Ammonia decomposition in catalytic membrane reactors: Simulation and experimental studies

Catalytic decomposition of NH 3 with H 2 ‐selective microporous silica membranes for CO x ‐free hydrogen production was studied theoretically and experimentally. The simulation study shows that NH 3 conversion, H 2 yield and H 2 purity increase with the Damköhler number ( Da ), and their improvement is affected by the effect of H 2 extraction as well as NH 3 and N 2 permeation through the membranes. The experimental study of NH 3 decomposition was carried out in a bimodal catalytic membrane reactor ( BCMR ), consisting of a bimodal catalytic support and a H 2 ‐selective silica layer. Catalytic membranes showed H 2 permeances of 6.2–9.8 × 10 −7 mol m −2 s −1 Pa −1 , with H 2 / NH 3 and H 2 / N 2 permeance ratios of 110–200 and 200–700, respectively, at 773 K. The effect of operating conditions on membrane reactor performance with respect to NH 3 conversion, H 2 yield and H 2 purity was investigated, and the results were in agreement with those calculated by the proposed simulation model.