The Effect of Oxygen on Bunsen Reaction with HI<sub>X</sub> Solution in Sulfur-Iodine Hydrogen Production Process

Abstract

The Sulfur-Iodine thermochemical hydrogen production process (SI process) has been focused as one of the most promising method for hydrogen production by water splitting. SI process consists of three sections as follow; (1) Bunsen reaction, (2) H2SO4 decomposition and (3) HI decomposition. The O2 produced in a H2SO4 decomposition section could be supplied directly to the Bunsen reaction section without additional separation. Meanwhile, the reactant solution supplied to a Bunsen reaction section could be supplied as the type of a HIx (I2 + HI + H2O) solution, since only the separation of I2 in a HIx solution recycled from a HI decomposition section is very difficult. Therefore, we carried out the reaction using SO2 and SO2-O2 mixture gases in presence of the HIx solution to identify the effect of O2 in the Bunsen reaction. From the results, the amount of I2 unreacted under the feed of SO2-O2 mixture gases was very small higher than those under the feed of SO2 gas only, while the amount of HI produced was relatively decreased. In addition, the amount of impurities in each phase produced from the Bunsen reaction with the HIx solution was hardly affected by the O2/SO2 molar ratios.