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Biodiesel is one of the ideal options, considering it is a renewable, biodegradable, non-toxic, environmentally friendly fuel with low pollutant emission. However, biodiesel encounters challenges, mostly connected to its high manufacturing costs, that hinder its continued development and advancement. Focusing on more affordable and environmentally friendly inputs, such as suitable and abundant feedstock and efficient catalysts, is crucial. This paper aims to summarize the literature on biodiesel production and life cycle assessment (LCA) studies, critically review the catalyst and oil feedstock employed, and the findings of the LCAs, focusing on spotting prospective low-cost feedstock sources. Furthermore, an overview of recent LCA-related works applied in various biodiesel processes incorporating various catalysts and oil feedstock was evaluated. The application of LCA and its environmental impacts in biodiesel production was discussed and summarised in table form. The importance of using a sustainable and favorable approach could result in cost-efficient biodiesel production. Additionally, the advantages and limitations of the LCA in biodiesel production have been discussed. Last, the status and challenges of LCA in biodiesel production are covered. The findings of using cheaper feedstock are expected to inspire future studies and help industry professionals develop sustainable biodiesel production. • A comprehensive review of LCA framework and biodiesel process technologies were covered. • LCA of biodiesel production using various catalysts and oil feedstock was reviewed. • Challenges and status were discussed for sustainable biodiesel production. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) and hydrogen (H 2) present substantial feedstock potential for advancing sustainability in the chemical industry. In this paper, a new integrated system is proposed consisting of four subsystems, including an ICT-OEC six-step Cu–Cl cycle, a CO 2 capture using monoethanolamine (MEA), an ammonia production unit, and a methanation unit. The simulation of these subsystems was carried out using Aspen Plus software. Based on literature indicating a 3-step Cu–Cl cycle producing 125 TPD of hydrogen, comparative simulations of a similar-capacity six-step Cu–Cl cycle were conducted for the current analysis. All related values correspond to it. Converting CO 2 into methane and nitrogen into ammonia holds great promise in reaching the net-zero target and fostering sustainability. A comprehensive cradle-to-gate Life Cycle Assessment (LCA) investigates the environmental impacts of ammonia and methane production using green hydrogen and CO 2. Significantly, the utilization of renewable energy sources such as nuclear, wind, and hydropower in the CO 2 refinery process generates a net negative Global Warming Potential (GWP). It was noted that the GWP value of the electrical grid could increase significantly, reaching up to 370,000 kg CO 2 eq., particularly when producing 23,277.2 kg/h of ammonia and 2141.71 kg/h of methane at a hydrogen consumption rate of 5211 kg/h (125 metric tons of H 2 per day). The significant environmental impact of the CO 2 refinery process is notably influenced by the choice of electrical grid mix as the energy source. However, in the case of photovoltaics as an energy source, the value of 0.517 kg sb eq, surpasses that of the electrical grid mix. However, nuclear energy emerges as a particularly low-GWP impact, with values of −4190 and −4140 CO 2 kg eq. for the 3-step and 6-step Cu–Cl cycles, respectively. The findings suggest that the CO 2 refinery process generates a carbon credit in both scenarios. Based on the findings of this study, policymakers have a basis for developing effective strategies to address and alleviate environmental impacts. [Display omitted] [ABSTRACT FROM AUTHOR]

Additive Manufacturing has revolutionized manufacturing processes, offering design flexibility and advances in various applications. The integration of lattice structures into lightweight designs has attracted attention due to their ability to optimize properties such as stiffness, strength and energy absorption. This paper explores the trade-off between mass reduction and productivity while evaluating the environmental sustainability of lattice structures manufactured with Laser-based powder bed fusion for metals Using Life Cycle Assessment, two design variants for an automotive component are compared: a topologically optimized version with a solid bulk section, and a second design with lattice structures for additional weight reduction. Experimental measurements and a detailed analysis of the laser strategy were performed to build the Life Cycle Assessment inventory. The integration of lattice structures allowed a weight reduction of 6 %, but resulted in a significant decrease in productivity and a higher environmental impact. Surprisingly, lattice geometries, often perceived as green solutions, can have negative sustainability implications due to longer manufacturing times and impact of auxiliary equipment. Successful implementation of environmentally sustainable designs requires a balance between mass reduction and productivity while addressing potential environmental consequences. [ABSTRACT FROM AUTHOR]

Brazil is the world's leading charcoal producer, mainly used as an energy source and reducing agent for iron ore in the pig iron and steel industry. Despite its vast production, much of the Brazilian charcoal production remains low-tech and inefficient, with limited utilization of by-products. To address potential environmental impacts, promote a circular economy, and reduce energy waste in the charcoal production chain, this study presents the benefits of using wood carbonization by-products through a Life Cycle Assessment (LCA). The analysis was performed by comparing four scenarios: i) Current wood carbonization; ii) Wood carbonization with combustion of non-condensable gases; iii) Wood carbonization with energy recovering of non-condensable gases for electricity generation; and iv) Assessing the utilization of insoluble tar and biomass waste for generating additional electricity, and the use of Pyroligneous Extract (PE) in eucalyptus cultivation. The results demonstrate that by-product utilization prevents energy waste, with an estimated potential to generate 0.19–0.26 MWh per ton of charcoal in Scenarios 3 and 4. Furthermore, 3.3 t of CO2 eq./t of charcoal are sequestered from the atmosphere, and Scenarios 2, 3, and 4 can increase this amount by 5.06%, 6.7%, and 0.48%, respectively. This paper introduces an innovative assessment of PE utilization during eucalyptus cultivation, resulting in a 6.16% reduction in greenhouse gas emission and a 46.98% decrease in abiotic resource consumption, attributed to PE's potential to partially reduce pesticide consumption. [Display omitted] • Photochemical Oxidation is the main impact category due to CO emissions in carbonization kilns. • Potential to generate 0.19–0.26 MWh of electricity per ton of charcoal through by-products utilization. • Forest residues and insoluble tar increase electricity generation potential by 36%. • Charcoal by-products offset GHG emissions from 14 to 203 kg/ton of charcoal. • Pyroligneous Extract use leads to 6% lower GHG emissions and 47% decrease in abiotic resource consumption. [ABSTRACT FROM AUTHOR]

By 2050, food production's environmental impacts are projected to double without intervention. Crucial changes in dietary habits are needed, and seafood can be pivotal. The focus in calculating burdens using life cycle assessment (LCA) indicators has shifted towards exploring interconnections within the Water-Energy-Food (WEF) nexus. Addressing this evolution, this manuscript has applied an innovative methodology to calculate a WEF nexus index (WEFni). This index seamlessly integrates both environmental and nutritional profiles across diverse case studies involving fisheries, aquaculture, and processing production systems in the European Atlantic area. The results showed that when it comes to fishing, purse seine fishing obtained the highest score (99%). For the aquaculture activities, seafood (>73%) obtained better results than fish farming. About processing treatments, freezing (>79%) has lower environmental loads than canning. In addition, a sensitivity analysis was carried out according to a caloric- and edible-based functional unit as well as the modification of the weighting factors assigned to each footprint, in which important variations were reported in the WEFni of most case studies. Consequently, although the methodological guidelines supporting the WEFni have great potential to serve as an ecolabeling tool, certain aspects need to be re-evaluated. On the other hand, it could be interesting to include the potential biodiversity loss, as well as other socioeconomic indicators, with the purpose of considering a more sustainability criteria. Finally, the contribution of this paper to the food industry literature is of paramount importance, as it represents a first step towards holistic assessments and easy-to-understand ecolabelling processes that can promote sustainable production and consumption. • A joint analysis of environmental burdens and nutritional profiles was carried out. • The functional unit and weighting factors were modified in a sensitivity analysis. • WEFni revealed: purse seine high score, shellfish outperformed fish farming, and freezing had lower burdens. • The procedure followed has potential applicability to other products. • Further indicators are needed if a holistic analysis of sustainability is to be made. [ABSTRACT FROM AUTHOR]

This paper reviews the published research pertaining to the use of superheated steam for carbon fibre reinforced polymer (CFRP) composite reclamation. Superheated steam has been used for this purpose for around a decade and was initially investigated to prevent the degradation of reclaimed fibres, which occurs during the oxidative char removal step of most pyrolysis-based reclamation techniques. The review evaluates the various methodologies employed with particular focus on the physical, mechanical, and chemical properties of the reclaimed fibres, and the environmental impact of using superheated steam for carbon fibre reclamation as determined by life cycle assessment. Superheated steam studies report recovering carbon fibres with retained tensile moduli of around 90%–100% and tensile strengths of 65%–100% when compared to virgin carbon fibres, however, when optimised it is shown that carbon fibres can be recovered with no loss in stiffness and strength. Most studies are still at laboratory- or pilot-scale, however, several companies are collaborating with researchers to investigate the potential of this reclamation method on a larger scale. Early analysis on the energy use of carbon fibre reclamation using superheated steam shows that energy savings of 25% could be made by recycling CFRP waste using superheated steam and using the recovered carbon fibres to displace virgin carbon fibres rather than landfilling and incinerating this waste. • Review of the developments pertaining to superheated steam use for carbon fibre reinforced polymer reclamation. • Superheated steam reclaimed carbon fibres retain tensile strengths of 65%–100% and tensile moduli of around 90%–100%. • Review of the life cycle assessment of superheated steam-based carbon fibre reinforced polymer reclamation. • Examples of superheated steam reclamation processes entering the pilot-plant/industrial phase. [ABSTRACT FROM AUTHOR]

In the Chemical Process Industry (CPI) only hydrogen production from steam methane reforming produces more greenhouse gas emissions than light olefins production. Various solutions have been proposed to reduce the CO2 emissions from olefins production. It is not clear which solution is best, particularly when you consider other sustainability factors. In this paper we report the results of our cradle-to-gate life cycle assessment (LCA) of three highly promising solutions: a so-called low-emission steam cracking furnace, the electrically driven RotoDynamic reactor (RDR), and a blue hydrogen-fired furnace. Life cycle inventory data is obtained from a first principles model for steam cracking, validated with industrial data, and combined with data obtained from process simulation. Our study shows that if the electrical supply is grey then the RDR-based cracking process has a 41% higher impact on climate change than the reference base case, a conventional plant with state-of-the-art furnaces. The low-emission furnace is only 7.2% higher. When using a mixed electrical grid, like Belgium's, the climate change impact for the RDR is 1.5% higher and the low emission furnace is 6.6% lower. With a grid that uses fully renewable power generation the RDR solution is an impressive 27% lower than the base case and the low-emission furnace 17% lower. We also analysed the impact of firing the furnaces with blue hydrogen from (a) a conventional steam-methane reformer and (b) an innovative gas-heated reformer: both (a) and (b) using carbon capture and storage (CCS). The climate change impact is reduced by 8% and 18% respectively compared to the base case. Since the blue hydrogen solution uses very little electricity, the climate change impact is insensitive to the method of electrical power generation. • Prospective LCA of 3 promising steam cracking concepts has been performed. • RotoDynamic reactor results in 27% lower carbon footprint if powered by a "green" grid. • Low-emission furnace has a 16% lower carbon footprint in a "green" grid. • Low-emission furnace is preferable if the case of "grey" or mixed grid. • "Blue" hydrogen combustion allows a reduction of carbon footprint up to 18%. [ABSTRACT FROM AUTHOR]

Tourism places pressures on the environment through the services provided (accommodation, food, leisure activities, and transport), meanwhile it is particularly vulnerable to global warming as climate is a crucial component of destinations' attractiveness. As a result, research focusing on the impacts of tourism has increased significantly. Practitioners consult a plethora of frameworks and publications to environmentally assess tourism but none of the existing guidelines provides specific recommendations making difficult to obtain reliable results that can be properly replicated and compared. This paper discusses the use of Footprint family indicators in tourism through a review of studies that measure the Water, Carbon, and Ecological Footprint of tourists. Results show a lack of specific data, and an absence of consensus about the system boundaries and methodologies used for calculation. Food production and transportation are the main drivers of environmental burdens. The Footprint indicators help to understand the trade-offs between environmental effects which can be used to prioritize sustainability efforts in the tourism industry. Additionally, this study presents a critical analysis of the influence on the trip's Footprint of the services provided to different rated tourism experiences (high, medium, and low rated) and offers a reflective comparison on the pressure exerted by visitors and the local population. • Tourism Footprint studies lack trustworthy datasets due to gaps in specific data. • Lack of consensus on boundaries in tourism Footprint studies hinders result comparison. • Tourism Footprint studies generally ignore end-of-life environmental impacts. • High-rated vacations impose the highest environmental burdens. • Tourists exert more pressure on natural resources and ecosystems than residents. [ABSTRACT FROM AUTHOR]

In recent years, sustainability concerns gained traction in the scientific literature on cleaner production, as well as in industry and application. In this regard, the circular economy (CE) is intended to contribute to the current ecological transition, providing economic advantages and preserving global society for future generations. CE initiatives have been implemented in recent decades to offset the harmful environmental consequences of supply chain operations. Notably, CE strategies can be applied at different supply chain levels, in product design, manufacturing, transportation, consumption, and disposal. Using the Life Cycle Assessment (LCA) methodology, the present research examines a case study from the Italian egg industry, highlighting the environmental benefits and social implications of initiatives supporting CE (i.e. the use of recyclable and biodegradable packaging and the adoption of a short supply chain). The implementation of those CE strategies shows a 22% reduction in Kg CO 2 -eq emissions, proposing that circular concepts should be incorporated into sustainable supply chain management. Notably, this paper analyses the environmental implications of the intermediate phases of the egg industry supply chain. Both primary and secondary data have been collected. We collected primary data via direct interviews with companies' managers throughout all the study phases. As a result, despite various external issues affecting the company decisions, the paper shows that incorporating CE strategies may deliver demonstrable environmental benefits for the companies. In addition, other strategies that should be adopted in the long term have also been outlined. Finally, the implications that sustainable behaviours of the companies can entail have been examined. [ABSTRACT FROM AUTHOR]

In machining processes, there are contradictions between high efficiency and environmentally-friendly machining. This indicated that there is a major potential for sustainable machining to both increase efficiency and protect ecological balance. For this, the employment of effective methods has become imperative to reduce resource use. In this way, the use of analysis and optimization tools to select the tool material, cutting parameters, cooling/lubrication conditions, etc., will be a benefit for minimizing waste without sacrificing efficiency. In the literature, researchers have used various methods to reveal the requirements of sustainability. However, reaching the concept of sustainable machining by using one more than technique confuses the readers. Therefore, it was deemed necessary to present and discuss the current methods, models and analyzes in a comprehensive review paper. In this context, this paper reviewed the previously published works, especially focusing on sustainability and energy consumption modeling methods in machining operations. At the end of the study, it was seen that LCA provides a systematic and quantitative view of the system and thus can act as a decision support tool. Moreover, it can give an idea to the manufacturers about the improvement of the process and the areas of innovation. However, the method has several disadvantages such as relatively expensive and specific software, obtaining inventory data, impractical to use, time-consuming and requires large amounts of data. Various mathematical models and algorithms have been developed to deal with the complex situations and offer a more practical use compared to LCA. However, it is difficult to state that clear results have been achieved thanks to these models. It was seen that in complex machining processes, only approximate results can be found with models, which leads to questioning the reliability of the models. [ABSTRACT FROM AUTHOR]

Fly ash (FA) and recycled coarse aggregate (RCA) have been extensively studied, aiming to improve the sustainability of concrete. The biomineralisation method has also been researched to enhance the performance of concrete. However, introducing FA and RCA may decrease the strength of concrete, and the biomineralisation method may create extra environmental impact (EI) due to the production of bacteria and corresponding chemical agents. It is hard to directly judge the influence of these methods on the sustainability of concrete. This paper proposes to explore the sustainability of concrete with FA, RCA, and biomineralisation methods by life cycle assessment. Six scenarios were established, and Six EI categories of the six scenarios were quantified. The quantified EI values considering their corresponding strength were obtained and compared. The results showed that: using FA decreased EI, using RCA showed a limited effect on decreasing EI, the biomineralisation method significantly decreased EI, and using the treated RCA increased EI due to its high consumption of chemical agents in the treating procedure. In summary, biomineralisation enhanced FA concrete performance is recommended to substitute traditional concrete widely after comprehensively comparing sustainability, workability, strength, and durability. Finding more sustainable calcium sources and nutrition can further improve its sustainability. [ABSTRACT FROM AUTHOR]

In this paper, the results of a sustainability assessment for the study of the reuse of un-melted feedstock powder in Directed Laser Deposition are reported. Ti6Al4V ELI powder was employed as material for the study and the un-melted powder was collected and reused as raw material for subsequent cycles of deposition. A total of three deposition cycles were completed and data for a Life Cycle Assessment were compiled. From the experimental work results, the un-melted powder suffered minimal changes that did not affect the critical characteristics analysed. The Life Cycle Assessment showed that reusing the powder, and consequently reducing the total mass of raw material consumed, resulted in significant environmental benefits. All the categories considered saw approximately a 15%–25% environmental impact reduction when reusing the powder as compared to a scenario when only virgin material is used. Most of the environmental footprint was seen in the production of the powder as compared to the transportation and manufacturing stages. The production phase, when reusing and when using only virgin powder, accounted for 89% and 95% of the total environmental impact respectively. This meant the environmental benefits due to the lower mass of powder used far outweighed the increase in water and energy required for the powder reuse process in the manufacturing stage. Thus, feedstock powder reuse in Directed Laser Deposition process is seen to have a significant environmental benefit as compared to the usage of virgin powder alone. [ABSTRACT FROM AUTHOR]

In this paper, the dominance of the physical effects of ultrasound (US) pretreatment in improving the delignification of wheat straw at a 1:20 solid/liquid (biomass/water) ratio is reported showing low-frequency/high power (25 kHz, 2 or 3 kW) as preferred conditions. The sonochemical pretreatment with alkali was identified as an optimal method to make the cellulose more susceptible to further enzymatic hydrolysis, thereby increasing the yield of soluble sugars. Previous bench-scale studies have shown that US pretreatment has a positive effect on delignification, nevertheless this has not yet been demonstrated on a larger scale. The objective of this study was to demonstrate the effectiveness of US pretreatment for wheat straw delignification from lab to semi-industrial scale (40 kg biomass) in terms of sugar yield and energy efficiency. A 59.2% of lignin removal was recorded after the cavitational treatment of wheat straw with a subsequent 68 ± 5.7% yield in terms of enzymatic hydrolysis (52.6% glucose, 42.9% xylose and 4.5% arabinose). It was demonstrated that the positive effect of US alkali pretreatment of wheat straw on sugar yield was due to a combination of factors, including (i) an easier accessibility of the biomass carbohydrate network to enzymes due to the increased wheat straw porosity, (ii) the partial removal of lignin, which increases the relative proportion of carbohydrates in the treated biomass, and (iii) the disordering (amorphization) of the cellulose structure, which promotes carbohydrate hydrolysis as well as saponification of the acetyl groups in the hemicellulose. With respect to the Life Cycle Assessment (LCA) and the Cost Benefit Analysis the US pretreatment process herein reported was compared to an alternative Steam Explosion pretreatment. The results of the LCA analysis showed, that for all five environmental categories (energy consumption, global warming potential, water and fossil depletion, and the land occupation) the US pretreatment has advantages in comparison with the standard industrial Steam Explosion pretreatment. [Display omitted] • Residual biomass as sustainable source for the production of fermentable sugars. • Ultrasound as alternative technology for the scalability of biomass conversion. • First study on ultrasound pretreatment of wheat straw at semi-industrial scale. • First study on enzymatic hydrolysis of pretreated biomass at semi-industrial scale. • Life Cycle Assessments of wheat straw valorization at semi-industrial scale. [ABSTRACT FROM AUTHOR]

Municipal waste management, especially in developed countries, has a significant impact on the environment and humans that need to be quantified and mitigated. This study aims to investigate and compare the environmental impact and occupational risks of the following three municipal waste collection methods in Italy: street bins, door-to-door collection, and a smart bins system. Six waste categories (paper, plastics, glass, metal, organic materials, and residual waste) are analysed. Environmental performances are calculated by the life cycle assessment (LCA) and material and flow analysis (MFA) methodologies. The ergonomic analysis is based on direct observation of municipal waste collectors and the application of standard assessment methods as RULA, NIOSH, and Snook Ciriello. show that the smart bins collection method is environmentally more effective in all the impact categories considered, thanks to the better quality of collected waste. The residual waste flow directed to landfills has a lower value in the case of smart bins (36.63%) in comparison with door-to-door (52.90%) and street bins (89.56%). The use of smart bins allows higher environmental benefits, passing for the Climate Change impact category from −2.80E+01 kg of CO2eq. of the door-to-door system and −2.74E+01 kg of CO2eq. of street bins to −7.13E+01 kg of CO2eq. of smart bins. Regarding the transport phase, the smart bins system determines a reduction of the impact of about 60% if compared with the door-to-door system for all the impact categories considered. On the other hand, acceptable occupational risks result in street and smart waste collection methods, while poor ergonomics conditions are observed during the door-to-door collection. Containers lifting and emptying are the most critical tasks. [Display omitted] • Smart technologies in urban waste management determines benefits in environmental terms. • Smart technologies in urban waste management preserves the operators' health condition. • Analysis of environmental impact and occupational risk of municipal waste systems. [ABSTRACT FROM AUTHOR]

The soil is not always suitable or competent to support a direct shallow foundation in construction. In many cases, to avoid costly deep foundations, it is indicated to replace, improve, or reinforce such soil. This paper focuses on evaluating the contribution to sustainability between different soil improvement techniques and the outcome of their application to the foundation of a single-family house as an alternative to the one built. The life-cycle performance in sustainability is compared between the baseline design (without intervention), backfilling and soil compaction, soil-cement columns, rigid inclusion of micropiles, and nailing of precast joists. To characterize sustainability, a set of 37 indicators is proposed that integrate the economic or environmental aspects of each design alternative and its social impacts. A sustainability ranking is obtained for the different alternatives based on the ELECTRE IS method for multi-criteria decision-making (MCDM). The sensitivity of the obtained results is evaluated against different MCDM methods (TOPSIS, COPRAS) and different criteria weights. The evaluation provides a cross-cutting view, comparing the ability and reliability of each technique to prioritize the ground consolidation solution that best contributes to the sustainability in the design of a building's substructure. • Evaluation of soil consolidation techniques for a single-family house's foundation. • A deep foundation is compared to four alternatives that consider soil improvement. • 37 indicators characterize the sustainability of substructure in residential buildings. • The aggregation of the different sustainability criteria is applied in 3 MCDM methods. • Nailing precast joists into the ground achieves the best sustainability result. [ABSTRACT FROM AUTHOR]

Toe cap for safety shoes is an extremely important protective equipment to prevent injuries caused by falling objects. It can be considered that more than 600 millions toe caps are disposed every year, without the possibility of disassembly them from the shoes. This represents a serious concern and sustainable solutions must be found to decrease the weight on the environment generated by the safety shoe market. In this context, a valid answer can be found in the use of carbon fiber prepreg scraps that can be employed in a circular economy approach, avoiding their disposal in landfill or through incineration, to produce certified and light toe caps. Unfortunately, carbon fiber scraps are associated to high production cost and environmental impacts (mainly due to the high energy requirement for the manufacturing of carbon fiber). Thus, the development of a zero-waste system is mandatory to achieve a conscious use of the resources. In this paper, a reclaim method for prepreg scraps and the relative manufacturing process for toe caps are assessed from the environmental point of view. The impacts are compared with those of a traditional process based on a thermoplastic material (Polycarbonate). Results demonstrate that the reclaim process is extremely sustainable due to the low energy requirements. However, some improvements of the manufacturing process are necessary to make toe caps realized with prepreg scraps more sustainable than the traditional ones. [Display omitted] • Environmental comparison between two different manufacturing methods for safety shoe toe caps. • Evaluation of a reclaim process for carbon fiber composite prepreg scraps. • The reclaim process for prepreg scraps is more sustainable than other recycling methods for composites. • The traditional process for manufacturing toe caps is more sustainable than the innovative reclaim method in the evaluated case study. However, to make the latter more sustainable, it is necessary to increase the service life of the molds. [ABSTRACT FROM AUTHOR]

To assess the potential benefits and impacts of circular bio-based buildings, life cycle assessment (LCA) is a valuable method to identify systems or elements that have negative effects on the environment during the whole building life. To achieve low carbon buildings, LCA should be performed during the early design stage of buildings, to influence the choice more environmentally led solutions. In this paper, LCA was used during the early design stage of a circular bio-based wall panel prototype to guide the decision-making process for the improvement of the panel's design. A cradle-to-cradle life cycle assessment was performed to compare the circular wall panel against other prefabricated wall panels, assembled using common construction materials and techniques. Results indicated that a circular design and some bio-based materials are not always synonymous with low environmental impacts. The first iteration of the circular panel had a GWP 100 of 231.1 kgCO 2 e/m 2 in the base case with one life cycle. This compared to 116 kgCO 2 e/m 2 and 181 kgCO 2 e/m 2 for the timber and steel frame panels respectively. The LCA was able to identify materials and components which contribute most significantly to the panels environmental impact. The identification of highly impacting materials in the initial panel design, LCA was used to guide the re-design of the circular bio-based panel. From investigating alternative materials for the insulation, cladding and internal substrate the environmental impact of the new design of the circular panel was lowered to 122 kgCO 2 e/m 2. This research demonstrates how LCA can be used in the design process to reduce carbon emissions in circular buildings by using bio-based materials. [Display omitted] • LCA was used to improve sustainability of a prototype of circular bio-based wall. • Scenario's development and comparison with common walls help identify hot spots. • Circular wall GWP is up to 95% higher than conventional walls (116 and 181 kgCO 2 /m2). • LCA identified lower impacting materials to reduce GWP of circular bio-based wall. • The circular panel GWP was reduced to 122 from 231 kgCO 2 /m2 of the initial design. [ABSTRACT FROM AUTHOR]

Despite the substantial effort on almost all levels during the last decades, the buildings' renovation rate needs to be at least doubled from the current 1% to meet ambitious energy efficiency goals. In the same way, the energy-intensive material replacement did not reach yet the desired grade in terms of sustainability measures and outlined goals heading to a low-carbon economy. This paper summarizes principles of sustainable development together with the current methodological framework relevant to the civil engineering and construction industry. The main part is devoted to the identification and understanding of principal factors preventing faster adoption of energy efficiency measures. High initial financial costs, investment risk over a long-term period, poor acceptance of sustainable measures, lack of information, and limited methodological framework for a reliable evaluation of environmental projects with the intergeneration context or understanding of externalities of human activities are identified as the main barriers to the sustainable building retrofits. These barriers are closely related each other and can be merged into several groups according to the stakeholders or scientific disciplines to amplify their primary impact. Notwithstanding, solution strategies based on narrow boundary conditions and limited multidisciplinary approach prevent substantial advances towards the sustainable building sector. In this regard, the major obstacles preventing the achievement of energy efficiency goals can be remedied by interdisciplinary cooperation. • Lacking multidisciplinary approach hinders sustainable measures adoption. • Limited public acceptance prevents a stronger political commitment. • Methods of social measures need to be studied for decision support. • Sustainable building industry transition is not a technical issue only. [ABSTRACT FROM AUTHOR]

• An integration model for biomass to methanol supply chain is built. • Using an agent-based simulation–optimization is recommended in analyzing and reporting results. • Two different technological pathways of producing methanol from biomass are benchmarked. • Major decision making is included in the agent-based simulation–optimization model. • Methanol from biogas is more favorable than gasification technology. Methanol is a key product in the chemical industry, not only for producing other higher economic value chemicals, but also serves as a source of renewable energy that can substantially reduce carbon emissions. However, limited data are available on methanol total supply chain costs that consists of production, biomass cost, investment cost and the efficiency of the conversion processes. This paper recommends using an agent-based simulation–optimization in analyzing and reporting results by system elements (techno-economic assessment) or unit processes (life cycle assessment) as well as by the overall product system, of methanol supply chain. Major decision making are included in the agent-based simulation–optimization model to evaluate methanol synthesis pathways. This evaluation includes biomass and methanol ordering policy, capital budgeting during the lifetime of the methanol supply chain, carbon emissions per metric ton of methanol with specific focus on contribution to Indonesia Gross Domestic Product. The principal results obtained from the agent-based simulation show a better conversion technology pathway that leads to lower carbon emissions, higher internal rate of return, shorter payback period, and less price sensitivity of the methanol supply chain. The article proposes methanol from biogas as the chosen conversion technology pathway by considering its capability of sequestering carbon dioxide from bio-digester and lower capital investment, as well as its economic attractiveness to methanol production investors. [ABSTRACT FROM AUTHOR]

• Impact-based water footprint of rolled steel production is first performed. • Fossil energy footprint and carbon footprint are evaluated by using LCA. • Maritime transport, iron power and direct emissions are major contributors. • Adjustment of industrial structure is essential for carbon mitigation of steel industry. The Iron and Steel Industry (ISI) is a difficult-to-mitigate sector that has considerable contributions to energy consumption, water pollution, and CO 2 emissions. Despite broad interest in energy consumption and CO 2 emissions generated by steel production, there are few impact-oriented Water Footprint (WF) assessments of steel production. This study evaluates the water, carbon and fossil energy footprints generated from rolled steel production on the basis of life cycle assessment. Key contributors attributing to those environmental impacts are also identified so as to explore their potential mitigation. Using the Monte Carlo model, an uncertainty analysis is conducted with the aim of providing reliable results for decision-making. Results show that the impact per ton China's rolled steel production has on global warming, human health, ecosystem quality, and resources is 4.40 × 103 kg CO 2 eq (GSD2 = 1.24), 4.15 × 10-3 Disability Adjusted of Life Years (DALY) (GSD2 = 1.31), 7.08 × 10-5 Species·yr (GSD2 = 2.04), and 4.39 × 104 MJ (GSD2 = 1.28), respectively. Global warming and freshwater ecotoxicity is the dominant contributor to the damage impact on human health and ecosystem quality, respectively. Results also show that the transport (freight ship) of raw materials and the production of iron powder are the two main contributors to the overall impact on the environment that rolled steel production has. Several policy recommendations are proposed in this paper, which focus on adjusting the steel industry's industrial structure, promoting the national-level carbon emissions trading in the ISI, promoting international cooperation, and improving public awareness of green and low-carbon development. Such policy recommendations provide decision-makers with valuable insights, which thus allow them to prepare the appropriate mitigation policies. [ABSTRACT FROM AUTHOR]

Agent-based models (ABMs) have been adopted to simulate different kinds of complex systems, from biological systems to complex coupled human-natural systems (CHANS). In particular, when used to simulate man-managed systems, they allow considering human behavioural aspects within the modelling framework. On the other hand, environmental Life Cycle Assessment (LCA) has become an acknowledged tool in research, industry and policy to assess systems' environmental sustainability. More recently, LCA is being applied to assess the potential environmental impacts of large scale policy actions (e.g., actions to combat climate change). This paper describes the application of a coupled ABM-LCA model to simulate cropping activities in the Grand Duchy of Luxembourg. The ABM considers farmers' proneness to risk, which was assessed via a naïve Bayesian model trained with the results of a survey distributed to the farmers of the study region. The goal of the study is to assess the effects of the agents' interactions, that can take place in a farmers' social network, on the agricultural activities. Geographic Information System (GIS) information, national statistics and naïve Bayesian model are used to parameterize agents' behaviour and interaction rules. We believe such assessment is necessary for the successful design of public adaptation strategies and subsidy schemes since governmental adaptation actions are needed to reduce emissions due to agricultural activities. Two scenarios (with different levels of farmers' environmental awareness) were simulated. The results show that the mean and variance of the distribution of farmers' environmental awareness change due to the effect of the interactions and, as a consequence, farmers' long-term decisions concerning agricultural activities are affected. This is reflected in the environmental impacts generated by such activities. [Display omitted] • A tight coupling between an ABM and a LCA module has been implemented. • Naive Bayesian model is a viable instrument to estimate farmers' proneness to risk. • Farmers' social network and interactions have been simulated using different criteria. • Farmers' green consciousness distribution slightly influences the simulated LCIA results. • Cumulative environmental impacts can be reduced via selected set of rules for agents. [ABSTRACT FROM AUTHOR]

Since the establishment of the Sustainable Development Goals, great concern has arisen on how to diminish the impacts that result from construction activities. In such context, Modern Methods of Construction (MMC) rise as a powerful way to reduce life cycle impacts through optimizing the consumption of materials. This paper focuses on the sustainability assessment of different modern construction techniques applied to concrete structures of single-family houses. The life cycle performance in terms of sustainability is compared between a conventional reference design, a precast design, a lightweight slab design with pressurized hollow discs, and a design based on double-wall structural elements. The sustainability is assessed through a set of 38 indicators that address not only the economic and environmental response of the designs, but also their social impacts as well. Five of the best known Multi-Criteria Decision-Making (MCDM) techniques (SAW, COPRAS, TOPSIS, VIKOR and MIVES) are applied to derive the life-cycle performance of each design into a single sustainability score. Since there is no consensus on which MCDM method works best in sustainability assessments, a Global Structural Sustainability Index (GSSI) combining and weighting the above is proposed here to aid the analysis of the results obtained. The results show that consideration of the three dimensions of sustainability leads to balanced designs whose preference need not coincide with those derived from each one-dimensional life cycle approach. • A traditional baseline solution is compared with three non-conventional MMC alternatives. • 38 indicators characterize the sustainability of a home's structural envelope. • GSSI index uses five MCDM techniques to aggregate the different sustainability criteria. • Methodology seeks to reduce the economic, environmental and social impacts on structures. • Concrete slab, lightened with pressurized discs, achieves the best sustainability result. [ABSTRACT FROM AUTHOR]

The Absolute Environmental Sustainability Assessment (AESA) framework is an emerging field in environmental research that aims at comparing the estimated environmental burden generated by a system on its life cycle to the carrying capacity that can be assigned to this system, i.e. the amount of impacts that it can cause without causing unacceptable impairment of ecosystem functional integrity. This paper aims to expand the AESA framework to multifunctional systems. We applied it to a simplified case study based on municipal solid waste (MSW) management, since such a system provides several functions such as reduction of the quantity and toxicity of waste, production of heat, electricity or secondary materials. Thus, we could identify the specific questions that arise from this multifunctionality in the context of AESA. Based on the theory of AESA, we developed a four-steps methodology to identify the most significant impacts at both system and global scales. That methodology consisted of (step 1) quantifying the impacts of the studied system with conventional Life Cycle Assessment (LCA) followed by a normalisation step; (step 2) quantifying the number of beneficiaries from this system; (step 3) identifying impact categories for which the studied system causes significant impacts and global carrying capacities are exceeded; and (step 4) quantifying the Assigned Carrying Capacity (ACC) of the system, based on a utilitarian perspective and its contribution to the satisfaction of human needs. We then applied this methodology to a simplified model of the MSW management implemented in the Lyon Metropolitan Area (France), as a proof of concept. Steps 1 to 3 helped elaborate a hierarchy of impact categories, highlighting which ones should be reduced in priority. Step 4 required significant knowledge about how the functions of the studied system were used, both directly and indirectly, to satisfy human needs. We used national Supply and Use Tables and several simplifying hypotheses to that end. We also tested different sharing principles based on macroeconomic indicators. This variety of sharing principles helped refine the hierarchy developed in Step 3 by identifying which carrying capacities were most certainly exceeded by the studied system. • Applying Absolute Environmental Sustainability Assessment to multifunctional systems • Methodological propositions to quantify system's contribution to human needs • Global and system exceedance of carrying capacities highlight hierarchy of impacts • Life Cycle Assessment of municipal solid waste management as a case study [ABSTRACT FROM AUTHOR]

This paper discusses a novel digital output using mathematical computation of life cycle sustainability assessment for design decisions on systemic holistic sustainability of technical systems. The computational social life cycle assessment (SLCA) combining the supply chain import data and social hotspot database for interacting countries in entire supply chain indicates that self-generation in electricity sector gives savings in community infrastructure (68%), governance (53%), human rights (50%), labour rights & decent work (24%), and health & safety (8%), SLCA categories compared to electricity import scenarios in the UK. The life cycle assessment shows the carbon-efficient energy systems for net zero greenhouse gas emissions (GHG) in increasing order of environmental impacts: hydroelectric, wind, biomass, geothermal and solar (4–76 gCO 2 eq./kWh). The technical and life cycle costing models show that within bioenergy, biomass combined heat and power systems give greater feasibility than microbial fuel cells with a levelized cost of electricity of 0.026 and 0.07 Euro/kWh. TESARREC™ (Trademark: UK00003321198), a novel web-based open-source digital output integrates intrinsic physicochemical, design, operating and systemic characteristics to model and analyse technical systems for sustainability and benchmark/standardise GHG of renewable, biomass and carbon dioxide capture and sequestration strategies for policy directives. [Display omitted] • Advances in mathematical computing and digitalisation for LCSA have been discussed. • Physicochemical-design-operating-systemic influences on technical and LCSA models. • Novel digital platform for a sustainable world: TESARREC™ Trademark: UK00003321198. • Hydroelectric-wind-biomass-geothermal-solar systems analysed for net zero GHG. • Biomass CHP and microbial fuel cell systems technoeconomic models discussed. [ABSTRACT FROM AUTHOR]