Highly enhanced ammonia decomposition in a bimodal catalytic membrane reactor for COx-free hydrogen production

Ammonia decomposition in a bimodal catalytic membrane reactor (BCMR) consisting of a Ru/gamma-Al2O3/alpha-Al2O3 bimodal catalytic support and a hydrogen-selective silica membrane in a single unit was proposed for COx-free hydrogen production in the present study. The bimodal catalytic membrane showed a H-2 permeance of 6.2 x 10(-7) mol/(m(2) s Pa) at 500 degrees C, with H-2/NH3 and H-2/N-2 permeance ratios of 200 and 720, respectively. Ammonia conversion was surprisingly enhanced form 45 to 95% at 450 degrees C in the BCMR after selective H2 extraction. The BCMR showed excellent stability with respect to both gas permeation properties and catalytic activities. (C) 2011 Elsevier B.V. All rights reserved.