In a first study, a process concept for the use of an oil yeast fermentation in combination with conventional thermocatalytic processes was evaluated for techno-economic feasibility. In electrochemical water splitting, green hydrogen and oxygen are produced as the main mass product. Until now, this oxygen has not been recycled in a value-added manner. In the refinery design conceived by WSSB, the oxygen is used for the first time in a value-added manner for process optimization of an oil yeast fermentation. The oil yeast fermentation subsequently provides sustainable yeast oil, which can be converted into biofuels and sustainable carbon fiber via conventional thermocatalytic processes. Furthermore, the oil yeast process generates high-purity, carbon-neutral CO2 which can be converted via thermochemical processes into synthetic fuels that can be combined in a bulk stream with biofuels. The techno-economic and LCA advantages of this process network called "PtX Plus" have been published (https://doi.org/10.1002/cite.202000114 ).
Furthermore, a collaborative project with colleagues from Israel was successfully obtained, which investigates the cell-free, enzymatic conversion of CO2 into formaldehyde. In this process, CO2 is converted into the platform chemical formaldehyde at room temperature using biogenic hydrogen carriers. This can be converted via further enzymatic processes into methanol, which in turn can be used as a raw material for conventional production processes, e.g. of synthetic fuels.