| 1. |
- Afrane, George, et al.
(författare)
-
A product chain organisation study of certified cocoa supply
- 2013
-
Ingår i: 6th International Conference on Life Cycle Management, LCM2013, 25-28 August 2013,Göteborg.
-
Konferensbidrag (refereegranskat)abstract
- Cocoa supplies may become limited in the future. Demands for sustainable cocoa sparked an exploration of the product chain organisation of conventional and certified cocoa from Ghana. The comparison shows that transparency requirements have led to a more complex product chain. Even so, certification has yielded important productivity increases resulting in environmental benefits (e.g. reduced greenhouse gas emissions) and improved livelihoods for smallholder farmers.
|
|
| 2. |
- Arvidsson, Rickard, 1985, et al.
(författare)
-
An Evaluation of Discharge Strategies for Plug-In Hybrid Electric Vehicles
- 2016
-
Ingår i: 25th Aachen Colloquium.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Discharge strategies for known routes are tested in a Volvo XC90 T8 PHEV in order to evaluate fuel consumption for the drivetrain of a real commuting cycle. An approximate optimal solution is obtained by dynamic programming. The method is implemented in the vehicle control system and compared to a heuristic strategy. The work has been carried out at Volvo Cars test facilities in Gothenburg. Results show that for a known route both combustion engine and battery efficiency increases in both tested methods, with decreased charge transfer through the battery and less charge sustain operation. The dynamic programming strategy has previously been shown to outperform rule based strategies in terms of fuel consumption by comparing the methods in simulation studies. In this study the dynamic programming solution reduced the consumption with - 4 %, and the heuristic strategy decreased consumption even further to - 8 %.
|
|
| 3. |
- Arvidsson, Rickard, 1985, et al.
(författare)
-
Battery parameter estimation from recorded fleet data
- 2016
-
Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627. ; 2016-Octobeer
-
Tidskriftsartikel (refereegranskat)abstract
- A method to identify battery parameters for a Li-ION hybrid battery model based on current and voltage measurements performed in a vehicle during 12 months of in use operation is investigated. This is different from previous work where a common approach is to use current pulse de-rating tests, HPPC, hybrid pulse-power capability, which uses predetermined amplitudes and frequencies of current pulses. Equivalent circuit linear models of different complexity were tested and evaluated in order to identify parameter dependencies at different state of charge levels and temperatures. The average accuracy of modelling the DC bus voltage provides a model goodness average higher than 75% for all analyzed individual log files. The models are used in order to estimate energy output from the battery and compared towards how the estimated voltage error propagates throughout a drive cycle. Both single RC equivalent circuit model and R-equivalent circuit model experienced goodness of fit at average 75 % and dual RC equivalent circuit model was less accurate with average 40 %.
|
|
| 4. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Blood cobalt? Life cycle human health impacts of a lithium-ion battery
- 2022
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Lithium-ion batteries have become the dominating technology for rechargeable batteries. However, they are associated with several social sustainability concerns. In particular, these concerns have been expressed for lithium-ion batteries that contain cobalt in the cathode, such as nickel-manganese-cobalt (NMC) batteries. Cobalt has been on the European Union’s list of critical raw materials since its first appearance in 2011. While not counted among the conflict minerals, the extraction and refining of cobalt in the Democratic Republic of the Congo (DRC) accounts for 70% of the global supply. Reports from this extraction include harsh working conditions, high presence of child laborers and forced evictions, particularly for the 20% share of the extraction conducted at small scale. In this work, the life-cycle health impacts of an NMC battery are quantified using the disability-adjusted life years (DALY) indicator. Health impacts from emissions are included, as well as health impacts from occupational accidents during small-scale cobalt extraction in the DRC and other processes. Two scenarios for occupational fatalities in small-scale cobalt extraction in the DRC were tested: one expert estimate at 2000 fatalities/years and one at only 65 fatalities/year based on reports in media. The results show that given 2000 fatalities/year, cobalt extraction and refining account for 18% of the total health impacts. However, the nickel in the cathode accounts for 30% and the copper used as a current collector for the anode accounts for 20%. Consequently, the results from this study show that while cobalt contributes notably to the health impacts of an NMC battery, nickel and copper are also important to consider for reducing health impacts. The main recommendations are to reduce emissions from nickel and copper extraction, to increase the share of recycled metals in lithium-ion batteries and to improve the occupational safety in small-scale cobalt extraction in the DRC.
|
|
| 5. |
|
|
| 6. |
- Arvidsson, Rickard, 1985, et al.
(författare)
-
Comparing Dynamic Programming Optimal Control Strategies for a Series Hybrid Drivetrain
- 2017
-
Ingår i: SAE Technical Papers. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International. - 0148-7191 .- 2688-3627. ; 2017-October
-
Tidskriftsartikel (refereegranskat)abstract
- A two-state forward dynamic programming algorithm is evaluated in a series hybrid drive-train application with the objective to minimize fuel consumption when look-ahead information is available. The states in the new method are battery state-of-charge and engine speed. The new method is compared to one-state dynamic programming optimization methods where the requested generator power is found such that the fuel consumption is minimized and engine speed is given by the optimum power-speed efficiency line. The other method compared is to run the engine at a given operating point where the system efficiency is highest, finding the combination of engine run requests over the drive-cycle that minimizes the fuel consumption. The work has included the engine torque and generator power as control signals and is evaluated in a full vehicle-simulation model based on the Volvo Car Corporation VSIM tool. Lowest fuel consumption is obtained by the new two-state method, with 12 % less fuel consumed compared to operating the engine in the system efficiency sweet spot.
|
|
| 7. |
- Arvidsson, Rickard, 1985
(författare)
-
Energy Efficient Longitudinal Control
- 2018
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vehicles are contributing to global and local environmental problems as a result of fossil fuels. A majority of the combustion engine population is driven by fossil fuels and electrified vehicles are also to a large extent dependent on electricity production from fossil fuels. Emission legislation and standardized test methods have lead the development of technology for the automotive industry. Increased efficiency, improved combustion control and aftertreatment systems have created cleaner and more fuel efficient drivetrains. Authorities and publications have highlighted an increased gap between in-use and certified vehicle consumption and emissions because of the test-cycles current design. In order to address these differences authorities have conducted changes within the test methods from 2017 and forward and a new test-cycle WLTP is introduced including real-driving-emission test procedures. Decreasing the gap of real driving emissions and consumption can also be improved outside the legislative test-cycles using forward looking sensors, map data and statistical models. The work considers controlling the drivetrain actuators more efficiently in a vehicle with predictive information. For this, dynamic programming is used to optimize engine speed trajectories during depletion mode for a series hybrid drivetrain. The result shows that choice of state and control signals has a direct impact on the engine speed trajectory and thereby the fuel consumption. Up to 21 % lower fuel consumption could be achieved for a series hybrid drivetrain compared to a rule based engine speed demand controller (along the best efficiency line) for the drivecycle analyzed. For a parallel hybrid drivetrain a DP method was compared to a heuristic strategy in order to determine the optimal discharge rate of the battery. In the simulation study done the DP method provided the best fuel consumption results. During evaluation of the physical tests the pre-optimized DP parameter set performed worse than the heuristic strategy. In the rig tests a fuel consumption reduction of 8 % was measured with the heuristic method, compared to a non predictive controller strategy. The DP algorithm provided 4 % reduction of fuel compared to a non predictive controller. The work has also considered different modeling methods of a high voltage battery from recorded fleet data. One individual vehicle recorded battery pack current and voltage for one year. The recorded data was used to identify battery parameters for electric equivalent circuits. The measured current was used to calculate a reference voltage from the circuit equivalent parameters that was compared to the measured voltage. The best result was obtained for a single RC circuit model which obtained the highest average goodness of fit in voltage for the entire training data set.
|
|
| 8. |
- Arvidsson, Rickard, 1985, et al.
(författare)
-
Geofencing as an enabler for Zero-Emission Zones
- 2018
-
Ingår i: 25th ITS World Congress Book of abstracts.
-
Konferensbidrag (refereegranskat)abstract
- Plug-in hybrid vehicles (PHEV) have the ability to operate as electric vehicles.There is a potential toreduce emissions overall and also control emissions in zones, if PHEV are controlled so that they only use electric drive in selected areas such as cities. Through collaboration between the Norwegian Public Roads Administration and Volvo Cars it was shown how a zero emission zone could be created in Oslo as part of the NordicWay Norwegian pilot. The zone was shared with Volvo Cars who optimized powertrain management to ensure no emission driving and sufficient battery power within the zone.
|
|
| 9. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Implementation of the crustal scarcity indicator into life cycle assessment software
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report provides a detailed description of how the crustal scarcity indicator (CSI) is implemented into the life cycle assessment (LCA) software OpenLCA. The original characterization factors for the CSI, called crustal scarcity potentials (CSPs), were designed to be paired with life cycle inventory data formulated as the amount (mass) of elements extracted from the crust. However, some inventory data is not formulated in terms of mass of elements extracted. For example, data in the Ecoinvent database – the world’s largest LCA database – can also be expressed in terms of the amount of mineral extracted, the amount of rock extracted, or the amount of ore extracted. In order to implement the CSI into OpenLCA in a way that captures such nonelement flows, we construct five categories of inventory data for material flows extracted from the crust. Type A flows are flows of elements, such as lead or tin, which the original CSPs can be paired with. Type B flows are flows of minerals, such as kieserite or stibnite. Type C flows are flows of rocks and groups of minerals, such as basalt or olivine. Type D flows are ores, like copper ore. Type A flows are paired with the CSPs of the respective element types. However, for type B, C and D flows, new CSPs were calculated based on their respective content of different elements. These new CSPs can be found in Appendix A-D. In addition, type E flows are those that are too vaguely formulated in the Ecoinvent database, for example as general metal or ore, making it impossible to derive CSPs. In the concluding discussion, we show that this implementation gives the CSI a wider coverage of different inventory flows than other existing mineral resource impact assessment methods implemented in different packages for OpenLCA. The implementation might thus be considered a guidance for a more all-encompassing implementation of other mineral resource impact assessment methods as well.
|
|
| 10. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
Quantifying the life-cycle health impacts of a cobalt-containing lithium-ion battery
- 2022
-
Ingår i: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 27, s. 1106-1118
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Lithium-ion batteries (LIBs) have been criticized for contributing to negative social impacts along their life cycles, especially child labor and harsh working conditions during cobalt extraction. This study focuses on human health impacts — arguably the most fundamental of all social impacts. The aim is to quantify the potential life-cycle health impacts of an LIB cell of the type nickel-manganese-cobalt (NMC 811) in terms of disability-adjusted life years (DALY), as well as to identify hotspots and ways to reduce the health impacts. Methods: A cradle-to-gate attributional life-cycle assessment study is conducted with the functional unit of one LIB cell and human health as the sole endpoint considered. The studied LIB is produced in a large-scale “gigafactory” in Sweden, the cobalt sulfate for the cathode is produced in China, and the cobalt raw material is sourced from the Democratic Republic of the Congo (DRC). Potential health impacts from both emissions and occupational accidents are quantified in terms of DALY, making this an impact pathway (or type II) study with regard to social impact assessment. Two scenarios for fatality rates in the artisanal cobalt mining in the DRC are considered: a high scenario at 2000 fatalities/year and a low scenario at 65 fatalities/year. Results: Applying the high fatality rate, occupational accidents in the artisanal cobalt mining in the DRC contribute notably to the total life-cycle health impacts of the LIB cell (13%). However, emissions from production of nickel sulfate (used in the cathode) and of copper foil (the anode current collector) contribute even more (30% and 20%, respectively). These contributions are sensitive to the selected time horizon of the life-cycle assessment, with longer or shorter time horizons leading to considerably increased or decreased health impacts, respectively. Conclusions: In order to reduce the health impacts of the studied LIB, it is recommended to (i) investigate the feasibility of replacing the copper foil with another material able to provide anode current collector functionality, (ii) reduce emissions from metal extraction (particularly nickel and copper), (iii) increase the recycled content of metals supplied to the LIB manufacturing, and (iv) improve the occupational standards in artisanal mining in the DRC, in particular by reducing fatal accidents.
|
|
| 11. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
The zinc paradox – a problem for USEtox-based indicators of national chemical footprints?
- 2016
-
Ingår i: SETAC Europe 22th Case Study Symposium, 20-22 September, Montpellier, France.
-
Konferensbidrag (refereegranskat)abstract
- Considering the immense problem of chemical pollution worldwide, there is a great need for methods that can be used to calculate indicators of chemical footprints. Such indicators can be calculated for products and services using life cycle assessment (LCA), but also for whole nations. Indicators of national chemical footprints may include emissions within the nation’s borders only, or also emissions related to consumption (thus having a life cycle perspective). A limited number of studies ( 50% of the toxicity impacts for both ecotoxicity and human toxicity. For ecotoxicity, this is not unreasonable considering the notable toxicity of zinc to aquatic organisms. For human toxicity, this result is more surprising. Zinc is an essential trace element for humans that many take as a dietary supplement to prevent zinc deficiency. Non-LCA sources describe zinc as “relatively harmless” to human health. The World Health Organisation (WHO) does not list zinc among the top ten chemicals of major public health concern, although there are other metals on the list (mercury, lead, cadmium and arsenic). These contradictory claims about zinc’s health impact seem to constitute a paradox. We present a review of existing studies assessing indicators of national chemical footprints, and of toxicological research related to zinc. We further discuss potential causes of this zinc paradox, as well as implications for assessments of indicators of national chemical footprints with USEtox.
|
|
| 12. |
- Chordia, Mudit, 1985, et al.
(författare)
-
Does the grade and source of lithium used in batteries matter?
- 2022
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Lithium-based batteries are increasingly being implemented for storing energy, both in transportation and stationary applications. As battery manufacturing matures and becomes more efficient, the environmental burdens of these batteries shift upstream, for example to the lithium supply. The majority of the current global lithium supply comes from two sources – spodumene mined in Australia and brines extracted in Chile. In this study, we review existing life cycle assessment literature on lithium production regarding data completeness and quality, as well as temporal and geographical relevance. Preliminary results indicate that the currently most used datasets in life cycle assessment studies of lithium-based batteries lack quality and representativeness of current operations. To address these gaps, this study compiles several new datasets for lithium production representing different geographies, technical processes, and lithium grades. First, we compare the inventory data of other existing lithium supply datasets, both older and newly compiled, regarding their quality and representativeness. Second, we look at future scenarios for lithium supply based on global proven reserves and analyze the influence of changing grades on future environmental impacts. Third, we examine the potential for reducing environmental impacts from the lithium-supply chain by linking all electricity inputs to renewable sources. Finally, we use the various lithium datasets compiled in this study to update the results of a giga-scale lithium-ion battery manufacturing in a recently published study. We focus on climate change and mineral resource use impacts. Additionally, to inform a growing debate in scientific literature around the water use impacts related to brine and freshwater extraction in water-stressed regions of the world, such as the salars in South America, we use regionalized water use assessment indicators to further assess the burdens of battery production from water use perspective.
|
|
| 13. |
- Chordia, Mudit, 1985, et al.
(författare)
-
Life cycle environmental impacts of current and future battery-grade lithium supply from brine and spodumene
- 2022
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 187
-
Forskningsöversikt (refereegranskat)abstract
- Life cycle assessment studies of large-scale lithium-ion battery (LIB) production reveal a shift-of-burden to the upstream phase of cell production. Thus, it is important to understand how environmental impacts differ based on the source and grade of extracted metals. As lithium is highly relevant to several current and next-generation cell chemistries, we reviewed the effect of varying grades in different sources of lithium (brine and spodumene) worldwide. The review covered the Ecoinvent database, scientific literature, and technical reports of several upcoming production facilities. The results showed that lower-grade lithium brines have higher environmental impacts compared to higher-grade brines. However, spodumene-based production did not show such a trend, due to different technical process designs of the facilities reviewed. Water use impacts are higher in lower-grade sources and are expected to increase with decreasing lithium concentration. This could specifically be an issue in brine-based production, where brine is extracted from already water scarce regions and evaporated, thus increasing the risk of freshwater availability. However, these aspects of water use are not addressed in existing life cycle impact assessment methods. In the context of large-scale LIB cell production, the reviewed lithium hydroxide production routes account for 5–15% of the climate change impacts.
|
|
| 14. |
- Lock, Jonathan, 1987, et al.
(författare)
-
Optimal Transient Real-Time Engine-Generator Control in the Series-Hybrid Vehicle
- 2019
-
Ingår i: ASME 2019 Dynamic Systems and Control Conference, DSCC 2019. ; 2
-
Konferensbidrag (refereegranskat)abstract
- We study the dynamic engine-generator optimal control problem with a goal of minimizing fuel consumption while delivering a requested average electrical power. By using an infinite-horizon formulation and explicitly minimizing fuel consumption, we avoid issues inherent with penalty-based and finite-horizon problems. The solution to the optimal control problem, found using dynamic programming and the successive approximation method, can be expressed as instantaneous non-linear state-feedback. This allows for trivial real-time control, typically requiring 10–20 CPU instructions per control period, a few bytes of RAM, and 5–20 KiB of nonvolatile memory. Simulation results for a passenger vehicle indicate a fuel consumption improvement in the region of 5–7% during the transient phase when compared with the class of controllers found in the industry. Bench-tests, where the optimal controller is executed in native hardware, show an improvement of 3.7%, primarily limited by unmodeled dynamics. Our specific choice of problem formulation, a guaranteed globally optimal solution, and trivial real-time control resolve many of the limitations with the current state of optimal engine-generator controllers.
|
|
| 15. |
- Nordborg, Maria, 1985, et al.
(författare)
-
Updated indicators of Swedish national human toxicity and ecotoxicity footprints using USEtox 2.01
- 2017
-
Ingår i: ENVIRONMENTAL IMPACT ASSESSMENT REVIEW. - : Elsevier. - 0195-9255. ; 62, s. 110-114
-
Tidskriftsartikel (refereegranskat)abstract
- In a recent paper, Sorme et al. (Environ. Impact Assess. Rev., 56, 2016), took a first step towards an indicator of a national chemical footprint, and applied it to Sweden. Using USEtox 1.01, they calculated national impact potentials for human toxicity and ecotoxicity. The results showed that zinc dominated impacts, both for human toxicity and ecotoxicity. We calculated updated indicators of the Swedish national human toxicity and ecotoxicity footprint using USEtox 2.01. We also compared impact potentials based on USEtox with the mass of chemical emissions. The two model versions produced relatively consistent results. Zinc is still a major contributor to the human toxicity and ecotoxicity impact potentials when-characterized with USEtox 2.01. The mass-based indicator pinpoints somewhat different substances than the impact-based indicators.
|
|
| 16. |
- Nordelöf, Anders, 1975, et al.
(författare)
-
Methodological Approaches to End-Of-Life Modelling in Life Cycle Assessments of Lithium-Ion Batteries
- 2019
-
Ingår i: Batteries. - : MDPI AG. - 2313-0105. ; 5:51, s. 1-15
-
Forskningsöversikt (refereegranskat)abstract
- This study presents a review of how the end-of-life (EOL) stage is modelled in life cycle assessment (LCA) studies of lithium-ion batteries (LIBs). Twenty-five peer-reviewed journal and conference papers that consider the whole LIB life cycle and describe their EOL modelling approach sufficiently were analyzed. The studies were categorized based on two archetypal EOL modelling approaches in LCA: The cutoff (no material recovery, possibly secondary material input) and EOL recycling (material recovery, only primary material input) approaches. It was found that 19 of the studies followed the EOL recycling approach and 6 the cutoff approach. In addition, almost a third of the studies deviated from the expected setup of the two methods by including both material recovery and secondary material input. Such hybrid approaches may lead to double counting of recycling benefits by both including secondary input (as in the cutoff approach) and substituting primary materials (as in the EOL recycling approach). If the archetypal EOL modelling approaches are not followed, it is imperative that the modelling choices are well-documented and motivated to avoid double counting that leads to over- or underestimations of the environmental impacts of LIBs. Also, 21 studies model hydrometallurgical treatment, and 17 completely omit waste collection.
|
|
| 17. |
- Peters, Gregory, 1970, et al.
(författare)
-
A Swedish comment on ‘review: the availability of life-cycle studies in Sweden’
- 2019
-
Ingår i: International Journal of Life Cycle Assessment. - : Springer Science and Business Media LLC. - 1614-7502 .- 0948-3349. ; 24:10, s. 1758-1759
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The article entitled ‘Review: the availability of life-cycle studies in Sweden’ by Croft and colleagues (January 2019, volume 24, issue 1, pages 6–11) has puzzled many researchers in Sweden. The stated purpose of the article is to review the availability of water and carbon footprinting studies and life-cycle assessment (LCA) studies in Sweden. Despite its title and purpose suggesting otherwise, the article appears to be about the accessibility of life-cycle case studies from Sweden in South Africa. It is problematic that the article claims to be a review in the title and text, but is presented by the journal as a commentary. We believe that the article’s method is unclear and that its title and results are misleading. The authors of the article found only 12 academic papers, 10 academic theses, 8 company reports, and 1 presentation. This result significantly underestimates the actual production and availability of Swedish LCA case studies.
|
|
| 18. |
- Wickerts, Sanna, 1992, et al.
(författare)
-
Energy storage with less metal scarcity? Prospective life cycle assessment of lithium-sulfur batteries with a focus on mineral resources.
- 2021
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to reduce the global dependency on fossil fuels by adopting renewable energy technologies and advancing electromobility, batteries are a key technology. Lithium-ion batteries (LIBs) are currently the dominant rechargeable battery technology, mainly due to their high energy density. However, most LIBs contain a number of geochemically scarce metals, e.g.cobalt, lithium and nickel. The production of LIBs is furthermore associated with considerable environmental impacts. Battery researchers and companies therefore try to develop the next generation batteries (NGBs) with the same or even higher energy densities than LIBs, while requiring less of scarce metals and causing lower environmental impacts. One promising NGB technology is the lithium-sulfur (Li-S) battery, with a potential to significantly improve energy density as compared to current state-of-the-art LIBs. Although Li-S batteries still face a number of scientific and technical challenges, they have a significant advantage over LIBs from a resource point of view: the cells do not require any scarce metals besides lithium. Using prospective life cycle assessment, we will assess the life-cycle environmental impacts of Li-S batteries and compare them to those of LIBs, both modeled at large-scale production. In order to investigate the effect of using less scarce metals on resource impacts, the mineral resource impact category will be given extra attention. We will therefore include a range of mineral resource impact assessment methods, e.g. the abiotic depletion indicator, the surplus ore indicator, and the recently developed crustal scarcity indicator, which takes an explicit long-term perspective on elemental resources in the Earth’s crust. The overall aim is thus to compare the prospective life-cycle impacts of this particular NGB to those of LIBs, with a focus on mineral resources.
|
|
