a lack or incorrect communication between the scientific community and citizens. Effective communication initiatives are therefore needed to enable consumers to move beyond prejudices that are excessively pro-glass and excessively anti-plastic. | Categorize the text article into one of the two categories:
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The global pollution crisis arising from the accumulation of plastic in landfills and the environment necessitates addressing plastic waste issues. Notably, polypropylene (PP) waste accounts for 20% of total plastic waste and holds promise for hydrophobic applications in the realm of recycling. Herein, the transparent and non-transparent superhydrophobic films made from waste PP are reported. A hierarchical structure with protrusions is induced through spin-casting and thermally induced phase separation. The films had a water contact angle of 159° and could vary in thickness, strength, roughness, and hydrophobicity depending on end-user requirements. The Bode plot indicated enhanced corrosion resistance in the superhydrophobic films. Antibacterial trials with Escherichia coli and Staphylococcus aureus microbial solutions showed that the superhydrophobic film had a significantly lower rate of colony-forming units compared to both the transparent surface and the control blank sample. Moreover, a life cycle assessment revealed that the film production resulted in a 62% lower embodied energy and 34% lower carbon footprint compared to virgin PP pellets sourced from petroleum. These films exhibit distinctiveness with their dual functionality as coatings and freestanding films. Unlike conventional coatings that require chemical application onto the substrate, these films can be mechanically applied using adhesive tapes on a variety of surfaces. Overall, the effective recycling of waste PP into versatile superhydrophobic films not only reduces environmental impact but also paves the way for a more sustainable and eco-friendly future. | Categorize the text article into one of the two categories:
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Considering the minimum environmental concerns associated with biodegradable mulch (BDM) films, these are widely seen as a promising alternative to traditional polyethylene (PE) films. However, lack of an in-depth evaluation of BDM plastic films has hindered its largescale applications. To fill this knowledge gap, this study was planned to comprehensively evaluate the environmental impacts of BDM films as an alternative to the traditional PE film utilizing an advanced life cycle assessment (LCA) technique coupled with multiple field experiments, including three solanaceous crops i.e. eggplant, pepper and cherry tomato. These crops were grown at three different experimental sites comprising Chengmai, Qionghai, and Ledong; all located in Hainan Province of China. The results revealed that an in-situ biodegradation of BDM during the waste disposal stage greatly reduced the environmental pollution and cumulative energy demand (CED). But such a positive effect was largely nullified by the stimulated environmental cost during its manufacturing stage. And thus, the average environmental impact and CED from cradle to grave were reduced by only 2.6% and 9%, respectively, under BDM film when compared with PE. The seven sites/years-based field trials of three solanaceous crops revealed that the average crop yield under both plastic mulching cultivations was increased by 52%, while the integrated environmental impact per ton yield was reduced by 30%, compared with conventional bare planting (CP). Overall, it can be inferred that BDM film is a sustainable alternative to traditional PE mulch film based on its reduced environmental impacts. | Categorize the text article into one of the two categories:
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The global discourse surrounding plastics has been marked by a profound perceptual schism, also for plastic packaging in the fresh food industry. The public opinion expresses mounting concerns in terms of such plastic packaging solutions. However, in many cases the unique material properties and the well-established methodology of Life Cycle Assessment (LCA) actually demonstrate the environmental advantage of plastics for food packaging. This paper delves into the chasm between the two perspectives, leveraging empirical evidence to resolve the divide. While performing both a consumer analysis and LCA, this paper underscores the potential for innovative, yet practical design solutions to harmonise the public opinion with counterintuitive positive environmental impacts. A transformative design solution that centres around the concept of shape and material renewal is proposed. It demonstrates how a simple, yet effective redesign can enhance both the environmental impact and consumer acceptance in the industry for mass-produced fresh food packaging. It emphasises the role of LCE in design, with a focus on the pre-consumer phase. The findings provide a practical approach, emphasising the need to reconcile theory with consumer desires, to forge a sustainable path forward in packaging design. | Categorize the text article into one of the two categories:
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The use of seaweed as a bioresource for plastic production is gaining momentum. However, the environmental impacts of the production of this novel bioplastic are still unknown. In this research, we assess the environmental impacts of the production of a bioplastic film at an experimental pilot scale using Life Cycle Assessment (LCA). The system boundaries chosen for this analysis include seaweed cultivation accounting for its carbon uptake, alginate extraction, production of bioplastic film at the pilot scale and different end-of-life pathways. The recirculation of different seaweed co-products from the alginate extraction step into the bioplastic film production is also assessed using scenario modelling and the analysis is completed with a carbon balance and an uncertainty analysis. The results show the main hotspot at the pilot scale is the last step in the production, film fabrication, mainly due to the glycerol in this process. The results also vary significantly depending on the end-of-life of the bioplastic, composting reduces the impacts by 30 % compared to incineration. | Categorize the text article into one of the two categories:
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This paper introduces a generic hybrid methodology for assessing economic and environmental impacts along interconnected supply chain markets, considering both the material/product level and the market mechanisms that govern resource allocation. The methodology is illustrated by considering a competitive market and benevolent social planner variant of a supply chain equilibrium (SCE) model, applied to the specific case of single-use and reusable plastic bottles in Belgium. The benevolent social planner optimises a societal welfare function that includes all relevant revenues and costs along the plastic bottle supply chains – including external environmental damage costs. These costs comprise climate damage and are incorporated into the SCE model by combining life cycle assessment data with economic data. The main advantage of this model setup is that it better represents policy reality because it allows to study the effectiveness and efficiency of the simultaneous implementation of multiple circular strategies, their interactions, and possible rebound effects. The findings indicate that when all climate costs are internalised simultaneously, the competitive market solution approaches that of the benevolent social planner. Yet, when policymakers have fewer instruments at their disposal in relation to the number of environmental externalities, the welfare impact of competitive market solutions is limited or even negative. Moreover, key circular economy practices such as material intensity reduction and green design are particularly lagging behind compared to their welfare-optimising levels. | Categorize the text article into one of the two categories:
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Ti-containing hollownest-structured zeolite (Ti-HSZ), constructed by the highly intergrowth of MWW lamellar crystals, has been proven to show excellent catalytic performance in the epoxidation of alkenes due to its highly exposed Ti catalytic active sites and unique hollownest morphology. However, up to date, only piperidine is reported to act as the structure directing agent of MWW crystalline phase for the formation of Ti-HSZ, which has limited its application in a wider range. In this work, Ti-HSZ has been successfully synthesized by using dual templates, including hexamethyleneimine as main template and dicyclohexylamine (or piperidine) as secondary template. Systematical experiments, including composition of synthetic gel, rotation rate of autoclave, and time of crystallization, have been conducted to explore the optional synthesis conditions of Ti-HSZ catalyst with high catalytic performance. It is found that, compared with HMI as solely template, the usage of dual templates HMI/PI or HMI/DCHA is important for the synthesis of Ti-HSZ material, which has important influence on its catalytic performance. In addition, the ratio of main template and secondary template also plays an important role on the catalytic activity of Ti-HSZ catalyst. Moreover, Ti-HSZ material prepared by dual templates owes good recycling stability. This work provides a new route to synthesize Ti-HSZ materials with high catalysis activity. | Categorize the text article into one of the two categories:
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Laboratory scale recycling of marine plastic litter consisting of polyethylene terephthalate (PET) bottle sorting, pyrolysis and chemical vapor deposition (CVD) was conducted to identify the technical and environmental implications of the technology when dealing with real waste streams. Collected seashore and underwater plastics (SP and UP, respectively) contained large quantities of PET bottles (33.2 wt% and 61.4 wt%, respectively), suggesting PET separation was necessary prior to pyrolysis. After PET sorting, marine litter was converted into pyrolysis oil and multi-walled carbon nanotubes (MWCNTs). Water-based washing of litter prior to pyrolysis did not significantly change the composition of pyrolysis products and could be avoided, eliminating freshwater consumption. However, distinct differences in oil and MWCNT properties were ascribed to the variations in feedstock composition. Maintaining consistent product quality would be one of challenges for thermochemical treatment of marine litter. As for the environmental implications, life cycle assessment (LCA) demonstrated positive benefits, including improved climate change and fossil depletion potentials. The highest positive environmental impacts were associated with MWCNT production followed by pyrolysis oil and PET recovery. The benefits of proposed approach combining PET sorting, pyrolysis and CVD allowed to close the waste loop by converting most of the marine litter into valuable products. | Categorize the text article into one of the two categories:
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Methanol-to-olefins (MTO), as an alternative pathway for the synthesis of light olefins (ethylene and propylene), has gained extensive attention. Accurate prediction of light olefins yields can effectively facilitate process monitoring and optimization, as they are significant economic indexes and stable operation indicators of the industrial MTO process. However, the nonlinearity and dynamic interactions among process variables pose challenges for the prediction using traditional statistical methods. Additionally, physical-based methods relying on first-principle theory are always limited by an insufficient understanding of reaction mechanisms. In contrast, data-driven methods offer a viable solution for the prediction based solely on process data without requiring extensive process knowledge. Therefore, in this work, a data-driven approach that integrates spatial and temporal self-attention modules is proposed to capture complex interactions. Furthermore, Bayesian optimization is employed to determine the optimum hyperparameters and enhance the accuracy of the model. Studies on an actual MTO process demonstrate the superior prediction performance of the proposed model compared to baseline models. Specifically, 24 process variables are selected as the high-dimensional inputs, and yields of ethylene and propylene, as the low-dimensional outputs, are successfully predicted at various prediction horizons ranging from 2 to 8h. | Categorize the text article into one of the two categories:
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Life cycle assessment modelling of multi-cycle recycling systems is challenging. There is still neither consensus on applying allocation approaches nor a one-size-fits-all solution. This study proposes an allocation approach embedded with the responsibility distribution of stakeholders rather than the standard approach, which is assessed based on stages. It is applied to the case study of plastic packaging recycling and compared to simple and economic allocation cut-off methods. A total of four multiple recycling or cascade utilisation scenarios are assessed, consisting of the linear system (disposal), mechanical recycling, waste to energy and chemical recycling, for at least one of the cycles. Scenario 2, with mechanical recycling as the end-of-life management in all three multiple cycles, has the lowest overall GHG emissions (∼4.8 t CO2eq/t plastic packaging) regardless of allocation method, even after considering deducted savings due to the degraded quality along the cycles. The simple cut-off method could not drive the selection in the first cycle toward the recycling alternatives (Scenario 2–4) with overall lower emissions as the GHG saving from utilising recycled resources are accounted for in the second cycle. Regarding eutrophication potential, as the burdening impact of disposal is significantly higher, recycling options accounted for following the simple cut-off method are preferable even when the burdening effect is entirely embraced by the first cycle without the unburdening accounting. Economic allocation cut-offs provide a better incentive to recycle in the assessed cycles. However, the standard accounting is by stages such as material production, product manufacturing, recycling and disposal. It is unclear whose responsibility, either the raw material producer (MP), the product manufacturer (PM) or the consumer (C). The proposed method with defined responsibility (e.g. 6.2 t CO2eq/t by MP; 2.9 t CO2eq/t by PM; 0.5 t CO2eq/t by C in Scenario 1) is more effective for environmental mitigation strategies (e.g. taxation and incentives, deposit refund scheme) of the plastic life cycle. The scenarios assessment serves as a stepping stone to optimise the allocation among the identified stakeholders in future work according to local conditions. | Categorize the text article into one of the two categories:
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Pt-based alloy nanomaterials with nanodendrites (NDs) structures are efficient electrocatalysts for methanol oxidation reaction (MOR), however their durability is greatly limited by the issue of transition metals dissolution. In this work, a facile trace Ir-doping strategy was proposed to fabricate Ir-PtZn and Ir-PtCu alloy NDs catalysts in aqueous medium, which significantly improved the electrocatalytic activity and durability for MOR. The as-prepared Ir-PtZn/Cu NDs catalysts showed distinct dendrites structures with the averaged diameter of 4.1 nm, and trace Ir doping subsequently improved the utilization of Pt atoms and promoted the oxidation efficiency of methanol. The electrochemical characterizations further demonstrated that the obtained Ir-PtZn/Cu NDs possessed enhanced mass activities of nearly 1.23 and 1.28-fold higher than those of undoped PtZn and PtCu, and approximately 2.35 and 2.67-fold higher than that of Pt/C in acid medium. More excitingly, after long-term durability test, the proposed Ir-PtZn and Ir-PtCu NDs still retained about 88.9% and 91.6% of its initial mass activities, which further highlights the key role of Ir-doping in determining catalyst performance. This work suggests that trace Ir-doping engineering could be a promising way to develop advanced electrocatalysts toward MOR for direct methanol fuel cell (DMFC) applications. | Categorize the text article into one of the two categories:
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This review explains the various methods of conversion of Carbon dioxide (CO2) to methanol by using homogenous, heterogeneous catalysts through hydrogenation, photochemical, electrochemical, and photo-electrochemical techniques. Since, CO2 is the major contributor to global warming, its utilization for the production of fuels and chemicals is one of the best ways to save our environment in a sustainable manner. However, as the CO2 is very stable and less reactive, a proper method and catalyst development is most important to break the CO2 bond to produce valuable chemicals like methanol. Litertaure says the catalyt types, ratio and it surface structure along with the temperature and pressure are the most controlling parameters to optimize the process for the production of methanol from CO2. This article explains about the various controlling parameters of synthesis of Methanol from CO2 along with the advantages and drawbacks of each process. The mechanism of each synthesis process in presence of metal supported catalyst is described. Basically the activity of Cu supported catalyst and its stability based on the activity for the methanol synthesis from CO2 through various methods is critically described. | Categorize the text article into one of the two categories:
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Since metal-organic frameworks (MOFs) have low electrical conductivity, the application of single MOFs as electrochemical sensor materials is very rare, and the construction of high-performance hydrogen peroxide (H2O2) sensors based on MOFs is still a difficult challenge. In this paper, a nickel-based MOF (Ni-MOF) material was synthesized using an ionic liquid as both solvent and ligand through an ionothermal method. The morphological and structural characterizations were studied by scanning electron microscopy, X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy and thermogravimetric analysis. Electrochemical sensing performance of the Ni-MOF modified glassy carbon electrode towards H2O2 was evaluated by cyclic voltammogram and chronoamperometry in an alkaline solution. The electrochemical H2O2 sensor was found to lead to a linear response from 0.5 μM to 2.0 mM with a detection limit of 0.18 μM. Moreover, the sensor also revealed good anti-interference ability and stability. To further assess the electrochemical properties, electrochemical activity of the Ni-MOF to oxidation of methanol was investigated by cyclic voltammetry. During the methanol oxidation reaction measurement, the Ni-MOF not only exhibited a high current density, but also found a good electrochemical activity for intermediate oxidation products. The above studies proved that the Ni-MOF material synthesized using the ionic liquid as a ligand can be used not only as an electrochemical H2O2 sensor but also as an electrocatalyst for methanol oxidation. | Categorize the text article into one of the two categories:
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As the world is transitioning towards a low-carbon economy, it is becoming important to develop ways to reduce carbon dioxide (CO2) emissions. Chemical looping, a low carbon technology for the industry, is considered as a potential breakthrough technology and a viable option for efficient fuel conversion and carbon capture and storage, with the successful completion of pilot plant trials in the USA. The conversion of captured CO2 to methanol can be considered a promising method for significantly reducing CO2 emissions, while the produced methanol can be used as a convenient energy carrier for hydrogen storage. This study focuses on a process of converting microalgae, a potential fuel feedstock, into methanol by utilizing CO2 generated within the process. The specific focus lies on the conversion of the microalgae into methanol through dual-stage chemical looping and efficient process integration with maximum energy recovery. Aspen Plus® was used to simulate the facility producing 42 mt (metric tons) methanol/h using 60.1 mt/h CO2 and 8.2 mt/h H2. The process was divided into four-module operations: drying, chemical looping gasification, syngas chemical looping, and methanol synthesis. The energy efficiency of this process is around 45–51% which is comparative with the concentrated CO2-based methanol and typical biomass-based syngas to methanol processes. Because the separated CO2 obtained via chemical looping is utilized for methanol synthesis, the carbon-negative value is attained. | Categorize the text article into one of the two categories:
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To the aim of accelerate the methanol oxidation reaction (MOR), rationally designing novel MOR catalyst is highly desired. Hence, NiCo alloy resides in carbon layers decorated with Mo2C platinum-based catalyst (Pt/NiCo-Mo2C@NDC) is fabricate. For the fabrication, NiMoO4 nanorods (NRs) are firstly coated with CoZn-ZIF and then subjected to anneal treatment and NaBH4 reduction procedure. In the system, CoZn-ZIF serves as the sacrificial template and reducing agent, rendering bifunctional effect: CoZn-ZIF provides doped nitrogen sources, which are beneficial to the overall conductivity and deposition of Pt nanoparticles. Besides, it could act as the carbon sources for the reaction formation of the Mo2C during high temperature calcination, which delivers the excellent co-catalytic effect. Meanwhile, NiCo alloy can be fabricated during the annealing treatment and alter the structure properties of the catalyst, showing the Ni content-depended electrochemical performance. Therefore, the catalyst exhibits remarkable electrocatalytic activity and stability. Moreover, we also focus on the structure-activity relationships to provide insight into the effect of alloy and molybdenum carbide on catalytic activity. | Categorize the text article into one of the two categories:
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This article describes the synthesis of methanol by the direct hydrogenation of CO2 over Cu/ZrO2 catalyst at different ZrO2 concentrations (5, 10, 15, 20 and 25wt.%) in a three-phase phase reactor. The techniques of N2 adsorption/desorption, x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, temperature-programmed desorption by CO2, N2O chemisorption and inductively coupled plasma optical emission spectrometry were employed for catalyst characterization. At a reaction temperature of 180°C, pressure of 3.0 MP and 0.020g/mL of the catalyst, the conversion of CO2 and the yield of methanol were 10% and 25g/kg.h, respectively. Surface area of the metallic copper was increased from 8.1 to 9.5m2/g with the presence of ZrO2 from 5 to 15wt.%. The methanol turnover frequency exhibited a linear relationship with ZrO2 concentration. Methanol synthesis rate was progressively increased with increasing fraction of dispersed copper. A comparative study with the literature revealed better activity of this novel catalyst at relatively low reaction conditions. | Categorize the text article into one of the two categories:
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Plastic waste is internationally recognized as a problem, fueled by increased public awareness of environmental concerns and the steady increase in waste import bans. Modern sorting and recycling technologies are mature, but face implementation limitations in highly dense urbanized regions such as Singapore due to significant space constraints and expensive labor. Distributed plastic sorting and recycling facilities at small-scale closer to points of plastic waste generation offer the possibility of increasing the recovery of plastic waste streams in urbanized settings. To quantify the environmental performance of such systems, this study compares the life cycle greenhouse gas emissions of large-scale centralized facilities versus distributed small-scale facilities for sorting and recycling plastic bottles and takeaway containers generated in the central region of Singapore. An agent-based model is used to simulate different scenarios of plastic waste generation, collection routes, sorting, and recycling. The simulation results are used in a multi-level life cycle assessment to quantify the greenhouse gas emissions of the plastic sorting and recycling network as well as its individual entities. The results reveal that the life cycle greenhouse gas emissions of small-scale distributed plastic recycling compared to large-scale centralized systems are sensitive to the transport distance traveled and the type of trucks used. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the scientific committee of the 27th CIRP Life Cycle Engineering (LCE) Conference. | Categorize the text article into one of the two categories:
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Methanol steam reforming (MSR) is a potential method for producing hydrogen in situ. Finding excellent catalysts to improve reaction activity and CO2 selectivity is crucial. In this study, we used density functional theory (DFT) methods and the CP2K software package to investigate the mechanism of the MSR reaction on dual-atom catalysts of PtZn/TiO2 and PdZn/TiO2. The results showed that the most favorable reaction paths on these two catalysts are the same, namely CH3OH→CH3O→CH2O→CH2OOH→CHOOH→CHOO→CO2, in which the rate-determining step is CH2O+OH→CH2OOH with reaction barriers of 1.17 eV on PtZn/TiO2 and 1.29 eV on PdZn/TiO2, respectively. The reported PtZn/TiO2 and PdZn/TiO2 catalysts show improved activity compared to pure metal or corresponding alloy catalysts. The synergistic effect between metal atoms and the surface of TiO2 supports as well as the role of Zn atom doping were discussed. This work provides a new perspective for the design of atomic-level catalysts for the MSR reaction. | Categorize the text article into one of the two categories:
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Single-use plastics waste is a thermosetting-thermoplastic polymer generated specifically from packaging industries. Incineration, landfilling, combustion, open discharge in liquids fail its effective disposal. Co-combustion via co-processing is a novel technique for disposal. In this study, investigative thermogravimetric analysis of the co-combustion of lignite coal (AL) and single-use plastic waste (PW) in the blend ratios of 50:50, 60:40, 70:30 was carried out under non-isothermal conditions to promote co-combustion via co-processing technique for environment-friendly disposal. Thermal degradation behavioral study was carried out at higher blending ratios of 30–50%. The effect of the mass ratio of PW to AL on co-combustion characteristics was analyzed. The Freeman-Carroll, Sharp-Wentworth methods derived energy of activation for the process of co-combustion in the limits of 65–155 kJ/mol, 44–75 kJ/mol. Volume Contracting and Diffusional Reaction 2D solid-state reaction mechanisms were followed by the co-combustion system as derived by Coats-Redfern and Kennedy-Clark methods. Master plot method validated the same results. The co-combustion performance was evaluated using co-combustion (CSI), ignition (IG), burnout (IB) indices. The highest CSI value was reported for the 60:40 blend. Burnout temperature (Tb) decreased with an increase in blending ratio and suggested an effective co-combustion process. Blend (70:30) reported the highest interaction in blends and confirmed the synergistic effect. The principal component analysis described the co-combustion process as three stages (100–200, 265–425, 425–700) oC with specific materials. The co-combustion process was optimized using the methodology of surface response and validated using neural network models (NNM 4,5) for the effect of temperature and blend ratio on mass loss. The characterization study confirmed the presence of minerals alumino-silicates, dimorphs pyrite, marcasite, gypsum, barite, hydrated sulfates, calcite, siderite, and functional groups –OH, -CH2, -Si-O responsible for autocatalytic reactions. Life cycle assessment confirmed the sustainability of the co-combustion process of lignite and plastic waste. The present study benefits for scale-up, optimization, waste to energy conversion, pollution reduction, and environmentally friendly disposal via the co-combustion process. | Categorize the text article into one of the two categories:
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Flexible plastic packaging is still one of the most difficult streams to recycle due to the presence of multilayers. With multilayers being very functional during their use phase, the delamination of multilayer structures is promising because it enables the recovery of the constituent polymer layers without any degradation and/or dissolution, thus creating economic and environmental benefits. However, there is hardly any data available on the optimization of the delamination process for multilayer flexible plastic films (MFPFs), as well as the potential scale-up in terms of economic and environmental factors. Therefore, this study investigates the effect of experimental parameters such as temperature, solid/liquid (S/L) ratio, particle size, and stirring rate on the delamination rate of various MFPFs. Among these parameters, the combination of temperature and S/L ratio has the most pronounced effect on increasing the delamination rate. On the other hand, particle size does not have a significant influence on the delamination rate. Under optimal delamination conditions, more than 90% delamination is achieved in 60 min, particularly for PET-based MFPF. Simulations of the delamination process in Aspen Plus® reveal that the composition of MFPF has a significant effect on the energy consumption during the delamination process. The slower delamination kinetics of MFPFs can be compensated for through process optimization, but this typically results in higher energy requirements. The life cycle assessment (LCA) confirms that high energy consumption results in high CO2 emissions; thus, design for MFPFs, together with process optimization, are key aspects of obtaining a competitive delamination process with economic and environmental benefits. | Categorize the text article into one of the two categories:
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The new compounds Pyridoxal N-allyl-S-methylthiosemicarbazone (L) and the dioxomolybdenum(VI) complex [MoO2(L)CH3OH] have been synthesized and characterized by elemental analysis, UV–Vis, FT-IR, Raman and 1H NMR spectra, and also by the single crystal X-ray diffraction technique. Single crystals of the cis-dioxomolybdenum(VI) complex were obtained by evaporating its methanol solution. According to the single-crystal X-ray diffraction investigation, the molybdenum atom in the complex is in a distorted octahedral coordination. The sixth coordination site is occupied by the oxygen atom of a methanol solvent molecule. The methanol coordination between the oxygen and molybdenum atoms is the weakest bond, with a MoO bond length of 2.355 Å. The geometries and vibrational spectra of the pyridoxal thiosemicarbazone (L) and its complex are explained by quantum chemical calculations. | Categorize the text article into one of the two categories:
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To attend the growing consumer demand for novel ready-to-eat fresh cut fruits packaging polylactic acid (PLA)-based active packaging was realized. The aim of these packaging is to provide an improved protection and even to extend their shelf-life. PLA-based active packaging was prepared by adding nanoclays and surfactants in its formulation. The evaluation of PLA-nanocomposite packaging was done in comparison to pristine PLA and conventional plastic (polyethylene terephthalate, PET) using fresh-cut melons. Physicochemical properties were investigated by the means of weight loss, visual appearance, pH, colour, and firmness. In addition, microbial profile was tested via microbiological assays. In order to evaluate the environmental impact of PLA-based active packaging compared to commonly used PET, life cycle assessment (LCA) was conducted. In terms of physicochemical and antimicrobial properties, the results clearly showed that the presence of nanoclays and surfactants in the PLA formulations improved their performance, thus contributing to bring the characteristic and behaviour of PLA packages close to those of PET. Furthermore, assessment of life cycle environmental impacts indicated that PLA packaging with nanoclays had the highest environmental performance. | Categorize the text article into one of the two categories:
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Plastic industry is ubiquitous worldwide, and the generation of “plastic waste” has been steadily increasing to the point of being considered a high impact pollutant. The expanded polystyrene (EPS) plastic industry aware of the issue is interested on trying recycling post-consumer material. Through a recent study made in an alliance between the private sector and the academy, the feasibility of the EPS “mechanical” recycling was proven; therefore, a possible solution through a circular economy model. The aim of the present paper was to investigate the potential environmental impacts avoided by the circular economy scenario previously developed, through a life cycle assessment (LCA) performed for the city of Guayaquil, where 64% of all the plastic manufacturing industries in the country are located. The entire life cycle of 1.00 kg of 5 × 5 inch. food containers were assessed from the production stage until its end-of-life stage: focusing on three different valorization paths, circular economy closed-loop (container-to-container) proposal with electricity share of 2019 and another with the 2027 future one, and traditional linear economy (container-to-landfill). Results showed that the scenario C that considers the recycling of post-consumer EPS waste and the electricity share proposed for 2027 have lower impacts in 14 out of 16 categories, in specific for the Land use (−31%), Ozone Depletion (−28%), Acidification (−24%) and Terrestrial and Marine Eutrophication (−21%). These results strongly suggest that the recycling of these kind of plastic waste could benefit the environment greatly. | Categorize the text article into one of the two categories:
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The facile and fast synthesis of copper sulfide with controllable stoichiometric composition, crystal phase and shape, without using any additional surfactant and structure directing agent, is still highly attractive and remains a challenge. A supercritical methanol synthetic method was presented in this work, by which pure Cu1.8S and Cu9S5/CuS complexes with different particles size and phase composition could be synthesized by tuning the reaction temperature and time. It was demonstrated that higher temperature and longer time were beneficial to the formation of copper sulfides with higher Cu/S ratio and could cause obvious red shifts of band gap energies from 1.34 to 1.54eV for copper sulfides. Furthermore, crystal phase evolution from Cu9S5 to Cu1.8S was also observed in the preparation process. It was proposed that CuS was produced firstly by decomposing the complex Cu(CN2H4S)2(CH3COO)2, and then reduced to Cu9S5 which was further evolved into Cu1.8S. | Categorize the text article into one of the two categories:
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Several approaches to improve the catalytic performance of SSZ-13 and SAPO-34 for application as acid catalysts in the methanol-to-olefins (MTO) reaction were explored. Silylation of mesoporous SSZ-13 with a Si/Al ratio of 20 zeolite resulted in increased lifetime in the MTO reaction. Lowering the acidity of SSZ-13 by increasing the Si/Al ratio to 50 also increased the lifetime. The generation of additional mesoporosity in SSZ-13 with a Si/Al ratio of 50 by use of the organosilane octadecyl-(3-trimethoxysilylpropyl)-ammonium chloride (TPOAC) only resulted in a minor improvement of the lifetime. Attempts to synthesize mesoporous SSZ-13 at high Si/Al ratios by use of (C22H45 N+(CH3)2 C4H8 N+(CH3)2 C4H9)Br2 (C22-4-4Br2) were unsuccessful, and instead ZSM-5 zeolite was obtained. Similarly, SAPO-34 could not be made hierarchical by using C22-4-4Br2 as a mesoporogen. In this case, other AlPO-phases were obtained. Mesoporous SAPO-34 was synthesized by using TPOAC in the synthesis gel. The additional intracrystalline mesoporosity did not lower the deactivation rate of SAPO-34 as was earlier observed for SSZ-13. The total methanol conversion capacity per acid site for microporous and mesoporous SAPO-34 were however comparable. The lower acidity of the acid sites in SAPO-34 led to the complete utilization of the micropore space. This is to be contrasted to SSZ-13 zeolite, for which the increased rate of coke formation results in more extensive coking deactivation and underutilization of the micropore space. | Categorize the text article into one of the two categories:
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To integrate plastic packaging into circular economy models, end-of-life (EoL) management is attracting increasing attention. The integration of plastic products into a circular economy holds great promise to mitigate the polluting effects and climate impact of certain disposal options, such as emissions from incineration or leakage from landfill sites to the environment with consequent fragmentation to microplastics. To determine the environmental sustainability of the EoL options for plastic products, Life Cycle Assessments (LCAs) are frequently used. This research identified the accuracy of the modeling of EoL scenarios for post-consumer (PC) plastic packaging in the reviewed 49 studies. The selected LCA studies were examined to identify gaps between the real world and modeled EoL scenarios, anticipating their potential influence on the direct and indirect environmental impacts reported in LCA which give guidance for policy-making. It was found that the EoL modeling in product-based LCA studies is mostly simplified in terms of the recycling process, transportation, waste packaging composition, and waste management practices, while important aspects like additives and microplastics were not taken into account. These findings show the foundation for future LCA studies to achieve a closer-to-practice EoL modeling for plastic products to leverage their integration into a circular economy. | Categorize the text article into one of the two categories:
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The hydrogenation of CO2 to methanol is one of the promising CO2 utilization routes in the industry that can contribute to emissions mitigation. In this work, improved operating conditions were reported for the sustainable catalytic hydrogenation of CO2 to methanol using Cu/ZnO/Al2O3 catalyst operated at 70 bar and 210 °C. The CO2 feedstock used for this process is pure CO2 produced from the cryogenic upgrading process of biogas or hydrocarbon industries and ready-to-use hydrogen purchased at 30 bar and 25 °C. The process was modeled and simulated using the commercial Aspen Plus software to produce methanol with a purity greater than 99% at 1 bar and 25 °C. The simulation results revealed that an adiabatic reactor operated with a CO2/H2 ratio of 1:7 produces methanol with a yield ≥99.84% and a CO2 conversion of 95.66%. Optimizing the heat exchanger network (HEN) achieved energy savings of 63% and reduced total direct and indirect CO2 emissions by 97.8%. The proposed methanol process with an annual production rate of 2.34 kt/yr is economically sound with a payback period of nine years if the maximum H2 price remains below $0.97/kg. Hence, producing or purchasing gray H2 from a steam reforming plant is the most viable economic source for the process. | Categorize the text article into one of the two categories:
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A series of metal-organic frameworks MOF-808-X (6-connected) were synthesized by regulating the ZrOCl2·8H2O/1,3,5-benzenetricarboxylic acid (BTC) molar ratio (X) and tested for the direct synthesis of dimethyl carbonate (DMC) from CO2 and CH3OH with 1,1,1-trimethoxymethane (TMM) as a dehydrating agent. The effect of the ZrOCl2·8H2O/BTC molar ratio on the physicochemical properties and catalytic performance of MOF-808-X was investigated. Results showed that a proper ZrOCl2·8H2O/BTC molar ratio during MOF-808-X synthesis was fairly important to reduce the redundant BTC or zirconium clusters trapped in the micropores of MOF-808-X. MOF-808-4, with almost no redundant BTC or zirconium clusters trapped in the micropores, exhibited the largest surface area, micropore size, and the number of acidic-basic sites, and consequently showed the best activity among all MOF-808-X, with the highest DMC yield of 21.5% under the optimal reaction conditions. Moreover, benefiting from the larger micropore size, MOF-808-4 outperformed our previously reported UiO-66-24 (12-connected), which had even more acidic-basic sites and larger surface area than MOF-808-4, mainly because the larger micropore size of MOF-808-4 provided higher accessibility for the reactant to the active sites located in the micropores. Furthermore, a possible reaction mechanism over MOF-808-4 was proposed based on the in situ FT-IR results. The effects of different reaction parameters on DMC formation and the reusability of MOF-808-X were also studied. | Categorize the text article into one of the two categories:
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We herein report a facile and effective ultrasonication method to non-covalently functionalize graphene with copper phthalocyanine-3,4′,4″,4‴-tetrasulfonic acid tetrasodium salt (TSCuPc) as a promising catalyst support for Pt nanoparticles. With the assistance of TSCuPc, Pt nanoparticles are homogeneously deposited on the surface of graphene, and their dispersivity and electrochemical active surface area (ECSA) are obviously enhanced. Studies of cyclic voltammetry and chronoamperometry demonstrate that the as-prepared Pt/TSCuPc–graphene catalyst exhibits much higher electrocatalytic activity and stability than the Pt/graphene and commercial Pt/C catalysts for methanol oxidation. It is concluded that the strategy of TSCuPc-functionalized graphene with Pt catalysts will be potential in design and synthesis of the highly efficient electrocatalysts for DMFCs applications. | Categorize the text article into one of the two categories:
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Over the past decades, there were a few reports on the use of sonochemical method to prepare noble metals catalysts for fuel cells. However, the synthetic processes were conducted under high frequency (200 kHz)/long reaction time in most cases. In this work, Pd and PdxPt nanoparticles were prepared by sonochemical method under low frequency (20 kHz) in a shorter time (20–40 mins). In the first time, a sequentialsonochemical synthesis was explored to achieve a core/shell structure of PdxPt nanoparticles. Consequently, the unique core-shell structure was formed with two shells surrounding the Pd core. The Pd core was firstly grown. In the second step, the Pd2+ ion existing in the Pd core reduced simultaneously with Pt4+ ion in the solution as the first layer of PdPt alloy. Further, the Pt layer was formed subsequently. The Pd-based catalysts exhibited a superior ORR selective activity and exceptional methanol-tolerance property compared with the commercial Pt/C catalyst. In 0.5 M CH3OH + 0.5MH2SO4 solution, the best performance was achieved on Pd3Pt/C catalyst with increased overpotential of 24 mV. However, overpotentials was increased 174 mV on commercial Pt/C catalyst. The excellent performance of the Pd3Pt/C catalyst is ascribed to its combination of preferable growth of the Pd (1 1 1) plane, small particle size (∼4 nm), unique core/shell structure as well as the electronic effects between Pd and Pt. These results have demonstrated that the sequential ultrasonic synthesis is an effective method for the synthesis of binary/trinary catalysts in a green approach. | Categorize the text article into one of the two categories:
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The merits of temporary carbon storage are often debated for bio-based and biodegradable plastics. We employed life cycle assessment (LCA) to assess environmental performance of polyhydroxyalkanoate (PHA)-based plastics, considering multiple climate tipping as a new life cycle impact category. It accounts for the contribution of GHG emissions to trigger climate tipping points in the Earth system, considering in total 13 tipping elements that could pass a tipping point with increasing warming. The PHA was either laminated with poly(lactic acid), or metallized with aluminum or aluminum oxides to lower permeability of the resulting plastics toward oxygen, water vapor and aromas. The assessments were made accounting for potential differences in kinetics of evolution of greenhouse gases (CO2, CH4) from bioplastic degradation in the end-of-life. Results show that: (1) PHA films with high biodegradability perform best in relation to the climate tipping, but are not necessarily the best in relation to radiative forcing increase or global temperature change; (2) sugar beet molasses used as feedstock is an environmental hot spot, contributing significantly to a wide range of environmental problems; (3) increasing PHA production scale from pilot to full commercial scale increases environmental impacts, mainly due to decreasing PHA yield; and (4) further process optimization is necessary for the PHA-based plastics to become attractive alternatives to fossil-based plastics. Our study suggests that multiple climate tipping is a relevant impact category for LCA of biodegradable bioplastics. | Categorize the text article into one of the two categories:
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Life cycle assessment (LCA) is used widely to compare the relative impacts of different packaging materials for a specific food product, but few studies evaluate how a single packaging material contributes to a variety of food items. Plastic is a common material used for food packaging. This study conducts an analysis of 28 studies that conduct an LCA of food products to quantify the impact of plastic packaging relative to the total life cycle impact of food products. For most of the 13 environmental indicators reported, plastic packaging is responsible for less than 10% of total life cycle emissions of 23 out of the 30 foods studied. Relative packaging emissions tend to be higher for liquids and food products packaged in small quantities, although the absolute values of energy use and greenhouse gas (GHG) emissions are small. To make LCA results more accessible to non-scientific audiences, this study compares the results to a reference value of the emissions of vehicle travel. The environmental impact caused by the packaging from per capita annual food consumption is less than the environmental impact of per capita daily vehicle travel for most food products analyzed, although annual beverage consumption can be responsible for the equivalent impact of 76 miles of driving. | Categorize the text article into one of the two categories:
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The current plastic industry is associated with climate change, fossil fuel depletion and littering of plastic waste. To reduce these environmental impacts, companies and governmental bodies are increasingly adopting strategies based on the concept Circular Economy. However, circular decision-making is usually based on analyses that do not provide enough insights in every sustainability dimension, risking burden-shifting. In this study, environmental, economic and social life cycle assessment (LCA) techniques have been integrated into an overarching sustainability life cycle assessment (LCSA) to assess the impact of recycling High Density Polyethylene (HDPE) non-beverage bottles. The study assesses the impact in 11 environmental categories, the life cycle costs, and the social risks associated with the related economic sectors. An ad-hoc system expansion approach was developed to overcome the multifunctionality issue so commonly challenging in circular systems. The results indicate that using recycled HDPE leads to significant reductions in all the considered environmental categories. The economic analysis indicated that the material cost of recycled HDPE is slightly lower than for virgin HDPE, but the manufacturing costs are higher and highly dependent on the specific value chain. The social risks of recycling were found to be higher than for virgin plastic production, and mainly occurring outside the country where the recycling takes place (The Netherlands). Nevertheless, this analysis presents high uncertainty due to the heterogeneity in the recycling sector of the database. This study shows how the LCSA approach can be used to assess and compare the impacts and benefits of circular strategies and calls for further efforts to develop higher disaggregated social risk databases. | Categorize the text article into one of the two categories:
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N-methylamine functionalities are valuable motifs, which play vital roles in the properties and activities of essential fine and bulk chemicals including molecules used in life science applications, and functional materials. Thus, N-methylations constitute an important class of reactions in organic synthesis and drug discovery, giving access to advanced compounds, pharmaceuticals, biomolecules, and agrochemicals. The diversity of these kinds of amine structures and their biological relevance stimulated researchers in academia and industry to develop more sustainable, atom-economical, and cost-effective methodologies for the synthesis of N-methylated molecules and pharmaceutical agents. For their preparation, N-methylation using methanol represents a convenient and resourceful methodology because methanol is an abundantly available bulk chemical and serves as an effectual methyl (–CH3) source. Moreover, methanol is less hazardous and produces water as the only by-product in methylation reactions. In this regard, in recent years, several discoveries have been made on the catalytic valorization of methanol as a powerful methylation reagent.This review aims to provide the most recent progress made in catalytic N-methylation of nitrogen-containing molecules employing methanol as a key C1 source from 2017 to August 2022. In particular, the synthesis of N-methylamines and related bioactive compounds starting from different organo-nitrogen compounds such as amines, nitroarenes, amides, sulfonamides, aldoximes, nitriles, and acyl azides using both homogeneous and heterogeneous catalysts including photo(redox) systems are discussed in detail. In addition, N-trideuteromethylation of amines or nitroarenes using deuterated methanol is described as a versatile synthetic tool for synthesizing N-trideuteromethyl labelled molecules, which play significant roles in pharmacological and metabolic activities. We sincerely hope that this review will be interesting and beneficial to scientists working in both academic research and industries in the areas of organic synthesis, medicinal, and biological chemistry. | Categorize the text article into one of the two categories:
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The electrochemical syntheses of series of novel adducts of 2-aminopyridine and methanol in Co(II), Ni(II), Cu(II) or Zn(II) chelates of the N,N,N-tridentate basic form of the Schiff base 2-N-tosylamino(2′-tosylaminobenzylidene)aniline (H2L), [M(L)L′] (M=Co, Ni, Zn, L′=2-aminopyridine; M=Cu, L′=CH3OH), were performed by using the corresponding metal as a sacrificial anode. The compounds were characterized by elemental analysis, IR spectroscopy, FAB mass spectrometry, 1H NMR and magnetic measurements. The crystal structures of the Zn and Ni derivatives as well as of the Schiff base have been determined by X-ray diffraction. In the 2-aminopyridine complexes this ligand is bound to the metal through the endocyclic nitrogen whereas the aminogroup is involved in intramolecular NH⋯O hydrogen bonds with one of the tosyl SO2 groups. | Categorize the text article into one of the two categories:
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Synthesizing methanol from CO2 and green hydrogen is a promising strategy to solve environmental issues and meet the increasing energy demand. In this work, Pd/MnO/In2O3 catalyst with highly dispersed Pd species was prepared via an in-situ reduction method using NaBH4 as the reducing agent. The highly dispersed Pd species promoted the dissociative of hydrogen and the hydride species could spill over to the MnO/In2O3 due to the strong metal-support interaction between Pd and MnO/In2O3, which improved the catalytic activity of Pd/MnO/In2O3 for CO2 hydrogenation to methanol. As a result, the methanol space-time yield of 1 wt% Pd/MnO/In2O3 was 4.8 times higher than that of MnO/In2O3. Moreover, the methanol selectivity of 1 wt% Pd/MnO/In2O3 was still higher than 70% at a temperature below 280 °C. The present in-situ reduction method is an effective route for the preparation of Pd/MnO/In2O3 catalyst for CO2 hydrogenation to methanol. | Categorize the text article into one of the two categories:
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In Part A of this two-paper work, a novel approach for treatment of CO2 from fossil fired power plants was studied. This approach consists of flue gases utilization as co-reactants in a catalytic process, the tri-reforming process, to generate a synthesis gas suitable in chemical industries for production of chemicals (methanol, DME, ammonia and urea, etc.). In particular, the further conversion of syngas to a transportation fuel, such as methanol, is an attractive solution to introduce near zero-emission technologies (i.e. fuel cells) in vehicular applications. In fact, the methanol can be used in DMFC (Direct Methanol Fuel Cell) or as fuel for on-board reforming to produce hydrogen for PEMFC (Proton Exchange Membrane Fuel Cell). Thus, in order to analyze the tri-reforming process, integrated systems, ITRPPs (Integrated Tri-Reforming Power Plants) for co-generation of electrical power and synthesis gas were defined and their performances were investigated. The integrated systems consist of a power island, based on a thermal power plant (a steam turbine power plant, ITRPP-SC, and a gas turbine combined cycle ITRPP-CC), and a methane tri-reforming island. This paper (Part B) focuses on the methanol synthesis process by using the syngas produced by the methane tri-reforming island. Therefore, the ITRPP plant configurations have been modified adding the methanol synthesis island and the performances of these integrated plants, that co-produce electrical power and methanol, have been evaluated. The energy and environmental analysis has been carried out by means of a numerical approach which has allowed to calculate the syngas composition, to define the energy and mass balances and to estimate the CO2 emissions for each configurations. Furthermore, the conventional technology for methanol generation, based on methane steam reforming with carbon dioxide addition, has been analysed and the performances of integrated systems (ISRPP, Integrated Steam Reforming Power Plant), that consist of a power island with a CO2 capture unit, the methane reforming island and the methanol synthesis island, have been investigated. Results point out that the energy and environmental sustainability of the integrated plants, based on the tri-reforming technology for the co-generation of electrical power and methanol, depends on the flue gases composition. Thus, the tri-reforming process can be considered a promising approach for treatment of CO2 when the exhausts contain low oxygen concentrations (i.e. flue gases from steam cycle power plant). | Categorize the text article into one of the two categories:
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Herein, we present a protocol for the on-demand preparation of methanol and formic acid via selective photo-oxidation of methane with H2O and O2 catalyzed by GaN. The detailed photosyntheses of methanol or formic acid from CH4/H2O or CH4/H2O/O2 are described, respectively. In addition, we provide experimental details for the accurate quantifications of the final gas/liquid products and photoexcited oxygenated radicals. Finally, we deliver the procedure for scaling up the transformation. For complete details on the use and execution of this protocol, please refer to Han et al. (2023). 1 | Categorize the text article into one of the two categories:
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Eliminating micropollutants in trace concentrations in water bodies is crucial and challenging due to their persistent and bioactive characteristics. Due to these characteristics, their detection and removal pose a challenge to the conventional removal methods and to the health of the community. To effectively remove the pollutants, it requires the design and development of an efficient technique compared to the conventional techniques. The design of highly efficient methanol sensor and the adsorption of micropollutants by a heterojunction involving Sb2S3 and polythiophene (PTh) looks promising. The adsorption study was targeted on RhB dye whereas methanol was targeted to sensing application. Sb2S3 nanoparticles was synthesized by hydrothermal methods and incorporated into thiophene solution during chemical oxidative polymerization of thiophene. The heterojunction was applied to remove RhB dye through the adsorption process. Freundlich isotherm model and Langmuir isotherm model were used to study the adsorption of RhB. The higher adsorption capacity was found in case of Sb2S3/PTh is 99.8 mg g−1, and the rate constant (K2) was found to be 0.0206 min−1. The catalysts follows the pseudo-first and second order kinetics in the removal of RhB dye. The rate constant for adsorption k1 is 0.1347 min−1 and the rate constant for diffusion is 0.297 min−1. Moreover, the PTh/Sb2S3 shows an effective methanol sensing up to 0.7 mM and the current response at 0.6756 V of the oxidation peaks shows the presence of methanol. | Categorize the text article into one of the two categories:
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Berries are highly perishable fruits and require both low storage temperature and suitable packaging throughout the supply chain to preserve their organoleptic qualities. However, the energy consumption of refrigerated equipment and the use of packaging materials, plastic in particular, might generate important environmental impacts. Besides, there is a strong commitment to reduce the use of plastic in the food industry. The aims of the current work are first to assess the energy consumption of refrigerated equipment and second to analyze the environmental performance of the strawberry supply chain. Various stages of the supply chain from transport from growers to retail storage were modeled using data from field measurement and interviews with professional stakeholders. Life Cycle Assessment (LCA) was performed for the strawberry supply chain. Different packaging materials, plastic (PET, RPET) and alternatives (molded pulp, recycled paper, cardboard), were used. The processes that generated the most important environmental burden were the packaging production and the long-distance refrigerated transport. To limit the impact related to packaging production, it is necessary to consider not only the type of packaging material but also the processes and energy consumption used in their manufacturing. | Categorize the text article into one of the two categories:
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High-silica MFI zeolite can hardly be prepared by the conventional hydrothermal synthesis route in the absence of amines, which is ascribed to the competitive growth of quartz, magadiite, or kenyaite phase. In this work, these impurity phases were excluded from the synthetic gel through a low-temperature crystallization method, while the growth of zeolite phase was promoted by seed-directed and C2H5OH filling. Consequently, well-crystallized ZSM-5 samples with controllable Si/Al ratios (46–205) and uniform particle sizes were successfully prepared, and the crystallization process was tracked by multiple characterization techniques, pointing toward a nonclassical particle attachment crystallization process. Interestingly, we found that the optimal C2H5OH/SiO2 ratio can be proportionally reduced by decreasing the H2O/SiO2 ratio in the synthetic gel. More importantly, the obtained high-silica MFI zeolite exhibited a much higher catalytic stability than the conventional sample synthesized using tetrapropylammonium as the template during the methanol-to-propylene and n-butene cracking reactions, which may be attributed to its fewer defect sites determined by 1H magic angle spinning nuclear magnetic resonance techniques. Overall, this work provides an efficient route for the large-scale production of high-silica ZSM-5 samples. | Categorize the text article into one of the two categories:
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This chapter gives a general overview of flexible plastic packaging. It also presents the benefits and limitations of flexible plastic packaging as they are reflected in life cycle assessment studies. Flexible packaging is also compared with rigid packaging. Emphasis is given to the recycling problem of flexible multilayer plastic packaging. Further, it describes the various options of recycling and the waste management hierarchies used by EU and US Environmental Protection Agency. | Categorize the text article into one of the two categories:
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As an important application for methanol-based energy-storage systems, methanol steam reforming (MSR) using appropriate catalysts can provide clean hydrogen via onboard production for fuel cells. However, owing to their unsatisfactory activity and stability, the use of the most common catalysts, including Cu-based and groups 8–––10 transition metals, remains challenging. Herein, a series of Na-promoted Co2C nanoprism catalysts containing different Na loadings was used for the first time in MSR. The 1Na/Co2C catalyst showed an excellent activity and stability for MSR, with H2 production rates as high as 4637.9 μmol/gcat/min at 250 °C, which outperforms most of the reported catalysts. In-depth characterizations revealed that a strong interaction between Na and Co2C stabilized the catalyst and promoted the dissociation of CH3OH and H2O. A further investigation of the reaction mechanism revealed that the reaction proceeded via the dehydrogenation of methanol and sequential water−gas shift reactions. Density functional theory calculations revealed that the Co2C (101) surface exhibited the lowest energy barrier and that the methoxy dehydrogenation was the rate-determining step. This work provides further valuable insights into the rational design of transition-metal carbide catalysts for MSR. | Categorize the text article into one of the two categories:
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Platinum decorated binary hetero-junctions of NiO and TiO2 of various mole-ratios have been synthesized for use of these as anode catalysts in the oxidation of methanol in alkali. The as synthesized composites are characterized by X-ray diffraction, spectroscopic and microscopic investigations. The ternary composite having 25.3 mass% of Pt deposited on the binary composite containing 34.36 mass% NiO and 40.34% TiO2 is found to be the best catalyst both in dark and illuminated condition. The peak current density in cyclic voltammetry, the charge transfer conductance, and the steady chronoamperometric current density are increased by about 1.8, 4, and 1.5 times respectively, on the illumination of anode, in comparison to these in the dark. The electrochemical impedance spectroscopy (EIS) and photo responsive current measurements indicate that mixing of NiO with TiO2 demonstrates a superior photo-electro catalytic performance for methanol oxidation plausibly due to enhancement of the electron-hole separation efficiency. Product analysis by HPLC reveals that the formation of formaldehyde, sodium formate, and methyl formate is facilitated on illumination while additional carbonate is formed in the dark. | Categorize the text article into one of the two categories:
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Pt nanoparticles with different mean sizes supported on carbon nanotubes were synthesized by microwave heating ethylene glycol solutions of platinum salt with different pH in present of CNTs as supports. TEM examinations showed that Pt particles become smaller and more uniform when the synthesis pH increased from 3.4 to 9.2. The mean particle size was 5.8, 5.2, 3.4 and 2.7nm when the synthesis pH was 3.6, 5.8, 7.4 and 9.2, respectively. The effects of the pH on Pt particle size and distribution were investigated. The pH was an important factor that influenced the particle size. Pt particles size could be thus selected by adjusting the synthesis solution pH. Pt/CNTs with suitable and uniform Pt particle size could be obtained. Electrochemical measurements showed that the Pt/CNTs catalyst prepared from the synthesis solution pH of 7.4 exhibited better performances for methanol electrooxidization than other samples. | Categorize the text article into one of the two categories:
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The increasing shortage of fossil resources and environmental pollution has renewed interest in the synthesis of value-added biochemicals from methanol. However, most of native or synthetic methylotrophs are unable to assimilate methanol at a sufficient rate to produce biochemicals. Thus, the performance of methylotrophs still needs to be optimized to meet the demands of industrial applications. In this review, we provide an in-depth discussion on the properties of natural and synthetic methylotrophs, and summarize the natural and synthetic methanol assimilation pathways. Further, we discuss metabolic engineering strategies for enabling microbial utilization of methanol for the bioproduction of value-added chemicals. Finally, we highlight the potential of microbial engineering for methanol assimilation and offer guidance for achieving a low-carbon footprint for the biosynthesis of chemicals. | Categorize the text article into one of the two categories:
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The synthesis of methanol from gases derived from biomass sources is an option to address the difficult problem of reducing carbon dioxide emissions from the transportation sector since this liquid fuel may be produced in principle in a neutral way with respect to emissions of this gas to the atmosphere. This paper deals with the production of methanol integrated with processes for the generation of electricity from coal or natural gas. The main advantage of this approach is that nearly all the generally expensive carbon of the biomass may be either incorporated in the methanol or play a role in compensating for the emissions of fossil fuel carbon released in generation. Provided the quantity of carbon dioxide captured and sequestered equals the corresponding quantity of carbon entering the process with the fossil fuel, both the methanol synthesized and the electricity generated are neutral with respect to emissions of this gas to the atmosphere. The paper considers linking the gasification of biomass to a coal case based upon the emerging integrated-gasification combined-cycle process (IGCC) for the generation of electricity and to a natural gas case involving the reforming of methane. | Categorize the text article into one of the two categories:
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A straightforward synthesis of carbohydrate templated isoxazolidines is described, by reaction of unprotected glycosylhydroxylamines (operating as 1,3-dipoles) with methyl acrylate using microwave activation. Rhamno- and erythro-isoxazolidines are recognized by plant cells, resulting in a strong ROS-production as a plant immune response, and exert a high antifungal activity against Botrytis cinerea. | Categorize the text article into one of the two categories:
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Localism or regionalization has become a popular topic in urban design, but recent critics raise the question of whether the local or regional scale is most desirable for industrial ecosystems. As a way to explore the claim that localized metabolism is more sustainable, this study examines the costs and benefits of two differentially scaled strategies for the management of post-consumer polyethylene terephthalate (PET) bottles originating in the city of Honolulu, Hawai'i: local incineration and trans-continental recycling. We first estimate total environmental impacts of two options using life cycle assessment, and then disaggregate them into local versus non-local impacts to examine the spatial distribution of costs and benefits. We further assess the environmental justification for localized waste management in relation to the broader socio-economic motivations that underlie the way that plastics are managed in Honolulu. In doing so we assess the scale at which waste management is optimized from an environmental standpoint as well as the non-environmental considerations such as security and safety that influence the politics of scale involved in urban metabolic design. By illustrating the trade-offs between a local versus global metabolic pathway for plastic waste, the results from our Honolulu case study are globally relevant for communities interested in sustainable urban design and in particular urban waste management. | Categorize the text article into one of the two categories:
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The plastic packaging, and in particular the multilayer flexible packaging, has several characteristics that make it essential in everyday life. However, the sustainability of used materials is undermined by the difficulties encountered for their recycling. The purpose of this study is to assess both the technical feasibility, and above all the environmental sustainability of an effective process enabling the recycling of polyamides-polyethylene multilayers packaging films. The technique used for the separation of the polymers is based on a selective dissolution, carried out using monoethylene glycol. The experimental tests made possible to identify the best conditions for treating the films and for maximizing yields and final products quality. The Life Cycle Assessment of the recycling process modelled at an industrial level, firstly allowed to determine the main process hotspots (i.e. the energy consumption). The LCA analysis was then extended, examining the life cycle of polyamides-polyethylene films with different end-of-life treatments, i.e. incineration, energy recovery and recycling. The results showed that the recycling process, carried out through the selective dissolution of the films, allows to reduce the overall environmental impacts of these materials along their life cycle. Therefore the recycling process analysed here can be considered an effective approach to increase environmental sustainability and recovery of raw materials. | Categorize the text article into one of the two categories:
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Boron was implemented to promote the catalytic behavior of H-ZSM-5 zeolite in methanol to propylene (MTP) process. A series of crystalline borosilicates with different boron contents were synthesized using a seed-assisted hydrothermal technique and characterized well. Results revealed that increasing the boron coefficient improved lifetime and propylene productivity of zeolite by 20 and 24%, respectively. Hierarchal micro-mesoporosity and the distribution of acid sites made a substantial contribution to H-[B]-ZSM-5 performance in MTP. Boron played a significant role in tuning the acidity of the catalyst and improved its stability by controlling the formation of heavy hydrocarbons (C5+) in the MTP reaction. | Categorize the text article into one of the two categories:
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Three innovative conservation materials were investigated by means of life cycle assessment (a calcium acetoacetate consolidant for carbonate surfaces, a TEOS-based consolidant for silicate substrates, and a photocatalytic suspension). So far not much attention has been paid to materials for the conservation of the built cultural heritage, with regard to their environmental performance. The main aim of this study was to assess the environmental footprint of the above-mentioned conservation materials which arises throughout their life cycle. In this way comparative data are made available for other future LCA studies on consolidants and photocatalytic suspensions. The most heavily polluting processes (i.e. “hotspots”) in the life cycle of the investigated conservation materials were identified, and, where possible, solutions for the further optimization of their environmental performance were proposed. In the case of life cycle of the two above-mentioned consolidants, the majority of emissions can be attributed to the synthesis of the constituent materials which are used to make the final products. Ethyl polysilicate is the largest contributor to the environmental footprint of the TEOS-based consolidant. On the other hand, in the life cycle of the calcium acetoacetate consolidant most of the environmental burdens are contributed by the synthesis of acetone-dicarboxylic acid. Around 0.47 kg of CO2 equivalent emissions affecting global warming are released to the air during the life cycle of 1 L of calcium acetoacetate (considering solely the upstream and core processes), whereas this value is higher in the case of the life cycle of the TEOS-based consolidant, i.e. 3.77 kg of CO2 equivalent emissions. In the case of the life cycle of the investigated photocatalytic suspension, although 1 L of this suspension is responsible for the release of only 0.1 kg of CO2 equivalent emissions over its life cycle (excluding the case-specific downstream processes) the heaviest environmental impact is caused by the production of packaging material (e.g. plastic buckets and other types of plastic containers). Taking into account the above-mentioned facts, there are not many possibilities for the reduction of the environmental burdens of the two investigated consolidants by the environmental optimization of the processes involved in the core and downstream stages of their life cycles. In the life cycle of the photocatalytic suspension, the environmental burdens related to greenhouse gas emissions could be reduced by more than 10% if a cleaner form of electricity production were to be adopted. A further aim of this paper is to promote sustainability in the field of management of the immovable cultural heritage. Although the described conservation materials have only a minor environmental effect in the field of the management of the immovable cultural heritage, the significance of sustainability is presented to conservators on a practical example. | Categorize the text article into one of the two categories:
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The explosive growth of China's express delivery industry has greatly increased plastic waste, with low-value plastics not effectively utilized, such as PE packaging bags, which are often not recycled and end up in landfills or incinerators, causing significant resource waste and severe plastic pollution. A gate -to- grave life cycle assessment was adopted to assess the impacts of express delivery plastic waste (EDPW) management models (S1, landfill; S2, incineration; S3, mechanical pelletization), with Suzhou, China as a case. Results showed that mechanical pelletization, was the most environmentally advantageous, exhibiting a comprehensive environmental impact potential of −215.54 Pt, significantly lower than that of landfill (S1, 78.45 Pt) and incineration (S2, -121.77 Pt). The analysis identified that the end-of-life disposal and sorting stages were the principal contributors to environmental impacts in all three models, with transportation and transfer stages of residual waste having minimal effects. In terms of all environmental impact categories, human carcinogenic toxicity (HTc) emerged as the most significant contributor in all three scenarios. Specifically, S1 exhibited the most detrimental effect on human health, while S2 and S3 showed positive environmental impacts. Based on these findings, it is recommended that the application and innovation in mechanical recycling technologies be enhanced, the promotion of the eco-friendly transformation of packaging materials be pursued, and a sustainable express delivery packaging recycling management system be established. These strategies are essential for achieving more eco-friendly management of EDPW, reducing its environmental pollution, and moving towards more sustainable express delivery management practices. | Categorize the text article into one of the two categories:
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Along with the rapid growth of the food delivery industry, concerns are growing regarding the management of plastic packaging waste. This study estimates the amount of plastic packaging from online food delivery services in Korea and assesses its environmental effects using life cycle assessments. This study also compares the environmental impacts of the adoption of multi-use containers, the use of recycled materials, and the increase in recycling rates proposed by the Korean government for efficient plastic waste management. A total of 72.93 kt of plastic packaging was consumed by online food delivery in 2020, polypropylene and polyethylene terephthalate accounted for 81.48% of the packaging materials consumed. The adoption of multi-use containers is the most environmentally effective alternative, but its negative impact on terrestrial ecotoxicity is approximately 5 times higher than that of others. Although the other two alternatives are 2–6 times less efficient than adopting multi-use containers, they can still play an important role in plastic waste management. Overall, these results provide empirical information on food packaging waste and insights into the sustainable management of plastics. Keywords: Food packaging, Plastic waste, Online food delivery service, Waste management, Environmental impact. | Categorize the text article into one of the two categories:
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The rapid increase of carbon dioxide content in the atmosphere has led to environmental problems such as the greenhouse effect, carbon dioxide hydrogenation to methanol will help to alleviate the burden on the environment. Energy-saving processes were proposed for separating methanol products from crude methanol produced through the direct hydrogenation of carbon dioxide. A flash system and nitrogen stripper were applied to remove carbon dioxide and hydrogen in the carbon dioxide hydrogenation products because of the high solubility of carbon dioxide in methanol. Conventional distillation (CDiC), differential pressure thermal coupling (DPDiC), and double effect distillation (DEDiC) were established to obtain high-purity methanol from crude methanol with high water content to achieve energy conservation. Total annual cost (TAC), carbon dioxide emissions, and exergy efficiency were conducted to evaluate the proposed distillation processes. The results show that the three-stage flash evaporation is more energy efficient than the two-stage flash evaporation, with an exergy loss of 16.7% and 24.0%, respectively. The DEDiC process has the highest exergy efficiency of 25.6%, while the DPDiC process demonstrates better economic and environmental performance. Thus, the DPDiC process provides an energy-saving option for crude methanol refining. | Categorize the text article into one of the two categories:
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The synthesis of CH3OH from CO2/H2 mixtures using Ga2O3–Pd/SiO2 promoted catalysts is strongly affected by the reaction products. At finite conversion, important amounts of water and carbon monoxide are also found in the system and, therefore, a comprehensive evaluation of their impact on the process is particularly relevant. An experimental program was conducted, using a plug-flow, differential reactor and a Berty-type CSTR recycle reactor, for a wide range of temperature (508–538K), pressure (1–4MPa), composition (H2/CO2 =1, 3 and 6) and space velocity, including H2–CO–CO2 and H2–He–CO2 ternary mixtures as well. The deleterious effect of CO is attributed to its strong chemisorptive bonding onto the metal, which hampers the generation and transfer of dissociated hydrogen, Hs, from the Pd crystallites to the Ga2O3; this effect alters both the activity and the selectivity of the catalyst. The detrimental impact of H2O, which is produced in every stoichiometric reaction of the system, is related to its interference on the availability of coordinatively unsaturated sites (cus) on the gallia surface. | Categorize the text article into one of the two categories:
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Quantitative evidence of health and environmental tradeoffs between individuals' drinking water choices is needed to inform decision-making. We evaluated health and environmental impacts of drinking water choices using health impact and life cycle assessment (HIA, LCA) methodologies applied to data from Barcelona, Spain. We estimated the health and environmental impacts of four drinking water scenarios for the Barcelona population: 1) currently observed drinking water sources; a complete shift to 2) tap water; 3) bottled water; or 4) filtered tap water. We estimated the local bladder cancer incidence attributable to trihalomethane (THM) exposure, based on survey data on drinking water sources, THM levels, published exposure-response functions, and disability-adjusted life years (DALYs) from the Global Burden of Disease 2017. We estimated the environmental impacts (species lost/year, and resources use) from waste generation and disposal, use of electricity, chemicals, and plastic to produce tap or bottled drinking water using LCA. The scenario where the entire population consumed tap water yielded the lowest environmental impact on ecosystems and resources, while the scenario where the entire population drank bottled water yielded the highest impacts (1400 and 3500 times higher for species lost and resource use, respectively). Meeting drinking water needs using bottled or filtered tap water led to the lowest bladder cancer DALYs (respectively, 140 and 9 times lower than using tap water) in the Barcelona population. Our study provides the first attempt to integrate HIA and LCA to compare health and environmental impacts of individual water consumption choices. Our results suggest that the sustainability gain from consuming water from public supply relative to bottled water may exceed the reduced risk of bladder cancer due to THM exposure from consuming bottled water in Barcelona. Our analysis highlights several critical data gaps and methodological challenges in quantifying integrated health and environmental impacts of drinking water choices. | Categorize the text article into one of the two categories:
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Designing effective catalyst to improve the activity of CO2 hydrogenation to methanol is a potential avenue to realize the utilization of CO2 resources. Herein we construct three kinds of Cu/Ce x Zr y O z (CCZ) catalysts with different crystal phases of Ce x Zr y O z solid solutions, which demonstrate distinct activity and methanol selectivity in the order of metastable tetragonal-CCZ (CCZ-t″, parts of oxygen in Ce x Zr y O z were replaced by tetragonal phase from cubic fluorite phase) > tetragonal-CCZ (CCZ-t) > cubic-CCZ (CCZ-c) for CO2 hydrogenation to methanol. Structural analysis reveals that oxygen vacancies, surface hydroxyls and unsaturated Cu species of CCZ all follow the same sequence as that of activity and methanol selectivity, indicating that the above features are beneficial to improve the catalytic reaction performance. Temperature programmed experiments and mechanism studies show that the interface between Cu and tetragonal (t and t″) Ce x Zr y O z can promote CO2 adsorption, and the adsorbed CO2 is more reactive and can generate active bidentate carbonate species, which can be hydrogenated to form active monodentate and bidentate formate species under CO2 and H2 atmosphere. These intermediates should be crucial to the formation of methanol product. CCZ-t″ has stronger H2 activation ability than CCZ-t, which makes the former catalyst have more intermediates and higher methanol selectivity. In contrast, CO2 mainly adsorbs on cubic Ce x Zr y O z support of CCZ-c, but its H2 spillover ability is low, which hinders the reaction process. In addition, the strong adsorption of surface intermediates on CCZ-c is also not conducive to methanol formation. Results here demonstrate that constructing active Cu-support interfaces may be an important approach to design effective catalyst for CO2 hydrogenation. | Categorize the text article into one of the two categories:
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Cu/ZnO microball catalysts were prepared by a two-step process, where ZnO nanorods supports were first grown hydrothermally followed by the impregnation of copper nanoparticles. Catalytic activities for methanol steam reforming by using Cu/ZnO microball were found to increase with higher copper content. Addition of urea during the metal impregnation process was found to enhance the methanol steam reforming catalytic activity attributed to the larger surface area of the catalyst. Activation energies of synthesized catalyst and CuZnAl commercial catalyst were calculated from the Arrhenius plots of the rate of reaction and were found to affect hydrogen yield. The lowest activation energy of 4.74kJmol−1 was achieved for the optimized catalyst which was half of the activation energy of commercial catalysts. | Categorize the text article into one of the two categories:
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Cu/ZnO/Al2O3 impregnation catalysts were studied for their copper surface area (reactive chemisorption of nitrous oxide) and catalytic activity for the synthesis of methanol from a CO/ H2 mixture (fixed-bed flow reactor). The results indicate that the presence of zinc causes an increase in the copper dispersion at concentrations up to ca 0.09 g Zn/g Al2O3. The copper surface area increases during methanol synthesis from CO/H2; the extra surface formed is stable in a carbon monoxide-containing atmosphere only. For catalysts with a constant copper loading, the catalytic activity is related to the nitrous oxide-titratable copper surface after reaction. The ZnO component of the catalyst has a substantial activity, which must be taken into account. Thus, it was found that the catalytic activity increases linearly with the copper surface area of the Cu/ ZnO phase, while it appears to be independent of the copper area of copper-on-alumina. | Categorize the text article into one of the two categories:
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We demonstrate that electrochemically corroded thick nitrogen-doped carbon (NC) layer encapsulated Pt/C (denoted as NC/Pt/C) has high activity and ultrahigh stability for both methanol oxidation and oxygen reduction reactions. The encapsulation of thick NC layers leads to very low initial activities due to tight coverage; however, after 80,000 cyclic voltammetry (CV) cycles of aging corrosion process, the activities increase to 2–3 times that of bare Pt/C and keep almost unchanged for next 50,000 CV cycles. In H2/O2 acidic membrane fuel cell with NC/Pt/C as cathode, high power densities (1.34–1.39 W cm−2) can be kept for 50,000 cycles, ranking it one of the most stable noble metal catalysts. The thick NC layers are corroded to be more microporous during the electrochemical aging process; the resultant micropores favor mass transport and can still closely bind and protect Pt particles within a long operation time, leading to the improved activity and stability. | Categorize the text article into one of the two categories:
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A solution to low recycling rates of plastic waste is the conversion into multi-walled carbon nanotubes (MWCNTs) that have high value and can create additional revenue for plant operators. The purpose of this study was to perform a life cycle assessment (LCA) of an integrated system that involves flexible packaging plastic waste (FPPW) pyrolysis, oil upgrading, and MWCNTs production. The objectives were to determine the environmental impact of MWCNTs synthesis from non-condensable pyrolysis gases, and to assess the environmental impact of MWCNTs synthesis from different plastic fractions. Integrating MWCNTs synthesis to the plastic pyrolysis process provides various environmental benefits including, reduction of contribution towards climate change, fossil depletion, human toxicity (cancer), and ionizing radiation potentials. Sensitivity analysis of MWCNTs yields provided the range of impacts on the environment and a critical yield of >2% for most impact categories was determined. Comparison of different plastic fractions indicated that using low PET content feedstock had lesser impact on the environment, and demonstrated comparable performance to mixed virgin plastics for most impact categories. The results highlighted the versatility of the integrated pyrolysis process for treating diverse plastic waste fractions with negligible effects from the impurities present in the actual FPPW during thermal processing. | Categorize the text article into one of the two categories:
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Plastic flexible films are increasingly used in many applications due to their lightness and versatility. In 2014, the amount of plastic films represented 34% of total plastic packaging produced in UK. The flexible film waste generation rises according to the increase in number of applications. Currently, in developed countries, about 50% of plastics in domestic waste are films. Moreover, about 615,000 tonnes of agricultural flexible waste are generated in the EU every year. A review of plastic films recycling has been conducted in order to detect the shortcomings and establish guidelines for future research. This paper reviews plastic films waste management technologies from two different sources: post-industrial and post-consumer. Clean and homogeneous post-industrial waste is recycled through closed-loop or open-loop mechanical processes. The main differences between these methods are the quality and the application of the recycled materials. Further research should be focused on closing the loops to obtain the highest environmental benefits of recycling. This could be accomplished through minimizing the material degradation during mechanical processes. Regarding post-consumer waste, flexible films from agricultural and packaging sectors have been assessed. The agricultural films and commercial and industrial flexible packaging are recycled through open-loop mechanical recycling due to existing selective waste collection routes. Nevertheless, the contamination from the use phase adversely affects the quality of recycled plastics. Therefore, upgrading of current washing lines is required. On the other hand, household flexible packaging shows the lowest recycling rates mainly because of inefficient sorting technologies. Delamination and compatibilization methods should be further developed to ensure the recycling of multilayer films. Finally, Life Cycle Assessment (LCA) studies on waste management have been reviewed. A lack of thorough LCA on plastic films waste management systems was identified. | Categorize the text article into one of the two categories:
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The manganese-catalyzed dehydrogenative coupling between methanol and amines for the synthesis of ureas and polyureas is described. Importantly, catalytic efficiency can be improved by the newly synthesized MACHO ligands. Furthermore, this highly atom-economical protocol demonstrates a broad substrate scope with good functional group tolerance, producing H2 as the sole byproduct. Mechanistic studies disclose that formamide is formed through manganese-catalyzed formylation of amine with methanol. Subsequent dehydrogenation affords a transient isocyanate, which is attacked by another equivalent of amine to provide the final product. | Categorize the text article into one of the two categories:
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Plastic recycling involves a range of potential environmental benefits, from curbing landfill and incineration rates to the reduction of greenhouse gas emissions. However, the main challenge is to find applications where recycled plastic can successfully provide the same functionality as the replaced virgin plastic. Particularly, the incorporation of recycled high-density polyethylene (HDPE) to polyethylene (PE) pipe grade resins is a great challenge that is not currently being implemented in the manufacture of pressure pipes. In this study, life cycle assessment (LCA) is applied to quantitatively evaluate the potential environmental impacts from producing PE pipe grade resins from recycled HDPE blended with virgin HDPE. The LCA involves four HDPE waste feedstocks (crates/caps, packaging/detergency bottles, post-consumer industrial containers, and automobile fuel tanks) and two PE pipe grades (PE80 and PE100). Moreover, different allocation approaches that affect the LCA of plastic recycling, namely the cut-off approach and the Circular Footprint Formula, were investigated. The recycled content was found to largely determine the LCA results. In this regard, the production of PE80 quality from the pure HDPE waste feedstocks (such as automobile fuel tanks and post-consumer industrial containers) allows a higher recycled content, thus resulting in lower impacts. Compared with a 100 % virgin resin, these two scenarios show 80 % and 53 % less carbon footprint if the waste feedstock is considered burdens free (cut-off allocation). These percentages however decrease to 32 % and 20 % if the impacts and benefits are shared according to the Circular Footprint Formula. These trends were similarly observed for most of the impact categories evaluated, such as, acidification and fossil resources. The robustness of these results is supported by error propagation via Monte Carlo simulation. | Categorize the text article into one of the two categories:
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A low-cost liquid lipase from genetically modified Aspergillus oryzae (Eversa® Transform 2.0) was used in this study for biodiesel production. The catalytic performance of this enzyme was evaluated using refined palm oil adjusted with different free fatty acid (FFA) content. The methanol-to-oil molar ratio was varied from 1:1 to 8:1 to determine the reaction rate, ester conversion and methanol tolerance of this enzyme at different FFA content. The reaction was carried out at low temperature (40 °C) for 24 h using very low enzyme concentration (0.2 wt%). The results showed that the enzyme could tolerate a higher dosage of methanol and could increase reaction rate and conversion when higher FFA content was present in the feedstocks. A biodiesel conversion of 97% could be obtained when the feedstocks contained ≥80 wt% FFA. Furthermore, a new semi-empirical model based on the Ping-Pong Bi-Bi mechanism has been developed to estimate the reaction kinetics of biodiesel production from feedstocks containing a mixture of triacylglycerol and FFA. In conclusion, Eversa® Transform 2.0 can be used for the production of biodiesel from low-quality feedstocks containing high FFA content in a sustainable and economical manner. | Categorize the text article into one of the two categories:
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The direct hydrogenation of CO2 to methanol has become a very active research field because CO2 can be prospectively recycled to mitigate greenhouse effect and store clean synthetic fuels. This reaction can be catalyzed by supported Cu catalysts and the catalysts display strong support or promoter effects. Sintering of Cu species accelerates the separation of Cu–oxide interfaces, reduces the active component, and diminishes the methanol selectivity. In this work, we report a Cu catalyst supported on La-modified SBA-15, where the Cu–LaOx interface is generated through the interaction of highly dispersed Cu nanoparticles with LaOx species bedded into the SBA-15 pore wall. The optimized Cu1La0.2/SBA-15 catalyst can achieve methanol selectivity up to 81.2% with no deterioration in activity over 100 h on stream compared with the La-free catalyst. A thorough study reveals that La species not only significantly improve the CO2 adsorption but also enhance Cu dispersion to produce well-dispersed active sites. The H/D exchange experiments show that the methanol synthesis displays a strong thermodynamic isotope effect and the Cu–LaOx interface plays a crucial role for the methanol synthesis rate in CO2/D2 feed. In situ DRIFTS studies reveal that *HCOO and *OCH3 species are the key intermediates formed during the activation of CO2 and methanol synthesis over the Cu1La0.2/SBA-15 catalyst. | Categorize the text article into one of the two categories:
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With rising concerns about adverse impacts of agricultural plastic waste in the soil environment and microplastic problems, many options have been proposed to prevent agricultural plastic pollution. To evaluate the options environmentally, this study conducted a comparative life cycle assessment of mulching films with different thicknesses (0.01 mm and 0.014 mm), materials (polyethylene and poly (butylene adipate-co-terephthalate)), and end-of-life options (recycling, incineration and biodegradation). The results indicate that biodegradable film presents the lowest net environmental impacts in aquatic pollution and toxicity indicators, while the 0.014 mm polyethylene film performs the best in global warming potential and fossil resource depletion. Either reducing the soil content or increasing the collection rate of waste polyethylene films can reduce their environmental impacts, and the reducing proportions of 0.014 mm polyethylene films were found to be larger than those of 0.01 mm polyethylene films. In general, the biodegradable mulching film is found to be more environmental-friendly than polyethylene film, but potential improvement could be considered for greener design of the products by increasing biobased material. More efforts can be put on developing reliable inventory datasets of biodegradable materials production. | Categorize the text article into one of the two categories:
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H-ZSM-5 zeolite is a typical catalyst for methanol-to-olefins (MTO) conversion. Although the performance of zeolite catalysts for MTO conversion is related to the actual location of acid sites in the zeolite framework, the catalytic roles of the acid sites in different pore channels of the H-ZSM-5 zeolite are not well understood. In this study, the MTO reaction network, involving the aromatic cycle, alkene cycle, and aromatization process, and also the diffusion behavior of methanol feedstock and olefin and aromatic products at different acid sites in the straight channel, sinusoidal channel, and intersection cavity of H-ZSM-5 zeolite was comparatively investigated using density functional theory calculations and molecular dynamic simulations. The results indicated that the aromatic cycle and aromatization process occurred preferentially at the acid sites in the intersection cavities with a much lower energy barrier than that at the acid sites in the straight and sinusoidal channels. In contrast, the formation of polymethylbenzenes was significantly suppressed at the acid sites in the sinusoidal and straight channels, whereas the alkene cycle can occur at all three types of acid sites with similar energy barriers and probabilities. Consequently, the catalytic performance of H-ZSM-5 zeolite for MTO conversion, including activity and product selectivity, can be regulated properly through the purposive alteration of the acid site distribution, viz., the location of Al in the zeolite framework. This study helps to elucidate the relation between the catalytic performance of different acid sites in the H-ZSM-5 zeolite framework for MTO conversion, which should greatly benefit the design of efficient catalyst for methanol conversion. | Categorize the text article into one of the two categories:
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Methanol steam reforming (MSR) is an attractive approach to produce hydrogen for fuel cells. Due to the limited catalyst loading volume and frequent start-ups and shut-downs on board, it is highly desired to develop an extremely active and robust catalyst. Herein, on the basis of industrial Cu/ZnO/Al2O3 catalysts, a series of CuZnAl-xMg catalysts with enhanced Cu-ZnO synergy were synthesized via magnesium assisted strategy. The incorporation of magnesium was found to be beneficial to the enhancement of catalytic activity and stability of catalyst. A combination of complementary characterizations (e.g. XRD, H2-TPR, N2O chemisorption, TEM, XPS analysis etc.) proves that isomorphous substitution of Cu2+ in malachite phase gives rise to more dispersive Cu and ZnO NPs, and the increased Cu+/Cu0 ratio indicates the strengthened Cu-ZnO synergy effect, which leads to the boosted stability during the thermal treatment. | Categorize the text article into one of the two categories:
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Plastic grocery bags are one of the most ubiquitous single-use packaging products. Recently, ‘eco-friendly’ options of plastic grocery bags have gained traction such as kraft paper, cotton, biodegradable, and reusable polypropylene non-woven bags. However, the impact of using various grocery bags in cities with dense population, well-developed infrastructure and thermal treatment as an end-of-life waste management option has been insufficiently documented. In this study, commonly found single-use (HDPE, biodegradable plastic, kraft paper) bags and reusable (cotton, polypropylene non-woven) bags were considered for the life cycle assessment (LCA). The usage characteristics (reusability, dimensions, carrying capacity) of bags, the production process (raw materials extraction, production processes), and emissions were determined as the significant factors contributing to the negative environmental impacts. In a model city with confined waste management, the assessment determined that the reusable polypropylene non-woven bag (PNB) caused the least overall negative environmental impacts when there are 50 instances of reuse, followed by single use HDPE plastic bag (HPB). The global warming potential (excluding biogenic carbon) was 14, 81, 17 and 16 times higher for HDPE plastic, kraft paper, cotton woven and biodegradable polymer bags, respectively, when compared to PNB. Moreover, kraft paper or cotton woven bags demonstrated the highest negative impacts for the impact categories including abiotic fossil depletion, freshwater-, marine- and terrestrial-ecotoxicities, human toxicity, acidification and eutrophication potentials. Further, sensitivity analysis indicated that the inflexion point for the PNB was minimum 4 reuses to avoid emission equivalent to the HPB. Singapore was adopted as the model city with confined waste management structure that imports most of the grocery bags, either as finished goods or as raw materials. Through comprehensive insights based on the new outlook of the integrated LCA model (cradle-to-grave) that included full-scale transportation component, the usage of the real case data from a city to develop the life cycle inventory, and consideration of the existing grocery bags options, the environmental assessment along with critical evaluation was conducted. | Categorize the text article into one of the two categories:
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The use of plastics in the automotive industry is favoured by their relatively low cost, but a sustainable treatment at their end of life is still challenging. The objective of this study is to contribute to the identification of best practices to increase the recovery rate of plastic materials from end-of-life vehicles (ELVs). European regulations for ELVs foresee that the reuse/recovery and reuse/recycling had to be increased to a minimum of 95% and 85% of the vehicle weight respectively by 2015. Three areas with room for possible improvement were identified in this study: the dismantling phase, the recycling processes, and the material recovery from automotive shredder residues (ASRs) as solid recovered fuels (SRFs). The economic feasibility of recovering specific plastic components from ELVs was assessed using a criterion based on the cost of dismantling, recycling and disposal of the components, as well as the environmental costs of the processes. Based on the results, disassembly and recycling could be cost-effective for a disassembly time below 180 s and a component mass above 600 g. For the recycling processes, the Life Cycle Assessment (LCA) methodology was applied to evaluate the environmental impacts of recycling HDPE from fuel tanks, polyamides PA6/PA66 and PET from automotive components. As the climate change indicator is concerned, Tthe LCA study showed that the impact for 1 kg of these secondary raw materials is respectively of 0.83, 0.16/0.17 and 2.17 kg CO2 eq, obtained from these fractions resulting more sustainable than the respective virgin materials. Electricity consumption was among the main contributors to the potential environmental impacts. The characterization process of ASRs was conducted to assess their compliance to certain types of SRFs. According to the results of the industrial tests, the treatment facility can recover only around 74% of an ELV. The characteristics of ASRs were compliant to be assimilated to a SRF. This study showed that the amount of plastics recoverable from ELVs has the potential to increase thus facilitating the fulfilment of EU recovery targets. | Categorize the text article into one of the two categories:
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The purpose of this research work is to perform the techno-economic assessment of a Power-to-MeOH technology that couples a model water eletrolyzer (either a polymer electrolyte or a solid oxide technology) with a model catalytic CO2 reactor. Simulations were made using ASPEN Plus V8.0. Regarding the SOEC/Methanol process, results of the simulation confirm the predominance of CAPEX on MeOH production cost. Cost reductions and lifespan improvement of SOEC technologies are found to be the major cost reduction drivers. Also, the speed at which the SOEC/Methanol facility is constructed is found to affect significantly the competitiveness of this process. Regarding the PEM/Methanol process, the cost breakdown analysis confirms the predominance of OPEX on the methanol cost, a value that is moderately impacted when the lifespan of the electrolyser is doubled. The energy efficiency of the electrolyser is therefore a key driver for a reduction of methanol production costs. Using state-of-the-art technologies, a methanol cost of 891 €/tonne was determined for the PEM/Methanol process and a methanol cost of 5459 €/tonne was determined for the SOEC/Methanol process. These costs represent respectively 2.5 and 15 times the current market price for methanol. However, promising methanol cost reductions are foreseeable by improving the water electrolysis technologies. | Categorize the text article into one of the two categories:
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For the purpose of selective CO2 capture and efficient methanol adsorption, versatile porous carbon adsorbents are prepared from waste cornstalk by using hydrothermal carbonization treatment and the subsequent KOH activation process. The resultant adsorbents are characterized with different techniques, and the effects of activation degree on the porous structure and chemical components are discussed. The influence of porous texture and heteroatoms doping on the performance of CO2 capture and methanol adsorption has been systematically analyzed. For CO2 capture, the ultra-micropore is the dominant factor under 1 bar, while the heteroatoms N and O have important cooperation effect under 0.15 bar. The methanol adsorption uptakes under 95 mbar and 10 mbar are closely associated with the specific surface area and ultra-micropore volume, respectively. The adsorbents exhibit remarkable CO2 adsorption uptake of 3.97 mmol g−1 at 1 bar, and desirable methanol adsorption uptake of 18.88 mmol g−1 at 95 mbar, in the temperature of 25 °C. The adsorbents also feature excellent reusability and good selectivity for CO2 over N2, as well as methanol over water. This work provides a feasible approach to prepare low-cost porous carbon adsorbents, which may inspire new research interests and provide necessary theoretical guidance for the application and investigation of biomass-derived carbonaceous adsorbents for CO2 capture and methanol adsorption. | Categorize the text article into one of the two categories:
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Within the context of climate change and population growth, the development of urban agriculture is of great environmental and economic significance in rapidly urbanizing China. Based on the primary survey data, this paper evaluated the carbon footprint (CF) and economic efficiency of urban agriculture in Beijing (China) using the life cycle assessment method (from cradle to consumption approach). Two cases were analyzed and compared considering their differences in on-farm cultivation and off-farm supply chains: a conventional small householder farm that sells its vegetables directly to consumers in a local market, and a large home-delivery agriculture (HDA) initiative that delivers its vegetables to the consumers’ home directly. Both cases were equipped with greenhouses with plastic covering but no heating system. The CF of the production, transportation and distribution of 1 kg fresh vegetables was estimated at 0.318 kg CO2-eq kg−1 and 0.624–0.652 kg CO2-eq kg−1 for conventional and HDA initiative farm, respectively. However, the HDA initiative showed a better environmental performance than the conventional operation when taking economic efficiency into consideration. The CF per unit of profit of HDA initiative (0.093–0.097 kg CO2-eq per CNY) was lower than conventional farm (0.111 kg CO2-eq per CNY). The lower CF per unit of product weight of the conventional farm was largely attributed to the high yield and the lower CF per unit of profit of the HDA initiative was mainly due to the outstanding economic profitability through income optimization. The major hotspots of CF in both cases were greenhouse plastic films in the cultivation phase (from cradle to farm gate) and transportation in the supply chain (from farm gate to consumption). Simulation of a switch to biodiesel instead of gasoline and diesel in combination with the replacement of current fossil-fuel-dominated electricity by hydro-powered electricity resulted in 20.0–21.8% reduction in the total CF. By identifying the CF hotspots of two farm cases, particular inputs and activities can be targeted for adjustment in order to effectively reduce the CF of urban agriculture in Beijing. | Categorize the text article into one of the two categories:
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Methanol-to-olefin conversion is one of the most successful approaches to producing light olefins. It has been proved that SAPO-34 is the best catalyst for this process. This molecular-sieve is characterized by high thermal stability, moderate acid sites, and shape selectivity. In this report, SAPO-34 was synthesized using the seed-assisted method. Effects of OSDA and seed on crystallinity and particle size were investigated using Central Composite Design. Samples were characterized by XRD, FE-SEM, FTIR, BET, EDX, and TPD. Results showed that the samples had excellent physicochemical properties. The design of Experiments could predict the results accurately (R2 > 0.9). It was demonstrated that template was the key factor in the seed-assisted synthesis of SAPO-34. Template consumption was reduced by 50%, and it was proved that the synthesis time could be effectively decreased to 3 h due to rapid nucleation. Samples exhibited 100% methanol conversion and up to 90% selectivity toward ethylene and propylene. | Categorize the text article into one of the two categories:
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In recent decades, global agriculture has been dominated by conventional practices associated with negative impacts such as the loss of biodiversity, changes in land use, habitat degradation and pollution. Faced with the urgent need of a sustainable shift, the organic scheme has emerged as an alternative to minimize agriculture's environmental footprint, requiring an assessment of the real impacts of both production methods. By means of a Life Cycle Assessment (LCA), the aim of this research is to evaluate the environmental impacts of conventional and organic apples with a cradle to grave approach. Apples grown in Washington state and consumed in Mexico City are considered as a case study and analyzed through seventeen impact categories. The results highlight five main findings. First, pesticides are identified as the main source of toxicity in the conventional model, underlining the relevance of biological pest control. Although the organic model does use authorized pesticides, these did not represent a significant impact. Second, the use of cardboard boxes for packaging implies changes in agricultural land occupation, as well as the use of plastic bags that impacts climate change, calling for no-waste or reduced packaging. Third, transportation is a key contributor to fossil depletion and climate change, noting the importance local production. Fourth, the final disposal of apples residues in landfills has implications for eutrophication, bringing out the importance of composting residues. Fifth, conventional apple production has a higher environmental footprint in most impact categories when compared to organic production for both surface-based and mass-based functional units. As such, this study recommends the production and consumption of local and in-season organic apples to reduce the negative environmental impacts and the effects on human health. | Categorize the text article into one of the two categories:
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Electrocatalytic activities and stabilities of Pt supported on SnO2-carbon and TiO2-carbon as electrocatalysts were examined for methanol oxidation and oxygen reduction reactions. The Pt/oxide-C catalysts were synthesized by photo-deposition method at RT. The samples prepared were characterized by X-ray diffraction, TEM analysis, cyclic and lineal voltammetry, CO stripping and chronoamperometry techniques. Electrochemical activities of Pt/oxide-C for methanol oxidation reaction (MOR) and methanol tolerance for oxygen reduction were compared with those of Pt/C (Pt-Etek). The MOR activity of Pt/SnO2-C was enhanced over those of the Pt/TiO2-C and Pt/C at different concentrations due to the small platinum particles size. Pt-Sn interaction produce changes in the platinum electronic properties that improve the electrochemical activity towards the methanol oxidation and stability to the methanol presence. The SnO2-C composite appear to be a promising support material that promote electrochemical reactions and stabilize catalytic particles in direct alcohol fuel cells. | Categorize the text article into one of the two categories:
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A series of novel honeycombed-like composites NiCo2O4/rGO-T (rGO: reduced graphene oxide, T: 200, 250 and 300 °C) were obtained by a pre-adjusted pH value aq. phase coprecipitation strategy assisted by citric acid, followed annealing in N2 flow. The NiCo2O4/rGO-250 shows the most uniformly highly-ordered honeycombed-like nanosheet array morphology consisting of ultrathin mesoporous nanosheets (~110 nm × 12 nm) interdigitated vertically grown on the rGO surface in both sides with the highest crystallinity, higher surface area (145 m2 g−1), bimodal pore size distribution (3.4 and 12.5 nm) along with the highly open macroporous networks. The NiCo2O4/rGO-250 electrode exhibits the highest current density for methanol oxidation reaction of 90 A g−1 at 0.6 V, as well as high cycling stability (94% after 500 cycles, returned to 98% with fresh electrolyte), which is the best one so far among reported catalysts with similar compositions. Simultaneously, NiCo2O4/rGO-250 electrode exhibits considerable specific capacitance of 1380 F g−1 at 1 A g−1, high rate performance (10 A g−1, 967 F g−1), and good cycling stability which remains 90% at 5 A g−1 after 1000 charge–discharge cycles for supercapacitor. The excellent electrochemical performance of the NiCo2O4/rGO-250 electrode can be attributed to the highly-ordered honeycombed-like mesoporous nanosheet array along with the greatly increased specific surface area exposing more active sites, the highly open macroporous networks formed by adjacent ultrathin NiCo2O4 nanosheets providing more ion/electron diffusion paths and effective contact area of electrolyte, and the strong NiCo2O4– rGO synergy endowing excellent conductivity and structural robustness, thus greatly facilitate the transfer of electrons and ions in electrode and at the electrolyte/electrode interface. | Categorize the text article into one of the two categories:
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Plastics are one of the most greenhouse gas (GHG) intensive and the fastest growing industries in the manufacturing sector. Environmental tradeoffs of plastics occur through all stages of their life cycles, accelerating climate breakdown and threatening our ability to maintain a sustainable climate. Herein, material flow analysis (MFA) of three major synthetic resins (PVC, PP, PE) in China was first conducted from production to end-of-life. Meanwhile, life cycle assessment (LCA) was applied to investigate “cradle-to-gate” environmental impacts of these synthetic resins, and then GHG emissions during each plastic life stage were quantified by the integrated LCA-MFA framework. Results suggested that GHG emissions during resin production were 5.42, 4.72 and 3.43 kg CO2eq for 1 kg PVC, PP and PE, respectively. Taken together, China generated 304 million metric tons (Mt) CO2eq in 2020 by synthetic resin production, and additional 44 and 55 Mt CO2eq were emitted due to further plastic product manufacturing and end-of-life management, respectively. Packaging was identified as the major GHG contributor during the use phase, which should be critically monitored for GHG management. The study provides a new perspective to reveal environmental hotspots that drive GHG emissions among plastic life cycles and guides policy-makers towards effective carbon control and sustainable plastic management. | Categorize the text article into one of the two categories:
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Post-consumer cushioning packaging waste made from expanded polystyrene or other conventional polymers is rarely recycled because of technical and economic constraints. Expanded packaging can also be made from renewable and biodegradable raw materials. In this case, the use of a renewable feedstock, such as starch, can reduce the oil dependence and biodegradability can enable the organic recycling of the final product. In this study, a life cycle assessment was performed on a prototype (a port-hole spacer for washing machines) developed in a research project by applying a biodegradable plastic expanded by means of microwave technology. Port-hole spacers for washing machines are mainly made from expanded polystyrene. Life cycle assessment results indicate that the prototype is characterized by a lower consumption of non-renewable energy resources (−50%) and lower greenhouse gas emissions (−60%) compared to the benchmark (expanded polystyrene packaging). This was mainly due to the use of a renewable feedstock (starch). The photochemical ozone creation potential resulted significantly lower (−90%) thanks to the abolition of the expanding agent (i.e. pentane) used in the polystyrene expansion process. The robustness of the results was assessed through data quality checks and a Monte Carlo simulation. A sensitivity analysis showed that the environmental profile of the prototype is mainly affected by the Land Use Change for global warming potential and by the type of starch used for eutrophication and acidification. The type of electricity used (i.e. fossil-based or renewable) for the microwave expansion process also affects the results. The use of biodegradable packaging makes it possible to increase the level of recovery by means of organic recycling. Considering the organic recycling rate in the countries where the washing machines are supplied it has been estimated that the cushioning packaging waste that goes to landfill would go from 52% (current scenario with expanded polystyrene packaging) to 37%, whereas recycling would go from 0.5% (mechanical recycling of expanded polystyrene) to 40% (organic recycling of the prototype). This paper shows that the use of a packaging system potentially suitable for inclusion in the industrial composting process opens new routes for waste treatment, thus increasing diversion from landfill. It can be argued that the combination of the use of renewable resources, and the possibility to get a compostable packaging product give rise to interesting future outlook. On one site a reduction of oil dependence can be achieved and, on the other side, the diffusion of packaging products not easy to recycle as post-consume waste and characterized by a very long persistence in the environment is reduced. This paper contributes to the current discussion on the benefits of bio-based and bio-degradable materials, whose production volumes are steadily increasing. | Categorize the text article into one of the two categories:
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The association between consumption of sugar sweetened beverages (SSBs) and diseases including diabetes, liver disease and dental disease is well known, yet SSBs continue to be aggressively promoted, including on university campuses. Healthy beverage initiatives (HBIs) are focused on improving health by decreasing consumption of SSBs. Some HBIs also aim to improve environmental sustainability, e.g. by substituting tap water for SSBs, including the HBI on the 10 campuses of the University of California. However, there is no study of HBIs’ potential environmental benefits. To address this knowledge gap we carried out an environmental life cycle assessment of greenhouse gas emissions, blue water use, and plastic pollution for both liquid content and container for the 940,773 liters of beverages consumed in one calendar year at the University of California, Santa Barbara. We found that climate and water impacts per liter for liquid contents of 10 SSB beverage types and the non-SSB versions of these 10 types without added sugar, were very similar and larger than that of the containers. Impacts of six container types varied widely, with climate impact highest for glass, and blue water and plastic impact highest for plastic containers, while aluminum had higher climate impact than plastic. We then evaluated the environmental benefits of 12 counterfactual HBI scenarios with different combinations of container types and liquid beverages for SSBs, non-SSBs, bottled water, and tap water. The scenario that replaced all other beverages with tap water eliminated almost all environmental impacts, while scenarios that reduced SSBs but increased beverages other than tap water took back many benefits of reduced SSBs. Our results show that to optimize potential environmental benefits, HBIs need to emphasize reducing consumption of all commercial beverages and replacing them with tap water, which will also optimize health benefits. Our methods and results will be valuable for higher education, other institutions, and communities seeking to maximize both health and environmental benefits of healthy beverage policies. | Categorize the text article into one of the two categories:
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We have established a facile and generalizable electrochemical synthesis of metallic mesoporous nanorods in the nanochannels of commercial polycarbonate membranes using microemulsions containing ionic liquids. Herein, we report the preparation of magnetic CoPt nanorods with various meso or nanopores distributions, depending on the microemulsion type (ionic liquid –in-water (IL/W), bicontinuous (β) or water-in-ionic liquid (W/IL)). The synthesized porous nanorods show a much enhanced electrocatalytic activity for methanol oxidation in comparison with compact Pt nanorods (up to 12 times) or Pt/C electrocatalyst (Pt nanoparticles or commercial black platinum). Therefore, the synthesized CoPt mesoporous nanorods could be excellent catalysts in direct methanol fuel cells (DMFC's), as they have high surface areas, large pore volumes and high corrosion stability, and they exhibit promising catalytic properties. | Categorize the text article into one of the two categories:
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The objective of this study was to calculate the carbon footprint (CF) of straw and plastic film mulching practices in order to identify the optimum field management for low-carbon agriculture. A four-year field experiment was conducted to determine the effects of different mulching measurements on greenhouse gas (GHG) emissions, grain yield, and CF of a winter wheat-summer maize cropping system in the Loess Plateau of China. Mulching treatments were no mulching (NM), straw mulching (SM), half plastic film mulching (HPM); full plastic film mulching (FPM), and ridge-furrow planting with film mulching over ridges (RPM). Plastic film mulching decreased N2O emissions compared with NM. However, SM significantly increased direct N2O emissions by 59.2% and indirect N2O emissions by 16.2%. Average annual total GHG emissions calculated by life cycle assessment were 5199–7631 kg CO2-eq ha−1 yr−1. Nitrogen (N) fertilizer was the largest contributor to total GHG emissions, accounting for >41%. For plastic film mulching treatments, the second greatest contributor was plastic film, accounting for 21.1–35.7% of total GHG emissions. In contrast, the second greatest contributor was direct and indirect N2O and CH4 emissions under NM (17.2%) and SM (21.6%). Emissions from diesel consumption was the third largest component of total GHG emissions. All mulching treatments showed significantly greater annual grain yield than the NM treatment. The CF of summer maize yield was higher than that of winter wheat. SM showed the lowest CF (0.38 kg CO2-eq kg−1), and plastic film mulching increased CFs compared with NM. These results suggest that SM should be the priority mulching practice used to increase yield and to reduce the CF of winter wheat-summer maize production in the Loess Plateau, China. Optimizing N fertilizer application rates should be one of the key production strategies employed to mitigate agricultural GHG emissions. | Categorize the text article into one of the two categories:
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Partial oxidation of methane to methanol is one of the best routes for liquid oxygenates preparation. The present study describes the application of a non-thermal plasma reactor operated under dielectric barrier discharge mode with/without catalyst addition for a single stage methane conversion to methanol. Air has been chosen as the oxidant for methane partial oxidation. It is found that both the reactant conversion and product distribution are strongly dependent on the reactor configuration, feed gases composition and also catalyst addition. A series of γ-Al2O3 supported Cu catalyst with metal oxide promoters (ZnO, ZrO2 and MgO) were integrated with plasma zone as to obtain in-plasma catalytic reactor. Typical results show that the synergistic effect due to plasma activation and catalytic action, significantly improves both CH4 conversion and CH3OH selectivity. The best methanol selectivity of ∼28% is achieved over the CuZrAl catalyst with a CH4 conversion of ∼11%, while plasma reactor provides only ∼18% CH3OH selectivity. The possible reaction mechanism of methanol formation inside the plasma reactor has been discussed, which highlights that the catalyst facilitates the adsorption of plasma excited species and improves the performance of the reactor. | Categorize the text article into one of the two categories:
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Biodiesel is a strategic measure to mitigate greenhouse gas emissions and other negative environmental impacts in line with oxidation of fossil fuels. Alkali-catalysed transesterification is the conventional production protocols in biodiesel production due to its technical reliability in line with low maintenance cost. Nonetheless, alkali-catalysed biodiesel production required to use the refined lipid feedstock due to low tolerance against impurities. TiO2 NPs have been widely employed as heterogeneous catalysts. Also, the use of TiO2 NPs could be beneficial because TiO2 adaptation in production of biodiesel could combine transesterification and esterification into a single process. Nonetheless, the general protocol in TiO2 NPs synthesis could not circumvent to use hazardous/toxic chemicals leading to serious/acute health and environmental problems. Several studies have demonstrated that green synthesis of TiO2 NPs using microorganisms and plants as alternate approaches can eliminate the problems associated with conventional methods without sacrificing the exceptional features of these nano materials. Hence, the main objective of this review is to offer fundamental insights and recent advances in green methods for producing TiO2 NPs driven by various microorganisms and plants extract along with quick summary of physio-chemical methods. In particular, the TiO2 NPs with reduced sizes (<60 nm) are possible to obtain using cost effective and eco-friendly green synthesis. Moreover, activity of TiO2 NPs as catalysts and their effect on biodiesel selectivity is discussed using catalytic trans-esterification, esterification, and simultaneous trans-esterification and esterification processes. The combinations of TiO2 NPs with other metallic and non-metallic materials are very selective and efficient for biodiesel production upto 98 %. This study appeals to research communities for adopting green synthesized TiO2 NPs as nanocatalysts for eliminating economic and environmental issues. | Categorize the text article into one of the two categories:
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The substantial environmental issues associated with plastic production have prompted researchers to accelerate the development of environmentally friendly biobased alternatives to reduce reliance on petroleum-based resources and mitigate emissions. Epoxidized Sucrose Soyate (ESS), a high-performance biobased epoxy resin obtained from soybean oil and sucrose, has shown promising potential in polymers and coatings applications. The success of ESS performance necessitates further investigations into its industrial-scale production and viability as an environmentally sustainable alternative to conventional petroleum-based resins. This study consists of a comprehensive techno-economic analysis (TEA) and cradle-to-gate life cycle assessment (LCA) to evaluate the technical, economic, and environmental feasibility of industrial-scale ESS production. The minimum selling price (MSP) of ESS at various production scales was estimated which offers insights into cost optimization. The MSP for 0.1, 1.0, and 10 ton/h processing capacity of sucrose soyate was calculated to be $9.57, $6.74, and $6.62 per kg of ESS, respectively. Relative to a comparable petroleum-based epoxy resin with similar functionality, such as bisphenol A diglycidyl ether (with a price range of $1.8 to $5.2 per kg), larger scales of ESS production have the potential to compete economically. The LCA results demonstrated the superior environmental performance of ESS, especially in the global warming potential category, indicating its potential as a compelling sustainable choice for replacing petroleum-based resins. This combined TEA and LCA study demonstrated the economic viability and environmental benefits of ESS, highlighting its promise as a sustainable alternative for industrial applications. | Categorize the text article into one of the two categories:
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Methylotrophy describes the ability of organisms to utilize reduced one-carbon compounds, notably methane and methanol, as growth and energy sources. Abundant natural gas supplies, composed primarily of methane, have prompted interest in using these compounds, which are more reduced than sugars, as substrates to improve product titers and yields of bioprocesses. Engineering native methylotophs or developing synthetic methylotrophs are emerging fields to convert methane and methanol into fuels and chemicals under aerobic and anaerobic conditions. This review discusses recent progress made toward engineering native methanotrophs for aerobic and anaerobic methane utilization and synthetic methylotrophs for methanol utilization. Finally, strategies to overcome the limitations involved with synthetic methanol utilization, notably methanol dehydrogenase kinetics and ribulose 5-phosphate regeneration, are discussed. | Categorize the text article into one of the two categories:
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A novel PtNiCo/three-dimensional graphene (PtNiCo/3DGN) catalyst was synthesized by sequential electrodeposition of three-dimensional graphene and PtNiCo nanoparticles. The catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman and electrochemical measurements. Electrochemical experiments revealed that PtNiCo/3DGN catalyst shows high activity for methanol oxidation with improved electrocatalytic capacity (the forward anodic peak current density of 790.4 mA mgPt -1), which is about 2.02 and 2.06 folds of that for PtNi/3DGN (390.2 mA·mg-1 Pt) and PtCo/3DGN (383.9 mA·mg-1 Pt), and much higher than Pt (144.0 mA·mg-1 Pt) and Pt/3DGN (277.2 mA·mg-1 Pt) catalysts. | Categorize the text article into one of the two categories:
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