| 1. |
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| 2. |
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| 3. |
- Anselm, Jonas, et al.
(författare)
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Bannlys alla politiska beslut som ger mer klimatutsläpp
- 2014
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Ingår i: Dagens Nyheter.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Torftig valdebatt. Dagspolitiken klarar inte att hantera ödesfrågan om klimatet, vilket oroar oss. Vi föreslår därför ett ”utsläppsmoratorium”: inga beslut får tas som ökar utsläppen av växthusgaser. Principen måste kopplas till mål om exempelvis förnybar energi och grön infrastruktur, skriver 23 forskare och debattörer.
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| 4. |
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| 5. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
A framework for energy use indicators and their reporting in life cycle assessment
- 2016
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Ingår i: Integrated environmental assessment and management. - : Wiley. - 1551-3777 .- 1551-3793. ; 12:3, s. 429-436
-
Tidskriftsartikel (refereegranskat)abstract
- Energy use is a common impact category in life cycle assessment (LCA). Many different energy use indicators are used in LCA studies, accounting for energy use in different ways. Often, however, the choice behind which energy use indicator is applied is poorly described and motivated. To contribute to a more purposeful selection of energy use indicators and to ensure consistent and transparent reporting of energy use in LCA, a general framework for energy use indicator construction and reporting in LCA studies will be presented in this article. The framework differentiates between 1) renewable and nonrenewable energies, 2) primary and secondary energies, and 3) energy intended for energy purposes versus energy intended for material purposes. This framework is described both graphically and mathematically. Furthermore, the framework is illustrated through application to a number of energy use indicators that are frequently used in LCA studies: cumulative energy demand (CED), nonrenewable cumulative energy demand (NRCED), fossil energy use (FEU), primary fossil energy use (PFEU), and secondary energy use (SEU). To illustrate how the application of different energy use indicators may lead to different results, cradle-to-gate energy use of the bionanomaterial cellulose nanofibrils (CNF) is assessed using 5 different indicators and showing a factor of 3 differences between the highest and lowest results. The relevance of different energy use indicators to different actors and contexts will be discussed, and further developments of the framework are then suggested.
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| 6. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Assessing the Environmental Impacts of Palm Oil
- 2011
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Ingår i: Palm Oil: Nutrition, Uses and Impacts. - : Nova Science Publishers, Inc.. - 9781612099217 ; , s. 159-186
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Palm oil is used for cooking in Southeast Asia and Africa and as a food additive in a number of processed foods world-wide. The production of palm oil is increasing, and it is of special interest from a nutritional point of view due to its high energy content and its significant content of micronutrients. In addition, palm oil is increasingly used to produce various biofuels. Due to large production volumes and diverse applications of palm oil, it is highly interesting and important to study the environmental impacts of its production. This chapter discusses how the environmental impacts of palm oil can be assessed, focusing on the life cycle environmental impacts of palm oil in comparison to similar products. A brief overview of life cycle assessment as a method is given, and results are presented together with suggestions for environmental improvements of palm oil cultivation and production. It is shown that the magnitude of the environmental impacts connected to palm oil in relation to other products is heavily affected by the choice of environmental indicators, which in LCA studies consist of both an environmental impact category and a so-called functional unit. Regarding impact categories, the global warming and acidification potentials of palm oil are lower than those of rapeseed oil per kg oil. The water footprint of palm oil and rapeseed oil are about the same on a mass basis, but for the two land use indicators soil erosion and heavy metal accumulation, rapeseed oil has a lower impact than palm oil. Specific interest is given to the life cycle energy use of palm oil in response to the unclear and diverse definitions of this impact category in different studies. It is concluded that there is a need to carefully define the energy use impact category when reporting on palm oil or similar products, and also to differentiate between different kinds of energy sources. If instead of mass the micronutrient content is applied as functional unit, palm oil still has lower global warming potential and acidification than rapeseed oil when compared on the basis of vitamin E content. However, if β-carotene content is used as functional unit, rapeseed oil is not relevant for comparison due to its negligible content of β-carotene. For that case, palm oil is therefore instead compared to tomatoes on a β-carotene basis, since tomatoes are rich in β-carotene. The tomatoes were shown to perform better then palm oil regarding global warming potential on a β-carotene basis. The effects of time and scale on the environmental impacts of palm oil, which includes changes in technical performance and electricity sources, are also discussed in this chapter. It is shown that combustion of the methane formed from the palm oil mill effluent can significantly reduce the global warming potential.
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| 7. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Energy use and climate change improvements of Li/S batteries based on life cycle assessment
- 2018
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 383, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- We present a life cycle assessment (LCA) study of a lithium/sulfur (Li/S) cell regarding its energy use (in electricity equivalents, kWhel) and climate change (in kg carbon dioxide equivalents, CO2 eq) with the aim of identifying improvement potentials. Possible improvements are illustrated by departing from a base case of Li/S battery design, electricity from coal power, and heat from natural gas. In the base case, energy use is calculated at 580 kWhel kWh−1 and climate change impact at 230 kg CO2 eq kWh−1 of storage capacity. The main contribution to energy use comes from the LiTFSI electrolyte salt production and the main contribution to climate change is electricity use during the cell production stage. By (i) reducing cell production electricity requirement, (ii) sourcing electricity and heat from renewable sources, (iii) improving the specific energy of the Li/S cell, and (iv) switching to carbon black for the cathode, energy use and climate change impact can be reduced by 54 and 93%, respectively. For climate change, our best-case result of 17 kg CO2 eq kWh−1 is of similar magnitude as the best-case literature results for lithium-ion batteries (LIBs). The lithium metal requirement of Li/S batteries and LIBs are also of similar magnitude.
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| 8. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Energy use indicators in energy and life cycle assessments of biofuels: review and recommendations
- 2012
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 31, s. 54-61
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Tidskriftsartikel (refereegranskat)abstract
- In this study we investigate how indicators for energy use are applied in a set of life cycle assessment (LCA) and energy analysis case studies of biofuels. We found five inherently different types of indicators to describe energy use: (1) fossil energy, (2) secondary energy, (3) cumulative energy demand, (4) net energy balance, and (5) total extracted energy. It was also found that the examined reports and articles, the choice of energy use indicator was seldom motivated or discussed in relation to other energy use indicators. In order to investigate the differences between these indicators, they were applied to a case. The life cycle energy use of palm oil methyl ester was calculated and reported using these five different indicators for energy use, giving considerably different output results. This is in itself not unexpected, but indicates the importance of clearly identifying, describing and motivating the choice of energy use indicator. The indicators can all be useful in specific situations, depending on the goal and scope of the individual study, but the choice of indicators need to be better reported and motivated than what is generally done today.
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| 9. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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How do we know the energy use when producing biomaterials or biofuels?
- 2012
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Ingår i: Proceedings of ECO-TECH 2012.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- How much fossil energy that is used in the production of biomaterials or biofuels (e.g. fuel used in harvesting) is a parameter of obvious interest when optimizing the production systems. To use more fossil fuels in the production of a biofuel than what will be available as the biofuel product is obviously a bad idea. With increasing interest in biomaterials and biofuels, a shift from a sole focus on fossil energy will be necessary. Optimized use of energy over the whole life cycle is one important parameter to ensure sustainability. However, to report and interpret values on life cycle energy use is not as straight forward as what might immediately be perceived. The impact category ‘energy use’ is frequently used but is generally not applied in a transparent and consistent way between different studies. Considering the increased focus on biofuels, it is important to inform companies and policy-makers about the energy use of biofuels in relevant and transparent ways with well-defined indicators. The present situation in how energy use indicators are applied was studied in a set of LCA studies of biofuels. It was found that the choice of indicator was seldom motivated or discussed in the examined reports and articles, and five inherently different energy use indicators were observed: (1) fossil energy, (2) secondary energy, (3) cumulative energy demand (primary energy), (4) net energy balance, and (5) total extracted energy. As a test, we applied these five energy use indicators to the same cradle-to-gate production system and they give considerably different output numbers of energy use. This in itself is not unexpected, but indicates the importance of clearly identifying, describing and motivating the choice of energy use indicator. Direct comparisons between different energy use results could lead to misinformed policy decisions.
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| 10. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
How much energy is used when producing biofuels?
- 2012
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Ingår i: World Bioenergy 2012, Jönköping, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Considering the increased focus on biofuels, it is important to inform companies and policy-makers about the energy use for production of biofuels in relevant and transparent ways, using well-defined indicators. The amount of fossil energy used in the production of a biofuel (e.g. diesel fuel used in harvesting) is a parameter of obvious interest when comparing different biofuels or when optimizing the production systems. With increasing worldwide production of different biofuels, a shift in focus from fossil energy to the entire energy use will also be necessary. In that context, not only reducing the use of fossil fuels in biofuel production, but also optimizing the use of all energy sources over the whole life cycle becomes an important to ensure the sustainability of biofuels. However, to report and interpret values on life cycle energy use is not straight forward due to methodological difficulties. The impact category ‘energy use’ is frequently used in life cycle assessment (LCA). But the term ‘energy use’ is generally not applied in a transparent and consistent way between different LCA studies of biofuels. It is often unclear whether the total energy use, or only fossil energy, has been considered, and whether primary or secondary energy has been considered. In addition, it is often difficult to tell if and how the energy content of the fuel or the biomass source was included in the energy use. This study presents and discusses the current situation in terms of energy use indicators are applied in LCA studies on biofuels. It was found that the choice of indicator was seldom motivated or discussed in the examined reports and articles, and five inherently different energy use indicators were observed: (1) fossil energy, (2) secondary energy, (3) cumulative energy demand (primary energy), (4) net energy balance, and (5) total extracted energy. As an illustration, we applied these five energy use indicators to the same cradle-to-gate production system (production of palm oil methyl ester), resulting in considerably different output numbers of energy use. This in itself is not unexpected, but indicates the importance of clearly identifying, describing and motivating the choice of energy use indicator. All five indicators can be useful in specific situations, depending on the goal and scope of the individual study, but the choice of indicator needs to be better reported and motivated than what is generally done today. Above all, it is important to avoid direct comparisons between different energy use results calculated using different indicators, since this could lead to misinformed policy decisions.
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| 11. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Life cycle assessment of Biodiesel - Hydrotreated oil from rape, oil palm or Jatropha
- 2008
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Ingår i: Annual Poster Exhibition at the Department of Chemical and Biological Engineering, Chalmers University of Technology, Mars 6th, 2008, Göteborg, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- There is a need for fuels based on renewable resources that have acceptable emission profiles and that are functional for truck engines used in heavy vehicles. Volvo has participated in the CONCAWE/EUCAR/JRC WTW study, which analyzed a number of candidate fuels, several process routes to produce each fuel as well as different raw material choices. However, the CONCAWE study did not include any second generation hydrogenated vegetable oil type biodiesel. In the present study, Volvo and Chalmers investigate and benchmark hydrogenated vegetable oils. Different production routes from different proposed raw materials are investigated using life cycle assessment modeling. Raw materials considered are oil from rape seed (grown in Germany), palm oil (grown in Malaysia) and oil from the fruits of Jatropha curcas (grown in India). The raw material is converted into hydrogenated oil at a production site in northern Europe and used at the European market. Results regarding life cycle global warming potential and energy use are presented.
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| 12. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Life Cycle Assessment of Cellulose Nanofibrils Production by Mechanical Treatment and Two Different Pretreatment Processes
- 2015
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 49:11, s. 6881-6890
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulose is a bionanomaterial with many promising applications, but high energy use in production has been described as a potential obstacle for future use. In fact, life cycle assessment studies have indicated high life cycle energy use for nanocellulose. In this study, we assess the cradle-to-gate environmental impacts of three production routes for a particular type of nanocellulose called cellulose nanofibrils (CNF) made from wood pulp. The three production routes are (1) the enzymatic production route, which includes an enzymatic pretreatment, (2) the carboxymethylation route, which includes a carboxymethylation pretreatment, and (3) one route without pretreatment, here called the no pretreatment route. The results show that CNF produced via the carboxymethylation route clearly has the highest environmental impacts due to large use of solvents made from crude oil. The enzymatic and no pretreatment routes both have lower environmental impacts, of similar magnitude. A sensitivity analysis showed that the no pretreatment route was sensitive to the electricity mix, and the carboxymethylation route to solvent recovery. When comparing the results to those of other carbon nanomaterials, it was shown that in particular CNF produced via the enzymatic and no pretreatment routes had comparatively low environmental impacts.
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| 13. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Life cycle assessment of hydrotreated vegetable oil from rape, oil palm and Jatropha
- 2011
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 19:2-3, s. 128-137
-
Tidskriftsartikel (refereegranskat)abstract
- A life cycle assessment of hydrotreated vegetable oil (HVO) biofuel was performed. The study wascommissioned by Volvo Technology Corporation and Volvo Penta Corporation as part of an effort to gaina better understanding of the environmental impact of potential future biobased liquid fuels for cars andtrucks. The life cycle includes production of vegetable oil from rape, oil palm or Jatropha, transport of theoil to the production site, production of the HVO from the oil, and combustion of the HVO. The functionalunit of the study is 1 kWh energy out from the engine of a heavy-duty truck and the environmentalimpact categories that are considered are global warming potential (GWP), acidification potential (AP),eutrophication potential (EP) and embedded fossil production energy. System expansion was used totake into account byproducts from activities in the systems; this choice was made partly to make thisstudy comparable to results reported by other studies. The results show that HVO produced from palmoil combined with energy production from biogas produced from the palm oil mill effluent has thelowest environmental impact of the feedstocks investigated in this report. HVO has a significantly lowerlife cycle GWP than conventional diesel oil for all feedstocks investigated, and a GWP that is comparableto results for e.g. rape methyl ester reported in the literature. The results show that emissions from soilcaused by microbial activities and leakage are the largest contributors to most environmental impactcategories, which is supported also by other studies. Nitrous oxide emissions from soil account for morethan half of the GWP of HVO. Nitrogen oxides and ammonia emissions from soil cause almost all of thelife cycle EP of HVO and contribute significantly to the AP as well. The embedded fossil production energywas shown to be similar to results for e.g. rape methyl ester from other studies. A sensitivity analysisshows that variations in crop yield and in nitrous oxide emissions from microbial activities in soil cancause significant changes to the results.
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| 14. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Life-cycle impact assessment methods for physical energy scarcity: considerations and suggestions
- 2021
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Ingår i: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 26:12, s. 2339-2354
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Most approaches for energy use assessment in life cycle assessment do not consider the scarcity of energy resources. A few approaches consider the scarcity of fossil energy resources only. No approach considers the scarcity of both renewable and non-renewable energy resources. In this paper, considerations for including physical energy scarcity of both renewable and non-renewable energy resources in life cycle impact assessment (LCIA) are discussed. Methods: We begin by discussing a number of considerations for LCIA methods for energy scarcity, such as which impacts of scarcity to consider, which energy resource types to include, which spatial resolutions to choose, and how to match with inventory data. We then suggest three LCIA methods for physical energy scarcity. As proof of concept, the use of the third LCIA method is demonstrated in a well-to-wheel assessment of eight vehicle propulsion fuels. Results and discussion: We suggest that global potential physical scarcity can be operationalized using characterization factors based on the reciprocal physical availability for a set of nine commonly inventoried energy resource types. The three suggested LCIA methods for physical energy scarcity consider the following respective energy resource types: (i) only stock-type energy resources (natural gas, coal, crude oil and uranium), (ii) only flow-type energy resources (solar, wind, hydro, geothermal and the flow generated from biomass funds), and (iii) both stock- and flow-type resources by introducing a time horizon over which the stock-type resources are distributed. Characterization factors for these three methods are provided. Conclusions: LCIA methods for physical energy scarcity that provide meaningful information and complement other methods are feasible and practically applicable. The characterization factors of the three suggested LCIA methods depend heavily on the aggregation level of energy resource types. Future studies may investigate how physical energy scarcity changes over time and geographical locations.
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| 15. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Potential improvements of the life cycle environmental impacts of a Li/S battery cell
- 2018
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The lithium sulfur (Li/S) battery is a promising battery chemistry for two reasons: it requires no scarce metals apart from the lithium itself and it brings the promise of high specific energy density at the cell level. However, the environmental impacts of this battery type remain largely unstudied. In this study, we conducted a life cycle assessment (LCA) of the production of an Li/S cell to calculate these impacts. The anode consists of a lithium foil and the cathode consists of a carbon/sulfur composite. The electrolyte is a mixture of dioxalane, dimethoxyethane, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium nitrate. The current collector for the cathode is an aluminium foil and a tri-layer membrane of polypropylene and polyethylene acts as separator. The functional unit of the study is 1 kWh specific energy storage. Three key environmental impacts were considered: energy use, climate change and lithium requirement. In our baseline scenario, we consider the pilot-scale production of a battery with a specific energy of 300 kWh/kg, having the mesoporous material CMK-3 as carbon material in the carbon/sulfur cathode, and using coal power and natural gas heat as energy sources. This scenario results in an energy use of 580 kWh/kWhstored and a climate change impact of 230 kg CO2eq/kWhstored. The main contributor to energy use is the LiTFSI production and the main contributor to climate change is electricity use during cell production. We then model a number of possible improvements sequentially: (1) reduction of cell production electricity requirement due to production at industrial-scale, (2) sourcing of electricity and heat from renewable instead of fossil sources (i.e. solar power and biogas heat), (3) improvement of the specific energy of the Li/S cell to 500 kWh/kg and (4) a shift of the carbon material in the cathode to carbon black (without considering changes in performance). By implementing all these four improvements, energy use and climate change impact can be reduced by an impressive 54 and 93%, respectively. In particular, the improvements related to industrial-scale production and sourcing of renewable energy are considerable, whereas the shift of carbon material is of minor importance. For climate change, the best-case result of 17 kg CO2eq/kWhstored is similar to the best-case results reported in the scientific literature for lithium-ion batteries (LIBs). Regarding lithium requirement, the lithium metal requirement of Li/S batteries and LIBs are also of similar magnitude (0.33-0.55 kg/kWhstored and 0.2 kg/kWhstored, respectively). Using different allocation approaches did not alter the main conclusions of the study.
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| 16. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Prospective, Anticipatory and Ex-Ante – What’s the Difference? Sorting Out Concepts for Time-Related LCA
- 2023
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Most life cycle assessment (LCA) studies have considered technologies as they are at the time of the study, often in a mature state. Increasingly, LCA studies attempt to assess emerging technologies in imagined states at future points in time, often referred to as prospective, anticipatory or ex-ante. However, a clear distinction between these LCA types is lacking. We aim to sort these concepts into a typology of time-related LCAs, contributing to more purposeful methodological choices. Existing frameworks for time-realted LCA types were reviewed and typology consisting of three dimensions was found to capture the most important differences. The first dimension is real time, which captures the time difference between the functional unit and the LCA. If the technology is modelled at approximately the same time as when the LCA is conducted, it can be called contemporary LCA. If the technology is modelled at a future point in time relative to the analysis, it can be called prospective LCA, and retrospective LCA if it is modelled at a past point in time relative to the study. Dynamic LCA accounts for that a technology can be “stretched out” along the real time dimension. The second dimension is technology maturity, which can be measured by technology readiness levels (TRLs). Ex-ante LCA considers technologies that are immature at the time of the study but model them in a future when they are assumed to have become mature, and is thus a specific type of prospective LCA. In contrast, ex-post LCA refers to studies of technologies that have reached maturity at the time of the study. Anticipatory LCA is effectively similar to ex-ante LCA but also entails the inclusion of numerous stakeholders in shaping the LCA study. Lab-scale LCA is a contemporary LCA of an immature technology with the aim of suggesting improvements to technology developers. The third dimension is causality. Some LCA studies mainly consider causes of a functional unit, which is often referred to as attributional LCA. Other LCA studies mainly consider effects of a functional unit, which can be called consequential LCA. While the former can be said to look backwards in time, the latter can be said to look forward in time from the perspective of the functional unit. Both types can, however, be retrospective, contemporary, or prospective LCAs as defined above. It is also possible to consider different types of causality, which relate differently to real time and technology maturity.
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| 17. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Terminology for future-oriented life cycle assessment: review and recommendations
- 2024
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Ingår i: International Journal of Life Cycle Assessment. - 1614-7502 .- 0948-3349. ; 29:4, s. 607-613
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Purpose Some future-oriented life cycle assessment (LCA) terms, particularly prospective and ex-ante, show notable increase in use in publications over the last decade. However, scholars have pointed out that it is currently unclear exactly what these terms mean and how they are related. This paper aims to explain defining differences between future-oriented LCA terms and provide terminology recommendations. Methods Existing definitions of future-oriented LCA terms were reviewed and analyzed. Workshops were held where defining differences of future-oriented LCA terms were discussed. Results Temporal positionality and technology maturity appear to be two critical aspects of future-oriented LCA. Prospective and ex-ante LCA are similar, with the possible difference that ex-ante LCA always involves an increase in technology maturity in the future. Considering the notable similarities, it seems reasonable to converge terms to mitigate field fragmentation and avoid terminology confusion. Conclusions To denote LCA studies with a future temporal positionality, we recommend using the term prospective LCA, defined as "LCA that models the product system at a future point in time relative to the time at which the study is conducted". Furthermore, since technology maturity is clearly a critical aspect for prospective LCA, we recommend prospective LCA studies to clearly define the maturity of the technologies modeled in the production system.
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| 18. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
The life cycle environmental performance of a new biomaterial: Wood-based nanocellulose
- 2014
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Ingår i: 20th SETAC Europe LCA case Study Symposium.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This is a study of the environmental performance of nanocellulose, which is a bio-based nanomaterial. Being stronger than steel, biodegradable, transparent, and antibacterial, many potential applications of nanocellulose exist, including composites and films. Global production is steadily increasing, and there are three main types of nanocellulose: (1) Nano-fibrillated cellulose (NFC), which consists of long, spaghetti-like fibers, (2) nano-crystalline cellulose (NCC), which consists of rice-shaped nanoparticles, and (3) bacterial nano cellulose (BNC), which is produced by bacteria. Of these three, NFC and NCC are currently the most produced ones. Many concerns have been raised regarding the high energy use from producing NFC from wood by disintegration of the cellulose fibers. In response to this, a number of production routes involving some kind of pretreatment to facilitate disintegration have been developed. We assessed three routes for NFC production: (1) no pretreatment, (2) the enzymatic production route, where pulp is pretreated by enzymes to facilitate disintegration, and (3) the carboxymethylation production route, where the pulp is pretreated with polyelectrolytes to facilitate disintegration. The routes were assessed with regard to their cradle-to-gate life cycle energy use with a functional unit of 1 kg NFC. Preliminary results show that the enzymatic route required approximately 80-100 MJ/kg, whereas the carboxymethylation route requires approximately 1000 MJ/kg. The route without pretreatment required approximately 200-400 MJ/kg. Notably, the carboxymethylation route had a much higher life cycle energy use than the believed-to-be energy intensive no pretreatment route. This is because the carboxymethylation route requires a large amount of fossil energy in the form of fossil input materials for various purposes. The results illustrate the value of a life cycle perspective when the production of new materials is planned. Comparing these energy use results to that of other nanomaterials as reported in the literature, such as carbon nanotubes and fullerenes (~1000-100000 MJ/kg) and traditional materials such as aluminium (~200 MJ/kg) and polypropylene (~100 MJ/kg) suggest that enzymatic NFC has a very low energy use. Suggestions for improvements are provided in the presentation, and implications for further upscaling are discussed.
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| 19. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Towards transparent and relevant use of energy use indicators in LCA studies of biofuels
- 2012
-
Ingår i: 6th SETAC World Congress / SETAC Europe 22nd Annual Meeting in Berlin.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The use of energy has led to resource crises during the history of mankind, such as the deforestation of the Mediterranean during antiquity, and of Great Britain before the 19th century, and the oil crisis in the 20th century and continuing. Considering this, the frequent use of the impact category ‘energy use’ in the environmental assessment tool life cycle assessment (LCA) is not surprising. However, in a previous study, some of the authors noted that the term ‘energy use’ was not applied in a transparent and consistent way in LCA studies of biofuels. In this work we investigate how energy use indicators are applied in a set of life cycle assessment (LCA) studies of biofuels. In the examined reports and articles, the choice of indicator was seldom motivated or discussed and we observed five inherently different energy use indicators: (1) fossil energy, (2) secondary energy, (3) cumulative energy demand, (4) net energy balance, and (5) total extracted energy. These five energy use indicators were applied to the same cradle-to-gate production system of palm oil methyl ester (PME), giving considerably different output results. This is in itself not unexpected, but indicates the importance of clearly identifying, describing and motivating the choice of energy use indicator. All five indicators can all be useful in specific situations, depending on the goal and scope of the individual study, but the choice of indicators need to be better reported and motivated than what is generally done today. Authors of LCA studies should first define the purpose of their energy use indicator (fossil scarcity, energy scarcity, energy efficiency, cost/benefit comparison) and may then make a motivated choice of the energy use indicator.
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| 20. |
- Behjat, Marta, 1991, et al.
(författare)
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A meta-analysis of LCAs for environmental assessment of a conceptual system: Phosphorus recovery from dairy wastewater
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 369:October
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Tidskriftsartikel (refereegranskat)abstract
- A significant increase in phosphorus-rich dairy wastewater coincides with a decrease in the availability of fossil phosphate rock resources in Europe. This confluence of events has led to the development of technologies for phosphorus recovery from dairy wastewater. This study aims to inform and guide such development with regard to life cycle environmental impacts prior to their implementation in dairy contexts. With the lack of inventory data at this point and the non-existence of earlier life cycle assessments on the use of phosphorus recovery technologies in a dairy context in literature, we performed a meta-analysis where we extracted and compared published results on life cycle environmental impacts from two fields (1) dairy industries, with a focus on the dairy wastewater treatment and (2) phosphorus recovery technologies in a municipal wastewater treatment context. The results show that despite its intended effect, normal dairy wastewater treatment in many cases still contributes significantly to eutrophication. Most of the phosphorus recovery technologies examined here exhibited a lower global warming potential and cumulative energy demand than those of dairy wastewater treatment processes. It indicates that problem shifting could be avoided when phosphorus recovery is introduced. However, no technologies involving incineration have had the impact of acidification reported which represents a potential knowledge gap since impacts are expected related to incineration emissions. A comparison between the extracted data for phosphorus recovery technologies shows that there are lower impacts related to technologies that recover phosphorus from the liquid phase, than from sludge or ash.
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| 21. |
- Behjat, Marta, 1991, et al.
(författare)
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Environmental assessment of phosphorus recovery from dairy sludge: A comparative LCA study
- 2024
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Ingår i: Waste Management. - 0956-053X .- 1879-2456. ; 187, s. 50-60
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Tidskriftsartikel (refereegranskat)abstract
- Phosphate rock is a finite, non-renewable mineral resource that is used primarily in fertiliser production. The scarcity and the increasing demand for this finite material led the European Commission to include it in the critical raw material list in 2014. As a consequence, efforts have been directed towards enhancing material use efficiency, initiating recycling efforts, and formulating waste policies to mitigate the criticality of raw materials. Interest in the development of technologies for nutrient recovery from organic waste streams has increased in recent years, and dairy processing sludge (DPS) is a potential input waste stream. Although the recovery of P from DPS can contribute to more circular flows of nutrients in society, it has to be assessed whether there are also overall environmental gains. This paper reports on a life cycle assessment (LCA) of the environmental impacts of three scenarios for phosphorus (P) recovery involving hydrothermal carbonization (HTC) and struvite precipitation and a comparison to a reference drying scenario. HTC produces a solid fraction (hydrochar), and a liquid fraction (process water) and in one of the scenarios (Scenario 3), leaching the hydrochar for additional P recovery is considered. From the process water as well as from the hydrochar leachate, P is precipitated in the form of struvite. Scenarios 1 and 2 both consider HTC and struvite production with the only difference that the hydrochar is used as a fuel instead of as a fertilizer in the latter case, and Scenario 3 adds leaching of the hydrochar with subsequent struvite production and considers that hydrochar is used as a fuel. In the fourth (reference) scenario, dewatering and drying of DPS is considered. The recovered product use in agriculture was not assessed at this stage. The assessment of the emerging technologies in Scenarios 1–3 was done by studying the technologies in early stages of development but modelling them as more developed in the future. Additional functions beyond the functional unit of one kg of P recovered were handled through a system expansion by substitution approach. This way, the system was credited for calcium ammonium nitrate (CAN) production in all scenarios and for wood chips production in Scenarios 2 and 3. Looking at net outcomes for all scenarios, the life cycle impact indicator results for scenario 2 are lower than the other scenarios in several impact categories. Large gains in scenario 2 are related to the avoided production of wood chips.
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| 22. |
- Behjat, Marta, 1991, et al.
(författare)
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Sustainability indicator identification and selection for an innovative conceptual system: Phosphorus recovery from dairy wastewater
- 2024
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Ingår i: Resources, Conservation and Recycling. - 0921-3449 .- 1879-0658. ; 207
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Tidskriftsartikel (refereegranskat)abstract
- In Europe, a decrease in the availability of phosphate rock resources has led to the development of emerging technologies for phosphorus recovery, with the purpose of generating products that can be used as fertilisers. An innovative conceptual system dedicated to the phosphorus recovery from dairy wastewater is considered in the paper. New technologies need to be assessed using relevant sustainability indicators. In this study, we developed an approach for identifying and selecting indicators. Based on searches of literature and expert interviews, three different tools were developed: an indicator screening framework, a questionnaire for finding actor priorities, and a list of indicator selection criteria. The new approach was successfully used to narrow down an initial set of 382 indicators identified in the literature to 26 that were considered representative and practicable for the assessment of the considered system.
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| 23. |
- Bengmark, Samuel, 1965, et al.
(författare)
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Chalmersutbildning kan ge högre lärarstatus
- 2009
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Ingår i: Göteborgs Posten, Debatt, nätupplagan.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Läraryrket behöver en uppvärdering och stora pensionsavgångar samt svårigheter att konkurrera om studenter till lärarutbildningen kräver åtgärder och nytänkande. Chalmers vill därför starta ämneslärarutbildning i data, fysik, kemi, matematik och teknik så att studenten kan få både en lärarexamen och en ingenjörsexamen, skriver bland andra Samuel Bengmark, programansvarig för Chalmers lärarutbildning.
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| 24. |
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| 25. |
- Bertanza, Giorgio, et al.
(författare)
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A comparison between two full-scale MBR and CAS municipal wastewater treatment plants: techno-economic-environmental assessment
- 2017
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 24:21, s. 17383-17393
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Tidskriftsartikel (refereegranskat)abstract
- A holistic assessment procedure has been used in this study for comparing conventional activated sludge (CAS) and membrane bioreactor (MBR) processes for the treatment of municipal wastewater. Technical, social, administrative, economic and environmental impacts have been evaluated based on 1 year of operational data from three full-scale lines (one MBR and two CAS) working in parallel in a large municipal treatment plant. The comparative assessment evidences a slight advantage of the conventional process in the studied case, essentially due to lower costs, complexity and energy consumption. On the other hand, the MBR technology has a better social acceptance and similar overall environmental footprint. Although these results are influenced by site-specific parameters and cannot be generalized, the assessment procedure allowed identifying the most important factors affecting the final scores for each technology and the main differences between the compared technologies. Local conditions can affect the relative importance of the assessed impacts, and the use of weighting factors is proposed for better tailoring the comparative assessment to the local needs and circumstances. A sensitivity analysis on the weighted final scores demonstrated how local factors are very important and must be carefully evaluated in the decision making process.
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