The effect of oxygen on Bunsen reaction with HIx solution in Sulfur-Iodine hydrogen production process

摘要

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) H_2SO_4 decomposition and (3) HI decomposition. The O_2 produced in a H_2SO_4 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 HI_x (I_2 + HI + H_2O) solution, since only the separation of I_2 in a HI_x solution recycled from a HI decomposition section is very difficult. Therefore, we carried out the reaction using SO_2 and SO_2-O_2 mixture gases in presence of the HI_x solution to identify the effect of O_2 in the Bunsen reaction. From the results, the amount of I_2 unreacted under the feed of SO_2-O_2 mixture gases was very small higher than those under the feed of SO_2 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 HI_x solution was hardly affected by the O_2/SO_2 molar ratios.