Fossil Resource Scarcity Research Articles

Model Predictive Control Design and Hardware in the Loop Validation for an Electric Vehicle Powertrain Based on Induction Motors

Electric vehicles (EV) have gained importance in recent years due to environmental pollution and the future scarcity of fossil resources. They have been the subject of study for many years, where much work has focused on batteries and the electric motor (EM). There are several types of motors in the market but the most widely used are induction motors, especially squirrel cage motors. Induction motors have also been extensively studied and, nowadays, there are several control methods used—for example, those based on vector control, such as field-oriented control (FOC) and direct torque control (DTC). Further, at a higher level, such as the speed loop, several types of controllers, such as proportional integral (PI) and model predictive control (MPC), have been tested. This paper shows a comparison between a Continuous Control Set MPC (CCS-MPC) and a conventional PI controller within the FOC method, both in simulation and hardware in the loop (HIL) tests, to control the speed of an induction motor for an EV powered by lithium-ion batteries. The comparison is composed of experiments based on the speed and quality of response and the controllers’ stability. The results are shown graphically and numerically analyzed using performance metrics such as the integral of the absolute error (IAE), where the MPC shows a 50% improvement over the PI in the speed tracking performance. The efficiency of the MPC in battery consumption is also demonstrated, with 5.07 min more driving time.

Analysis of the application of recycled polypropylene

Goal: Analyze the benefits of the application of recycled polypropylene in the evaporation tray of refrigerators in a multinational company of electro-electronic equipment. Design / Methodology / Approach: This research conducts a systematic literature review; performs a Life Cycle Analysis (LCA) of the polypropylene production, interpreting its results through a Pareto Diagram; and presents a case study in a multinational company of white line electro-electronic equipment. Results: The LCA results point out that propylene and the components released by the chemical plant cause the main negative externalities under the environment and human health, so that during PP production, propylene is responsible for 72% of the impacts under global warming and 86% in the face of scarcity of fossil resources. Thus, the case study proposes recycling polypropylene, following the Circular Economy guidelines by aligning the proposal with the Zero Waste policy, with modular design, with Reverse Logistics, and with Sustainable Development Goals. Research limitations: The work presents limitations inherent to literature review works, where filters are used to limit the search (limited to articles, published between 2012 and 2021 and written in English). Practical implications: The research encourages recycling, pointing out its contribution under the environmental, social and economic spheres. Originality / Value: The research presents originality and methodological value by combining qualitative and quantitative methods, and a theoretical and practical approach. Thus, it was possible to implement the research in the multinational company analyzed, and to measure the benefits obtained.

Life Cycle Assessment of sewage sludge mono-digestion and co-digestion with the organic fraction of municipal solid waste at a wastewater treatment plant

Wastewater treatment plants (WWTPs) aim to increase energy independence by intensifying biogas production. The study involved Life Cycle Assessment (LCA) comparing sewage sludge (SS) anaerobic co-digestion (AcD) with the organic fraction of municipal solid waste (OFMSW) at WWTP against SS anaerobic mono-digestion (AD). The LCA was based on the authors' research showing that methane production related to wet mass in AcD was higher than in AD by 86.4, 225.8, and 354.3 % for SS:OFMSW mixing ratios of 75:25, 50:50, and 25:75, respectively. The LCA was conducted for 1 kWh of biogas energy produced at a WWTP and included two subsystems: energy production (AD/AcD and CHP) and associated digestate management (drying, incineration with energy reuse, residual landfilling). CML-IA baseline 2013 and Recipe 2016 Midpoint (H) LCIA methodologies indicated the environmental impacts on abiotic depletion - fossil fuels (fossil resource scarcity), global warming, human toxicity (non-carcinogenic), freshwater, and marine aquatic ecotoxicity. AD of SS in all categories was characterized by the highest impact. The impact decreased with an increase in the OFMSW rate. Both methodologies showed a significant impact of AD and AcD on global warming, which indicated the need for the determination of the carbon footprint (CF) of 1kWh biogas energy production (gCO2 kWh−1) at WWTP, using IPCC 2021 GWP100 (incl. CO2 uptake). The CF was the highest for biogas energy production in SS AD (1509 gCO2 kWh−1) and it decreased with the increase of OFMSW content in AcD (872–481 gCO2 kWh−1). This was also observed for the management of associated digestate. CF changed from 1508 gCO2 kWh−1 for SS AD to 396 gCO2 kWh−1 for SS: OFMSW mixing ratio of 25: 75 in AcD. The environmental burdens associated with biogas energy production and digestate management were equally significant. Finally, the formula for economic and ecological comparison of SS AD and AcD with OFMSW was proposed.

Life cycle assessment of plastic and paper-based ultra high frequency RFID tags

The aim of the work is to assess the environmental impacts of Ultra High Frequency RFID tags. Through a Life Cycle Assessment approach, two case studies have been investigated, namely a standard plastic and a paper-based tags. Primary data on tags’ components, manufacturing and transportation were collected, while secondary data for the raw materials processing and tags’ end of life were retrieved. The Recipe Midpoint method was used to evaluate the impacts. Results show that, for both tags, the greatest contributions to global warming, terrestrial acidification, mineral and fossil resource scarcity are due to raw material extraction (more than 50%) and manufacturing phase (30–50%), which resulted impactful also on the ionizing radiation (70%). Interestingly, the paper tag allows to save up to 23% of the greenhouse gas emissions and decreases the impact on the above-mentioned categories, resulting the eco-friendly option. The conclusion of the work contributes to update the scientific literature, still poor in RFID environmental evaluations, and are useful for researchers interested in comparing the traditional handling systems’ impacts to the RFID scenario. Furthermore, the outcomes will be used as input for subsequent research, aimed at developing a tool to measure the return on the environment of RFID deployments.

Life cycle assessment of AnMBR technology for urban wastewater treatment: A case study based on a demo-scale AnMBR system

This study aims at assessing the environmental performance of a projected full-scale anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) at ambient temperature. To this aim, data from an AnMBR demonstration plant equipped with commercially available equipment, including industrial hollow fiber and degassing membranes, was used for projecting a full-scale facility. The use of real operation data allows to obtain robust results that contribute to improve the knowledge of the environmental performance of this technology, pointing out its strengths and the challenges that still need to be addressed. Life cycle assessment (LCA) was applied by means of Ecoinvent data base and ReCiPe2016 methodology considering 1 kg of removed COD as functional unit. Additionally, sensitivity and uncertainty analysis were conducted. Energy balance showed AnMBR performing as energy producer (net energy surplus up to −0.688 kWh·kg CODrem−1) and carbon sink (emissions credit up to 0.223 kgCO2eq·kgCODrem−1). Results also showed energy recovery, heavy metals in sludge, dissolved methane in the effluent, and effluent nutrient content as the most important aspects affecting LCA outcome. Construction phase affected some impact categories significantly (e.g., 51–71% in mineral resource scarcity, 18–27% in fossil resource scarcity, 21–28% in water consumption), therefore its exclusion should be carefully evaluated. CHP efficiency, dissolved methane recovery, filtration productivity, membrane scouring, reactor mixing, HRT and SRT appeared most influencing parameters. Finally, actions leading to increase the recovery and valorization of dissolved methane and/or of nutrients through, for instance, fertigation, improve the environmental performance of AnMBR for UWW treatment.

Preparation and environmental analysis of biodegradable polylactic acid and modified cellulose nanofiber composites

Polylactic acid (PLA) and cellulose nanofibers (CNFs) show promise as bio-based alternatives to non-degradable plastics, which pose environmental challenges. Yet, CNFs' hydrophilicity hampers their dispersion in hydrophobic PLA. This study modifies CNF surfaces with diisocyanate compounds to create hydrophobic isocyanate-modified CNFs (mCNFs), enhancing their compatibility with PLA. One isocyanate of the diisocyanate compound is grafted onto the surface of CNF and the isocyanate content varied by adjusting grafting reaction time. PLA-mCNF composites are produced by a twin-screw extruder and show improved mechanical properties and biodegradability compared to pristine PLA and PLA-unmodified CNF composite. The environmental impacts of PLA-mCNF composites are evaluated using a life-cycle assessment method and compared to corn grain-based PLA. The optimized PLA-mCNF composite (6 h of grafting reaction) has lower environmental impacts than corn grain-based PLA, with global warming and fossil resource scarcity of 3.021 kg eq and 0.813 kg oil eq, respectively. This study underscores the feasibility of optimizing PLA composite properties by employing a small proportion of toxic diisocyanate on CNF surfaces. The findings highlight the potential of such modified composites to offer improved sustainability and performance characteristics, contributing to the development of eco-friendly materials.

Life cycle assessment and techno-economic analysis for biofuel and biofertilizer recovery as by-products from microalgae

Although there are several studies on the hydrothermal carbonization of microalgae biomass for value-added products and their potential environmental impacts, the feasibility of scaling-up and the environmental and economic analysis need to be investigated. This study produced solid biofuel and biofertilizer under two operating conditions (170 °C, 10 min, 7 bar; or 130 °C, 50 min, 2 bar, respectively). Also, investigated the environmental performance and techno-economical viability of producing solid biofuel and biofertilizer from microalgae. Scale-up modeling used Aspen Plus software to obtain optimized production processes, energy data, equipment requirements, and costs, which were used to support the economic and environmental analyses. The Recipe Midpoint method showed that the solid biofuel had a higher environmental impact than the biofertilizer, especially in the Freshwater Eutrophication category (almost 7 times higher), Fossil Resource Scarcity (4.2 times higher), Global Warming, and Marine Ecotoxicity (both around 2.7 times higher). The damage assessment results showed that the production of solid biofuel was more impactful, with Human Health impacts 2 times higher, Ecosystem 1.6 times higher, and Resource 4.3 times higher than those caused by biofertilizer production. The biofertilizer production scenario emerged as the most economically viable option for hydrothermal carbonization valorization. The negative net present value and the inability to achieve the return on investment within a 30-year timeframe made the solid biofuel production scenario unviable. Thus, biofertilizer production from hydrothermal carbonization of microalgae biomass cultivated in wastewater is technically, economically, and environmentally feasible, whereas the same cannot be said for the biofuel evaluated.

Engineering properties and sustainability evaluation of crushed low grade magnesite mortars

China is the country in the world with the most abundant magnesite resources. The ever-increasing deposit of low grade magnesite ore derived from the process of magnesium products has occupied a substantial space and caused environmental damages. In this study, crushed low grade magnesite (CLGM) was prepared and then applied in mortar as fine aggregate to partially or entirely replace natural river sand (30%, 60%, and 100%), while 100% limestone sand (LSS) was applied as the reference group. The findings of this study demonstrated a positive correlation between the ratio of CLGM substitution and the improvement of both engineering properties and sustainable potential in the mortar. Compared with the control group at 28 d, the 100% CLGM mortar exhibited improvements of up to 6% in splitting strength, 25.86% in compressive strength, 16% in porosity reduction, 22.22% in impermeability enhancement, 27.52% in resistance to chloride ion penetration, 21.66% in frost resistance (after 150 cycles), and a remarkable 54.8% in anti-abrasion property. Furthermore, the sustainability evaluation assessed its potential societal value, and highlighted its reduced production costs (down 52.28%) and impressive environmental benefits (notable decreases of 28.3% in ozone depletion potential, 33.2% in land use potential, 38.7% in marine ecotoxicity, and 33.9% in fossil resource scarcity). These findings well demonstrated the feasibility of adopting magnesite tailings as a substitute of conventional aggregate within the construction sector along with substantial economic savings and positive environmental ramifications. The successful application of CLGM mortar in cleaner production can further facilitate the sustainable advancement of environment and construction industry.

Measuring the environmental impacts of sewage sludge use in agriculture in comparison with the incineration alternative

This study compares two scenarios for sewage sludge treatment i.e., agricultural-land application (LA) and incineration (INC), in an Italian context (Pavia province, Po Valley). The study was realised within a regional project aiming to obtain useful data to better address future sludge management policies. To do so, an attributional Life Cycle Assessment (LCA) approach was chosen and the multi-functionality was addressed by using system expansion. Results indicated that the scenario INC had higher impacts than scenario LA for the categories linked to process inputs and to the direct emissions of incineration, such as Global warming potential (= + 60 %)., Stratospheric Ozone Depletion, Ozone Formation, Mineral Resource Scarcity and Fossil Resource Scarcity. System expansion i.e., the production of non-renewable fertilisers, played a large role (higher impacts) in the categories related to resource scarcity in the INC scenario. On the other hand, LA scenario showed higher impacts than INC for direct emissions due to fertilisation (Marine and Freshwater Eutrophication, and Particulate Matter).In conclusion, the use of sewage sludge in agriculture seemed to be competitive with the alternative of incineration but both sludge quality and emission reduction during sludge distribution in the field play an important role in the reduction of environmental impacts.

Environmental Impact Analysis to Achieve Sustainability for Artisan Chocolate Products Supply Chain

Small-scale artisan chocolate producers target environmentally conscious consumers and must work with their supply chain partners to measure and improve their environmental impacts. This research evaluates the environmental impact along the supply chain of artisan dark chocolate products in Indonesia and creates an action plan to reduce environmental impact. The Life Cycle Assessment (LCA) methodology was used. The analysis considers cocoa production from the farm level to the processing of cocoa beans into bars in three stages for 1 kg of dark chocolate: the farm maintenance and harvesting stage; post-harvesting stage; and processing stage. At the farm maintenance and harvesting stage, the significant contributions are 72.5% of total abiotic depletion (AD), 47.2% of total global warming (GW), 80.2% of total eutrophication (EU). The significant contributions at the post-harvesting are 31.2% of total AD, 51.8% of total GW, 83% of total EU, 26.4% of total ozone layer depletion (ODP), 20.1% of total cumulative energy demand (CED) and non-renewable fossil (NRF), and 36.9% of total CED renewable biomass (RB). And at the processing stage, the significant contributions are 20.5% of total AD, 15% of total GW, 4% of total ODP, 13.1% of total acidification (AC), 12% of total EU, 10% of total fossil resource scarcity (FRS), and 1.6% of total CED NRF. Changes to the farm maintenance and harvesting stages contributed the most to environmental impact reduction by improving waste utilization and the treatment and selection of environmentally friendly materials.

Life Cycle Assessment of a novel functionally integrated e-axle compared with powertrains for electric and conventional passenger cars

Road transport significantly contributes to climate change and air pollution. Efforts to reduce transport sector emissions include deploying battery electric vehicles and designing their powertrains for improved performance. The European H2020 funded Functionally Integrated E-axle Ready for Mass Market Third GENeration Electric Vehicles (FITGEN) developed a novel functionally integrated e-axle (the FITGEN e-axle) for electric vehicles. This paper presents the environmental performance of the FITGEN e-axle. Using the Life Cycle Assessment (LCA) methodology, the study compares the FITGEN e-axle to the 2018 State-of-the-Art (SotA) e-drive, besides diesel and petrol-fuelled powertrains. The FITGEN powertrain reduces climate impacts by 10 % and energy consumption by 17 %, compared with the 2018 SotA e-drive due to the efficiency improvements and components integration. It also outperforms the 2018 SotA e-drive in several other impact categories, such as human toxicity (4–10 %), land use (19 %), and mineral depletion (8 %). However, the FITGEN powertrain only outperforms diesel and petrol powertrains in climate change and fossil resource scarcity impact categories. These findings imply that more efforts are required to improve the environmental profile of electric powertrains. Metal mining and production, especially for copper and aluminium, are critical for toxicity impacts. The sensitivity analysis demonstrates the robustness of the results, with no significant shift in their ranking order. The following aspects should be considered to improve the performance of electric powertrains from a life cycle perspective: improvement of components efficiency, reduced use of electronics and component integration, and use of low-carbon energy mix from their metal mining sites to production and use.

Environmental analysis of nylon 6,6 production from gamma-valerolactone derived from kenaf

Nylon, known for its outstanding physical properties, durability, and affordability, is in high demand across various industries. The majority of nylon is currently produced using petroleum-based raw materials, which causes negative environmental impacts such as greenhouse gas emission and fossil resource depletion. This has motivated research and development of eco-friendly production methods using biomass, we propose the environmental feasibility of kenaf-based nylon production strategy in the Republic of Korea. This study carries out a life cycle assessment (LCA) for analyzing the global warming potential (GWP) and fossil resource scarcity (FRS) of nylon 6,6 production from gamma-valerolactone (GVL) derived from kenaf. The life cycle inventory is analyzed based on the simulation data of the GVL-to-nylon 6,6 process and the two major environmental impacts are quantified when the biorefinery is operated at the Saemangeum agro-bio industrial cluster in Jeollabuk-do in Republic of Korea. The nylon 6,6 production in the Saemangeum can effectively reduce the GWP (61%) and FRS (67%) compared to the conventional nylon 6,6 production. Furthermore, if the GWP of the two materials used in the production of nylon 6,6 (HMDA, NaOH) can be reduced by 50%, the GWP per kilogram of nylon 6,6 produced will be reduced by 43% (1.91 kg CO2 eq.).

Phase change materials in solar photovoltaics: Bibliometric analysis, role in achieving sustainability, challenges and barriers

Bibliometric analysis plays a vital role in understanding the landscape and development of research in various fields, including phase change materials (PCMs) in photovoltaics (PV). PCM can regulate the temperature of the panels and improve their performance by absorbing and releasing large amounts of thermal energy during phase transitions. However, there are also some challenges associated with integrating PCM with PV technology. Based on bibliometric analysis, the current study aims to provide valuable insights for researchers, policymakers, and industry professionals who are interested in exploring the potential benefits of integrating PCM with PV technology, as well as to investigate the impact of this integration on the Sustainable Development Goals (SDGs). The bibliometric analysis presented in this paper covers studies published from 1977 until 2023 and includes an examination of the benefits, challenges, and limitations associated with integrating PCM with PV panels. The analysis also highlights potential areas for future investigation, such as the development of new materials that can enhance the performance of PCM in PV systems. The findings showed that, while there are still some challenges to be addressed, in relation to administrative, institutional, and regulations barriers, the integration of PCM with PV technology has significant potential to contribute to the SDGs, especially in promoting energy efficiency. Based on the bibliometric analysis, 74% of the research done on PV-PCM systems was related to the SDGs, where most of them focused on SDG 7, with a percentage of 86%. Previous findings revealed that PCMs improved the energy generation of a PV system by 40% to 42%, which confirms the contribution of PV-PCM to the accomplishment of SDG 7. Furthermore, the results show that adding PCMs to PV systems contributes to a higher impact on several environmental factors, such as global warming, fossil resource scarcity, ozone formation, and water consumption.

Environmental impact assessment of end-of-life fluorescent lamps in Rio de Janeiro, Brazil, under different recycling rate scenarios

Fluorescent lamps are hazardous materials, as they contain toxic elements, which may lead to environmental contamination. Therefore, assessing potential environmental impacts arising from inadequate lamp disposal is paramount. Studies addressing the Life Cycle Analysis (LCA) of end-of-life fluorescent lamps are, however, still scarce, and inappropriate lamp disposal remains a matter of concern, especially in developing and underdeveloped countries. In Brazil, fluorescent lamps are still used countrywide and are often inadequately discarded. However, studies assessing fluorescent lamp impacts and potential impact reduction through enhanced recycling are still scarce in the country, despite Brazil's size and high waste generation rates. Furthermore, Brazil's lamp recycling program is a recent measure and still falls short of the country's needs. Thus, this study aimed to assess potential environmental impacts of end-of-life fluorescent lamps in Rio de Janeiro, the second largest capital in Brazil, to the best of our knowledge, for the first time. Potential impact reductions due to higher recycling program adherence considering 5, 20, 80 and 100 % recycling rates were also assessed. The findings indicate that the impact categories most influenced by end-of-life lamps were terrestrial ecotoxicity, human non-carcinogenic toxicity, global warming potential, and fossil resource scarcity. Increased recycling rates, in turn, reduced the environmental impact potential for all evaluated categories, reaching an almost 90 % reduction in most categories when applying a 100 % recycling rate. The current national program target recycling rate of 20 %, however, already contributes to an average impact reduction of over 70 %, comprising a more viable national application rate and already significantly contributing to reduced impacts.

Chemical Degradation of Waste PET and Its Application in Wood Reinforcement and Modification.

In recent years, with the increasing scarcity of fossil resources and the worsening environmental pollution, the effective utilization of wood and plastic waste has become a critical issue. In this paper, propylene glycol (PG) was used as an alcoholysis agent to degrade waste poly(ethylene terephthalate) (PET), and unsaturated polyester (UPR) was synthesized by the polycondensation reaction. The Chinese fir was modified by chemical impregnation to obtain a new type of waste PET-based wood-plastic composites. It exhibits a compressive strength of about 107 MPa and a water absorption of less than 20%. These results highlight the outstanding modification effect on fir, demonstrating excellent mechanical properties and corrosion resistance. This study presents a green and efficient method for the preparation of wood-plastic composites and the recycling of waste PET, providing promising solutions for sustainable resource utilization and environmental protection.

Biogas-based systems: An opportunity towards a post-fossil and circular economy perspective in Italy

This study adopts a life cycle approach to analyse the principal critical elements, opportunities and limits of biogas production's socio-economic aspects and environmental implications. From this perspective, the biogas supply chain sustainability and the opportunity for a closed-loop approach have been assessed starting from existing studies. The analysis revealed that the biogas sector could play a strategic role in making energy systems more resilient in a context characterised by sudden changes, such as the current scenario. In particular, the research is focused on this sector's potential to support the energy transition in Italy, which presents a structural vulnerability related to fossil resource scarcity. The paper contributes to the literature on the sustainable assessment of the biogas supply chain and paves the way for future researchers to understand the complex issues involved in the biogas sector sustainable development process. Furthermore, it provides policy, managerial and social implications, showing that the complete diffusion of biogas – a renewable, scalable and flexible resource – can foster security and decarbonisation of the energy system. It can also create new business opportunities at the local level, promoting a circular and bio-based economy.

Life cycle assessment and circularity of polyethylene terephthalate bottles via closed and open loop recycling

Polyethylene terephthalate (PET) recycling is considered as one of the key approaches to achieving the circular economy (CE) of plastic waste. Bottle-to-Bottle and Bottle-to-Fiber recycling were assessed using Life Cycle Assessment (LCA) and Material Circularity Indicator (MCI). Three allocation methods (i.e., substitution, recycled content, and economic allocation) were used to deal with the recycling system. Producing bottle-grade PET resin and polyester fiber from PET bottle waste can reduce environmental impacts for most midpoint impact categories (e.g., 60% greenhouse gas emissions reduction and 85% fossil resource scarcity reduction). At the endpoint level, the damages to resources, ecosystem quality, and human health of the recycled PET bottles derived from Bottle-to-Bottle recycling were less than virgin PET bottles when using the substitution and recycled content methods. When using the economic allocation method, the final LCA findings highly depended on the recycled content used to produce the PET bottles. On the other hand, regardless of the allocation method used, recycled polyester fiber derived from Bottle-to-Fiber recycling caused less environmental damages than virgin polyester fiber. The MCI scores of Bottle-to-Bottle recycling in the baseline scenarios range between 0.20 and 0.31, whereas the MCI scores of the expected scenario in the future show a higher level of material circularity (0.55–0.60) as a result of 100% collection rate for recycling of PET bottles and the use of recycled PET as a feedstock. Therefore, higher collection rates and recycled content support Bottle-to-Bottle recycling. On the other hand, the MCI score of Bottle-to-Fiber recycling in the baseline scenario is 0.52. This high score resulted from the use of 100% recycled PET as a feedstock of polyester fiber. Recycling polyester fiber at the end-of-life could further increase the MCI to almost 0.7. However, to keep the materials at their highest quality and value, Bottle-to-Bottle recycling should be the preferred option.

Life cycle assessment of e-waste management system in Australia: Case of waste printed circuit board (PCB)

Electronic waste (e-waste) is one of the fastest-growing waste streams globally. Recycling is one of the environment-friendly waste management strategies that creates a net environmental gain in recovering valuable materials. In some countries, downstream recycling (high-value material recovery) is done overseas, and Australia is one of them. Waste printed circuit board (PCB) is a critical component of various electronic equipment, and it contains metals such as copper, tin, gold, aluminium, iron, silver, and others. Waste PCB, as apart of e-waste is mainly recycled overseas in Australia. However, the overall environmental impacts of recycling the waste stream overseas have yet to be investigated. The benefits of recovering the material in Australia have yet to be extensively understood from a supply chain perspective. This study aims to develop multiple scenarios using lifecycle assessment (LCA) methodology to identify the best possible solution for waste PCB disposal (final sink) derived from e-waste. Using SimaPro and Ecoinvent databases, four scenarios have been developed, along with a baseline scenario where waste PCB is recycled overseas. Receipe 2016 impact assessment methodology was utilized for the analysis, and results of the study showed that Scenario 2 (integrated material and energy recovery) is the best approach for waste PCB recycling in Australia, while landfill and direct incineration were the identified two worst scenarios in terms of final disposal option. When choosing local recycling over overseas recycling of waste PCB (material recovery only), it was found that impact categories such as global warming (human health) and fossil resource scarcity were reduced by 53% and 98%, respectively. In addition, the net positive environmental gain could be achieved for human non-carcinogenic toxicity by 7.16% when the waste stream is recycled in Australia. Uncertainty analysis of the study showed that in almost all major impact categories, material and energy recovery together scored high compared to scenarios when only material recovery was considered. This study is the first systematic attempt to characterize system-level lifecycle environmental impact assessment for waste PCB recycling. Future policies and regulations should focus on data transparency and availability across the value chain, local infrastructure development, and resource circularity. This study will add value to decision-making, policy on investment and future policy planning. It will also help industry and researchers develop optimized recycling-focused low-emission resource recovery supply chains.

A comparative environmental analysis of conventional and organic rice farming in Thailand in a life cycle perspective using a stochastic modeling approach

System stochasticity is an inherent characteristic of agricultural systems. Many studies have been conducted in Thailand to analyze the rice production systems. However, most of the prior work just focused on deterministic approach to investigate the rice production systems while disregarding the system variability. In this study, the conventional and organic rice farming systems in Thailand were compared considering the uncertainties associated with parameters. The system variability was taken into account by employing a stochastic modeling approach. The considered impact categories include global warming, ozone formation (human health), freshwater ecotoxicity, terrestrial acidification, fine particulate matter formation, freshwater eutrophication, and fossil resource scarcity. The results showed that yield had considerable influence on the environmental profiles of the two systems; organic and conventional farming showed similar results in terms of global warming on a per hectare basis, but the considerable difference was observed on a per tonne basis. The field emissions due to farm inputs were the most significant contributor to most of the impact categories. The fuel used for irrigation, land preparation, and harvesting also contributed significantly to several impact categories. On the other hand, the impacts of inputs production and material transportation were modest. Uncertainty analysis outcomes indicated that there was a noticeable deviation from the deterministic results in terms of global warming and freshwater ecotoxicity. However, when considering the associated uncertainties, no significant difference was observed between the environmental profiles of the two systems.

Integrated life cycle assessment of biotreatment and agricultural use of domestic organic residues: Environmental benefits, trade-offs, and impacts on soil application

Extensive agricultural activities have been shown to degrade soils, promoting research into improving soil quality. One such method is to increase the amount of organic matter in the soil, and domestic organic residues (DOR) are commonly used for this purpose. The environmental impact of DOR-derived products, from production to agricultural application, remains unclear in current research. With the aim to have a more comprehensive understanding of the challenges and opportunities in DOR management and reuse, this study extended the boundaries of Life Cycle Assessment (LCA) to include the transport, treatment, and application of treated DOR on a national level while also quantifying soil carbon sequestration that has been less addressed in relevant LCA studies. This study focuses on The Netherlands, where incineration predominates, as a representative case to explore the benefits and trade-offs of moving towards more biotreatment for DOR. Two main biotreatments were considered, composting and anaerobic digestion. The results indicate that biotreatment of kitchen and yard residues generally has higher environmental impacts than incineration, including increased global warming and fine particulate matter formation. However, biotreatment of sewage sludge has lower environmental impacts than incineration. Substitution of nitrogen and phosphorus fertilisers with compost reduces mineral and fossil resource scarcity. In fossil-based energy systems like The Netherlands, replacing incineration with anaerobic digestion yields the highest benefit for fossil resource scarcity (61.93 %) due to energy recovery from biogas and the predominant use of fossil resources in the Dutch energy system. These findings indicate that replacing incineration with biotreatment of DOR may not benefit all impact categories in LCA. The environmental performance of substituted products can significantly influence the environmental benefits of increased biotreatment. Future studies or implementation of increased biotreatment should consider trade-offs and local context.