Thermomechanical simulation of SiC-block-made sulfuric acid decomposer

Ishikura, Shuichi; Terada, Atsuhiko  ; Noguchi, Hiroki  ; Kasahara, Seiji  ; Onuki, Kaoru; Hino, Ryutaro

The Japan Atomic Energy Agency (JAEA) has been conducting R&D on hydrogen production by the thermo-chemical Iodine-Sulfur (IS) process to meet massive hydrogen demand in future hydrogen economy. In the IS process, sulfuric acid (HSO) is evaporated and decomposed into HO and SO in a HSO decomposer operated under high temperature condition up to 500C. We have proposed a new decomposer concept of a block type heat exchanger made of SiC ceramic which has a salient corrosion resistant performance under severe corrosion condition. To verify mechanical feasibility of the concept, temperature distributions of sulfuric acid and helium gas were analyzed with newly coded analytical system applicable to binary mixture such as HSO whose boiling point depends on concentration. Thermo-mechanical simulations with a general-purpose FEM code, which used the heat exchange simulation results, showed that maximum stress generated around the dryout region, which was about half of allowable tensile stress of SiC.