Development of Chemical Reactors for Thermochemical Water-Splitting IS(Iodine-Sulfer) Process

Japan Atomic Energy Agency is developing chemical reactors for a pilot test plant of thermochemical IS process. Sulfuric acid (H 2 SO 4 ) decomposer, one of the key equipments of IS process plant, can vaporize concentrated sulfuric acid and decompose it into SO 3 and H 2 O using sensible heat of high temperature helium gas. Feasibility of a sulfuric acid decomposer featuring multi-block-type heat exchanger made of SiC ceramics was examined by preliminary analysis of structural strength, test-fabrication of the ceramic block, and seal performance tests between SiC blocks and metal flanges. Multi-phase flow analysis code coupled to chemical reaction was developed to establish a system of “design by analysis” for facilitating the development of chemical reactors. The codes handles process solutions which exhibit complicated phase behavior. Performance of the codes was confirmed by preliminary bench model analyses, which reproduced behavior of chemical gas absorption and also of liquid-liquid phase separation phenomena.