The CIRCULAIR consortium consists of 10 partners from 6 European countries

Circulair partners

Bauhaus Luftfahrt is an interdisciplinary research organisation located in Taufkirchen near Munich, Germany. As an aviation think tank, Bauhaus Luftfahrt tackles questions about tomorrow’s air transport and provides scientifically based answers. One focus of Bauhaus Luftfahrt is to research long-term options for the transformation targeting climate-neutral aviation.

Role within CIRCULAIR: Bauhaus Luftfahrt is the coordinator of CIRCULAIR. The scientific task of Bauhaus Luftfahrt is to model the CIRCULAIR fuel production pathway in order to analyse its future performance in terms of economic, social and environmental parameters.

Core competencies for CIRCULAIR implementation:

  • Contribution to several research projects as partner and coordinator to investigate innovative options to supply large amounts of sustainable aviation fuel in the future
  • Capabilities for the modelling of HTL conversion developed in H2020 HyFlexFuel

Strong experience in the analysis of synthetic fuel production pathways based on renewable hydrogen and CO₂


Aarhus University was founded in 1928 and covers the entire research spectrum from fundamental research to applied and strategic research plus research-based advice to authorities. Aarhus University has about 37.500 students (including 1.900 PhD students and almost 700 postdoctoral scholars) and about 7,600 employees. The university has strong international connections, and one out of four PhD students is international.

Role within CIRCULAIR: Aarhus University is leading the development of the integrated hydrothermal liquefaction and wet oxidation process. Manure and straw will be processed using the existing pilot scale reactor at Aarhus University’s Foulum facilities to produce bio-crude, process water, hydrochar and gas for further processing and valorisation in the other work packages. Aarhus University will carry out the wet oxidation of process waters to establish an integrated autothermal process.

Core competencies for CIRCULAIR implementation:

  • Track record in successfully operating pilot scale facilities for hydrothermal liquefaction and wet oxidation
  • Many years of experience in optimisation of HTL and WO process conditions using laboratory scale batch reactors
  • Established analytical facilities to characterise bio-crude and aqueous products from HTL and WO

Located in Northern Denmark, Aalborg University has been ranked as the best engineering university in Europe, according to the prestigious ‘Best Global Universities’ ranking. CIRCULAIR activities will be managed by the Advanced Biofuels research group within the Aalborg University Energy department, a world-leading research institution engaging in green transition.

Role within CIRCULAIR: Aalborg University will lead the activities on biocrude upgrading to sustainable aviation fuels. Their activity will include the fundamental pre-treatment (demineralization) of biocrude and advanced trickle-bed hydroprocessing. Aalborg University will enhance the process to increase both quantity and quality of the jet fuel product.

Core competencies for CIRCULAIR implementation:

  • One of the leading worldwide research institutions in continuous hydroprocessing of HTL-derived liquids in both batch and continuous devices, with thousands of hours on stream
  • A unique strategy for the upgrading of HTL biocrude, featuring demineralization and multi-stage processing
  • Analytical capabilities for fuel characterization, according to ASTM standards
  • Extensive track record in national and international research projects

Founded in 1818 after devastating famines, the University of Hohenheim (Stuttgart, Germany) is not only engaged in intensive basic research but has traditionally also been committed to developing innovative solutions for urgent social matters. To do so, the University of Hohenheim combines unique scientific disciplines among German universities, with a leading role in agricultural and food science.

Role within CIRCULAIR: The Department of Conversion Technologies of Biobased Resources of the University of Hohenheim is leading the research on solid carbon utilisation and sequestration. The main scientific task is the evaluation of carbon capture possibilities by HTL char application in agriculture and as an adsorbent in the CIRCULAIR process chain itself.

Core competencies for CIRCULAIR implementation:

  • Strong practical background in thermochemical conversion of residual biomass for new char-based products and their application in agriculture
  • Advanced analytics and methods for the characterisation and evaluation of new char-based products

Capabilities for HTL-char handling and nutrient recovery developed in H2020 HyFlexFuel


The Complutense University of Madrid is a public university located in the capital of Spain. It is the largest face-to-face university in Spain and has more than 65,000 students and 6,800 professors. Specifically, the Catalysis and Separation Processes (CyPS) group has been working for decades on developing new technologies for the separation of hydrocarbons, the recovery of value-added products from aqueous streams, and the separation and valorization of gaseous mixtures.

Role within CIRCULAIR: The scientific task of Universidad Complutense de Madrid is to valorize the side streams of the HTL-WO process in order to obtain neutral or negative CO₂ emissions SAF. CO₂ purification and capture from the gas streams for its conversion into methanol. Volatile fatty acids and ammonia recovery from the aqueous phase.

Core competencies for CIRCULAIR implementation:

  • Extensive experience in developing research projects with public funds and with private companies
  • Competencies for the development and optimization of adsorption and liquid-liquid extraction processes

Experience in industrial process simulation, having developed proprietary simulators for cyclic adsorption processes


Topsoe is a world-leading supplier of catalysts and process technologies for the energy sector, environmental protection, chemical and petrochemical industries. At Topsoe, research and development is an integrated part of the company, and the development work is carried out in close collaboration with marketing, production and engineering. Hydrotreating of biocrude is a promising new product of Topsoe and Topsoe has positioned itself as a world leading-company within hydrodeoxygenation of renewable oil.

Role within CIRCULAIR: Topsoe will carry out hydrocracking pilot tests in order to maximize the jet fuel yield. Furthermore, Topsoe will provide catalyst for the hydroprocessing of the oil carried out by RISE and Aalborg University and carry out oil analysis.

Core competencies for CIRCULAIR implementation:

  • Capabilites to carry out advanced pilot plant testing to maximize jet fuel yields
  • Capabilities to make and provide hydroprocessing catalyst for other partners
  • World-leading experience in upgrading of biocrudes

Circlia Nordic is a Danish company with a global perspective and a strong commitment towards creating a circular economy and revolutionising the sustainable fuel production. We specialise in developing an HTL process that efficiently converts difficult recyclable waste streams into valuable bio-crude. Circlia Nordic’s mission is to solve environmental challenges through innovative technologies.

Role within CIRCULAIR: Design and implementation of an HTL-WO reactor.

Core competencies for CIRCULAIR implementation:

    • Leadership position in the HTL process technology and commercialisation
    • Expertise in process design and engineering
    • Proprietary heat exchanger and pressure exchanger design for commercial-scale HTL plants
    • IPR on the integration of HTL and wet oxidation
    • Experience on pumping, product separation, heat exchanger designs from an ongoing project for developing a full-scale demonstration of a wastewater sludge to fuel HTL plant.

Eni is an energy company concretely supporting a just energy transition, with the objective of promoting an efficient and sustainable access to energy for all.

Eni has the strategic target to achieve zero emissions for all internal and external activities, including scope 1, 2 and 3, by 2050. Among the levers to provide a variety of fully decarbonised products, in 2014 and 2019 Eni converted two conventional refineries into bio-refineries. Currently, Eni is operating two bio-refineries processing vegetable oil and waste & residues as bio-feedstocks to produce HVO-diesel, bio-LNG, bio-jet and HVO-naphtha.

Role within CIRCULAIR: Eni will provide detailed jet fuel characterisation and testing activities. Additionally, will analyse bio-crude samples and will thereby support the academic partners with its R&D mass spectrometry capabilities. As a major industrial partner, Eni will provide support to the techno-economic evaluation of the CIRCULAIR integrated technology on an industrial level.
Core competencies for CIRCULAIR implementation:

  • Expertise as a major EU fuel producer, focused on the conversion of its conventional refineries into bio-refineries
  • Eni R&D expertise in jet fuel and complex samples (bio-crudes) characterisation

RISE is an independent state research institute of Sweden. As an innovation partner for the entire society, RISE helps develop technologies, products, services and processes that contribute to a sustainable world and a competitive business life. Internationally, RISE is a unique investment in cross-border research and innovation. With a unified organization and a common ambition, RISE shall strengthen Sweden as a country of innovation, and secure an edge in global competition.

Role within CIRCULAIR: The scientific task of RISE is to investigate an alternative upgrading process for HTL biocrude using slurry hydro-treatment.

Core competencies for CIRCULAIR implementation:

  • Strong expertise in biocrude hydroprocessing using slurry hydro-treatment
  • Test and scale-up of the hydrotreatment process under realistic conditions
lup (1)

L-up is a consulting agency specialised in national and European R&D funding programmes with longstanding experience in collaborative R&D projects, especially in high-tech areas such as transport, ICT, security, energy, materials, health, biotechnology or circular economy.

Since 2001, L-up has been advising companies – from SMEs to large enterprises – as well as research bodies. L-UP has accompanied more than 180 projects within the FP6, FP7, Horizon 2020 and Horizon Europe programmes.

Role within CIRCULAIR: L-up supports the general management and coordination and supervises  dissemination, communication and exploitation activities.

Core competencies for CIRCULAIR implementation:

  • Support project monitoring through specific dashboards and documents (Project and Risk Management Plans).
  • Support organisation of project meetings, contractual and financial management and consolidation of official reporting.
  • Create communication material and monitor communication/ dissemination/exploitation actions.