A techno-economic feasibility study on gas-to-liquid (GTL) aviation fuel produced from feedstocks of bio-methane, CO2, electricity and hydrogen was done. The study assumed the use of steam reforming and Fischer-Tropsch (FT) for methane and reverse-water-gas-shift or co-electrolysis plus FT when using CO2/hydrogen as feedstock.
This production pathway was found to be cost-efficient, area-independent, scalable and globally sufficient, technically mature and ready to implement, and approximately CO2 neutral. Key merits of the pathway lie in its system integration properties. First, it allows the flexibility of shifting between the feedstocks for economic optimization with fluctuating electricity prices and with shifting availability of CO2 from biomass flue gas between summer and winter. Second, the bio-methanation of the CO2 content of biogas and the recycling of any CO2 and CO off-gas emissions from the GTL allow for an almost 100 % carbon conversion efficiency from methane to liquid fuels. Together with using flue gas CO2 and atmospheric CO2 as feedstock, it makes the pathway fully sufficient and a real and globally scalable solution. Third, being based on biogas and CO2, the fuels will be practically CO2 neutral.
The biogas feedstock is further motivated by biogas facilities being attractive agricultural management facilities allowing agriculture to reduce its greenhouse gas emissions significantly and allowing for optimized nutrient management and soil carbon management as well as advanced treatment and value addition to biomass feedstocks. Moreover, storing bio-methane on the gas grid allows for the most cost-efficient balancing of the fluctuating wind and solar power, as gas turbines and motors constitute the cheapest back-up capacity installed, and as such the pathway provides the supplementing service of efficiently and sufficiently storing electricity in the renewable energy system.
Finally, locating electrolysis, bio-methanation and GTL on district heating grids constitute a significant economic advantage of the pathway, and any location allowing the use of the process heat loss from these units will have a high competitive advantage.
Following this pathway, jet fuel was found to be realistically available at costs around 2-3 times today’s fossil jet fuel price. Comparing this to costs of available bio-jet fuels today, the price level is attractive.
Prof. Henrik Wenzel
University of Southern Denmark
Odense M, Denmark
Prof. Henrik Wenzel is Head of the Life Cycle Engineering Center at University of Southern Denmark and professor of Life Cycle Engineering and Environmental System Analysis. He is member of the Danish Bioeconomy advisory board for the Government, the Independent Research Fund Denmark, and the Technical advisory board of the Waste and Resource Network Denmark. He has 30 year of experience in system analysis including Life Cycle assessment, energy system analysis, resource criticality assessment and socio-economic analysis and he has studied energy systems and energy technologies in a systems perspective for 20 years. Most recently, his work has centered around electrofuel technologies and their integration into the energy system, and he has studied sustainable aviation fuel supply pathways in collaboration with key stakeholders from the aviation sector, including chairing the work on sustainable fuels within the recent Aviation Sector Climate Partnership in Denmark. He will present the latest finding from a Nordic project on jet fuel from the gas-to-liquid pathway and the status of the aviation sector’s electrofuel strategy.
Denmark has a target to be based on 100 per cent renewable energy in 2050 and has made an ambitions target to reduce greenhouse gas emissions by 70 per cent in 2030 compared to 1990. The process for setting this target started on 2006 and builds on a longer tradition for broad political consensus about energy policies and targets. In this keynote the concrete technological changes as well as some of the political measures needed are outlined. The role of several technologies is outlined including e.g. energy efficiency, energy storage, electrification, district heating, renewable energy, hydrogen. The costs of such transition is high concerning investments. On the other hand the costs of operation a system based on 70 per cent renewable energy is lower considering fossil fuels and bioenergy. One of the main challenges in the implementation of renewable energy system changes is connected to implecations on the fiscal budget rather than the costs of the technologies and the integrated energy system. Research shows that these systems have the same costs as continiesin a more fossil fuel based system. Many of the initiatives have CO2 abatement gains economically rather than CO2 abatement costs. The case of Denmark is related to the European Green deal and debate about the EU level decarbonisation target for 2030.
Prof. Brian Vad Mathiesen
Aalborg University
Aalborg, Denmark
Brian Vad Mathiesen, Professor in Energy Planning and Renewable Energy Systems at Aalborg University, holds a PhD in fuel cells and electrolysers in future energy systems (2008). His research focuses on technological and socio-economic transitions to renewables, energy storage, large-scale renewable energy integration and the design of 100% renewable energy systems. He is one of the leading researchers behind the concepts of Smart Energy Systems and electrofuels. He is on the Clarivate, Web of Science Highly Cited list (2015-2020), thus among the top 1% most cited researchers globally. Among other positions, he is member of the EU Commission expert group on electricity interconnection targets in the EU as well as Research Coordinator of the Sustainable Energy Planning Research group, Principal Investigator (PI) of the RE-INVEST and sEEnergies projects, and Programme Director for the MSc in Sustainable Cities. He has been PI, work package leader and participant in more than 60 research projects as well as editorial board member of The Journal of Energy Storage (Elsevier) and The Journal of Sustainable Development of Energy, Water & Environment Systems; Associate Editor of Energy, Ecology and Environment (Springer) and Editor of the International Journal of Sustainable Energy Planning and Management. Furthermore, he is a member of The Danish Academy of Technical Sciences (ATV) and a board member at The Danish Energy Technology Development and Demonstration Program (EUDP).
The pressure to rapidly and comprehensively reduce global greenhouse gas emissions is constantly increasing - forest fires in many regions of the world, the increase in extreme weather events and melting glaciers provide us with clear evidence of this. The energy sector is responsible for a large part of greenhouse gas emissions. Therefore the conversion of the energy supply towards climate neutrality plays a decisive role. Using Germany as an example, the lecture shows various development pathways towards a climate-neutral energy supply, which are based on hourly simulation and optimization of the entire energy system and its transition. Social perspectives and behaviors are taken into account, because this transformation will only succeed if society follows the chosen pathway. The results of the investigation show that - depending on social behavior - the German energy transition relies on a more or less large amount of imported synthetic energy sources that are produced from renewable electricity in other regions in order to achieve the goal of a climate-neutral energy supply at reasonable costs. In addition important implications can be derived from the analysis with regard to necessary technology and system developments, which are valid far beyond the German example.
Prof. Hans-Martin Henning
Fraunhofer ISE
Freiburg, Germany
Prof. Dr. Hans-Martin Henning is Director of the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, Germany and Professor of “Solar Energy Systems” at the Institute of Sustainable Systems Engineering in the Faculty of Engineering, University of Freiburg. He is member of acatech (German National Academy of Science and Engineering) and spokesperson of the Fraunhofer Energy Alliance. Prof. Dr. Henning obtained his PhD in physics at Oldenburg University in 1993. Since 1994, he has been working at Fraunhofer ISE in Freiburg, holding several different positions of responsibility over the years. In 2014 he was appointed Professor of Technical Energy Systems at the Karlsruhe Institute of Technology KIT and in 2017 Director of Fraunhofer ISE. Henning’s research focus lies in building energy technology and energy system analysis. He plays a leading role in the development of computer models for the holistic simulation and optimization of complex energy systems. The simulation results are used as a basis for investigations to develop national / regional energy systems with consideration of all energy carriers and consumption sectors.
