Sustainability assessment methods for circular bio-based building materials: A literature review.

Using circular bio-based building materials is considered a promising solution to reduce the environmental impacts of the construction industry. To identify the pros and cons of these materials, it is essential to investigate their sustainability performance. However, the previous sustainability assessment studies are heterogeneous regarding the assessment methods and objectives, highlighting the need for a review to identify and analyse these aspects. Moreover, there is still a lack of studies reviewing the methodological issues and implications of the assessment methods, as well as the current end-of-life scenarios and circularity options for these materials. To address these gaps, this study conducts a systematic and critical review of a sample of 97 articles. The results indicate that Life Cycle Assessment (LCA) is the most frequently applied method, yet most studies are cradle-to-gate analyses of materials. Otherwise, very few studies consider the end-of-life phase, and most of the end-of-life scenarios analysed are unsustainable and have low circularity levels. The analysis also highlights the methodological issues of the assessment methods used, with a particular focus on LCA, such as a lack of consensus on system boundaries, functional units, and databases for facilitating sustainability assessments associated with the use of circular bio-based building materials. Two primary recommendations emerge from the analysis. Firstly, for LCA studies, it is recommended to increase transparency and harmonisation in assessments to improve the comparability of results. Besides, to overcome data availability issues, it is recommended to use data from multiple sources and conduct sensitivity and uncertainty analyses. Secondly, more sustainability assessments (including the three pillars) considering the whole life cycle with more sustainable end-of-life scenarios and circularity options for these materials should be conducted.

Status and barriers to circular bio-based building material adoption in developed economies: The case of Flanders, Belgium.

Circular bio-based building materials (CBBMs) provide a potential solution to reduce the climate impacts of buildings and offer opportunities to transition the construction industry to a circular model. Promoting the use of these materials can also bring economic, environmental, and social benefits from valorising biowaste and by-products from other sectors. Despite their potential, CBBMs have not received sufficient attention globally, and their adoption is hindered by various barriers. However, it is unclear what the CBBMs' use status is, what adoption barriers exist, how these barriers interact, and what should be done to address them. This study addresses these knowledge gaps through a systematic study using mixed methods to investigate the adoption status and barriers to these materials in developed economies by using a specific case analysis in Flanders. The data analysis results show that hemp-based, cork-based, and straw-based materials are the most used, while the market for CBBMs is very limited in the region. Twenty-three potential adoption barriers were identified and selected from the existing literature, then ranked based on their mean scores. The t-test analysis helps to identify 13 critical barriers, which are grouped into five categories, including cost and risk-related barriers, technical and cultural-related barriers, the government's role-related barriers, information and quality-related barriers, and market-related barriers. Among them, cost and risk-related barriers, including "concern about the high initial cost", "risks and uncertainties involved in adopting new materials", and "perception of the extra cost being incurred", are the three most critical barriers to CBBM adoption in Flanders. Kendall's W test shows good consensus among the two expert groups-with and without hands-on experience in utilising CBBMs-in their rankings of the barriers. Meanwhile, the Mann-Whitney U test indicates no statistically significant differences in the ranks of barriers between the two expert groups. The interview results confirm almost all survey results and provide deeper insights into the status and barriers to adopting these materials. Practical and policy implications are discussed based on these findings to inform policy deliberations on promoting CBBMs. This study may also be a good reference for scholars and industry practitioners to better understand issues impacting decision-making towards the adoption of CBBMs in the construction industry.

FLAVIA-LCT - Framework for systematic literature review to analyse vast InformAtion in life cycle thinking studies.

With the increasing interest in Life Cycle Thinking (LCT) applications for assessing the sustainability of processes, products and services, up-to-date syntheses and evidence-based critical outcomes analysis are required to guide future studies and policymakers. The systematic literature review is probably the most suitable approach for highlighting evidence of effects, impacts, and methodological choices, mapping the current knowledge and gaps in LCT fields, including methods such as Life Cycle Assessment, Life Cycle Costing, Social Life Cycle Assessment and Life Cycle Sustainability Assessment. Although several statements and guidelines for health care and ecology disciplines and one checklist for systematic literature review limited to Life Cycle Assessment (STARR-LCA) exist, it is still missing a framework for conducting systematic literature reviews in LCT field. This paper proposes a "Framework for systematic Literature review to Analyse Vast InformAtion in Life Cycle Thinking studies" (FLAVIA-LCT) to assist and guide researchers in structuring the processes of gathering, synthesising, and reporting outcomes from search strategy development to critical evaluation, considering the essential information to be included in a review manuscript. This framework can be used by anyone planning a literature review on one or more LCT methods.

Industrial Symbiosis for Sustainable Management of Meat Waste: The Case of Smilowo Eco-Industrial Park, Poland.

This study presents the developing process of the Smilowo Eco-Park, located in the Notec valley region (Poland), is a part of the biggest Polish agri-food consortium, from its initial small waste management company to its final structure as an eco-industrial park using industrial symbiosis methods. The industrial symbiosis applied in the Eco-park promotes a business model which covers the whole life cycle of the products starting from the plant growing by animal feed preparation, livestock breeding, meat preparations, meat-bone meal production from animal waste, and the use of pig slurry as a fertilizer. The Eco-park model is presented in the form of a system of connected stream flows of materials and energy covering the full lifecycle of products, from cereal cultivation, through the production of industrial feed, and poultry and pig breeding for the production of meat products. The solutions used include the prevention of environmental pollution through the modernization of existing processes, implementation of new technologies, reduction of waste and its reuse, recycling, and recovery of materials and energy, the substitution of raw materials with waste, and thermal treatment of waste and its use as biofuel. This case study allows for analyses of the organizational and technical key strategic activities which enable waste, including hazardous waste, to be transformed into valuable materials and energy. These activities have modified the system of material and energy flows through the value chain to realize the goal of allowing profitable management of waste according to circular economy methods and also indicates methods of supporting modifications of supply chains in terms of implementation of the industrial symbiosis business model according to its relationship with sustainable development, cleaner production, and circular economy models. EIP Smilowo annually utilizes 300,000 t meat waste, produces 110,000 t meat bone meal biofuel, uses 120,000 t of pig manure as fertilizers, produces 460,000 GJ bioenergy, eliminates 92,000 t CO2 emissions.

Life Cycle Assessment and Environmental Life Cycle costing of a unitised regenerative fuel cell stack.

Life Cycle Assessment (LCA) and Environmental Life Cycle Costing (eLCC) are useful methods for evaluating the environmental, energy and economic performances of innovative energy storage technologies. By using these methods, the production process of a small Polymer Electrolyte Membrane Unitized Regenerative Fuel Cell (PEM-URFC) stack has been investigated, aiming to assess its environmental, energy and economic impacts at the early design stage and to identify the contributions of its various components on these impacts. Indeed, the PEM-URFC stack includes Critical Raw Materials that affect the product's sustainability. Results show that the highest contributions are associated with the platinum group metals used for the catalyst and, to a lesser degree, the materials and energy used for the bipolar plates and porous transport layers. However, considering that the datasets for representing the impacts of one of the electrocatalysts (Iridium Ruthenium Oxide) are still missing in LCA commercial databases and literature, a sensitivity analysis is performed assuming its impact to be similar to that of other Platinum Group Metals (PGMs) extracted with them (e.g., Platinum, Nickel, Palladium, etc.). The analysis shows a high difference in results due to data and methodological assumptions, making the assimilation of Iridium Ruthenium Oxide to Rhodium the worst scenario, increasing environmental impacts by 37.54 %, energy impacts by 40.48 % and environmental price by 45.08 %. Moreover, the study identified issues for applying life cycle thinking approaches on URFC devices that must be resolved in future studies (e.g., increase the reliability of catalyst inventory data or improve guidelines on energy storage technologies).

What Is the Relation between Circular Economy and Sustainability? Answers from Frontrunner Companies Engaged with Circular Economy Practices.

The circular economy (CE) concept has become a major interest for companies, promising new business opportunities and a decrease in environmental impacts. Though research on circular business models has recently increased, few scholars have investigated how companies engaged with CE view the connection between CE and sustainability. To address this gap, this paper uses a semi-quantitative survey and semi-structured interviews conducted with companies based in Italy and the Netherlands. Purposive sampling was employed to target firms associated with national and international CE networks, as these companies already engage with CE practices. The survey was distributed online to over 800 firms, of which 155 provided information on their understanding of the CE concept and its relationship with sustainability. The survey results are complemented through findings from 43 interviews with a subset of the survey respondents. The survey answers show that companies view CE as one of the tools to achieve sustainable development, particularly in the environmental domain, where the focus lies on environmentally friendly resource use. Yet, the respondents are less confident whether CE increases economic and social benefits of firms. Interviews show that a majority of respondents position sustainability as the overarching concept. However, most companies advocate that the private sector should strive for both sustainability and circularity, though the distinction between the two concepts in daily business operations seems synthetic and futile to some. These findings provide an important stepping stone for better understanding how firms could apply CE practices to move towards a more sustainable society.

An eco-balance of a recycling plant for spent lead-acid batteries.

This study applies Life Cycle Assessment (LCA) methodology to present an eco-balance of a recycling plant that treats spent lead-acid batteries. The recycling plant uses pyrometallurgical treatment to obtain lead from spent batteries. The application of LCA methodology (ISO 14040 series) enabled us to assess the potential environmental impacts arising from the recycling plant's operations. Thus, net emissions of greenhouse gases as well as other major environmental consequences were examined and hot spots inside the recycling plant were identified. A sensitivity analysis was also performed on certain variables to evaluate their effect on the LCA study. The LCA of a recycling plant for spent lead-acid batteries presented shows that this methodology allows all of the major environmental consequences associated with lead recycling using the pyrometallurgical process to be examined. The study highlights areas in which environmental improvements are easily achievable by a business, providing a basis for suggestions to minimize the environmental impact of its production phases, improving process and company performance in environmental terms.