SOFCs can achieve high electrical efficiency by utilizing steam reforming because the absorption reformate heat could be supplied from the heat from the stack and the anode off-gas combustor in the hotbox. However, water supply system leads to high manufacturing cost in BOP and may lead to decreased reliability of systems because of sensitive control. On the other hand, partial oxidation (POX) reforming system ensures the simplified system, while POX reforming system leads to lower electrical efficiency than in that of steam reforming because of fuel consumption in reforming.

From the background written above, we are focusing adapting full-scale CO₂reforming (dry reforming) to SOFC systems to expand the capability of SOFCs. To reveal the feasibility of the dry reforming SOFC system, we have previously investigated the performance and durability of catalysts (reformer) and a cell stack in simulated dry reforming by comparing with that of steam reforming.

In this study, we investigated the performance of SOFC hotbox adapting dry reforming. The thermally self-supported state was successfully demonstrated in dry reforming operation. Additionally, this study discusses the heat balances of a hotbox under dry and steam reforming conditions. From the obtained results, we will introduce the problem and capability of the dry reforming SOFC system and discuss its feasibility.