Operation of Co-SOEC reactors for syngas production utilizing CO2 from air

Abstract

The conversion of electrical energy into chemical energy or feedstock is an important element of the transformation of the energy system. Electrolysis reactors with solid oxide cells (SOC) can convert water and carbon dioxide into hydrogen or syngas with highest efficiency. These products can in turn be converted by downstream reactors into fuels or feedstocks for the chemical industry.

This contribution reports the investigation of a 100 kW SOC reactor and BoP components for syngas production with direct carbon dioxide capture from air. The goal is to improve efficiency and robustness of the SOC reactor. Using experimental results, a transient simulation model of the system was developed and validated. Operating and control strategies are presented. For that purpose, transient maneuvers were investigated and parameters such as ramp speeds or controller gains were derived. These strategies were tested on an SOC reactor test rig and iteratively improved together with simulations.

By this interaction of experiment and simulation, it was possible to lower temporal and spatial temperature gradients. For example, in the case of a power increase of 45 %, the maximum temporal gradient was reduced by 40 % using an enhanced heater control. Further use cases are a change of the syngas composition and startup procedures.