Life Cycle Environmental Impact Assessment Research Articles

Thermal performance and life cycle analysis of 3D printed concrete wall building

Automated construction process with extrusion-based 3D concrete printing (3DCP) is widely recognised due to its ability to construct complex freeform geometrical shapes. Furthermore, the automation process reduces labour and minimises material wastage, thus improving productivity. The structural performance of printed structures has been widely discussed; however, addressing the knowledge gap in energy performance and their environmental impact needs further investigation. Thus, this study investigated and compared the insulation characteristics, life cycle cost and environmental impact assessment of 3DCP structures with traditional reinforced concrete members. The evaluation of the insulation properties of 3D printable concrete allows the characterisation of operational costs and greenhouse gas emissions incurred from the additional heating and cooling systems. Furthermore, this study also suggested a method to enhance the thermal resistance of 3DCP with recycled fibre recovered from face mask waste. A comparison between face mask fibre-reinforced 3D-printed wall element and conventional reinforced concrete wall is also performed across the thermal, life cycle cost and environmental impact parameters. The results showed that the insulation properties of 3DCP walls were increased by 49.5% with the addition of face mask fibres compared to RC walls. This results in reduced energy consumption from additional heating and cooling systems along with a reduction in greenhouse gas emissions, thereby improving the energy performance of the building. Further, face mask fibre-reinforced printed walls showed a reduction in the life cycle cost, mainly in the operation stage, due to the low labour requirement and elimination of formwork. Moreover, a significant reduction in the depletion of resources and ozone depletion was observed for 3DCP face mask fibre-reinforced walls, along with the reduced impact on human health and ecosystem damage. Consequently, the incorporation of face mask fibres into the 3DCP process paves the way for its potential in constructing energy-efficient and environmentally sustainable buildings.

Strategy-based optimization and life cycle environmental impact assessment of a stable photovoltaic power-to-hydrogen system

With the growing global emphasis on reducing greenhouse gas emissions and transitioning to a low-carbon economy, renewable hydrogen is expected to play a vital role in the chemical industry. However, there is a contradiction between the continuous and stable hydrogen demand of chemical process systems and the intermittent and fluctuating nature of renewable energy systems when coupling them together in the industrial chemical production. There are currently few studies addressing year-round stable hydrogen load systems while considering renewable energy intermittency and capacity optimization. Moreover, the comprehensive life cycle environmental impact study of such stable renewable-hydrogen production system is extremely limited. Therefore, this study focuses on a photovoltaic power-to-hydrogen system that can operate stably for 8,760 h per year, specifically targeting its application in the chemical industry. Two operating strategies of the hydrogen system were considered: fully off-grid and ultra-light grid-connected scenarios. The capacity configuration under each scenario was optimized using gird search algorithm, with the objective of minimizing the levelized cost of hydrogen. Based on the optimization results, the energy flow network, cost-effectiveness, and comprehensive life cycle environmental impacts of such system were analyzed. The results show that the ultra-light grid-connected hydrogen production system, due to the support of the power grid, has improved the reliability of the hydrogen production system and significantly reduced the capacity configuration of system components, thereby demonstrating better performance in terms of economics and overall lifecycle environmental impact compared to a completely off-grid hydrogen production system. Its global warming potential (GWP) and levelized cost of hydrogen under electricity sales scenario are 12% and 31% lower, respectively, compared to fully off-grid hydrogen production. Considering China’s future demand for large-scale renewable hydrogen, ultra-light grid-connected hydrogen production may become the primary transitional pathway in the near to medium term.

Plastic Paradox in Blue Carbon Ecosystems.

Plastics are rapidly accumulating in blue carbon ecosystems, i.e., mangrove forests, tidal marshes, and seagrass meadows. Accumulated plastic is diverted from the ocean, but the extent and nature of impacts on blue carbon ecosystem processes, including carbon sequestration, are poorly known. Here, we explore the potential positive and negative consequences of plastic accumulation in blue carbon ecosystems. We highlight the effects of plastic accumulation on organic carbon stocks and sediment biogeochemistry through microbial metabolism. The notion of beneficial plastic accumulation in blue carbon ecosystems is controversial, yet considering the alternative impacts of plastics on oceanic and aboveground environments, this may be the "lesser of evils". Using environmental life cycle impact assessment, we propose a research framework to address the potential positive and negative impacts of plastic accumulation in blue carbon ecosystems. Considering the multifaceted benefits, we prioritize expanding and managing blue carbon ecosystems, which may help with ecosystem conservation, as well as mitigating the negative effects of plastic.

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.

Life-Cycle Environmental Impact Assessment of Primary Beverage Containers: Glass versus Plastic Bottles

Life-Cycle Environmental Impact Assessment of Primary Beverage Containers: Glass versus Plastic Bottles

Life cycle environmental impact assessment of titanium dioxide production in China

Titanium dioxide (TiO2), a widely used superior and versatile material, has imposed considerable energy and environmental impacts with its increasing demand and production. To guarantee the sustainable development of TiO2, this study assesses and forecasts the multiple environmental impacts of two mainstream TiO2 production technologies using the life cycle assessment (LCA) method. Results show that toxicity is the dominant environmental impact caused by TiO2 production. The chloride route has better environmental performance than the sulphate route except for global warming. Sulfuric acid, electricity, and steam are the key factors contributing to environmental burdens. Production of TiO2 pigment is the key stage to cause environmental impact for the sulphate route, whereas, the production of high‑titanium slag and TiO2 pigment are dominant stages for the chloride route. Nonrenewable-fossil is the largest source of cumulative energy demand (CED) consumption in both routes. Therefore, scenarios on renewable electricity transition under carbon neutral target and enhancing chloride route are simulated, revealing a 43% reduction of environmental impact mitigation potential. Finally, policy implications on the transition to renewable energy, chloride technology, and circular economy for TiO2 production are proposed.

Life cycle environmental impact assessment of green tea production in China

Tea is the second most popular beverage in the world after water, and the potential environmental problems during the entire life cycle stages of its production have not been thoroughly discussed. This study aims to investigate the overall environmental impact of green tea production as a typical perennial crop in China with the system boundary from “cradle to gate”. Scenario analysis is carried out to investigate the factors of green tea processing scales and packaging methods on the overall environmental impact level of green tea production in China. Results showed that the average overall global warming potential of procuring 1 kg dry green tea in China ranges from 10.4 to 15.6 kg CO2eq, depending on different processing scales and packaging methods. The processing stage is the dominant contributor to the overall environmental impact of producing 1 kg dry green tea product due to the use of electricity. Electricity consumption in the processing stage and chemical fertilizer application in the planting stage are identified as the environmental hotspots throughout the life cycle of green tea production in China. Optimizing energy structure and improving energy use efficiency in the processing stage, as well as reducing the amount of chemical fertilizer application are the critical measures needed to mitigate the environmental emissions of green tea throughout the life cycle.

Comparative Life Cycle Environmental Impact Assessment of Fruit and Vegetable Waste Valorization by Anaerobic Digestion as an Alternative in a Mediterranean Market

Landfilling and incineration are the most widely used methods for the management and treatment of fruit and vegetable waste (FVW) in Mediterranean markets, despite their potential environmental impact. A comparative life cycle assessment was conducted in this study to evaluate the environmental improvements from replacing the current landfill disposal method for FVW management and treatment in the wholesale market of Amman (Jordan) with an integrated anaerobic digestion process followed by composting. The proposed FVW treatment scenario is the best treatment option for all the assessed impact categories under the system expansion approach. Significant reductions in global warming and terrestrial ecotoxicity impacts categories would be achieved, reaching up to 322% and 352%, respectively, when compared to the current treatment scenario. Furthermore, the higher production of electrical energy (413%), as well as the production of co-products that would avoid the production of 100 kg/d of inorganic fertilizers, would contribute to such a low value of avoided impacts.

Life cycle environmental impact assessment of slaughterhouse wastewater treatment

Slaughterhouses are significant industrial water users, ranking second highest in the livestock processing sector, and a potential pollution source for water bodies due to effluent discharge. This paper uses the wastewater composition of an actual slaughterhouse and models three alternative scenarios for the wastewater management; no treatment and discharge, primary treatment and discharge, and tertiary treatment followed by partial water reuse. All three scenarios are assessed in terms of their environmental performance following a Life Cycle Assessment, by using the Environmental Footprint 3.0 method. The results revealed that the best scenario for the slaughterhouse wastewater treatment is the third scenario with an overall footprint of 0.255 milliEcopoints (mPt), compared to 2.45 mPt and 1.31 mPt of the first and the second scenario, respectively.

Prospective life cycle environmental impact assessment of renewable energy-based methanol production system: A case study in China

Integrating renewable electricity and green hydrogen with CO2 utilization to produce chemicals has drawn much attention due to its low carbon emission characteristics. The goal of this paper is to investigate the environmental sustainability of producing a steady hourly output of methanol by utilizing electricity and hydrogen produced via renewable energy resources, and CO2 captured from a coal-fired power plant located in Inner Mongolia, China. Six renewable energy-based electricity and hydrogen systems are considered based on photovoltaic, wind turbines and combinations thereof, including battery and grid technologies. The environmental impact indicators of these system are compared comprehensively through life cycle assessment approach, including not only global warming potential but also fossil fuel depletion, water & soil & air pollution indices and human health index. The results indicate that the most environmentally friendly system is Case B2 which uses photovoltaic to produce hydrogen and electricity, with battery for energy storage and excess electricity sold back to grid. It shows apparently the best sustainability performance in global warming potential, which is 0.105 kg CO2-eq per kg methanol. In general, the proposed six systems outperform conventional methanol production systems in terms of global warming potential and abiotic depletion potential, with reductions ranging from 74% to 92% and 51.1%–73.8% respectively, but they have high levels in other environmental sustainability indicators such as human toxicity, eutrophication potential, and ozone layer depletion potential due to the photovoltaic electricity generation unit. The findings highlight that it is essential to consider a comprehensive range of environmental sustainability indicators when developing renewable energy-based methanol systems on a large scale.

Life cycle environmental impact assessment of cotton recycling and the benefits of a Take-Back system

This study assessed the contribution of mechanically recycled cotton to reducing environmental impacts of fabric production by blending the recycled cotton with 100% virgin cotton of different types, including the U.S., BCI-Brazilian, Global average, and China. GHG emissions, water footprint, air pollution, and land use were investigated for producing 1 kg fabric, considering a 'cradle-to-gate' approach. A 'Take-Back' system was modeled using the circular economy concept to illustrate potential impact reduction by avoiding virgin cotton. Impact reduction scenarios were created considering varying blending ratios (i.e., virgin/ recycled), focusing on 70% virgin and 30% recycled cotton (target). Results reveal that compared to the baseline impacts, the target scenario could reduce environmental impacts by 2.2–8.6% (GHG emissions), 0.6–24.5% (water footprint), 1.4–11.6% (air pollution), and 3.1–25.2% (land use). In summary, recycled cotton could partially substitute 100% virgin cotton for fabric production. Besides, implementing and scaling up the 'Take-Back' system could reduce environmental impacts and contribute to environmental sustainability.

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.

Can free-floating electric bike sharing promote more sustainable urban mobility? Evidence from a life cycle environmental impact assessment

Electric shared micromobility has been popularized and developed worldwide in recent years. However, its environmental impact remains unclear. Based on user travel behavior and actual operational data, a life cycle assessment (LCA) study quantitatively estimates the environmental impacts of China's free-floating e-bike sharing (FFEBS) promotion, including human health, ecosystems, and resources. The results show that the low utilization makes FFEBS not an environmentally friendly mode of transportation. Taking into account the travel mode shift towards FFEBS, under the current operating efficiency of FFEBS, the substitution rate of car travel needs to reach about 40% to obtain environmental benefits. However, FFEBS can barely obtain environmental benefits on fine particulate matter formation, Human toxicity, Ozone formation, Freshwater and Marine eutrophication, Terrestrial acidification, and Terrestrial ecotoxicity, which is largely attributed to the negative effects of batteries and electronic components and the required rebalancing and recharging activities. As utilization continues to increase, it is estimated that each kilometer of FFEBS trips could reduce the impact of fossil resource scarcity and global warming by up to about 11.87 g oil eq and 32.06 g CO2-eq, respectively. This empirical study can not only help authorities, operators and the public better understand the environmental impact of FFEBS, but also provide a valuable reference for formulating effective measures to improve the sustainability of the FFEBS and urban transportation systems.

Life cycle environmental impact assessment of lab-scale preparation of porous alumina pellets as substrate for hydrogen separation metal layer-based membranes

PurposeThe study aimed to identify the environmental hotspots of lab-scale preparation of high purity porous Al2O3 pellets with suitable feature to work properly as metal layer-based deposition substrates for hydrogen separation membranes. The work intention was providing hints that may help the designing of upscaled systems, fundamental for the development of a possible future industrial production of hydrogen separation metal layer-based membranes technology.MethodsThe goal of this study was achieved assessing and analyzing environmental impacts of Al2O3 pellet production at lab scale. Primary data were collected in Padua laboratories of National Research Council of Italy. Secondary data were retrieved from Ecoinvent 3.7 database. Life cycle assessment (LCA) was performed using Environmental Footprint 3.0 method employing SimaPro 9.3 as software. Moreover, the CML LCIA method v. 4.7 was used to verify the robustness analysis of characterized results.ResultsLife cycle impact assessment highlighted as the main driver of environmental impacts was mainly associated to the pellet consolidation process and their morphological characterization stage. In particular, the impact of the first energy consuming process resulted strictly related to the peculiar energy mix used (linked to the laboratory geographical location). Conversely, morphological characterization stage was found to affect mainly the mineral resource depletion category due to the Au coating used for performing scanning electron microscope (SEM) analyses.ConclusionsThe study identified the environmental hotspots related to lab-scale preparation of porous alumina pellets as substrate for hydrogen separation metal layer-based membranes. The optimization strategies evaluated in this work were addressed to improve the environmental profile of experimental activities considering several scenarios, in view of a possible industrial scale-up.

Management of Environmental Life Cycle Impact Assessment of a Photovoltaic Power Plant on the Atmosphere, Water, and Soil Environment

Photovoltaic power plants are considered to be environmentally friendly solutions to the production of electricity. Solar energy conversion does not release toxic compounds into the environment. However, the construction of solar power plant components (photovoltaic modules, sup-porting structure, inverter station, electrical installation) is extremely consumptive of energy and materials. Massive volumes of minerals, fossil fuels, and electricity are consumed during the manufacturing process. Efficient management of energy and environmental resources seems to be critical for national policy. It is crucial to admit that the post-consumer management of the components of a photovoltaic power plant is connected with a certain quantity of energy and matter and a negative impact on the natural environment. A life cycle assessment was carried out on a real 2 MW photovoltaic power plant located in the northern part of Poland. The analysis was carried out applying the ReCiPe 2016 model and the Life Cycle Assessment (LCA) approach. The impact of the examined renewable energy system was evaluated using 22 impact categories and 3 emission areas (air, water, soil). Life Cycle Assessment analysis was carried out for 2 post-consumer development scenarios (landfill and recycling). The examination of the collected results reveals that photovoltaic modules are the element causing the most negative environmental repercussions connected to the release of dangerous compounds into the atmosphere. Post-consumer development in the form of recycling would provide major environmental benefits and reduce detrimental environmental consequences across the whole life cycle of the photovoltaic power plant. The obtained research results enabled the formulation of pro-environmental recommendations aimed at the long-term development of the life cycle of solar power plants.

Life cycle environmental impact assessment for battery-powered electric vehicles at the global and regional levels

As an important part of electric vehicles, lithium-ion battery packs will have a certain environmental impact in the use stage. To analyze the comprehensive environmental impact, 11 lithium-ion battery packs composed of different materials were selected as the research object. By introducing the life cycle assessment method and entropy weight method to quantify environmental load, a multilevel index evaluation system was established based on environmental battery characteristics. The results show that the Li–S battery is the cleanest battery in the use stage. In addition, in terms of power structure, when battery packs are used in China, the carbon footprint, ecological footprint, acidification potential, eutrophication potential, human toxicity cancer and human toxicity noncancer are much higher than those in the other four regions. Although the current power structure in China is not conducive to the sustainable development of electric vehicles, the optimization of the power structure is expected to make electric vehicles achieve clean driving in China.

Thermodynamic and environmental analysis of auto-thermal supercritical water co-gasification polygeneration system of sewage sludge with coal

An auto-thermal supercritical water (SCW) co-gasification polygeneration system has been developed to treat sewage sludge (SS) with coal addition for H2 and heat production. Thermodynamic analysis based on Gibbs free energy minimization and life cycle environmental impact assessment of the system was performed under different conditions. The sensitivity analysis results show that H2 yield increased first and then decreased with the increase of preheated water when the proportion of dry coal to dry SS was less than 1.75 but decreased monotonically when the proportion was over 2. It is necessary to add 21% dry coal of raw SS amount when the system was energy self-sufficient to treat SS directly for avoiding pretreatment energy consumption. The largest exergy destruction was in the SCW gasification reactor which could be over 11500 kW for a 10 t/h processing requirement under 650 °C. The energy and exergy efficiency of the SS SCW co-gasification system can be improved effectively by adding coal, which can reach 79.5% and 47.9% under the preheated water ratio of 1 and the dry coal ratio of 3, respectively. Under this condition, 347.1 kg/h H2 and 20.5 t/h steam could be produced. The global warming potential (GWP) of the system was only 1.10–2.5 kg CO2-eq by the life cycle assessment considering carbon capture and storage (CCS) at a dry coal ratio of 3 based on the natural enrichment of CO2-rich gas by the SCW gasification technology.

Environmental impacts of solar thermal power plants used in industrial supply chains

A systematic literature review was conducted to investigate the environmental impact of solar thermal power plants in the industrial supply chains. A number of different solar thermal power collectors like parabolic trough (PT), linear Fresnel (LFR), solar dish (SD) and solar towers (ST) were considered and analysed. The first observation was that PT collectors generate the lowest level of Green House Gas (GHG) emissions, followed by LFR, DT and SD plants. There was a lack of studies dealing with the GHG emissions of LFR and SD plants, which demonstrated a need of conducting more studies to gain better understanding of their environmental performances. The second observation was that different environmental assessment software tools used for analysing the environmental impact showed conflicting results because of the different approaches used in the characterization factors management in each software. Those software tools include: SimaPro, Gabi, System Advisor Model (SAM), Umberto and Thermoflex + PEACE. The standardization of environmental software tools and life cycle impact assessment methods is required to prevent discrepancies in life cycle assessment results. The third observation was the need for integrated environmental and economic assessments to provide a comprehensive evaluation of the solar thermal plants as it will enable investors, policy-makers and researchers to make informed decisions about the environmental and economic impacts of those plants.

Life Cycle Environmental Impact Assessment and Applicability of Synthetic Resin Formwork.

In this study, the environmental impacts of the production and field application of synthetic resin formwork were quantitatively compared to the Euro form. The noise test results showed an average of 107.3 dB (A) for the Euro form and 99.7 dB (A) for the synthetic resin formwork. Additionally, when the number of uses was considered, the CO2 emissions from the synthetic resin formwork were approximately 32% lower than the Euro form. Based on these results, it is expected that the use of synthetic resin formwork will reduce material production by half and reduce CO2 emissions compared to channel formwork.

Life Cycle Environmental Impact Assessment of Aquaculture Products in the Gaza Strip, Palestine

This study used the life cycle assessment (LCA) approach to evaluate the environmental impacts resulting from aquaculture ponds and associated activities. The assessment focused on eutrophication, acidification, global warming, energy use, and local nutrient emissions. Two farms, Fish Fresh and Al-Bahar, were analyzed to determine the contribution of different components in fish farming systems to various impact categories. Data on fish feed, onsite electricity, feed milling electricity, fuel intensity, water input, and fish production were meticulously collected through a comprehensive questionnaire and insightful interviews conducted over a one-year period in 2020. Furthermore, valuable information was diligently gathered regarding the nitrogen and phosphorus emissions in aquaculture ponds, with a focus on feed inputs. Environmental indicators were evaluated using a functional unit of 1 ton and 1 kg of live fish weight. Results reveled that global warming impacts varied between the two farms, with feed production being the primary contributor, accounting for 74.73% and 76.30% of total emissions, respectively. Acidifying emissions were mainly generated through fish production, accounting for 74.8% and 76.3% of the total for Fish Fresh and Al-Bahar farms, respectively. Eutrophication was primarily driven by fish production, while feed production and transportation operations also made noticeable contributions. The average emissions per kilogram of fresh fish were higher for the Fish Fresh farm compared to Al-Bahar in terms of global warming, acidification, and eutrophication. Energy consumption and water dependence also varied between the farms. These findings emphasize the importance of considering environmental impacts throughout the life cycle of fish farming in the Gaza Strip.