Critical operating conditions for co-SOEC reactors for syngas production with Fischer-Tropsch recirculation

Abstract

In the frame of the current energy transition, the efficient storage of electrical energy represents a main challenge. In this regard, its conversion into chemical energy is pivotal for Power-to-X technologies, where solid oxide cells (SOC) reactors play a significant role. In electrolysis, SOC reactors yield hydrogen or syngas, which are relevant feedstocks for the production of synthetic fuels and chemicals, for instance by the Fischer-Tropsch (F-T) process. This research investigates a 100 kW SOC reactor with 24 single stacks for syngas (H2/CO) production with the aim to evaluate different H2/CO ratios and feed gas compositions upon transient operation regimes, where F-T recirculation inlet feeds were considered. Critical operating conditions were identified: the content of methane of up to 5% at open circuit voltage was the most detrimental condition due to the endothermic nature of methane internal reforming causing large thermal gradients. Operation strategies to mitigate failures will be discussed. An outlook of how transient simulations could predict failures and critical operating conditions, prior to experimental SOC reactor testing, will be presented.