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| 2. |
- Lönnqvist, Tomas, 1979-, et al.
(författare)
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Stimulating biogas in the transport sector in a Swedish region - An actor and policy analysis with supply side focus
- 2019
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Ingår i: Renewable & sustainable energy reviews. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1364-0321 .- 1879-0690. ; 113
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Forskningsöversikt (refereegranskat)abstract
- This article addresses incentives and barriers for the development of biogas production and use in transport. It is based on statistics, interviews with biogas actors in a Swedish region, as well as a literature study. These actors perceive that the stagnating vehicle gas demand is the major barrier for biogas development. Policy support could stimulate the vehicle gas demand to strengthen incentives for investments along the entire biogas value chain. There are opportunities on the supply side to increase biogas production based on waste and residues, to improve digestate handling, and to expand the gas distribution infrastructure. However, the sector perceives a high risk in biogas investments partially due to the low predictability of Swedish policy instruments and this, together with the stagnated demand for vehicle gas, are identified as the main barriers for biogas development. Thus, policy makers should focus on these barriers if the intention is to develop the use of biogas in transport.
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| 3. |
- Andersson, Joakim, et al.
(författare)
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A comparison of two hydrogen storages in a fossil-free direct reduced iron process
- 2021
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 46:56, s. 28657-28674
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogen direct reduction has been proposed as a means to decarbonize primary steelmaking. Preferably, the hydrogen necessary for this process is produced via water electrolysis. A downside to electrolysis is the large electricity demand. The electricity cost of water electrolysis may be reduced by using a hydrogen storage to exploit variations in electricity price, i.e., producing more hydrogen when the electricity price is low and vice versa. In this paper we compare two kinds of hydrogen storages in the context of a hydrogen direct reduction process via simulations based on historic Swedish electricity prices: the storage of gaseous hydrogen in an underground lined rock cavern and the storage of hydrogen chemically bound in methanol. We find the methanol-based storages to be economically advantageous to lined rock caverns in several scenarios. The main advantages of methanol-based storage are the low investment cost of storage capacity and the possibility to decouple storage capacity from rate capacity. Nevertheless, no storage option is found to be profitable for historic Swedish electricity prices. For the storages to be profitable, electricity prices must be volatile with relatively frequent high peaks, which has happened rarely in Sweden in recent years. However, such scenarios may become more common with the expected increase of intermittent renewable power in the Swedish electricity system.
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| 4. |
- Andersson, Joakim, et al.
(författare)
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Improving the economics of fossil-free steelmaking via co-production of methanol
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 350, s. 131469-
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Tidskriftsartikel (refereegranskat)abstract
- Steelmaking is responsible for 7% of the global net emissions of carbon dioxide and heavily reducing emissions from currently dominating steelmaking processes is difficult and costly. Recently, new steelmaking processes based on the reduction of iron ore with hydrogen (H-2) produced via water electrolysis have been suggested. If the electricity input to such processes is fossil-free, near-zero carbon dioxide emissions steelmaking is achievable. However, the high electricity demand of electrolysis is a significant implementation barrier. A H-2 storage may alleviate this via allowing a larger share of H-2 to be produced at low electricity prices. However, accurately forecasting electricity market dynamics is challenging. This increases the risk of investment in a H-2 storage. Here we evaluate a novel methanol-based H-2 storage concept for H-2-based steelmaking that also allows for the coproduction of methanol. During electricity price peaks, the methanol can be reformed to produce H-2 for the steelmaking process. During prolonged periods of low electricity prices, excess methanol can be produced and sold off, thus improving the prospects of storage profitability. We use historical electricity prices and a process model to evaluate methanol and fossil-free steel co-production schemes. Methanol co-production is found to have the potential to improve the economics of H-2 supply to a fossil-free steelmaking process by up to an average of 0.40 (sic)/kg H-2 across considered scenarios, equivalent to a 25.0% reduction in H-2 production electricity costs.
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| 5. |
- Andersson, Joakim, et al.
(författare)
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Large-scale storage of hydrogen
- 2019
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Ingår i: International journal of hydrogen energy. - : Elsevier Ltd. - 0360-3199 .- 1879-3487. ; 44:23, s. 11901-11919
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Tidskriftsartikel (refereegranskat)abstract
- The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale, the approach is not applicable in all regions due to varying geological conditions. Therefore, other storage methods are necessary. In this article, options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies, such as liquid hydrogen, methanol, ammonia, and dibenzyltoluene, is found to be advantageous in terms of storage density, cost of storage, and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting, these variable costs may be tolerable.
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| 6. |
- Andersson, Joakim, et al.
(författare)
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Methanol as a carrier of hydrogen and carbon in fossil-free production of direct reduced iron
- 2020
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Ingår i: Energy Conversion and Management. - : Elsevier. - 2590-1745. ; 7:100051
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Tidskriftsartikel (refereegranskat)abstract
- Steelmaking is responsible for around 7% of the global emissions of carbon dioxide and new steelmaking processes are necessary to reach international climate targets. As a response to this, steelmaking processes based on the direct reduction of iron ore by hydrogen produced via water electrolysis powered by renewable electricity have been suggested. Here we present a novel variant of hydrogen-based steelmaking incorporating methanol as a hydrogen and carbon carrier together with high-temperature co-electrolysis of water and carbon dioxide and biomass oxy-fuel combustion. The energy and mass balances of the process are analyzed. It is found that this methanol-based direct reduction process may potentially offer a number of process-related advantages over a process based on pure hydrogen, featuring several process integration options. Notably, the electricity and total energy use of the steelmaking process could be reduced by up to 25% and 8% compared to a reference pure-hydrogen process, respectively. The amount of high-temperature (>200 °C) heat that must be supplied to the process could also be reduced by up to approximately 34%, although the demand for medium-temperature heat is substantially increased. Furthermore, the suggested process could allow for the production of high-quality direct reduced iron with appropriate carburization to alleviate downstream processing in an electric arc furnace, which is not the case for a process based on pure hydrogen.
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| 7. |
- Andersson, Joakim, 1993-
(författare)
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Non-geological hydrogen storage for fossil-free steelmaking
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the last half-century, global steel use has increased more than threefold and further growth is expected, particularly in developing economies. However, steelmaking is currently responsible for 7% of the global net carbon dioxide (CO2) emissions, and any substantial further optimization of existing processes that utilize fossil fuels for iron ore reduction is infeasible. Therefore, steelmaking must change for climate change mitigation targets to be achievable. Hydrogen (H2) steelmaking using H2 produced via electrolysis is one way forward. A challenge is the substantial electricity demand of electrolysis. H2 storage may lower the electricity cost of electrolysis by allowing a larger share of H2 to be produced when the electricity price is low. Existing experience with large-scale H2 storage is limited to salt caverns and the construction of such caverns requires suitable geological formations, which are neither ubiquitous nor well-distributed. However, geologically-independent H2 storage technologies have not previously been evaluated for integration with H2 steelmaking. This is the aim of this thesis. H2 storage technologies were reviewed and liquid H2 carriers were identified as the most techno-economically feasible non-geological options. Out of these liquid carriers, methanol (CH3OH) was found particularly promising for H2 steelmaking due to the low heat demand of its dehydrogenation, its low-cost storage, and the high technological readiness of plants for both its production and dehydrogenation. A complete CH3OH-based H2 storage concept was developed, including processes for CO2 and heat supply. Its ability to reduce the H2 production cost in a H2 steelmaking process was evaluated via a deterministic optimization method based on historical electricity prices. Results indicate that CH3OH-based storage may be competitive with geological storage options, especially for cases with long-duration electricity price patterns. The option to also sell off accumulated CH3OH from the storage was investigated. Such steel and CH3OH co-production may improve storage utilization and reduce the risk of investment into H2 storage as it allows for profitability to be reached under a more diverse set of electricity market conditions.
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| 8. |
- Gustafsson, Kåre, et al.
(författare)
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BECCS with combined heat and power : Assessing the energy penalty
- 2021
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836 .- 1878-0148. ; 108
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Tidskriftsartikel (refereegranskat)abstract
- Bio-energy with carbon capture and storage (BECCS) is widely recognised as an important carbon dioxide removal technology. Nevertheless, BECCS has mostly failed to move beyond small-scale demonstration units. One main factor is the energy penalty incurred on power plants. In previous studies, this penalty has been determined to be 37.2 %?48.6 % for the amine capture technology. The aim of this study is to quantify the energy penalty for adding the hot potassium carbonate (HPC) capture technology to a biomass-fired combined heat and power (CHP) plant, connected to a district heating system. In this context, the energy driving the capture process is partly recovered as useful district heating. Therefore, a modified energy penalty is proposed, with the inclusion of recovered heat. This inclusion is especially meaningful if the heat has a substantial monetary value. The BECCS system is examined using thermodynamic analysis, coupled with modelling of the capture process in Aspen PlusTM. Model validation is performed with data from a BECCS test facility. The results of this study show that the modified energy penalty is in the range of 2%?4%. These findings could potentially increase the attractiveness of BECCS as a climate abatement option in a district heating CHP setting.
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| 9. |
- Krüger, Andries, et al.
(författare)
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Integration of water electrolysis for fossil-free steel production
- 2020
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Ingår i: International journal of hydrogen energy. - : Elsevier Ltd. - 0360-3199 .- 1879-3487. ; 45:55, s. 29966-29977
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates the integration of water electrolysis technologies in fossil-free steelmaking via the direct reduction of iron ore followed by processing in an electric arc furnace (EAF). Hydrogen (H2) production via low or high temperature electrolysis (LTE and HTE) is considered for the production of carbon-free direct reduced iron (DRI). The introduction of carbon into the DRI reduces the electricity demand of the EAF. Such carburization can be achieved by introducing carbon monoxide (CO) into the direct reduction process. Therefore, the production of mixtures of H2 and CO using either a combination of LTE coupled with a reverse water-gas shift reactor (rWGS-LTE) or high-temperature co-electrolysis (HTCE) was also investigated. The results show that HTE has the potential to reduce the specific electricity consumption (SEC) of liquid steel (LS) production by 21% compared to the LTE case. Nevertheless, due to the high investment cost of HTE units, both routes reach similar LS production costs of approximately 400 €/tonne LS. However, if future investment cost targets for HTE units are reached, a production cost of 301 €/tonne LS is attainable under the conditions given in this study. For the production of DRI containing carbon, a higher SEC is calculated for the LTE-rWGS system compared to HTCE (4.80 vs. 3.07 MWh/tonne LS). Although the use of HTCE or LTE-rWGS leads to similar LS production costs, future cost reduction of HTCE could result in a 10% reduction in LS production cost (418 vs. 375 €/tonne LS). We show that the use of HTE, either for the production of pure H2 or H2 and CO mixtures, may be advantageous compared to the use of LTE in H2-based steelmaking, although results are sensitive to electrolyzer investment costs, efficiencies, and electricity prices.
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| 10. |
- Larsson, Mårten, et al.
(författare)
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Bio-methane upgrading of pyrolysis gas from charcoal production
- 2013
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 3, s. 66-73
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Tidskriftsartikel (refereegranskat)abstract
- This article presents a novel route for bio-methane synthesis utilizing pyrolysis gas from charcoal production. It is a retrofit option that may increase overall process efficiency in charcoal production while adding a valuable product. The pyrolysis gas from charcoal production can be used for bio-methane production instead of burning, while the required heat for the charcoal production is supplied by additional biomass. The aim is to evaluate the energy efficiency of bio-methane upgrading from two types of charcoal plants, with and without recovery of liquid by-products (bio-oil). Aspen simulations and calculations of the energy and mass balances are used to analyse the system. The yield of bio-methane compared to the import of additional biomass is estimated to be 81% and 85% (biomass to bio-methane yield) for the syngas case and the pyrolysis vapour case, respectively. When the biomass necessary to produce the needed electricity (assuming ηel = 33%) is included, the yields amount to 65% and 73%. The results show that the suggested process is a competitive production route for methane from lignocellulosic biomass.
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