To assess the environmental sustainability aspects of the IRIS technologies, ex-ante LCAs were carried out, considering a broad range of environmental impact categories like climate, resource efficiency and pollution (emissions to air, soil and water). The overall goal was to quantify the potential environmental effects from upscaling the technologies, in reference to a conventional benchmark considering the potential benefit of the IRIS innovations. A second goal was to identify critical issues of each technology early on, so that risks could be identified and IRIS could steer the development in the right direction. The data availability for the ex-ante LCAs varied greatly for different reasons, so each assessment should be discussed and interpreted separately. Biobased indigo: This ex-ante LCA is based on a recent internal study (2024). The alternative with the highest climate mitigation potential was the 2023 process (50%), followed by the fermentation process (46%) and finally the 2020 process (15%). The overall results from the study indicate that the proposed indigo solution has significant potential for environmental impact mitigation. Microbial dyes derived from atmospheric CO2 :This ex-ante LCA was modelled using specific process data obtained from partner’s pilot production. The results show that the climate impact of the biobased dye (2.5 kg CO2-eq/kg of dye) is 13% lower than the benchmark (2.9 kg CO2-eq/kg of dye). In general, the results indicate that microbial dye can reduce the environmental impact from the dyeing process, and the magnitude of this reduction depends on the synthetic dye chosen as benchmark. Moreover, further reductions could be achieved with further development and upscaling during the project.Upscaling encapsulated heat and light-sensitive biobased colorants: This ex-ante LCA of the encapsulated pigments corresponds to the results from an LCA carried out under the European project BARBARA. The results suggest that the encapsulated pigments could offer a reduction in environmental impact from synthetic dyes in 13 out of the 16 impact categories studied. The modifications to the process to be tested in IRIS are expected to reduce energy demand, which would also lead to further environmental impact mitigation. Upscaling enzymatic denim dyeing process: This ex-ante LCA was modelled using the results from a scientific study published recently. The results show that enzymatic dyeing could potentially reduce the climate impact from the denim dyeing process by 95%. In general, the results from the ex-ante LCA indicate that a significant potential for impact reduction can be achieved with this technology, and even further by a shift to a more circular feedstock which will be explored in IRIS.PVC free biobased print: This ex-ante LCA for biobased printing was modelled using specific data provided by CTB from their previous work and experience developing the technology, with the addition of energy demand estimations for heating and drying processes. The results suggest that there is potential for environmental impact reduction, but further research is needed to understand the true magnitude of this potential. Moving forward, more specific data for the stabilizer, PHA production and alternative feedstocks would improve the quality of results.

This study presents an exploratory Life Cycle Assessment (LCA) of the environmental impacts associated with the valorization of pyrolysis oil, based on pilot and lab-scale data. The assessment follows a cradle-to-gate approach, focusing on the production of one kilogram of crude extract, with system boundaries and data adapted to Swedish conditions. The analysis identifies climate change as the most significant impact category, primarily driven by the disposal of spent solvent and heat generation during pyrolysis and distillation. Benchmarking against fossil-based precursors suggests that the crude extract has lower environmental impacts, indicating potential for sustainable substitution. Sensitivity analyses reveal that allocation methods and assumptions regarding solvent losses can influence results, though not substantially alter conclusions. Data quality is deemed sufficient for the study’s internal purpose, with high geographical relevance and acceptable uncertainty. The findings highlight the need for improved solvent recovery and heat integration in future process development, while acknowledging limitations due to the absence of a defined end-use product.

Purpose: The textile industry faces major challenges in reducing environmental impacts along the whole value chain. The overall aim of this paper was to assess the potential environmental benefit of a circular textile value chain, by evaluating a garment partly made from a chemically recycled cellulose carbamate fibre. The cellulose carbamate technology is a novel technology that turns cotton-rich textile waste into a cotton-like regenerated fibre. Methods: Life cycle assessment was performed to evaluate the environmental impacts of a garment made from the chemically recycled fibre, considering the whole life cycle. The evaluation also considered that the garment was part of a take-back system, meaning that the garment is collected for recycling after consumer use and thereby helps in closing the loop of the circular textile value chain. The focus of the assessment was on climate impact, water scarcity impact and land use impact. Furthermore, sensitivity analyses were included to test parts of the European Commission’s product environmental footprint method, e.g. the impact of applying the circular footprint formula. Results and discussion: The results showed that using a recycled cellulose carbamate fibre over primary conventional cotton showed benefits in all considered environmental impact categories; compared to organic cotton, the benefits were also shown for the land use impact category; the cradle to gate processes were the main hotspots for the garment’s life cycle, meaning that using a recycled feedstock is not the only measure needed to reduce environmental burdens;  the use phase, and in particular using the garment to its full life length, is crucial for mitigating the environmental impact per garment use; and methodological choices related to the use of recycled feedstock, and sending materials to recycling at end-of-life, affect the outcome of the study. Conclusions: Selecting a chemically recycled cellulose carbamate fibre over primary fibres showed environmental benefits for the evaluated garment, but there are however trade-offs between different environmental impact categories and fibre types. Furthermore, using recycled fibres is one important step in reducing the environmental concerns of garments, but it is important to also make improvements along the whole textile value chain. 

In this study, life cycle assessment has been applied to analyse the environmental impacts from a novel technology to recycle textile waste developed within the project RE:Spin. This technology allows for the dissolution of textile fibres and re-spinning them into new fibres within the same process setting, reducing the amount of process steps and increasing efficiency. The goal of this life cycle assessment is to analyse and quantify the potential environmental impacts of the RE:Spin process, to validate the hypothesis that the technology can potentially reduce the environmental impacts of chemical recycling. A secondary goal of the study is to identify hotspots as knowledge support for further developments. The study has a cradle-to-gate scope; and includes the processes of shredding, dissolution, filtration, coagulation, washing and drying. The study also includes support processes for recovery and recirculation of solvents and chemicals. The inventory data has been provided by the project partners, consisting only of lab-scale data from the tests and experiments carried out within the project. This data has been complemented by industrial scale simulations using a specialized software called WinGEMS, which provided mass balances and material flows for the system while energy use was calculated separately. The study analysed all the environmental impact categories required in the environmental footprint 3.1 framework. The results indicate that the RE:Spin technology has the potential to reduce the environmental impact of chemical recycling of cellulosic fibres. The potential environmental impacts from the RE:Spin fibres seem to achieve reductions in most impact categories in reference to conventional fibres, as well as in reference to the results obtained in other studies for chemical recycling of cotton. However, this outcome depends on certain key assumptions, such as the foreground system for ethanol production and heat generation. The most important aspect to focus on for future developments is to ensure a high recovery and recirculation rate of ethanol, sodium hydroxide and hydrochloric acid; which can potentially reduce the environmental impact from the RE:Spin process even further, while avoiding emissions of losses to air and water.

The fashion industry faces major challenges in reducing its environmental impacts along the textile value chain, from fibre production, via various processing steps, use phase and to the end-of-life stage. A major challenge is how to shift from the current linear industry to a circular one, where textiles are both sustainably produced, and after the full life length, recycled into new fibres with high value applications. The aim of this study was to evaluate the environmental impacts of post-consumer textile fibre-to-fibre recycling by cellulose carbamate technology, in terms of climate impact, water scarcity impact, cumulative energy demand and land use impact. By performing life cycle assessment, it was shown that the chemically recycled cellulose carbamate fibre has a climate impact of about 2.2 kg CO2-eq per kg fibre, water scarcity impact of 1.6 m3 H2O-eq per kg fibre, cumulative energy demand of 90 MJ-eq per kg fibre and land use impact of about 92 Pt per kg fibre (when applying mass allocation of co-products). Hotspots identified during the fibre production technology were electricity use and production of sodium hydroxide. In a sensitivity analysis, it was shown that the choice of electricity has a major influence on the results, and by using a renewable electricity mix over an average Finnish electricity mix, the impact could be decreased for all impact categories, except when using bioenergy, which would increase the land use impact. Compared to primary fibres like viscose and conventional cotton, these impacts are in the lower to middle range, showing potential to lower environmental impacts when moving towards an increased amounts of recycled post-consumer textile fibre with high value applications, that can replace primary fibres. 

Life cycle assessment (LCA) is an established method to assess the various environmental impacts associated with all the stages of a building. The goal of this project was to calculate the environmental releases for a whole office building and investigate the contribution in terms of environmental impact for different parts of the building, as well as the impact from different stages of the life cycle. The construction process was followed up during production and the contractors provided real-time data on the input required in terms of building products, transport, machinery, energy use, etc. The results are presented for five environmental impact categories and, as expected, materials that constitute the main mass of the building and the energy used during operation contribute the largest share of environmental impact. It is usually difficult to evaluate the environmental impact of the materials in technical installations due to the lack of data. However, in this study, the data were provided by the contractors directly involved in the construction and can, therefore, be considered highly reliable. The results show that materials for installations have a significant environmental impact for four of the environmental impact categories studied, which is a noteworthy finding.

Purpose: This article aims to explore how different assumptions about system boundaries and setting of baselines for forest growth affect the outcome of climate impact assessments of forest products using life cycle assessment (LCA), regarding the potential for climate impact mitigation from replacing non-forest benchmarks. This article attempts to explore how several assumptions interact and influence results for different products with different service life lengths. Methods: Four products made from forest biomass were analysed and compared to non-forest benchmarks using dynamic LCA with time horizons between 0 and 300 years. The studied products have different service lives: butanol automotive fuel (0 years), viscose textile fibres (2 years), a cross-laminated timber building structure (50 years) and methanol used to produce short-lived (0 years) and long-lived (20 years) products. Five calculation setups were tested featuring different assumptions about how to account for the carbon uptake during forest growth or regrowth. These assumptions relate to the timing of the uptake (before or after harvest), the spatial system boundaries (national, landscape or single stand) and the land-use baseline (zero baseline or natural regeneration). Results and discussion: The implications of using different assumptions depend on the type of product. The choice of time horizon for dynamic LCA and the timing of forest carbon uptake are important for all products, especially long-lived ones where end-of-life biogenic emissions take place in the relatively distant future. The choice of time horizon is less influential when using landscape- or national-level system boundaries than when using stand-level system boundaries and has greater influence on the results for long-lived products. Short-lived products perform worse than their benchmarks with short time horizons whatever spatial system boundaries are chosen, while long-lived products outperform their benchmarks with all methods tested. The approach and data used to model the forest carbon uptake can significantly influence the outcome of the assessment for all products. Conclusions: The choices of spatial system boundaries, temporal system boundaries and land-use baseline have a large influence on the results, and this influence decreases for longer time horizons. Short-lived products are more sensitive to the choice of time horizon than long-lived products. Recommendations are given for LCA practitioners: to be aware of the influence of method choice when carrying out studies, to use case-specific data (for the forest growth) and to communicate clearly how results can be used.

The construction sector faces the challenge of mitigating climate change with urgency. Life cycle assessment (LCA), a widely used tool to assess the climate impacts of buildings, is seldom used for bridges. Material-specific phenomena such as concrete carbonation and biogenic carbon storage are usually unaccounted for when assessing the climate impacts from infrastructure. The purpose of this article is to explore the effects these phenomena could have on climate impact assessment of road bridges and comparisons between bridge designs. For this, a case study is used of two functionally equivalent design alternatives for a small road bridge in Sweden. Dynamic LCA is used to calculate the effects of biogenic carbon storage, while the Lagerblad method and literature values are used to estimate concrete carbonation. The results show that the climate impact of the bridge is influenced by both phenomena, and that the gap between the impacts from both designs increases if the phenomena are accounted for. The outcome is influenced by the time occurrence assumed for the forest carbon uptake and the end-of-life scenario for the concrete. An equilibrium or 50/50 approach for accounting for the forest carbon uptake is proposed as a middle value compromise to handle this issue. © 2017 Informa UK Limited, trading as Taylor & Francis Group

In the collaborative forum Positive footprint housing® Riksbyggen is building the Viva residential quarter, which is a sustainability project at the very forefront of what is possible with contemporary construction. The idea is that this residential quarter should be fully sustainable in ecological, economic and social terms. Since 2013, a number of pilot studies have been completed under the auspices of the Viva project framework thanks to financing from the Swedish Energy Agency. The various building frame alternatives that have been evaluated are precast concrete, cast in-situ concrete and solid wood, all proposed by leading commercial suppliers. The report includes a specific requirement for equivalent functions during the use phase of the building, B. An interpretation has been provided that investigates the building engineering aspects in detail, as well as an account of the results based on the social community requirements specified in Viva, durability, fire, noise and energy consumption in the Swedish National Board of Building, Planning and Housing building regulations (BBR), plus Riksbyggen’s own requirements, Sweden Green Building Council’s Environmental Building Gold (Miljöbyggnad Guld) and 100-year life cycle. Given that the alternatives have different long-term characteristics (and also that our knowledge of these characteristics itself varies), these functional requirements have been addressed by setting up different scenarios in accordance with the EPD standard EN 15978. Because Riksbyggen has specified a requirement for a 100-year life cycle, we have also opted for an analysis period of 100 years. The results show no significant differences between concrete and timber structures for the same functions during the life cycle, either for climate or for primary energy. The minor differences reported are accordingly less than the degree of uncertainty involved in the study. The available documentation on the composition of the relevant intumescent paint coating on solid wood frames differs from source to source, so it was not possible to fully allow for the significance of this. The LCA has not included functional changes in the building linked to load-bearing characteristics, noise, moisture, health or other problems that may result in increased maintenance and replacement. The concrete houses have been dimensioned for 100 years, for instance, in accordance with tried and tested standards and experience. The solid wood house is not dimensioned in the same way, and this has led to us having to assume various scenarios.

The results also show the following:

• The uncertainties involved in comparing different structures and alternative solutions are very significant. The results are affected by factors such as life cycle, the functional requirements taken into consideration, transportation, design and structural details, etc.

• Variations in the built items and a considerable degree of uncertainty in the assumptions make it difficult to obtain significant results on comparisons. Only actual construction projects with known specific data, declared from a life cycle perspective that takes into account actual building developer requirements and involving different scenarios (best, documented and worst-case) for the user stage can currently be compared.

• In the other hand, comparisons restricted to different concrete structures only, or to different timber structures only, ought to involve a lower degree of uncertainty. These would then provide results that are significant as well as improvement requirements that are relevant.

• There is potential for improving concrete by imposing requirements on the material

• There is potential for improving solid wood frames by developing and guaranteeing well-documented long-term characteristics for all functional requirements.

The LCAs were performed as an iterative process where all parties were given the opportunity to submit their viewpoints and suggestions for changes during the course of the work. This helped ensure that all alternatives have been properly thought through.

Because, during the project, Riksbyggen opted to procure a concrete frame, in the final stage the researchers involved focused on ensuring the procurement process would result in the concrete frame as built meeting the requirements set out above. As things currently stand, the material requirements for the concrete are limited by the production options open to the suppliers, and this is therefore being investigated in the manufacture of precast concrete frames for the Viva cooperative housing association.

A variety of climate mitigation strategies is available to mitigate climate impacts of buildings. Several studies evaluating the effectiveness of these strategies have been performed at the building stock level, but do not consider the technological change in building material manufacturing. The objective of this study is to evaluate the climate mitigation effects of increasing the use of biobased materials in the construction of new residential dwellings in Sweden under future scenarios related to technological change. A model to estimate the climate impact from Swedish new dwellings has been proposed combining official statistics and life cycle assessment data of seven different dwelling typologies. Eight future scenarios for increased use of harvested wood products are explored under different pathways for changes in the market share of typologies and in energy generation. The results show that an increased use of harvested wood products results in lower climate impacts in all scenarios evaluated, but reductions decrease if the use of low-impact concrete expands more rapidly or under optimistic energy scenarios. Results are highly sensitive to the choice of climate impact metric. The Swedish construction sector can only reach maximum climate change mitigation scenarios if the low-impact building typologies are implemented together and rapidly.