Production of CO₂-neutral liquid fuels by integrating Fischer-Tropsch synthesis and hydrocracking in a single micro-structured reactor: Performance evaluation of different configurations by factorial design experiments

Humankind must drastically reduce CO$_{2}$ emissions within the next three decades to limit global climate change. Defossilization of the transport sector must contribute to the achievement of this ambitious aim. One promising option is the production of synthetic liquid fuels from CO$_{2}$, water, and renewable electrical energy. Liquid fuels will also be used in the future, especially for heavy-duty vehicles and aviation. We studied the production of liquid fuels by integration of Fischer-Tropsch Synthesis (FTS) and Hydrocracking (HC) in a single micro-structured reactor. Thereby, we addressed the aspects of process simplification and process intensification. Both are particularly important for flexible small-scale plants for decentralized application in context of the energy transition. In this study, we systematically investigated the performance of the integrated FTS/HC process depending on different operating conditions (pressure, temperature, weight hourly space velocity, H$_{2}$/CO synthesis gas ratio) and integration configurations by applying a factorial design approach. Beyond the selectivity of the process towards liquid fuels, we especially focus on the product quality affected by the type of produced hydrocarbons. We identified significant influence parameters on process performance, which is essential to know for practical application. We showed that the crude product quality was significantly influenced by the integration pattern. Therefore, we suggested more elaborate integration configurations to overcome the challenge of suboptimal operation conditions for the FT and HC catalyst and improve the product quality