Sustainable Fuels, Chemicals and PtX, an AAU Energy mission

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    The main vision of the Sustaianble Fuel mission is the production of green, renewable, and carbon footprint reduced fuels. This includes both biofuels produced from biomasses and biogenic redidues as well as liquid and gaseous fuels produced from electrolysis and PtX.


    Decarbonising the heavy transportation, aviation, and shipping sectors, which are expanding fast and increasing the overall fossil fuel consumption, relies on biofuel and renewable fuels. The specific challenge is to increase the competitiveness of next generation biofuel and renewable fuel technologies in aviation and shipping, compared to fossil fuel alternatives. This will require integrated biorefinery solutions where all fractions of the biomass is used in the production of fuel and value added bio-chemicals. Residue fractions from the bioferinery can be used directly in electrolysis or in combination with biogas production to yield varoius PtX products.

    A crucial requirement is to improve the efficiency of the conversion processes to 75-80% yield. Existing technologies usually use just one or two fractions of the biomass for liquid biofuels production. By combining biorefining with PtX higher overall fuel yields can be achieved.

    The 2017-2018, European demand for aviation and maritime fossil-fuels were 17 Mt/y and 50 Mt/y, respectively. Many availability assessments have been carried out covering a range of biomass feed stocks in Europe. Feedstock costs need to remain competitive, and sustainability criteria need to be met. Hence, the focus needs to be on residue biomasses e.g. lignocellulocis residue from the agricultural industry and biogenic municipal solid waste as well as new types of biomasses grown on non-agricultural (marginal) land and in the sea (algae, seaweed, and halophytes). The RED II report defines a series of sustainability and GHG emission criteria that bioliquids used in transport must comply with to be counted towards the overall 14% target and to be eligible for financial support by public authorities[2], all RED II listed biomasses can be part of this mission.

    Electro Fuels

    Moreover, electrofuels produced in PtX plants from flauctuating renewable electricity sources, water electrolysis and CO2 from biomass or carbon capture also offer tremendous potential for decarbonizing heavy transportation and the chemical industry.  Electrolyzers in this context can be used to as a means of storage of excess renewable electricity from wind turbines and solar PV panels, thereby  offering grid balancing services and facilitating the renewable energy penetration, which is crutial to lower the cost of the renewable electricity itself, which inturn determines the cost of green e-fuels.

    Renewable electrofuels, such as methanol or pure green hydrogen can be used in fuel cells, which are highly efficient electrochemical energy conversion devices that are modulare and versatile enough to cover numerous applications, including heavy-duty transportation and stationary power stations or combined heat and power applications.

    The mission is therefore, to develop and deploy PtX plants for the production of electrofuels, which both benefit the penetration of flactuating renewable electrricity in the territory and benefits from the such penetration in terms of cost. It is important to creat synergy between the development and production of electrofuels and the demand side, by optimizing fuel cells or combustion engines to work effeciently with the new renewable fuels. Therefore, going forward it will be crutial to not only use the new fuels in exsiting powertrain platforms for various heavy-duty transportation, but also develope new and more efficient fuel cell-based/ hybrid powertrains that that run on hydrogen or electrofuels (methanol, ammonia and methane).

    The superior vision of the Sustainable Fuel Mission is to develop innovative and economical biofuels processes, which produces several types of fuels from 100% renewable and sustainable resources - thereby resulting in significant GHG emission reduction potential, or even negative emission fuels by coupling processes with CCS. The target is at least 20% reduction in GHG emission related to the processing compared to current state of the art technology (e.g. 1G starch and vegetable oil). Today, one of the main obstacles for biofuels implementation is the tight economy in stand-alone biofuels processes. The research carried out in the SFM target economically attractive processes, with significant increased feasibility and robustness compared to stand-alone 1G biofuels processes. From the operational point of view, these sustainable fuels production systems also raise a lot of challenges to process control and monitoring technologies, in order to keep the operation in a safe, reliable, efficient and envirnmental-friendly manner. By combining the feedstocks and technologies, as well as advanced process control and monitoring technologies, we will be able to demonstrate a significant reduction of 25-50% in the cost of producing advanced biofuels.

    Production of 2G liquid biofuels have been under commercialization for the past 5-6 years. Around 2010 a handful of pilot- and small demonstration units (1-4 tons per hour) were built in Denmark (Inbicon), Sweden (SEKAB), China (COFCO), Italy (Beta Renewables) and the US. Since then, a handful of full-scale plants (40-50 tons of biomass per hour) have been constructed in Italy, Brazil, and in the US. All full-scale plants have experienced operational difficulties and none of them has been able to achieve full-scale capacity. For all the full-scale plants, the economics are tight, and although it is possible to make a project with good returns, it requires stable operation and yields from the plants. The combination of large capital investments, low margins for error in the project economics, and the perceived technology risk has prevented investors from going into the cellulosic biofuels industry to the extent and as soon as expected. It is becoming increasingly clear that stand alone 2G plants producing fuel as the sole product and with the ability to handle only one type of feedstock is not going to be the way to move forward. Today, no single biofuel is envisioned to replace the current fossil-based fuels and several biofuels will be required to meet the demands of the current transportation sector. Future biofuel processes will have to show similarities to today’s petro-chemical refineries by including a web of complex and synergistic processes to arrive at numerous fuel products (as well as making a value-added profit from side streams). Therefore, and objective of the SFM mission is to develop and assess integration opportunities between emerging biofuels technologies and current refinieres to levarage on the existing infrastructure and past investments.

    The research objectives and the collaborations of the SFM aims to directly work on this problem with lack of feasibility of stand alone biofuels processes. The overall goal and ambition of the mission is to develop and optimise integrated suistainable fuel processes producing multiple fuel and value added products, utilising all feedstock fractions, and integrate with PtX for increased economic, envirionmental, and societal feasibility.

    Sustainability Goals

    The SFM is in line with EU goals:

    EU has set the 2030 targets of a 40% cut in greenhouse gas emissions compared to 1990 levels and at least a 32% share of renewable energy consumption. A minimum share of at least 14% of fuel for transport purposes must come from renewable sources by 2030 and the share of advanced biofuels and biogas must be at least 1% in 2025 and at least 3,5% in 2030. A major concern with liquid biofuels for the transportation sector is the sustainability of such fuels with respect to actual GHG reduction potential, land-use-change issues, and biomass availability. Secondly, cost competitiveness with current fossil fuels is a major barrier for deployment of current technologies for production of biofuels. The environmental and economic sustainability of producing liquid biofuels is largely dependent on the feedstock used for the process. As part of the 2030 goals palm and soybean oil biofuels cannot grow above each country’s 2019 consumption levels and should gradually decline from 2023 onwards until reaching 0% in 2030. Instead, focus should be on demonstrating and implementing biofuels processes based on 2nd generation feedstocks and aquatic biomasses – often called 3rd generation feedstocks. REDII includes a detailed and restrictive list of the biomasses and wastes that can be used for the production of advanced biofuels. Thus, the research within the SFM lays on the development of sustainable advanced biofuel using as feedstock the raw materials listed in the REDII directive.

    The SFM is in line with the Innovationfond mission roadmap:

    Green fuels for transport and industry (Power-to-X, etc.)

    The SFM is in line with several of the AAU Engineering Faculty’s nine sustainable focus areas, e.g.:


    The SFM contributes to at least 7 of the 17 UN Sustainable Development Goals:

    SDG2 – By developing production pathways for bio-fuels using non-food biomass from sustainable food production systems without compromising agricultural productive lands. SDG6 – By providing a method of aquatic bio-remediation, bodies of water suffering from excess nutrients can be restored.

    SDG7 – By ensuring access to affordable, clean, and sustainable bio-fuels and e-fuels, by optimizing production pathways with multiple feedstocks and multiple high-value outputs.

    SDG8 – By opportunities for new high-value-added businesses to grow from the concepts and outputs of the project in the aquatic biomass, biomass processing, pharma- and cosmetics, and biofuels industries.

    SDG9 – By enhancing scientific research in, development, and promoting new innovative industrial processes for biofuel production and e-fuels production.

    SDG12 – By promoting efficient use of natural resources through the enabling of fuel heavy industries to rely on sustainable production of bio-fuel and by holistic redistribution of nutrients from struggling recipients to productive farmlands.

    SDG14 – By providing a market for small-scale artisanal producers of aquatic biomass, and providing a method for aquatic bio-remediation of bodies of water suffering from excess inflow of nutrients from land-based activities.

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    Societal Impact

    The following impacts will be targeted.

    • Contribute to the green transition by deveoping and optimising suitainable fuel and biofuel processes from waste biomass and new type of biofuel feedstock grown on marginal land and in the sea
    • Significantly Increased conversion rates and process yields for all processes increasing the economic feasibility of the processes
    • Greatly improved circular economy by production of multiple fuel and side-products from waste feedstocks increasing the economic feasibility of the processes
    • Greenhouse gas emission reduction by at least 60% compared to fossil avaition and shipping fuels
    • Decentralized valorization of >400 M ton of low grade waste feedstock for advanced biofuels production
    • Enhancing the balance between urban and rural land by creating business opportunities and jobs for rural and remote areas (forest and agriculture)
    • Hydrogen cost for traditional 1G HEFA-SPK biofuels are 80% and 12% of total cost - these cost can be reduced by at least 50% (compared to 1G) using 2G feedstocks and green hydrogen production from process side-streams.
    • It is anticipated that advanced biofuels, mainly 2G biobiofuels, will boost EU economy by creating 1.2 million jobs and a revenue of 400 billion euros by 2030.
    • Contributes to at least 4 of the 17 UN development goals e.g. (7) Affordable and clean energy, (8) Decent work and economic growth, (9) industry innovation and infrastructure, (11) Sustainable cities and communities, and (13) Climate action.
    • Development feedstock agnostic thermochemical processes with energy recovery potential > 80 %.
    • Holistic assessment of the entire value chain to reduce GHG emissions of biofuels and to be compliant with REDII, but targeting negative emission fuels through CCS coupling.
    • Targeting liquid fuel cost <15€/GJ.


    The Sustainable Fuels Mission are collaborating with:

    • AQUA-COMBINE consortium (as coordinator of the EU project)
    • FLEXI-GREEN FUEL consortium (as partner in the EU project)
    • WaterValue consortium 
    • NextGenRoadFuels consortium
    • Urban Waste Hydrofaction consortium
    • 4Refinery consortium
    • HyFlexFuel consortium
    • Energy Systems in Transition consortium
    • Power2Met project (haldor topsoe, REintegrate)
    • GreenCem project (Aalborg portland, Reintegrate)
    • Oil Gas Transition consortium (UK, NO and DK)

    Future collaboration:

    • We are looking for partners towards industrial exploitation of research output and technology commercialisation
    • Academic partners for fundamental research.
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    Research Objectives

    In order to achieve the vision of the SFM the following research objectives will be targeted:

    • Hydrothermal pretreatment to extract sugars from lignocellulosic feedstocks
    • Enzymatic hydrolysis of lignocellulosic sugars and organic fraction of municipal solid waste to yield fermentable sugars
    • Catalytic conversion of hemicellulose sugars to furanic based fuels
    • Fermentation processes to ferment biomass sugars to fuel or fuel intermidiates (e.g. sugar to lipid fermentation)
    • CO2 sequestration using microalgae, harvest, and conversion of microalgae lipids to biofuels
    • Biorefining process optimisation of new types of feedstocks e.g. halophyte plants and seaweed
    • Production of H2 in microbial electrolysis using fermentation residues as the organic feedstock
    • Production of biogas and H2 from biorefinery residues and conversion to fuel using PtX processes
    • Thermochemical conversion of biomass and waste into drop-in fuels
    • Explore the physico-chemical properties and potential synergies of wet biomasses and organic wastes in prospective of their continuous processing  for biofuels production
    • Conversion/valorization of a wide range of lignocellulosic biomasses (agricultural and forestry residues) and organic residues (sewage sludge, municipal solid wastes, animal manure) by Hydrothermal Liquefaction to produce an energy-dense biocrude intermediate from which drop-in fuels can be derived
    • Develop upgrading operations on the HTL biocrude for heteroatoms removal by hydrotreating
    • Develop distillation strategies linked to the upgrading of the oil to obtain various fraction based on the boiling point distributions (gasoline, jet-fuel, diesel, marine fuel, chemicals..) and maximize value creation.
    • Production of hydrogen via water electrolysis using renewable electricity
    • Reversible cells (solid oxide cells) for grid balancing and PtX plants
    • Use of green hydrogen for hydrothemal  liquefaction and therefore integration of electrolysis systems in HTL processes
    • Process design & optimization, process integrations including BECCS and BECCU, techno-economic assessments, and LCA studies
    • Advanced process control and monitoring technologies for different biofuel, sustainable fuels and PtX process systems.



Mette Hedegaard Thomsen - AAU Energy
Mette Hedegaard Thomsen
Direct phone: +45 9356 2196

mission Vice Chair

Zhenyu Yang - AAU Energy
Zhenyu Yang
Direct phone: +45 9940 7608
E-mail: yang@ENERGY.AAU.DK

Research groups committed to this mission

Bioenergy and Bioproducts - AAU Energy research group

Advanced Biofuels - AAU Energy research group

Electro Fuels - AAU Energy research group

Offshore Process Control and Cybernatics - AAU Energy research group

Fuel Cell Systems - AAU Energy research group