Faced with the serious environmental and ecological crises brought about by the emission and accumulation of carbon dioxide (CO2), it is urgent to develop efficient carbon dioxide (CO2) capture, utilization, and storage technologies. Among these technologies, direct electrochemical reduction of CO2 to CO is an interesting and seemingly simple approach. High-temperature CO2 electrolysis which is based on solid oxide electrolysis cell (SOEC) device and operates above 600 °C is considered a promising solution, thus has attracted worldwide attention. However, in the high-temperature co-electrolysis process, cell degradation significantly affects its practical application, mainly due to interface agglomeration, carbon deposition, and decomposition. This project aims for the simulation of a heat exchanger for a solid oxide electrolysis cell when performing co-electrolysis. The main goal is to evaluate the temperature profile of the fuel gas. Simulation will be performed, using a cross-flow plate heat exchanger model. The root of the problem is carbon deposits in the formerly used electric gas heater causing malfunctions. Besides the evaluation of a heat exchanger as an alternative, an optional subtask, if realistic regarding the schedule, is to review carbon deposit formations in the heat exchanger.