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Publikasjoner (10 av 105) Visa alla publikasjoner
Mehrara, M., Zetterholm, J., Toffolo, A. & Wetterlund, E. (2026). Risk, flexibility, and investment in Fischer–Tropsch fuels: Insights from real options analysis. Cleaner Energy Systems, 13, Article ID 100232.
Åpne denne publikasjonen i ny fane eller vindu >>Risk, flexibility, and investment in Fischer–Tropsch fuels: Insights from real options analysis
2026 (engelsk)Inngår i: Cleaner Energy Systems, ISSN 2772-7831, Vol. 13, artikkel-id 100232Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The transition to sustainable transportation fuels requires investment in emerging biomass-to-liquid production pathways under uncertain market and policy conditions. This study applies a real options analysis framework to evaluate the economic viability and timing of investments in biomass- and power-to-liquid pathways by identifying conditions where an investor should invest, defer, or abandon investments. The analysis is conducted for Sweden, reflected by its large biomass base and well-developed forest industry and ambitious defossilization policies. Results indicate that large price gaps between feedstock and produced fuels are not by themselves sufficient to trigger investment; in volatile markets, investors may still defer because the option to wait has economic value. Thus, even at identical price levels across scenarios, outcomes range from commitment to inaction depending on volatility. Moreover, when investments do occur, they are consistently deferred until the final year of the investment window. While modest subsidies may suffice under stable price conditions, volatile markets with high drifts require significantly greater support to counteract the incentive to defer investments. Electricity cost structures and carbon pricing must be targeted to support the transition toward electrified fuel production pathways. The insights from this study can inform the design of policy instruments that align investor incentives with global transition goals.

sted, utgiver, år, opplag, sider
Elsevier, 2026
Emneord
Biofuel, eFuel, Geometric Brownian motion, Investment behavior, Real option analysis, RFNBO
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-116092 (URN)10.1016/j.cles.2026.100232 (DOI)
Forskningsfinansiär
Swedish Energy Agency, P2021-00083Bio4Energy
Merknad

Full text license: CC BY-NC-ND

Tilgjengelig fra: 2026-01-21 Laget: 2026-01-21 Sist oppdatert: 2026-01-21
Mehrara, M., Mesfun, S., Ahlström, J., Toffolo, A. & Wetterlund, E. (2025). Electrification-enabled production of Fischer-Tropsch liquids – A process and economic perspective. Applied Energy, 393, 126083, Article ID 126083.
Åpne denne publikasjonen i ny fane eller vindu >>Electrification-enabled production of Fischer-Tropsch liquids – A process and economic perspective
Vise andre…
2025 (engelsk)Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 393, s. 126083-, artikkel-id 126083Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Transitioning to biofuels is crucial for reducing greenhouse gas (GHG) emissions in transportation, but limited biomass availability requires maximizing carbon efficiency. This study evaluates Fischer-Tropsch liquid (FTL) production from biomass, focusing on the impact of partial electrification and carbon capture and storage (CCS) on efficiency and flexibility. Five configurations—ranging from a biomass-intensive base case to a fully electrified process—are simulated and assessed through techno-economic and GHG evaluations under fluctuating energy prices. Full electrification achieves the highest carbon efficiency, increasing carbon-to-liquid fuel conversion from 37 % to 91 %, but faces challenges due to high electricity demand (up to 2.5 MWh per MWh of fuel) and reliance on low-carbon grids. Partial electrification offers a cost-effective alternative, reducing production costs by up to 40 % compared to fully electrified cases, while maintaining a carbon efficiency of around 60 %. CCS enables net-negative emissions, though its viability hinges on sufficiently strong carbon pricing incentives. Compliance with sustainability mandates, such as Renewable Fuels of Non-Biological Origin (RFNBO) requirements, depends on access to decarbonized electricity. Overall, partially electrified BtL pathways enhance carbon utilization, reduce emissions, and offer resilience to market fluctuations. These pathways provide a promising balance of environmental and economic performance, outperforming both traditional BtL under high biomass prices and fully electrified e-fuels in terms of cost. Their advantages make them attractive from both investment and policy perspectives—especially in markets supported by stable electricity prices, carbon incentives, and sustainability-driven regulation.

sted, utgiver, år, opplag, sider
Elsevier BV, 2025
Emneord
Advanced biofuels, E-fuels, Fischer-Tropsch, Biomass gasification, Techno-economic assessment
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-112704 (URN)10.1016/j.apenergy.2025.126083 (DOI)001495240900002 ()2-s2.0-105005090044 (Scopus ID)
Forskningsfinansiär
Swedish Energy Agency, P2021-00083Bio4Energy
Merknad

Validerad;2025;Nivå 2;2025-05-19 (u5);

Full text license: CC BY 4.0;

Tilgjengelig fra: 2025-05-19 Laget: 2025-05-19 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Gebart, R., Emami, N., Försth, M., Hardell, J., Ji, X., Lundgren, J., . . . Åkerfeldt, P. (2025). Introduction to Industrial Hydrogen Technology. Luleå: Luleå University of Technology
Åpne denne publikasjonen i ny fane eller vindu >>Introduction to Industrial Hydrogen Technology
Vise andre…
2025 (engelsk)Annet (Annet vitenskapelig)
sted, utgiver, år, sider
Luleå: Luleå University of Technology, 2025. s. 218
HSV kategori
Identifikatorer
urn:nbn:se:ltu:diva-115472 (URN)
Merknad

Full text license: CC BY-NC-ND

Tilgjengelig fra: 2025-11-22 Laget: 2025-11-22 Sist oppdatert: 2025-11-22bibliografisk kontrollert
Allansson, J., Toffolo, A. & Samuelsson, B. (2025). Spatially-explicit optimization of hydrogen supply chains utilizing offshore wind power. Optimization and Engineering
Åpne denne publikasjonen i ny fane eller vindu >>Spatially-explicit optimization of hydrogen supply chains utilizing offshore wind power
2025 (engelsk)Inngår i: Optimization and Engineering, ISSN 1389-4420, E-ISSN 1573-2924Artikkel i tidsskrift (Fagfellevurdert) Epub ahead of print
Abstract [en]

Hydrogen production coupled with renewable energy sources (RES) is a promising solution to utilize otherwise curtailed electricity. Hydrogen is also seen as a potential solution in several hard-to-abate industries, such as the maritime industry. This opens the opportunity for hydrogen supply chains utilizing RES to supply hard-to-abate industries with hydrogen. These hydrogen supply chains utilize either electricity cables or hydrogen pipelines to transport energy. Previous studies show that the most cost-efficient means of transportation depends on both the distance and the amount of energy to be transported. In the context of offshore energy production, the problem is further expanded by the conditions of offshore infrastructure. To capture the effect of offshore conditions in the supply chain design, this paper presents a MILP model that minimizes the cost of a power-to-gas hydrogen supply chain, including the decision of where in the supply chain the electrolyzer should be located. The model is applied to a case in southern Sweden with renewable offshore wind supplying electricity to produce hydrogen as maritime fuel for a ferry. The results show that the relation between offshore and onshore distances, together with increased costs for offshore infrastructure, greatly influence the choice of transmission mode. Hence, this study found that a hybrid solution with offshore electricity transmission to the closest point onshore followed by onshore hydrogen transmission through pipelines to be the least cost option for energy transmission in the hydrogen supply chain.

sted, utgiver, år, opplag, sider
Springer, 2025
Emneord
Hydrogen, Optimization, Supply-chain, Renewable energy, Transportation and distribution, Wind-to-hydrogen
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-116032 (URN)10.1007/s11081-025-10062-5 (DOI)2-s2.0-105025376023 (Scopus ID)
Forskningsfinansiär
Swedish Energy Agency, 2315912-0611
Merknad

Full text license: CC BY 4.0;

Funder: Nordic Energy Research, NER (2315912-0611)

Tilgjengelig fra: 2026-01-19 Laget: 2026-01-19 Sist oppdatert: 2026-01-19
Fischer, R. & Toffolo, A. (2024). Game theory-based analysis of policy instrument consequences on energy system actors in a Nordic municipality. Heliyon, 10(4), Article ID e25822.
Åpne denne publikasjonen i ny fane eller vindu >>Game theory-based analysis of policy instrument consequences on energy system actors in a Nordic municipality
2024 (engelsk)Inngår i: Heliyon, E-ISSN 2405-8440, Vol. 10, nr 4, artikkel-id e25822Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The transition of energy systems requires policy frameworks and instruments to make both energy suppliers and consumers contribute to the common goal of emission reductions and to fairly allocate costs and benefits among market actors and the government. Assuming that market actors – suppliers and consumers adhering to their economic interests – would benefit from cooperating to mitigate emissions, this study applies a game theory-based approach to investigate the interaction between a local electricity supplier and a group of heating consumers not connected to district heating. Selected policy instruments are tested, and their consequences are analyzed in the context of a representative Nordic municipality. The results show that the auction-based Contract for Difference policy instrument is the most suitable one in the studied Nordic context to achieve significant levels of CO2 emissions reduction. It creates a higher level of strategic interaction between the actors, that would be lacking otherwise, under the form of transfer payments from consumers to supplier, and avoids costs to the general taxpayer. While this is sufficient to promote the investments in renewables by the supplier, additional subsidy policies are required to enable the heating consumers to invest in more capital-intensive energy efficiency measures or biomass heating.

sted, utgiver, år, opplag, sider
Elsevier, 2024
Emneord
Carbon emissions, Energy system optimization, Energy transition, game theory, Heating systems, policy instruments, Renewable energy
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-104506 (URN)10.1016/j.heliyon.2024.e25822 (DOI)001188411500001 ()38390069 (PubMedID)2-s2.0-85185440071 (Scopus ID)
Forskningsfinansiär
Luleå University of Technology
Merknad

Validerad;2024;Nivå 2;2024-03-07 (hanlid);

Full text license: CC BY

Tilgjengelig fra: 2024-03-07 Laget: 2024-03-07 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Dal Cin, E., Lazzaretto, A. & Toffolo, A. (2023). A novel extension of the SYNTHSEP methodology for the optimal synthesis and design of supercritical CO2 cycles in waste heat recovery applications. Energy Conversion and Management, 276, Article ID 116535.
Åpne denne publikasjonen i ny fane eller vindu >>A novel extension of the SYNTHSEP methodology for the optimal synthesis and design of supercritical CO2 cycles in waste heat recovery applications
2023 (engelsk)Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 276, artikkel-id 116535Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The reduction of anthropogenic emissions of greenhouse gases requires decreasing the overall consumption of primary energy. Thus, waste heat recovery at medium-to-high temperature is an opportunity for generating electricity while reducing the need for primary resources. Recently, supercritical carbon dioxide power cycles (S-CO2) are emerging as a promising solution. However, a method lacks to simultaneously optimize their layout and design parameters, without relying on superstructures defined a priori. To this end, this paper suggests a novel extension of the superstructure free SYNTHSEP methodology, a bottom-up approach for the optimal synthesis and design of thermodynamic cycles, to handle also super- and transcritical cycles. An Evolutionary Algorithm combining elementary cycles makes it possible to define optimal S-CO2 configurations without limiting the search space of the optimization problem. The objective consists in finding the S-CO2 topology and design parameters that maximize the mechanical power extractable from waste heat streams in the temperature range from 200 to 700 °C, typical of the industrial sector. Results demonstrate the capability of the method to find optimal cycle layouts for any given waste heat temperature, and to achieve, at the same conditions, cycle efficiencies up to 5 % higher in relative terms than the best ones in the literature.

sted, utgiver, år, opplag, sider
Elsevier Ltd, 2023
Emneord
Decarbonization, Evolutionary algorithm, Optimization, Supercritical CO2 cycles, SYNTHSEP, Waste heat recovery
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-94899 (URN)10.1016/j.enconman.2022.116535 (DOI)000917121500001 ()2-s2.0-85143603372 (Scopus ID)
Merknad

Validerad;2023;Nivå 2;2023-01-12 (sofila)

Tilgjengelig fra: 2023-01-12 Laget: 2023-01-12 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Markeby Ljungqvist, H., Risberg, M., Toffolo, A. & Vesterlund, M. (2023). A realistic view on heat reuse from direct free air-cooled data centres. Energy Conversion and Management: X, 20, Article ID 100473.
Åpne denne publikasjonen i ny fane eller vindu >>A realistic view on heat reuse from direct free air-cooled data centres
2023 (engelsk)Inngår i: Energy Conversion and Management: X, E-ISSN 2590-1745, Vol. 20, artikkel-id 100473Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

This paper examines the opportunities to reuse excess heat from direct free air-cooled data centres without incorporating heat pumps to upgrade the heat. The operation of a data centre in northern Sweden, Luleå, was simulated for a year. It was established that heat losses through the thermal envelope and from the humidification of the cooling airflow influenced the momentary energy reuse factor, iERF, with up to 7%. However, for the annual energy reuse factor, ERF, the heat losses could be neglected since they annually contributed to an error of less than 1%. It was shown that the ideal heat reuse temperature in Luleå was 13, 17, and 18 °C with an exhaust temperature of 30, 40 and 50 °C. The resulting ERF was 0.50, 0.59 and 0.66, meaning that a higher exhaust temperature resulted in potentially higher heat reuse. It could also be seen that raising the exhaust temperature lowered the power usage effectiveness, PUE, due to more efficient cooling. Using heat reuse applications with different heat reuse temperatures closer to the monthly average instead of an ideal heat reuse temperature for the whole year improved the ERF further. The improvement was 11–31% where a lower exhaust temperature meant a higher relative improvement.

sted, utgiver, år, opplag, sider
Elsevier, 2023
Emneord
Data centre, Energy reuse factor, Excess heat, Heat recovery, Heat reuse, Waste heat
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-102311 (URN)10.1016/j.ecmx.2023.100473 (DOI)001097565900001 ()2-s2.0-85174895802 (Scopus ID)
Forskningsfinansiär
Swedish Energy Agency, 43090-2EU, Horizon 2020, 768875
Merknad

Validerad;2023;Nivå 2;2023-11-15 (hanlid);

Full text license: CC BY

Tilgjengelig fra: 2023-11-06 Laget: 2023-11-06 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Mesfun, S., Engvall, K. & Toffolo, A. (2022). Electrolysis Assisted Biomass Gasification for Liquid Fuels Production. Frontiers in Energy Research, 10, Article ID 799553.
Åpne denne publikasjonen i ny fane eller vindu >>Electrolysis Assisted Biomass Gasification for Liquid Fuels Production
2022 (engelsk)Inngår i: Frontiers in Energy Research, E-ISSN 2296-598X, Vol. 10, artikkel-id 799553Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Gasification is a promising pathway for converting biomass residues into renewable transportation fuels and chemicals needed to comply with the ambitious Swedish environmental targets. The paper investigates the integration of a molten carbonate electrolysis cell (MCEC) in biofuel production pathway from sawmill byproducts, to improve the performance of gas cleaning and conditioning steps prior to the final conversion of syngas into liquid biofuels. The energy, material, and economic performance of process configurations with different gasification technologies are simulated and compared. The results provide relevant information to develop the engineering of gas-to-liquid transportation fuels utilizing renewable electricity. The MCEC replaces the water-gas shift step of a conventional syngas conditioning process and enables increased product throughput by as much as 15%–31%. Depending on the process configuration and steam-methane reforming technology, biofuels can be produced to the cost range 140–155 €/MWh in the short-term.

sted, utgiver, år, opplag, sider
Frontiers Media S.A., 2022
Emneord
biomass gasification, molten carbonate electrolysis cell, biofuels, gas conditioning, forest industry byproducts, technoeconomic, biomass to liquid
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-92083 (URN)10.3389/fenrg.2022.799553 (DOI)000824162900001 ()2-s2.0-85133904573 (Scopus ID)
Prosjekter
Renewable transportation fuels and systems (Förnybara drivmedel och system), project no. 48371–1
Forskningsfinansiär
The Swedish Knowledge Centre for Renewable Transportation Fuels (f3)Bio4EnergySwedish Energy Agency
Merknad

Validerad;2022;Nivå 2;2022-07-06 (sofila)

Tilgjengelig fra: 2022-07-06 Laget: 2022-07-06 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Fischer, R. & Toffolo, A. (2022). Is total system cost minimization fair to all the actors of an energy system? Not according to game theory. Energy, 239(Part C), Article ID 122253.
Åpne denne publikasjonen i ny fane eller vindu >>Is total system cost minimization fair to all the actors of an energy system? Not according to game theory
2022 (engelsk)Inngår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 239, nr Part C, artikkel-id 122253Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A common approach to energy system optimization is to minimize overall costs at system level, regardless of the actors actually bearing those costs. This paper presents an approach inspired by Nash game theory concepts, in which the actors involved in an energy system determine their optimal strategies according to their own economic interests (profit functions) in a non-cooperative or in a cooperative way. A simple case study, considering an electric utility and individual heating consumers in the municipal energy system of a small town in northern Sweden, shows the differences between the two approaches. The game theory approach is able to represent more realistic interactions among the actors of an energy system, fair in fulfilling their conflicting economic interests, and, therefore, a more suitable tool for decision makers evaluating the impacts of policy instruments.

sted, utgiver, år, opplag, sider
Elsevier, 2022
Emneord
Energy system optimization, Game theory, Profit functions, Nash equilibrium, Nash bargaining solution, Policy instruments
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-87437 (URN)10.1016/j.energy.2021.122253 (DOI)000711163200014 ()2-s2.0-85116893248 (Scopus ID)
Merknad

Validerad;2021;Nivå 2;2021-10-14 (beamah)

Tilgjengelig fra: 2021-10-08 Laget: 2021-10-08 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Mirzaei, N., Toffolo, A., Engvall, K. & Kantarelis, E. (2021). Flexible production of liquid biofuels via thermochemical treatment of biomass and olefins oligomerization: A process study. Chemical Engineering Transactions, 86, 187-192
Åpne denne publikasjonen i ny fane eller vindu >>Flexible production of liquid biofuels via thermochemical treatment of biomass and olefins oligomerization: A process study
2021 (engelsk)Inngår i: Chemical Engineering Transactions, ISSN 1974-9791, E-ISSN 2283-9216, Vol. 86, s. 187-192Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The use of residual biomass streams for production of liquid fuels will help in achieving the goal of renewable transportation fuels and sustainable society. Hence, efficient, and reliable processes offering a flexible product distribution proven at commercial scale are required. This study explores the technical feasibility of producing gasoline and diesel range hydrocarbons from thermochemical processing of biomass via the production of light olefins (C2-C4) and their subsequent oligomerization through mathematical modelling and simulation using MATLAB software. Different biomass processing scenarios were considered, including a standalone biomass gasification plant and integrated biomass pyrolysis- char gasification (O2- or air-blown) process. Process analysis indicated that the integrated plant offers 10-11% higher carbon efficiency. The processing step with the highest carbon penalty for all the cases is the syngas composition tailoring via water-gas shift reaction.

sted, utgiver, år, opplag, sider
Italian Association of Chemical Engineering - AIDIC, 2021
HSV kategori
Forskningsprogram
Energiteknik
Identifikatorer
urn:nbn:se:ltu:diva-86525 (URN)10.3303/CET2186032 (DOI)2-s2.0-85109755837 (Scopus ID)
Forskningsfinansiär
Swedish Energy AgencyThe Swedish Knowledge Centre for Renewable Transportation Fuels (f3)
Merknad

Validerad;2021;Nivå 1;2021-08-13 (alebob);

ISBN för värdpublikation: 978-88-95608-84-6

Tilgjengelig fra: 2021-08-05 Laget: 2021-08-05 Sist oppdatert: 2025-10-21bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0002-4532-4530