Total Environmental Impact Research Articles

Minimizing the polymer content of compressed transparent synthetic wood from renewable biomass sources: A comparative life cycle assessment

Transparent wood derived from renewable biomass resources has an enormous potential for utilizing in constructions, electrons devices, energy storage, etc. However, due to its high polymer content, the currently described transparent wood could not be developed in a sustainable manner. Herein, a feasible strategy for synthesizing compressed transparent wood was proposed to minimize the content of polymerized poly(methyl methacrylate) in composites, involving the poly(methyl methacrylate) partial-filling into the delignified wood and densification. This synthesis method prompted a substantial reduction of poly(methyl methacrylate) content (58.8%) in the obtained compressed transparent wood contrasted with the typical transparent wood (91.8% poly(methyl methacrylate) content). Besides, an ideal optical transmittance of 77.9% with 0.4 mm thickness and an optical haze of 49.2% with 0.7 mm thickness at 800 nm wavelength were achieved. Also, the improved tensile strength and flexural strength of compressed transparent wood were up to 85.0 MPa and 145.3 MPa, respectively. Additionally, a comparative life cycle assessment was conducted to assess the environmental impacts. The total environmental impact score was separately reduced by 23%, and 28% compared to the typical transparent wood and poly(methyl methacrylate) polymer, suggesting the feasibility of sustainable manufacture of transparent wood materials by decreasing polymer content. The compressed transparent wood also showed much lower thermal conductivities (0.28–0.31 W/mk) than glass and contributed to offering uniform illumination.

Comprehensive analysis and optimization for a novel combined heating and power system based on self-condensing transcritical CO2 Rankine cycle driven by geothermal energy from thermodynamic, exergoeconomic and exergoenvironmental aspects

In this paper, a novel combined heating and power (CHP) system is proposed to realize full-scale utilization of geothermal energy and efficient multi-generation, which not only performs preferable overall performance than previous homogeneous system, but also offers an effective energy cascade utilization approach for self-condensing transcritical CO2 (TCO2) Rankine cycle. Based on the established mathematical models, the performance comparison is conducted for proving the superiority of the novel CHP system. Then, an overall performance analysis is implemented to reveal the combined effects for six key parameters on system thermodynamic, exergoeconomic and exergoenvironmental performances. Furthermore, multi-objective optimization considering system overall performance is conducted. The results show that for the novel CHP system, the largest relative improvement rate of system exergy efficiency (ηexg) and declining rate of total unit product exergy cost (cP,total) versus the previous CHP system are 15.03 % and 18.89 %, respectively. The final optimization results of ηexg, cP,total and total unit product exergy environmental impact (bP,total) are determined as 51.10 %, 14.12 $/GJ and 9.00 mPts/GJ, respectively. This paper fulfills an elaborate performance analysis and optimization for the novel CHP system, which fills the research gap of efficient and promising CHP system based on self-condensing TCO2 Rankine cycle.

Optimal 4E evaluation of an innovative solar-wind cogeneration system for sustainable power and fresh water production based on integration of microbial desalination cell, humidification- dehumidification, and reverse osmosis desalination

Reliable freshwater production is vital for tackling two of the most critical challenges the world is facing today: climate change and sustainable development. Present work presents an innovative cogeneration system based on solar and wind energies for sustainable production of freshwater, power, and wastewater treatment. For freshwater production and wastewater treatment in this system, the integration of a microbial desalination cell with a humidification-dehumidification and reverse osmosis desalinations has been used. The mentioned systems provide their heat demand from solar energy, and when solar radiation is unable to provide this heat, a hydrogen internal combustion engine drive produces the required heat for the freshwater plant. Excess heat from the hydrogen internal combustion engine is fed into the organic Rankine cycle for more power generation in the whole system to reduce system waste heat and increase efficiency. PEM electrolyzer has been used to supply the hydrogen needed by the internal combustion engine, and this system uses wind turbines to supply the power demand. To evaluate the performance of the whole system, energy, exergy, exergeoeconomic, and exergoenvironmental (4E) analyses have been carried out. Finally, to improve the performance parameters of the system, multi-objective optimization using the Salp swarm algorithm has been used. Investigation of the results show that the proposed system can produce 720 kW of electricity and 5.36 m3/h of freshwater. The energy efficiency of the system is 22.09 %, and its overall cost rate and overall environmental impact rate are 540.33 $/hr and 17.37 Pt/h, respectively. Among the qualitative results obtained in this research, it is possible to mention the high exergy destruction, cost destruction, and environmental impact destruction of the internal combustion engine compared to other equipment used in the proposed system, and this point shows the need to improve this equipment, similar to previous researches. The five-objective optimization results of the proposed system showed that the performance parameters of the system, such as polygeneration energy efficiency, total cost rate, and total environmental impact rate, can be improved by 6.2 %, 1.44 %, and 0.52 %, respectively. The payback period of the proposed system in the optimal state is 6.95 years.

Sustainable waste management and waste-to-energy in the context of a circular economy through various waste management technologies.

Inappropriate waste management is a considerable ecological risk, leading to detrimental effects on the soil, air, and water quality. It is imperative to address these concerns promptly to minimize the repercussions of solid waste on public health and the ecosystem. It is evident that the level of economic growth directly impacts waste generation. This study intends to use the life cycle assessment (LCA) technique to evaluate the environmental impacts of four alternative municipal solid waste (MSW) management scenarios in Peshawar City, Pakistan. The goal is to discover an option that is both sustainable and minimizes environmental damage. The study examined the system boundaries encompassing the collection and transportation of MSW, along with its processing and final disposal, employing composting, anaerobic digestion (AD), material recovery facilities (MRF), and landfill methods. Comprehensive field studies and an in-depth literature review provided the data regarding Peshawar's existing MSW management system and the proposed scenarios, all of which was inventoried in the OpenLCA 1.10.3 database. Following data collection, the CML-IA technique was employed to analyze the data, measuring the environmental footprint in terms of climate change potential, human toxicity, acidification potential, photochemical oxidation, and eutrophication. A sensitivity analysis was also performed to identify the influence of varying recycling rates on the environmental strain correlated with the proposed scenarios. The analysis results indicated that scenario S2, which combined composting, landfilling, and MRF, exhibited the least environmental impact compared to the other considered scenarios. Furthermore, the sensitivity analysis reflected an inverse correlation between alterations in the recycling rate and the total environmental impact. To counter the environmental problems arising from waste generation, it is essential to incorporate principles of the circular economy into the MSW management approach.

Resilience of sustainability for a smart production system to produce biodiesel from waste animal fat

The smart production system is implemented for more effective labor, less waste, and a reduction of energy consumption. Biofuels are significant substitutes for conventional fuels and decreases air pollution and carbon monoxide, can be made through a smart production system with automated machines. Biodiesel can be produced using an assortment of sources that can be both edible and inedible, but animal fat is a sensible alternative among inedible sources because of its affordable price and ease of availability. The model studies the smart biodiesel production system with energy utilization and less carbon emissions to produce pure biodiesel. The multi-objective mathematical model minimizes the total biodiesel supply chain cost followed by minimizing the total biodiesel supply chain environmental impact and enhancing its social impact. The smart production system with a variable production rate produces the biodiesel with less impurities, but still impurities in the biodiesel, that can be detected by a two-stage autonomated inspection system. The impure biodiesel is remanufactured in the biorefineries at the end of every natural production cycle. For the best utilization of energy, various energy costs, such as lighting and air handling costs are calculated. The improved augmented ϵ-constraint approach with lexicographic optimization is utilized to solve the model. The four mathematical examples are studied, and the repercussions of mathematical experiments reveal that the animal fat purchasing cost is 44.32% of the total cost, and the percentage of impurities in biodiesel can be decreased through minimum energy consumption. The managerial insights of the model, graphical representation, and sensitivity analysis of key parameters are provided in this research. The conclusions can be useful to investors in a sustainable smart production system and biofuel policymakers.

Characteristic and mechanism of pollution by laser cleaning high-value vehicle parts with a complex structure in remanufacturing industry

Remanufacturing high-value vehicle parts is of substantial significance for the circular economy because it provides a second service life and reduces solid waste generation. Laser cleaning is a promising method in the remanufacturing industry owing to its high energy, precision, and efficiency. However, the pollution caused by laser cleaning remains unknown and has rarely been reported, limiting the application of this method. In this study, pollution removal and conversion using a high-energy laser were explored, and environmental life cycle and health risk assessments were conducted. The results showed that high-energy lasers might induce new organic pollutants, such as olefins, alkynes, and aldehydes. During laser cleaning, thermal elastic expansion and shock wave generation were the main mechanisms of rust removal, and evaporation and small-scope boiling were used for waste oil removal. The mean concentration of PM10 was above 7000 µg/m3 in laser rust removal, and the total concentration of volatile organic compounds (VOCs) was the highest in laser oil removal (∼ 2568 µg/m3). Particulate matter contained high amounts of Fe, Al, and Mn. An environmental life cycle assessment indicated that laser cleaning for stain removal significantly reduced the total environmental impact compared with that of traditional solvent-ultrasonic cleaning (∼ 40.0%) and sandblasting (∼ 83.3%). This study provides an environmental protection basis for increasing the use of laser cleaning in the remanufacturing industry.

Environmental Sustainability of Building Materials in Turkey: Reference Information Recommendations for European Green Deal Declarations

This study provides weight and normalization reference information for declaring the environmental information of building materials produced and exported in Turkey. Reference information was first determined for the global warming potential based on greenhouse gas (GHG) emissions, which is the subject of the European Union Green Deal Carbon Border Adjustment Mechanism (CBAM). For a more holistic approach, reference information is also recommended for environmental impact categories acidification, air pollution, ecological toxicity, eutrophication, fossil fuel depletion, human health, indoor air quality, land use, ozone depletion, photochemical smog formation, and water depletion, in addition to GHG emissions. Reference information is determined based on the life cycle assessment (LCA) methodology defined in the international standards ISO 14040 and ISO 14044. Semi-structured interviews were held with twenty-one industry stakeholders in Turkey to determine the weight reference values. The results obtained from the semi-structured interviews were combined using the analytic hierarchy process (AHP) method. Normalization reference information was determined by compiling Turkey’s national emission values. The suggested reference information has been tested using a case study. Total environmental impact scores were calculated for floor coverings and exterior wall finishes, including global warming potentials based on GHG emissions, and eleven other environmental impact categories. The findings support the need to use regional reference information in Turkey. The reference information recommended in this study can be used both in declarations within the scope of the EU Green Deal and in other possible environmental impact declarations resulting from building materials.

Designing a green-resilient closed-loop supply chain to preserve business continuity under interrelated disruptions (a case study of the automotive battery industry)

Improving profitability, implementing the recycling cycle to reduce resource consumption, and managing interrelated disturbances to maintain business continuity are important issues for supply chain management. Accordingly, this study proposes a multi-objective optimization model to design a green-resilient closed-loop supply chain considering pricing decisions under multiple interrelated disturbances. Herein, the fuzzy c-means clustering method is employed to lessen probable scenarios and cluster main suppliers and target markets to reduce mathematical complexity. The multi-objective model is solved by adopting the improved augmented ε-constraint method to achieve the minimum total cost, total environmental impact, and network non-resiliency. The mixed uncertainty is coped with by developing a novel robust optimization method. Finally, an automotive battery manufacturing industry case study is applied to the model. The results reveal that the mutual effects of disturbances intensify the deterioration of objective functions. Also, the dynamic pricing of products reduces the financial vulnerability of the supply chain.

Assessing the wastewater reclaim system consisted of wastewater plant - hybrid constructed wetland - ultra filtration and reverse osmosis in a chemical industrial park, a multi-criteria decision-making analysis

Wastewater reclaim in industrial parks can effectively reduce the dependence on external water resources, few literatures evaluated the reclaim system from perspectives of economy, technology, and environmental impact. It is very popular across China that a constructed wetland is linked with a wastewater plant and then discharged the tailwater into surface waters, based on current situation, pilot experiment, and other available techniques, six scenarios for wastewater reclaim system were designed for Shanghai Chemical Industrial Park. Using life cycle assessment, it was found that in scenario of pilot experiment, most environmental impact was derived from wastewater plant and ultra filtration - reverse osmosis, in which ultra filtration - reverse osmosis accounted >20 % for POCP, AP, and EP, Wastewater plant accounted >86 % for ADP, ODP. It was showed that electricity and sludge were most important parameters affecting LCA, when electricity consumption was reduced by 20 %, total standardized environmental impact would be changed in the range of 1.40 %–1.65 %, the most significant change was HTP (6.12 %–6.32 %) when 20 % up and downward change in sludge amount, followed by MAETP (5.27 %–5.36 %). A multi-criteria decision-making analysis was conducted on all the scenarios based on environmental impact, life cycle cost, technical efficiency, it was showed that the scenario designed for pilot experiment was the best available technique, which was consisted of wastewater plant, hybrid constructed wetland, ultra-filtration and reverse osmosis, and reused as desalted water. A wastewater reclaim plant is suggested from the result of this paper. It was believed that this study could provide references for construction of wastewater reclaim system in industrial parks of the world.

Waste analysis and energy use estimation during MR-HIFU treatment: first steps towards calculating total environmental impact

ObjectivesTo assess the environmental impact of the non-invasive Magnetic Resonance image-guided High-Intensity Focused Ultrasound (MR-HIFU) treatment of uterine fibroids, we aimed to perform a full Life Cycle Assessment (LCA). However, as a full LCA was not feasible at this time, we evaluated the CO2 (carbon dioxide) emission from the MRI scanner, MR-HIFU device, and the medication used, and analyzed solid waste produced during treatment.MethodsOur functional unit was one uterine fibroid MR-HIFU treatment. The moment the patient entered the day care-unit until she left, defined our boundaries of investigation. We retrospectively collected data from 25 treatments to assess the CO2 emission based on the energy used by the MRI scanner and MR-HIFU device and the amount and type of medication administered. Solid waste was prospectively collected from five treatments.ResultsDuring an MR-HIFU treatment, the MRI scanner and MR-HIFU device produced 33.2 ± 8.7 kg of CO2 emission and medication administered 0.13 ± 0.04 kg. A uterine fibroid MR-HIFU treatment produced 1.2 kg (range 1.1–1.4) of solid waste.ConclusionsEnvironmental impact should ideally be analyzed for all (new) medical treatments. By assessing part of the CO2 emission and solid waste produced, we have taken the first steps towards analyzing the total environmental impact of the MR-HIFU treatment of uterine fibroids. These data can contribute to future studies comparing the results of MR-HIFU LCAs with LCAs of other uterine fibroid therapies.Critical relevance statementIn addition to (cost-) effectiveness, the environmental impact of new treatments should be assessed. We took the first steps towards analyzing the total environmental impact of uterine fibroid MR-HIFU.Key points• Life Cycle Assessments (LCAs) should be performed for all (new) medical treatments.• We took the first steps towards analyzing the environmental impact of uterine fibroid MR-HIFU.• Energy used by the MRI scanner and MR-HIFU device corresponded to 33.2 ± 8.7 kg of CO2 emission.Graphical

Optimizing Concrete Grade for a Sustainable Structural Design in Saudi Arabia

Buildings and facilities undergo several stages: the product stage, the construction stage, the use stage, the end-of-life stage, and the recycling stage. The life cycle of any facility or building contributes to embodied carbon (EC) emissions. The product stage, also known as the cradle-to-gate stage (A1–A3), registers the highest emissions, estimated to account for 70% of the total environmental impact. The continuing population growth in Saudi Arabia necessitates urgent action to identify and implement solutions for reducing greenhouse gas emissions and mitigating environmental risks. This study investigates the optimal method to analyze the grade of concrete for specific structural elements (columns) in a particular work area, adhering to accurate and methodological standards outlined in the Saudi Building Code (SBC). The bill of quantities (BOQ) determined the amount of building materials for the structure considered in this study. Reliable embedded carbon coefficients (ECCs) for structural materials such as concrete and steel were determined following life cycle assessment principles. They were analyzed using the Inventory of Carbon and Energy (ICE; Version 2.0) and Global Warming Potential (GWP). The obtained values varied based on the components of each mixture. This study determined the cost of each concrete mixture and steel, selecting the optimal mixture based on both EC and material cost. Since the quantity of cement significantly affects EC emissions in a concrete mixture, it is essential to select appropriate plasticizers and concrete types. This study evaluated the C30, C40, C50, C60, and C70 mixtures. Among these, the C70 mixture demonstrated the best environmental impact and was the least expensive compared to the basic C40 mixture for the estimated quantities of concrete and steel. The estimated reductions in cost and environmental impact were 33% and 27%, respectively. This groundbreaking study paves the way for low-carbon structural design in large hotels across Saudi Arabia, offering valuable insights for future projects and contributing significantly to energy conservation.

Assessment of Environmental Impacts of Thermal Caisson Geothermal Systems

This paper investigates the total environmental impacts of a thermal caisson (TC) system by implementing a life cycle assessment methodology. The total environmental impacts consider the comprehensive effect on the environment across two life cycle stages: manufacturing and operation. A comparison between the TC results and two different HVAC systems, including air-conditioning/furnace and conventional ground-source heat pump (GSHP) systems, was made by adopting the ReCiPe 2016 methodology. This study reveals that the operation phase is the predominant contributor to environmental impacts across systems, mainly due to its extended duration. Specifically, the operational impacts of GSHPs are substantial, accounting for approximately 87% of total environmental impacts. A TC GSHP system demonstrates a notable environmental advantage, achieving a 79% reduction in total environmental impact when compared to traditional AC/furnace systems. This represents a 21% improvement over conventional GSHP systems. Despite this substantial reduction in total environmental impact, the TC GSHP system shows an almost 5% increase in the resource availability damage category relative to the conventional GSHP, which is attributed to its higher material consumption. These results highlight the TC GSHP system’s superior efficiency in reducing environmental impacts and its potential as a more sustainable alternative in residential heating and cooling applications.

Method for Calculating the Avoided Impact of Specific Information and Communication Technology Services

Particular Information and Communication Technology (ICT) services can help avoid environmental impact in larger contexts. However, there is no commonly agreed bottom-up methodology for calculation of the total net reduction effect of specific digital ICT services. Life Cycle Assessment (LCA) is a common denominator for most methodologies. The most common method is the Attributional LCA (ALCA), and recently the emerging handprint ALCA estimating so-called positive environmental impacts. Moreover, Consequential LCA (CLCA) can be used to capture market effects. The third conceptual approach is Input-Output LCA. The purpose is to propose and test a new method based on some of the existing ones. The existing concepts are compared and a synthesis is made to create a practical but still useful method. The new method is applied to two illustrative cases in the ICT domain; the introduction of a 5G enabled drone for pipe inspection and the 5G enabled health consultation. Compared to simplified ALCA, the difference between the absolute scores for the baseline system and the target system changes around 10% when the proposed simplified CLCA (SCLCA) method is used. The results show that SCLCA, when combined with analytical methods for expressing digital ICT services’ own impact, is a fruitful approach which is both practical and feasible. The new method includes formulae for calculating the total lifetime environmental impact of a specific ICT Equipment when reused or replaced.

Are electric vehicles really the optimal option for the transportation sector in China to approach pollution reduction and carbon neutrality goals?

Profound worldwide fleet electrification is thought to be the primary route for achieving the target of carbon neutrality. However, when and how electrification can help mitigate environmental impacts and carbon emissions in the transport sector remains unclear. Herein, the overall life-cycle environmental impacts and carbon saving range of two typical A-class vehicles in China, including electric vehicle (EV) and internal combustion engine vehicle (ICEV), were quantified by the life cycle assessment model for endpoint damage with localization parameters. The results showed that the EV outperformed the ICEV for the total environment impact after a travel distance of 39,153 km and for carbon emissions after 32,292 km. The ICEV was more carbon-friendly only when the driving distance was less than 3229 km/a. Considering a full lifespan travel distance of 150,000 km, the whole life-cycle average environmental impacts of EV and ICEV were calculated as 8.6 and 17.5 mPt/km, respectively, but the EV had 2.3 times higher impacts than the ICEV in the production phase. In addition, the EV unit carbon emission was 140 g/km, 46.8% lower than that of the ICEV. Finally, three potential reduction scenarios were considered: cleaner power mix, energy efficiency improvement and composite scenario. These scenarios contributed 19.1%, 13.0% and 32.1% reductions, respectively. However, achieving carbon peak and neutrality goals in China remains a great challenge unless fossil fuels are replaced by renewable energy. The research can provide scientific reference for the method and practice of emission reduction link identification, eco-driving choice and emission reduction path formulation.

Environmental and economic life cycle assessment of emerging sludge treatment routes

Before implementing large-scale emerging sludge treatment methods, it is crucial to conduct a comprehensive analysis of their environmental impacts and economic costs at the system level. This study utilizes standardized Life Cycle Assessment (LCA) and Life Cycle Cost (LCC) accounting methods to evaluate four emerging sludge treatment routes: anaerobic fermentation (AF), pyrolysis (PY), hydrothermal carbonization (HTC), and alkaline thermal hydrolysis (ATH). These routes are compared with two traditional sludge treatment routes, anaerobic digestion (AD) and aerobic composting (AC). The results indicate that the conventional route AD is the optimal choice in terms of environmental pollution, carbon emission control, and life cycle cost. The emerging routes AF and ATH have significant environmental benefits from carbon source recovery and protein recovery. However, they require approximately twice the cumulative energy demand of AD and additional consumption of chemicals, which imposes a greater environmental burden. While PY and HTC outperform the conventional sludge treatment routes in terms of the total environmental impact (1.79E-10, 1.72E-10) due to energy recovery and the use of clean energy sources. AF and PY demonstrate better economic performance (842.11 and 712.00 CNY) compared to the traditional route AC (905.06 CNY). However, both HTC and ATH incur costs approximately 1.3 times higher than AC due to their high energy and material demands. Furthermore, sensitivity analysis reveals that emerging treatment routes are highly influenced by energy and resource recovery and consumption. Therefore, reducing the energy and resource inputs for emerging routes could significantly decrease their environmental impact and cost, maximizing their resource recovery advantages.

Green design strategies for sustainable supply chain considering channel leadership

We have observed from practice that to create new economic and environmental values, both the upstream and downstream firms in sustainable supply chain are motivated to invest in green design. Channel leadership as an important factor affecting the channel profit distribution will reshape the investment motivation of enterprises. In this paper, we construct six kinds of pricing and green design decision models to explore the optimal green design strategies for sustainable supply chain consisting of one manufacturer and one retailer under different channel leadership, and investigate the interaction between channel leadership and green design strategy, and their impacts on sustainable supply chain performance, environment and consumer surplus. We find that regardless of the channel leadership, the wholesale and retail prices of products under different green design strategies are always affected by the cost effect of green design. In terms of boosting the green design level and market demand, increasing the consumer surplus and enterprises profits, only when the manufacturer is the channel leader and the green design cost effect is small, the retailer can implement green design better. Moreover, when the manufacturer implements green design, the better channel structure between the retailer-led and Nash equilibrium game depends on the green design cost effect, but both are better than the manufacturer-led. However, when the retailer implements green design, the channel structure of Nash equilibrium game is always better. We finally illustrate that under different channel leadership, which green design strategy is more conducive to reducing the total environment impact of products depends on the joint effect of green design cost effect and green design environment effect.

Human-powered hydroponic systems: An environmental and economic assessment

Hydroponic systems like vertical farming have been proposed as an alternative and potentially more sustainable option for growing vegetables than conventional soil-based production methods. However, the energy required for the functioning of hydroponic systems is a key contributor to the total environmental impact and economic cost. Human-powered hydroponic systems, which utilise human muscular exertion to power the system, have not been thoroughly investigated, despite their potential as a cost-efficient alternative and less harmful to the environment. This paper presents a prototype of a novel human-powered hydroponic system and assesses its environmental impact and economic costs using life cycle assessment (LCA) and life cycle costing (LCC), considering the cultivation of lettuce as a case study. A scenario analysis was performed to assess the environmental impact of lettuce production using a human-powered hydroponic system compared to conventional soil or greenhouse-based production methods. Using SimaPro LCA software, 18 impact categories included in the ReciPe Midpoint (H) method were evaluated. The results indicated that the battery, followed by the power system, represented the primary environmental hotspots of the human-powered hydroponic system. Improving the yield (production of 6 lettuces of 500 g vs 200 g per 40-day growing cycle) of the human-powered hydroponic system can reduce the environmental impact of lettuce production compared to conventionally soil-based produced lettuce in 11 out of the 18 evaluated impact categories, and when compared to greenhouse-produced lettuce, it generates lower impacts in 14 out of 18 categories. Regarding economic cost, considering a yield of 1.2 kg (6 lettuces of 200 g) per 40-day growing cycle with the human-powered hydroponic system, it is more expensive for the consumer than buying lettuce produced with conventional soil-based open-field agriculture and greenhouses, and break-even points are not achievable within 15 years (the lifespan of the system). However, when considering a yield of 3 kg (6 lettuces of 500 g), the break-even point with greenhouse-produced lettuce was achieved between 10 and 11 years. Therefore, although a break-even point is not achievable within the considered lifespan of the developed system, it could be reached if the yield of the system increased and/or if the system had a longer lifespan, which is mainly determined by the lifespan of the battery.

Life cycle environmental impact assessment of natural gas distributed energy system

Natural gas distributed energy is recognized as a pivotal means to enhance energy efficiency and mitigate carbon dioxide emissions through localized energy cascading. Positioned as a key option for advancing the Sustainable Development Goals, this system optimizes energy utilization near end-users. While maximizing energy efficiency, it is imperative to address potential environmental challenges. A thorough, comprehensive environmental assessment, facilitated by the life cycle assessment method, proves instrumental in meeting this standard. Employing this method enables an intuitive grasp of the environmental strengths and weaknesses inherent in natural gas distributed energy within the power structure. This insight serves as a foundation for informed project decision-making, fostering the growth of the industry. We selected six environmental impact assessment categories based on the CML 2001 method, and conducted the life cycle analysis across four stages. China's inaugural natural gas distributed energy demonstration project was chosen as a model case, and an environmental impact assessment inventory was established, utilizing survey data and literature for comprehensive data collection and analysis. Results from case testing yield environmental impact assessment outcomes, with a specific sensitivity analysis for stages with notable environmental impact factors. The study underscores that the operation phase has the highest environmental impact, comprising 78.37% of the total combined environmental impact, followed by the fuel production phase. Comparative analyses with coal-fired and conventional natural gas power generation, based on dimensionless literature data, reveal that abiotic resources depletion potential is the primary contributor to the environmental impact of 1 kWh of electricity product, constituting 52.76% of the total impact value, followed by global warming potential. Concrete strategies have been outlined for decision-making in both the operational and planning phases of natural gas distributed energy projects. The strengthening of policies is pinpointed towards grid connection and scale expansion.

Carbon tax vs. carbon trading in China: which is better for promoting sustainable development of remanufacturing companies?

To accelerate achieving carbon neutrality, the promotion of low-carbon development in the manufacturing industry has been facilitated by the government's implementation of policies such as carbon taxation and carbon emissions trading. These measures have been put in place to reduce carbon emissions and enhance sustainability within the manufacturing sector. Remanufacturing is an important direction for the low-carbon transformation of enterprises, and improving remanufactured product quality is crucial to the sustainability of remanufacturing enterprises. To elucidate the influence of policies aimed at reducing carbon emissions on the quality of remanufactured products, we developed a game model involving three key players: the original equipment manufacturer (OEM), the remanufacturer (IR), and retailers. This model was constructed based on the heterogeneous consumer demand for both new and remanufactured products. The study delved into the effects of various governmental policies aimed at reducing carbon emissions on the quality-related decisions made by remanufacturing enterprises. Our primary focus was on the implementation of two specific policies: a high-level carbon taxation policy and a carbon trading policy characterized by elevated carbon pricing. These policies create a favorable environment for remanufacturers (IR) to enhance the quality of their products. The sales of remanufactured products are influenced by the purchasing preferences of consumers, and carbon reduction policies can be effective in reducing the total environmental impact of manufacturing. Carbon trading policy is most conducive to environmental protection and achieves a win-win situation for economic and environmental benefits for OEMs and IRs when the carbon tax per unit is compared with the carbon trading price. Hence, this situation is favorable for the sustainable growth of existing remanufacturing businesses. Consequently, the government's requirement for subsidies to enhance the quality of remanufactured products and boost the competitiveness of IRs in the market becomes less pronounced.

Green versus Grey Framing: Exploring the Mechanism behind the Negative Footprint Illusion in Environmental Sustainability Assessments

Given the complexity of assessing the environmental sustainability of products, consumers rely on cognitive strategies to simplify complex information and develop quick judgments, often referred to as heuristics, when processing eco-information. One of these heuristics is called ‘the Negative Footprint Illusion’: Consumers erroneously estimate the total environmental impact of a combination of a green and non-green product as lower than the same non-green product alone. In this research, we test this bias and explore its underlying mechanism. We evoke a more summative vs. more evaluative mindset by framing the response scales negatively (in terms of environmental damage, referred to as ‘grey scaling’) vs. positively (in terms of environmental friendliness, referred to as ‘green scaling’). This is carried out by using an online between-subject experiment in which respondents either respond on an evaluative response scale (green scaling), or a summative response scale (grey scaling). A hamburger and bio-apple were used as stimuli (either shown together or apart). First, the results show that the negative footprint is only apparent in the green scaling condition. Second, respondents who score higher on environmental concern show a stronger negative footprint illusion for the green scaling condition. Our study not only elucidates the cognitive mechanisms driving the negative footprint illusion but also offers strategic directions for both theoretical advancement and practical applications in environmental decision-making, highlighting effective ways to mitigate this bias.