HYDROGEN PURIFICATION USING ZIRCONIA-SILICA COMPOSITE MEMBRANES FOR THERMOCHEMICAL PROCESS

For the purpose of purifying H-2 from a gaseous mixture of thermochemi cal water decomposition processes, the characteristics of zirconia-sil ica composite membranes coated on porous ceramic tubing were investiga ted up to 773 K. The maximum content of the Zr(OC3H7)(4) in the metal- alkoxides solution used successfully in the coating process was 60 mol %. Separation experiments of gaseous mixtures of H-2-H2O-HBr (UT-3 pr ocess) and of HI-H2O (IS process) were carried out at 423-773 K, and i t was found that hydrogen can be purified as a reject stream and that HBr and HI can be recovered on the permeation side through the membran es. (C) 1997 International Association for Hydrogen Energy. All rights reserved.