| 1. |
- Akselsson, Cecilia, et al.
(author)
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A Combined Measurement and Modelling Approach to Assess the Sustainability of Whole-Tree Harvesting—A Swedish Case Study
- 2021
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In: Sustainability. - : MDPI AG. - 2071-1050. ; 13:4
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Journal article (peer-reviewed)abstract
- The demand of renewable energy has increased the interest in whole-tree harvesting. The sustainability of whole-tree harvesting after clear-cutting, from an acidification point of view, depends on two factors: the present acidification status and the further loss of buffering capacity at harvesting. The aims of this study were to investigate the relationship between these two factors at 26 sites along an acidification gradient in Sweden, to divide the sites into risk classes, and to examine the geographical distribution of them in order to provide policy-relevant insights. The present status was represented by the acid neutralizing capacity (ANC) in soil solution, and the loss of buffering capacity was represented by the estimated exceedance of critical biomass harvesting (CBH). The sites were divided into three risk classes combining ANC and exceedance of CBH. ANC and exceedance of CBH were negatively correlated, and most sites had either ANC < 0 and exceedance (high risk) or ANC > 0 and no exceedance (low risk). There was a geographical pattern, with the high risk class concentrated to southern Sweden, which was mainly explained by higher historical sulfur deposition and site productivity in the south. The risk classes can be used in the formulation of policies on whole-tree harvesting and wood ash recycling.
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| 2. |
- Arnell, Magnus, et al.
(author)
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Modelling anaerobic co-digestion in Benchmark Simulation Model No. 2 : Parameter estimation, substrate characterisation and plant-wide integration
- 2016
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In: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 98, s. 138-146
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Journal article (peer-reviewed)abstract
- Anaerobic co-digestion is an emerging practice at wastewater treatment plants (WWTPs) to improve the energy balance and integrate waste management. Modelling of co-digestion in a plant-wide WWTP model is a powerful tool to assess the impact of co-substrate selection and dose strategy on digester performance and plant-wide effects. A feasible procedure to characterise and fractionate co-substrates COD for the Benchmark Simulation Model No. 2 (BSM2) was developed. This procedure is also applicable for the Anaerobic Digestion Model No. 1 (ADM1). Long chain fatty acid inhibition was included in the ADM1 model to allow for realistic modelling of lipid rich co-substrates. Sensitivity analysis revealed that, apart from the biodegradable fraction of COD, protein and lipid fractions are the most important fractions for methane production and digester stability, with at least two major failure modes identified through principal component analysis (PCA). The model and procedure were tested on bio-methane potential (BMP) tests on three substrates, each rich on carbohydrates, proteins or lipids with good predictive capability in all three cases. This model was then applied to a plant-wide simulation study which confirmed the positive effects of co-digestion on methane production and total operational cost. Simulations also revealed the importance of limiting the protein load to the anaerobic digester to avoid ammonia inhibition in the digester and overloading of the nitrogen removal processes in the water train. In contrast, the digester can treat relatively high loads of lipid rich substrates without prolonged disturbances.
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| 3. |
- Arnell, Magnus, et al.
(author)
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Multi-objective performance assessment of wastewater treatment plants combining plant-wide process models and life cycle assessment
- 2017
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In: Journal of Water and Climate Change. - : IWA Publishing. - 2040-2244 .- 2408-9354. ; 8:4, s. 715-729
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Journal article (peer-reviewed)abstract
- Multi-objective performance assessment of operational strategies at wastewater treatment plants (WWTPs) is a challenging task. The holistic perspective applied to evaluation of modern WWTPs, including not only effluent quality but also resource efficiency and recovery, global environmental impact and operational cost calls for assessment methods including both on- and off-site effects. In this study, a method combining dynamic process models – including greenhouse gas (GHG), detailed energy models and operational cost – and life cycle assessment (LCA) was developed. The method was applied and calibrated to a large Swedish WWTP. In a performance assessment study, changing the operational strategy to chemically enhanced primary treatment was evaluated. The results show that the primary objectives, to enhance bio-methane production and reduce GHG emissions were reached. Bio-methane production increased by 14% and the global warming potential decreased by 28%. However, due to increased consumption of chemicals, the operational cost increased by 87% and the LCA revealed that the abiotic depletion of elements and fossil resources increased by 77 and 305%, respectively. The results emphasize the importance of using plant-wide mechanistic models and life cycle analysis to capture both the dynamics of the plant and the potential environmental impacts.
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| 4. |
- Börjesson, Pål, et al.
(author)
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Future demand for forest-based biomass for energy purposes in Sweden
- 2017
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 383:January, s. 17-26
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Journal article (peer-reviewed)abstract
- This paper assesses the potential changes in the demand for forest-based biomass for various energy purposes in Sweden in 2030 and 2050, respectively. The assessment is based on a review of scenarios and predictions of how the Swedish energy system may develop, taking into account techno-economical conditions. It includes potential changes in district heating, electricity production in combined heat and power plants, industrial process energy, and production of biofuel for road transportation. In addition, the potential demand for forest-based feedstock in the chemical and petrochemical sector, replacing current use of fossil feedstock, is analysed. The assessment suggests that Sweden may see an additional demand for forest fuels at about 30 TW h in 2030 and 35–40 TW h in 2050. This can be compared with the current use of biomass for energy in Sweden at 130 TW h per year, and the estimated potential increase of sustainable harvest of logging residues (slash and stumps) at some additional 20 TW h per year, based on current conditions. If also potential demand for forest-based feedstock in the chemical and petrochemical industry is included, another 10–15 and 25–30 TW h of biomass per year may be needed in 2030 and 2050, respectively. The future demand is sensitive to the pace and magnitude of energy efficiency improvements and electrification in the various sectors. If far-reaching energy efficiency improvements and electrification are realised, the total additional demand for biomass as energy and industry feedstock may be about 20 and 30 TW h per year in 2030 and 2050, respectively, thus roughly corresponding to the sustainable harvests of logging residues. If, however, efficiency improvements and electrification are only marginal, then the additional demand for biomass as industry and energy feedstock may reach 70 TW h and 100 TW h per year in 2030 and 2050, respectively. In these cases, the use of logging residues will not suffice and additional biomass would be needed. A combination of regulations and incentives is recommended to accelerate the fuel and feedstock switch, especially in the transportation and industrial sectors, and incentives promoting a substantial improvement in energy efficiency and electrification in all sectors.
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| 5. |
- Cintas Sanchez, Olivia, 1982, et al.
(author)
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The potential role of forest management in Swedish scenarios towards climate neutrality by mid century
- 2017
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 383:January, s. 73-84
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Journal article (peer-reviewed)abstract
- Swedish climate policy targets net zero greenhouse gases (GHG) by mid-century, with road transport independent of fossil fuels by 2030, requiring far-reaching changes in the way energy is used. Forest management is expected to support carbon sequestration and provide biomass for various uses, including energy. In this paper, we combine two energy scenarios with four forest scenarios and quantify GHG balances associated with energy-use for heat, electricity, and road transport, and with forest management and production, use, and end-of-life management of various forest products, including products for export. The aggregated GHG balances are evaluated in relation to the 2-degree target and an allocated Swedish CO2 budget. The production of biofuels in the agriculture sector is considered but not analyzed in detail.The results suggest that Swedish forestry can make an important contribution by supplying forest fuels and other products while maintaining or enhancing carbon storage in vegetation, soils, and forest products. The GHG neutrality goal is not met in any of the scenarios without factoring in carbon sequestration. Measures to enhance forest productivity can increase output of forest products (including biofuels for export) and also enhance carbon sequestration. The Swedish forest sector can let Sweden reach net negative emissions, and avoid “using up” its allocated CO2 budget, thereby increasing the associated emissions space for the rest of the world.
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| 6. |
- Ekener, Elisabeth, 1963-, et al.
(author)
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Developing Life Cycle Sustainability Assessment methodology by applying values-based sustainability weighting - Tested on biomass based and fossil transportation fuels
- 2018
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In: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 181, s. 337-351
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Journal article (peer-reviewed)abstract
- The production and use of transportation fuels can lead to sustainability impacts. Assessing them simultaneously in a holistic way is a challenge. This paper examines methodology for assessing the sustainability performance of products in a more integrated way, including a broad range of social impacts. Life Cycle Sustainability Assessment (LCSA) methodology is applied for this assessment. LSCA often constitutes of the integration of results from social LCA (S-LCA), environmental life cycle assessment (E-LCA) and life cycle costing (LCC). In this study, an S-LCA from an earlier project is extended with a positive social aspect, as well as refined and detailed. E-LCA and LCC results are built from LCA database and literature. Multi Criteria Decision Analysis (MCDA) methodology is applied to integrate the results from the three different assessments into an LCSA. The weighting of key sustainability dimensions in the MCDA is performed in different ways, where the sustainability dimensions are prioritized differently priority based on the assumed values of different stakeholder profiles (Egalitarian, Hierarchist, and Individualist). The developed methodology is tested on selected biomass based and fossil transportation fuels - ethanol produced from Brazilian sugarcane and US corn/maize, and petrol produced from Russian and Nigerian crude oils, where it delineates differences in sustainability performance between products assessed. The outcome in terms of relative ranking of the transportation fuel chains based on sustain ability performance differs when applying different decision-maker profiles. This result highlights and supports views that there is no one single answer regarding which of the alternatives that is most sustainable. Rather, it depends strongly upon the worldview and values held by the decision maker. A key conclusion is that sustainability assessments should pay more attention to potential differences in underlying values held by key stakeholders in relevant societal contexts. The LCSA methodology still faces challenges regarding results integration but MCDA in combination with stakeholder profiles appears to be a useful approach to build on further.
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| 7. |
- Fagerström, Anton, et al.
(author)
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Economic and Environmental Potential of Large‐Scale Renewable Synthetic Jet Fuel Production through Integration into a Biomass CHP Plant in Sweden
- 2022
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In: Energies. - : MDPI AG. - 1996-1073. ; 15:3
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Journal article (peer-reviewed)abstract
- The potential of bio‐electro‐jet fuel (BEJF) production with integration into an existing biomass‐based combined heat and power (CHP) facility was investigated. The BEJF is produced via Fischer–Tropsch (F–T) synthesis from biogenic CO2 and H2 obtained by water electrolysis. Techno-economic (TEA)‐ and life. cycle (LCA)‐ assessments were performed to evaluate the production cost and environmental impact of the BEJF production route. The BEJF mass fraction reached 40% of the total F–T crude produced. A reduction of 78% in heating demands was achieved through energy integration, leading to an increase in the thermal efficiency by up to 39%, based on the F–T crude. The total production cost of BEJF was in the range of EUR 1.6–2.5/liter (EUR 169–250/MWh). The GWP of the BEJF was estimated to be 19 g CO2‐eq per MJ BEJF. The reduction potential in GWP in contrast to the fossil jet baseline fuel varied from 44% to more than 86%. The findings of this study underline the potential of BEJF as a resource‐efficient, cost‐effective, and environmentally benign alternative for the aviation sector. The outcome is expected to be applicable to different geograph-ical locations or industrial networks when the identified influencing factors are met.
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| 8. |
- Fagerström, Anton, et al.
(author)
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Large scale bio electro jet fuel production integration at CHP-plant in Östersund, Sweden
- 2021. - B 2407
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Reports (other academic/artistic)abstract
- This document reports the findings of the project “Large scale bio electro jet fuel production integration at CHP-plant in Östersund, Sweden”. BEJF is an electrofuel produced in a synthesis process where biogenic carbon dioxide (CO2) is the main carbon source and hydrogen from electrolysis of water using renewable electricity is the main energy source. The project is a feasibility study for a factory for such fuel located at Jämtkraft's facility for CHP in Östersund. Thus, the aim of the project is to assess the feasibility for producing renewable aviation fuel at a specific location considering and evaluating e.g., different processes, operations and integrations, costs, environmental impact, business models and actors.IVL The Swedish Environmental Research Institute, Jämtkraft (JK), Chalmers University (CU), Lund University (LU), Nordic Initiative for Sustainable Aviation (NISA), and Fly Green Fund (FGF) have been the primary implementers in this project. Other project stakeholders (AFAB, and The Power Region), have provided relevant data to the various working groups. The project has included experimental work, modelling and calculations, as well as literature-based studies but not the construction of any facilities.
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| 9. |
- Harris, Steve, et al.
(author)
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Sharing is daring, but is it sustainable? : An assessment of sharing cars, electric tools and offices in Sweden
- 2021
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In: Resources, Conservation and Recycling. - Stockholm : Elsevier BV. - 0921-3449 .- 1879-0658. ; 170, s. 105583-
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Journal article (peer-reviewed)abstract
- The sharing economy has emerged as a potential way to reduce the environmental impact and costs of using products, whilst increasing their accessibility. However, there is a paucity of literature on its sustainability implications. To help fill this void we provide a first indicative assessment of the potential sustainability implications for the sharing of three product groups in Sweden, namely cars, small electrical tools and offices. A quantitative assessment of Greenhouse Gas (GHG) emissions, resource use and waste based on case studies, is used as a basis to develop scenarios of upscaling sharing at national level. This is combined with a qualitative scoring framework to assess the socio-economic impacts. Office sharing was found to have a significant potential to reduce GHG emissions by 164-243 KtCO(2)e/yr. Car sharing has a larger potential but has a wide range of uncertainty with potential reductions of 0.5-3.7 MtCO(2)e (if 80% of cars in Sweden were sharing cars), depending on how many owned cars are replaced by a shared vehicle. However, 80% ownership of battery electric vehicles offer a greater potential benefit with a saving of up to 8.2 MtCO(2)e. In terms of the reduction in material use, there are potential savings of 232,000 t/yr and 24.4-34.4Mt/yr for cars and offices, respectively. However, the tool sharing case does not demonstrate such large potential for national reductions. The qualitative analysis on socioeconomic implications showed largely positive results across the indicators. However, further research is needed to assess the impacts on jobs and the local economy for the shared product groups, and to more fully understand how shared offices effect health and well-being of users. Finally, to avoid potential rebound effects additional support is needed to promote electric cars to avoid fleets of fossil fuel cars with high emissions, a flexible stock of desks without large empty office spaces, and proximity of tool sharing to minimise transport.
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| 10. |
- Holmquist, Hanna, 1982, et al.
(author)
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The potential to use QSAR to populate ecotoxicity characterisation factors for simplified LCIA and chemical prioritisation
- 2018
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In: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 23:11, s. 2208-2216
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Journal article (peer-reviewed)abstract
- Purpose: Today’s chemical society use and emit an enormous number of different, potentially ecotoxic, chemicals to the environment. The vast majority of substances do not have characterisation factors describing their ecotoxicity potential. A first stage, high throughput, screening tool is needed for prioritisation of which substances need further measures. Methods: USEtox characterisation factors were calculated in this work based on data generated by quantitative structure-activity relationship (QSAR) models to expand substance coverage where characterisation factors were missing. Existing QSAR models for physico-chemical data and ecotoxicity were used, and to further fill data gaps, an algae QSAR model was developed. The existing USEtox characterisation factors were used as reference to evaluate the impact from the use of QSARs to generate input data to USEtox, with focus on ecotoxicity data. An inventory of chemicals that make up the Swedish societal stock of plastic additives, and their associated predicted emissions, was used as a case study to rank chemicals according to their ecotoxicity potential. Results and discussion: For the 210 chemicals in the inventory, only 41 had characterisation factors in the USEtox database. With the use of QSAR generated substance data, an additional 89 characterisation factors could be calculated, substantially improving substance coverage in the ranking. The choice of QSAR model was shown to be important for the reliability of the results, but also with the best correlated model results, the discrepancies between characterisation factors based on estimated data and experimental data were very large. Conclusions: The use of QSAR estimated data as basis for calculation of characterisation factors, and the further use of those factors for ranking based on ecotoxicity potential, was assessed as a feasible way to gather substance data for large datasets. However, further research and development of the guidance on how to make use of estimated data is needed to achieve improvement of the accuracy of the results.
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