A Study on the Silica Membrane Preparation for a Hydrogen Permselective Membrane Reactor in the Thermochemical IS Process

摘要

The thermochemical splitting of water has been proposed as a clean method for hydrogen production. The IS process is one of the thermochemical water splitting processes using iodine and sulfur as reaction agents. HI decomposition procedure to obtain hydrogen is one of the key operations in the process, because equilibrium conversion of HI is low (22% at 450 °C). The silica membranes prepared by sol-gel method were applied to the decomposition reaction of HI vapor for improvement of one pass conversion of HI. The permeation characteristics of hydrogen and nitrogen belong to the Knudsen flow pattern, but water is different. The hydrogen permeation was dominated by the activated diffusion, and the activation energy of hydrogen was ca. 5 kJ/mol.