Life Cycle Assessment Analysis Research Articles

Cross-linked structures reinforced the bamboo fiber/poly(lactic acid) composites with high heat resistance and their environmental impact through the life cycle assessment analysis

In order to prepare low-cost and heat-resistant poly(lactic acid) (PLA) composites, in this study, bamboo fiber (BF) was added to stereo-complex crystal PLA (SC-PLA) to prepare heat-resistant composites. Poly[(phenyl isocyanate)-co-formaldehyde] [a polyaryl polymethylene isocyanate (PAPI)] was used to form cross-linked structures between SC-PLA and BF, and the effects of PAPI-cross-linked structures on the crystallization properties, mechanical properties, and heat resistance of BF/SC-PLA composites with different BF contents were systematically investigated. When 15% BF was added, the mechanical properties of the composite were significantly improved. The tensile strength increased by 85.5% compared to the unmodified composite, reaching 34.7 MPa, which was even higher than that of the SC-PLA composite (33.1 MPa). In addition, in order to explore the impact of the PAPI-modified BF/SC-PLA composite on the environment and carbon emissions, a life cycle assessment (LCA) of the composites was conducted. The addition of BF effectively reduced the impact of the composite on the environment. Notably, the emissions of CO2 decreased by approximately 11.7%, and the freshwater, marine, and land ecotoxicity were also significantly reduced. This work provided a reference for the preparation of low-cost and heat-resistant PLA composites for heat-resistant food packaging and disposable tableware and expanded the application of PLA products in the field of heat-resistant materials.

Reuse of polyvinyl chloride residues—in powder and fiber forms—as potential components for green mortar pavers

Plastic wastes are considered a significant environmental pollution load because of their mostly non-biodegradable nature. Consequently, the need to lessen the environmental impact calls for employing eco-friendly strategies such as reusing materials in construction. The objective of this study is to analyze the mechanical behavior and environmental impacts of mortar elements, with a specific focus on pavers, by incorporating waste polyvinyl chloride (WPVC) as aggregate and partially replacing cement. Two distinct forms of this waste were considered in the investigation: (i) as it is generated in industrial processes, mainly in fiber form, WPVCf, and in the form of powder obtained by sieving the former, WPVCp. The ratio of conventional mortar materials replaced by WPVC and the final water-to-binder ratio changed based on waste type and mix workability. The experimental work involved preparing 84 pavers, each measuring 100 mm × 150 mm × 60 mm. For each type of paver, 12 samples were prepared, ensuring a minimum of 4 sets of test data for each curing period (7, 14, and 28 days). Flexural strength tests, conducted in accordance with the Colombian standard NTC 2017, utilized a standard flexural test machine with a 150 kN capacity. A specially designed steel tool applied a point load at the center of each paving block, maintaining a minimum distance of 10 millimeters from the edges. The findings demonstrated that pavers containing fiber plastic waste exhibited the requisite strength for paved walkways, even in the short term, when the weight ratio of WPVCf to sand (WPVCf/S) was 24 %. These results derive an eco-friendly solution for reusing PVC wastes currently deposited directly in landfills. Moreover, to analyze the environmental impacts of this solution, a Life Cycle Assessment (LCA) analysis was carried out in this research. The LCA results pointed out that dosing with a WPVCf/S ratio of 24 % emerges as the most ecologically responsible, manifesting substantial reductions across impact categories, such as a significant 23 % decrease in climate change, a 23 % reduction in Photochemical ozone formation, and a 22 % reduction in renewable energy consumption. This underscores the potential of WPVCf incorporation as a consequential step toward eco-friendly construction materials. Furthermore, this solution not only translates to diminished paving block costs by requiring less fine aggregate and cement but also contributes to reduced transportation expenses owing to the decreased weight of the pavers.

Environmental Assessment of Forest-Based Industry Products with CAD-Integrated LCA Tools: A Comparative Case Study of Selected Software

The study evaluates how the environmental impacts of wooden products could be assessed in the early stages of product development using CAD-integrated life cycle assessment (LCA) tools. Focusing on a wooden chair design, the study compares the environmental impact results derived from LCA tools integrated in SolidWorks, NX and Fusion against a traditional LCA analysis performed using SimaPro. Methods involve analysing a chair model to measure the environmental impacts across different life cycle phases, such as material extraction and manufacturing. The results reveal that manufacturing processes, particularly electricity use, significantly contribute to environmental impacts, especially marine and freshwater ecotoxicity. Comparisons between LCA tools integrated into commercial CAD software and SimaPro 9.5.0.1. showed that while the tools deliver comparable results for global warming potential and other categories, they struggle with certain impact categories. The main distinguishing features of the results were methodological. Overall, the results aligned the most with the impact values calculated in Solidworks Sustainability. The study concludes that CAD-integrated tools are useful for early-stage environmental assessments but have limitations, particularly in their material databases and life cycle scope. For a comprehensive assessment, combining these tools with more detailed analysis methods may be necessary. The research suggests improvements for CAD-based tools to enhance their effectiveness in evaluating the environmental impact of wooden products.

Assessing the environmental benefits of passenger cars electrification in metropolises: A case study of Singapore

Land-based transportation is a significant contributor to global greenhouse gas (GHG) emissions, with internal combustion engine vehicles being the predominant mode of transport in this sector. As the world population grows and urbanization accelerates, transport demand in metropolitan areas is projected to double by 2050, underscoring the critical need for sustainable transportation strategies, forecasting, and planning within an urban context. One challenge in this endeavor is the insufficient attention given to the distribution of vehicle grades within the overall car population during GHG impact assessment, despite the recognized importance of car grade by researchers and policymakers. In this study, we incorporate both engine type and vehicle grade distribution, derived from data on over 30,000 passenger cars registered with the Land Transport Authority of Singapore between 2018 and 2022, into our life cycle assessment analysis. This approach ensures that our scenario-based studies on prediction and planning are more comprehensive than those that consider only the most popular models. Furthermore, while Singapore benefits from a relatively clean electricity supply, the current limitations in charging infrastructure negatively affect the GHG impact of electric vehicles. The insights from this research will inform the development of transportation policies for metropolises like Singapore, contributing to the advancement of a more sustainable transportation system.

Comparative LCA-MCDA of high-strength eco-pervious concrete by using recycled waste glass materials

Sustainable management of construction and demolition (C&D) waste and waste glass (WG) presents a significant challenge in densely populated regions like Hong Kong. While the potential for using WG in concrete is acknowledged, there is limited research on how to optimally use these materials to achieve sustainability, cost-effectiveness, and mechanical integrity. This study addresses these challenges by employing an integrated life cycle assessment and multi-criteria decision analysis (LCA-MCDA) within a cradle-to-gate scope, utilizing site-specific data. The VIKOR method, known for its robust decision-making capabilities in complex environmental assessments, was used to identify optimal concrete mixtures based on environmental, economic, and mechanical performance. The results indicate that replacing 25% of natural aggregate with recycled WG materials provides the best balance across the evaluated criteria. Furthermore, additional environmental benefits can be achieved by substituting natural aggregates with recycled waste concrete aggregates. This research underscores the importance of life cycle thinking in construction materials decision-making, demonstrating that significant use of recycled WG reduces energy consumption and greenhouse gas emissions, offering a sustainable alternative to conventional concrete.

Environmental Benefits of Hydrogen-Powered Buses: A Case Study of Coke Oven Gas

This study conducted a Life Cycle Assessment (LCA) of alternative (electric and hydrogen) and conventional diesel buses in a large metropolitan area. The primary focus was on hydrogen derived from coke oven gas, a byproduct of the coking process, which is a crucial step in the steel production value chain. The functional unit was 1,000,000 km traveled over 15 years. LCA analysis using SimaPro v9.3 revealed significant environmental differences between the bus types. Hydrogen buses outperformed electric buses in all 11 environmental impact categories and in 5 of 11 categories compared to conventional diesel buses. The most substantial improvements for hydrogen buses were observed in ozone depletion (8.6% of diesel buses) and global warming (29.9% of diesel buses). As a bridge to a future dominated by green hydrogen, employing grey hydrogen from coke oven gas in buses provides a practical way to decrease environmental harm in regions abundant with this resource. This interim solution can significantly contribute to climate policy goals.

Long-Term Comparative Life Cycle Assessment, Cost, and Comfort Analysis of Heavyweight vs. Lightweight Construction Systems in a Mediterranean Climate

Massive construction systems have always characterized traditional architecture and are currently the most prevalent, straightforward, and cost-effective in many Mediterranean countries. However, in recent years, the construction industry has gradually shifted towards using lightweight, dry construction techniques. This study aims to assess the effects on energy consumption, comfort levels, and environmental sustainability resulting from the adoption of five high-performance construction systems in a multi-family residential building: (i) reinforced concrete structure with low-transmittance thermal block infill; (ii) reinforced concrete structure with light-clay bricks and outer thermal insulation; (iii) steel frame; (iv) cross-laminated timber (CLT); (v) timber-steel hybrid structure. To achieve this goal, a multidisciplinary approach was employed, including the analysis of thermal parameters, the evaluation of indoor comfort through the adaptive model and Fanger’s PMV, and the quantification of environmental and economic impacts through life cycle assessment and life cycle cost applied in a long-term analysis (ranging from 30 to 100 years). The results highlight that heavyweight construction systems are the most effective in terms of comfort, cost, and long-term environmental impact (100 years), while lightweight construction systems generally have higher construction costs, provide lower short-term environmental impacts (30 years), and offer intermediate comfort depending on the thermal mass.

Optimizing plastic waste inclusion in paver blocks: Balancing performance, environmental impact, and cost through LCA and economic analysis

Rising waste plastic and cement used in construction raises environmental concerns. Substituting cement with recycled plastic waste (PW) in paver blocks offers an eco-friendly solution. However, a comprehensive life cycle assessment (LCA) economic and performance analysis is lacking. This study addresses this gap by evaluating the compressive strength and durability properties of PSPB while also conducting LCA and economic evaluations to identify the most optimal solutions for enhanced performance. Compressive strength tests determined that a 30% PW replacement yielded optimal results. The durability tests showed that PW paver blocks have significantly lower water absorption compared to conventional blocks, and they maintained a compressive strength of 20 MPa, which is acceptable for light traffic applications, even at elevated temperatures. LCA highlights that cement usage accounts for over 80% of climate change emissions for conventional blocks. Sensitivity analysis shows shipping distance, truck capacity, and energy use greatly affect environmental outcomes. Complete replacement of cement with PW is considered more environmentally friendly. Economic analysis indicates plastic pavers are 52% more cost-effective than cement-based ones. This research offers vital insights into the practicality, environmental impact, and financial sustainability of integrating PW into paver blocks.

Lifecycle Assessment Analysis of Recycled Concrete Aggregate Incorporating Fly Ash and Hemp

The critical roles of recycling are increasing depending on depleted natural resources and its devastating consequences. Concrete has been one of the most used building materials for many years to response the basic need of human beings for shelter. The studies on the recycling of concrete are crucial to minimize negative effects of both the high amount of energy consumed during the production phase and the limited recycling opportunities after destruction. Considering the amount of construction and demolition waste (CDW) after the February 6, 2023 earthquakes in Türkiye, it is clear that recycling concrete (RC) may make a positive contribution to environmental sustainability and natural resources usage. In addition, as a result of the ongoing urban transformation projects throughout Türkiye, especially in Istanbul, there is a need to recycle CDW, the majority of which consists of concrete. This paper examines the equivalent CO2 emissions of recycled concrete aggregate (RCA) incorporation of various proportion fly ash and hemp based on previous studies by applying the Excel-based GreenConcrete LCA software developed at the University of California Berkeley Campus (UC Berkeley). As a result of the investigations, it is seen that the use of RCA, which is generated in large quantities both as a result of earthquakes and urban transformation projects, reflects positively on the environmental impacts in the LCA analysis. In addition, the use of concrete mixtures that contribute to the recycling of wastes such as fly ash and hemp used as admixtures contributes to reducing the environmental damage of these wastes and improving the concrete content.

Comparative analysis of life cycle assessment and material circularity indicator: study applied to smart electricity meter polycarbonate parts

Comparative analysis of life cycle assessment and material circularity indicator: study applied to smart electricity meter polycarbonate parts

Combining life cycle assessment and dynamic qualitative comparative analysis to analyze the environmental impacts of urban development across different provinces in China

Examining the environmental pollution landscape is a vital link for urban development. Across production, distribution, and usage stages of 24 provinces in China between 2010 and 2019, this study conducts Life Cycle Assessment and Dynamic Qualitative Comparative Analysis to explore the effects of conditional combination on environmental impact assessment indicators including Photochemical Oxidation, Eutrophication, Global Warming Potential, Human Toxicity, and Acidification. The results reveal that: (1) Shandong contributes most significantly to environmental impact assessment indicators in the production and distribution stages, while Inner Mongolia dominates the usage stage. In contrast, Beijing, Hainan, and Shanghai show lower contributions, though Hainan exhibits a rising trend in the Global Warming Potential index across all stages; (2) The production stage consistently accounts for the largest environmental impact, with notable differences in contributions from Beijing, Ningxia, Inner Mongolia, and Shanghai across the three stages; (3) Environmental impact is not driven by individual factors alone; rather, it is the combination of factors that proves influential. Complex nonlinear relationships are revealed between energy consumption patterns and environmental impacts in the production stage. The combination of transport operating distance and traffic volume has an interaction during the distribution stage. The usage stage leads only to the environmental impact of Eutrophication, which is caused by the resident population and ecological water consumption excluding residential water use. These findings present a new strategy for optimizing energy structure and water resource utilization, and emphasize the synergies to reduce the environmental impacts, providing instrumental implications for policymakers and government managers in environmental management and urbanization development.

Comparative Life Cycle Assessment and Life Cycle Cost Analysis of Bonded Nd-Fe-B Magnets: Virgin Production versus Recycling

Comparative Life Cycle Assessment and Life Cycle Cost Analysis of Bonded Nd-Fe-B Magnets: Virgin Production versus Recycling

Carbon Footprint Assessment: Case Studies for Hemp-Based Eco-Concrete Masonry Blocks

In recent times, climate change has become more evident than ever, and measures to slow down its negative effects are imperative for the future of the world. The scientific and economic communities of countries around the world, under the force of international climate agreements, are identifying solutions to reduce greenhouse gas (GHG) emissions by establishing appropriate measures and developing new strategies. In the context of these objectives, the effort to identify eco-sustainable practices for the construction industry is growing significantly. Recently, much research has focused on solutions for producing green building materials, as well as applying circular economy principles to achieve a balance between anthropogenic emissions and absorptions by greenhouse gas absorbers. The relevant indicators of the level of achievement of these major objectives can be identified, already from the construction design phase, with the help of Life Cycle Assessment (LCA) analysis. This paper presents a series of environmental impact analyses for an eco-friendly solution of precast concrete masonry blocks. Ecological concrete is manufactured with aggregates from biological waste resulting from hemp crops. Impact assessments were performed with the SimaPro 9.5 software application. Research has shown that in the production chain, which includes the materials resulting from the recycling and reuse of hemp concrete blocks, the contribution to the effort to achieve neutrality in terms of global warming is significant. The Cradle-to-Cradle scenario revealed that the recycling of hemp concrete masonry blocks at the end of their use, for a functional unit of 0.5 m3, has a GHG emission of 33.5228 [kg CO2-eq] and CO2 uptakes can reach the negative value of −53.8397 [kg CO2-eq]. Thus, the balance of GHG emissions is negative, with values of approximately −20.3169 [kg CO2-eq]. The LCA analyses also reflect a decreased damage to human health, natural resources, and biodiversity when hemp concrete is used for masonry blocks.

Transforming the feeding regime towards low-input increases the environmental impact of organic milk production on a case study farm in central germany

Abstract Purpose Despite the direct effect of the feeding regime on the environmental impacts of dairy farming systems, its level of intensity, particularly in organic systems, has rarely been investigated. This study compares the environmental impact of a high-input feeding regime with a grassland-based, low-input feeding regime scenario within an organic milk production system conducted on Gladbacherhof, the research farm of Justus Liebig University Giessen, in Central Germany. Methods An integrated Life Cycle Assessment (LCA) analysis was performed from a cradle-to-farm gate perspective to quantify five environmental impacts, namely Global Warming (GW), Non-Renewable Energy Use (NREU), Land Use (LU), Terrestrial Acidification (TA), and Freshwater Eutrophication (FE). All agronomic data of the Gladbacherhof research farm, averaged over the years 2010–2017, were included. When not directly measured on the farm, ecoinvent data were included. Results and discussion Contrary to our hypothesis, the results suggest that a grassland-based low-input system has a higher environmental impact as compared to a high-input system for each of the five impact categories when using fat and protein-corrected milk (FPCM) as the functional unit. A 50% reduction in concentrates and exclusion of maize silage from the feed ration in the modelled low-input production system lead to a 20% drop in milk yield. To balance the energy content in low-input feeding ration, longer grazing period and higher amount of hay, alfalfa, and grass silage are required. This in turn results in higher emissions from enteric fermentation, manure management, and feed production and hence in higher environmental impact, particularly for GW, TA, and FE. Conclusions This study is one of the few that directly explores the environmental impact of feeding intensity in an organic milk production system. Nevertheless, there is a lack of research on consolidated emission factors for several greenhouse gas (GHG) sources in organic livestock and cropping systems to perform more robust carbon footprint calculations that comply with the Intergovernmental Panel on Climate Change (IPCC) Tier 3 GHG reporting guidelines. To generalize the results at the regional or national scale, direct comparisons with a larger number of organic farms representative of high-input and low-input intensities are still essential.

Retrofitting of the Italian precast industrial building stock. LCA analysis as decision-making tool

The challenging European goal concerns the achievement of a carbon-free economy by 2050 must necessarily consider the improvement of the construction sector along with the redevelopment of the existing buildings. In fact, according to a European report concerning existing buildings, 80% of the built environment will remain the same by 2050. Nowadays buildings are responsible for 30% of the global final energy consumption and 37% of global energy and process emissions. As regards industrial buildings, they account for 33% of global final energy demand. The research aims to define some effective retrofitting measures to be applied in the existing Italian industrial facilities to improve their both energy and environmental performance. Several redevelopment scenarios and their possible combinations related to external envelope technological solutions and systems are analysed. The different interventions are applied to an existing Italian industrial building chosen as a case study and are compared by Life Cycle Assessment (LCA) analysis considering different environmental indexes (GWP, AP, PERT and PENRT). The calculation of the primary energy demand is also performed. Phase B6 accounts for about 80% of the whole environmental impact calculated considering 20 years as building lifetime. The redevelopment scenarios that foresee the intervention on the external envelope are the most impactful ones in terms of the production phase (A1-A3). Those related to the existing roof are characterised by a significant impact due to the demolition, disposal and landfill of finishing panels made of asbestos. The configurations that include the substitution of the existing heating system with an air-to-air heat pump coupled with renewables to produce electrical energy on-site are the most advantageous ones. The latter make the industrial building carbon-zero thanks to the considerable amount of surplus electrical energy produced on-site. In this case, phase D mostly recovers the environmental impact of the whole life cycle considering the different indexes.

Comparative analysis of life cycle assessment of biogas-powered and coal-powered power plant for optimized environmental operation

The major concerns that mankind faces today are limited reserves of conventional energy, growing energy demand, and environmental pollution. This study depicts a comparative analysis done for the life cycle assessment of the biogas-based plant and coal-based plant designed for Bikaji Foods International Ltd., India. OpenLCA version 1.11.0 software was used with the database ecoinvent 3.3 LCIA methods (ReCiPe Midpoint H) to analyze the environmental impact and investigate the effect of the biogas-based plant and the coal-based plant. The functional unit of 1 MJ of energy generated from biogas and coal was selected to represent the results of the production of 15,271,600 MJ of energy. The results for marine eutrophication, particulate matter formation, photochemical oxidant formation and terrestrial acidification for the biogas-based plant were 734.527 kg N-Eq, 6314.012 kg PM10-Eq, 1328.629 kg NMVOC and 3.933E04 kg SO2-Eq, respectively. Whereas, for coal-based plant, these values were 4919.442 kg N-Eq, 1.962E04 kg PM10-Eq, 6486.987 kg NMVOC and 13.448E04 kg SO2-Eq, respectively. The greenhouse gas emissions and fossil depletion from the biogas-based plant were found negligible as compared to the coal-based plant. Overall, it was found that the biogas-based plant has a more remunerative impact on the environment than the coal-based plant. This study recommends that local authorities and industrial communities should invest more and more in increasing the number of biogas plants at domestic as well as commercial levels and secure a clean and green future for coming generations.

Life cycle assessment (LCA) and economic analysis of two-stage anaerobic process of co-digesting palm oil mill effluent (POME) with concentrated latex wastewater (CLW) for biogas production

This study outlines the results of a process-based life cycle assessment (LCA) of the environmental performance of biogas production from co-digestion of palm oil mill effluent (POME) and concentrated latex wastewater (CLW) in the two-stage anaerobic digestion (AD) process. Biogas is utilized global across several sectors, including electricity generation, heating, and transportation. The Open LCA 2.0.2 software was used to evaluate the LCA at the midpoint level by using 18 different impact categories. This study reveals the three main contributions of the AD process, which were global warming (8.65 × 102 kg CO2eq), water consumption (5.32 m3), and land use change (3.39 × 102 m2 a crop eq), this result corresponded with the previous study in Malaysia that examined biogas production from the AD of POME In addition, alternative scenarios, in which a single substrate, have been established to quantify the impacts of potential improvements of biogas production to compare with base scenario of co-digestion. The results show that the environmental impacts of the base scenario released were lower than those of the single POME substrate of alternative scenario 1 in most impact categories. Furthermore, economic analysis is a crucial factor in the practical implementation of the AD process. Linking LCA with economic analysis offers a comprehensive perspective on sustainability, balancing environmental impacts with financial performance to optimize the potential of the AD co-digestion process. This is the first study to apply LCA and economic analysis to this specific co-digestion process in a two-stage AD system. The economic analysis of the two-stage AD of co-digesting POME and CLW was 1200 m3/d production of wastewater (70 % of POME and 30 % of CLW) based on the factories' data. The result indicates net present value, internal rate of return, and payback period of 515,813.94 USD, 9.13 %, and 8.87 years, respectively. This work proposed the potential approach for implementing the two-stage AD co-digestion of POME and CLW while concurrently producing valuable bioenergy carriers.

Life cycle assessment and cost analysis of innovative agar extraction technologies from red seaweeds

Developing efficient and sustainable extraction technologies for valuable biocompounds from seaweed is crucial to overcome the limitations of conventional technologies. This study aims to compare three innovative technologies for agar extraction from two red seaweed species, G. sesquipedale and G. vermiculophylla: subcritical water extraction (performed at 125 °C, 2.5 atm, 1 min, and at 140 °C, 3.8 atm, 1 s), moderate electric fields (applied at 85 °C for 120 min and 95 °C for 180 min), and a combination of both methods. The comparison used life cycle assessment and life cycle costing methodologies, considering a gate-to-gate approach. The combined technology demonstrated the lowest energy consumption, with 67 MJ/kgagar for G. vermiculophylla and 100 MJ/kgagar for G. sesquipedale. A carbon footprint reduction of up to 94 % was obtained when compared to the control, with 15.9 kgCO2 eq. /kgagar for G. vermiculophylla and 20.4 kgCO2 eq. /kgagar for G. sesquipedale. Using photovoltaic panels as alternative energy further cut carbon emissions by 50 %. The cost analysis showed that the combined technology was the most cost-effective extraction method.

Sustainable practices in construction: Exposing the Potential of Waste as a Resource.

Abstract This paper examines the critical issues facing the construction and demolition industry in the countries of the European Union, with a particular focus on Germany. It presents strategies for waste management and sustainable development goals in construction sector. The construction industry is responsible for a significant proportion of waste production, which underscores the urgency of addressing the impending waste management crisis. The paper highlights the necessity for the implementation of circular-oriented construction practices that prioritize recycling and the reduction of waste, aiming to improve the efficient use of resources in building design and construction. Using a real non-residential building demolition as a case study, the paper outlines specific steps to determine building materials and document demolition procedures. This study presents a variety of selective demolition strategies, with consideration of end-of-life scenarios for materials, including reuse, recycling, and downcycling. The analysis highlights the complexity of the demolition process, emphasizing the necessity for comprehensive evaluation methodologies. By closing the material cycle and prioritizing reuse and recycling, it is possible to achieve sustainable and long-term value retention of building materials. Additionally, methods such as life cycle assessment and material flow analysis for waste streams are introduced. The environmental impact of the demolition of the “Elementum” office building in Munich was analyzed and the CO2 emissions calculated, in relation to transport distances. Results were presented on the reduction in CO2 emissions due to the elimination of transport to landfill and the associated impact on the Life Cycle Assessment. By considering factors such as resource conservation, energy consumption, greenhouse gas emissions, waste generation and pollution, stakeholders can make informed decisions to mitigate negative environmental impacts.

One-step microwave pyrolysis-H3PO4 activation of woody biomass: Insight into the product characteristics and life cycle assessment

Microwave-assisted pyrolysis coupled with chemical activation was developed to prepare the woody biomass-derived activated carbon (AC) with desirable structural characteristics. In this study, sawdust powder was impregnated with phosphoric acid before being microwave-pyrolyzed to achieve AC. The utilization of microwave greatly enhanced the transformation of volatiles into gaseous components, and the yield of char increased when phosphoric acid accelerated the secondary polymerization of volatile matters. Microwave-induced activation may alter the interaction between activator and sawdust-derived organic species, enriching the categories of oily components. The char originating from microwave-activation treatment has a high graphitization degree, exhibiting superior thermal stability and hydrophilic property. Moreover, one-step microwave-activation approach increased specific surface area (978.2 m2g−1 versus 13.0 m2g−1 in conventional pyrolysis) and improved the formation of porous structure. The life cycle assessment analysis revealed that microwave-activation technique had a low environmental impact due to enhanced heating efficiency and reduced energy consumption.