CIRCULAIR

Circular fuel supply for air transport via negative emission HTL conversion

Duration

01.01.2023 - 31.12.2026

Achieving climate neutrality in Europe requires large quantities of truly sustainable fuels to provide long-term solutions for transport sectors where direct electrification is not feasible. CIRCULAIR addresses this challenge with an integrated biofuel concept that produces cost-effective aviation fuels and generates negative emissions. CIRCULAIR's key innovations include tight thermal coupling of biomass hydrothermal liquefaction (HTL) with exothermic wet oxidation of HTL process water. In this way, autothermal operation can be achieved, carbon can be fully utilized, and the problem of process water disposal during HTL can be solved. In addition, CIRCULAIR is developing innovative approaches for processing HTL crude oil into jet fuel and accelerating the approval of HTL fuels for civil aviation. The use of biomass resources is maximized by developing valorization systems for all relevant side streams along the process chain. In particular, acetic acid will be extracted from process residues and methanol will be synthesized from waste gas streams and renewable hydrogen. Importantly, CIRCULAIR will fill a gap in our knowledge of how to use the carbon in HTL biochar produced as a byproduct for carbon sequestration and soil improvement. Further utilization and fixation of this carbon can make a significant contribution to reducing the greenhouse gas footprint. The target net negative total emission will be quantified based on a life cycle analysis. Finally, technological and socioeconomic analyses will identify important benefits and tradeoffs associated with the advanced biofuel process.