Green Hydrogen Recovery from Natural Gas Grids by Vacuum Pressure Swing Adsorption
Lucas F.A.S. Zafanelli, Ezzeldin Aly, Adriano Henrique, Alı́rio E. Rodrigues, Georges Mouchaham, José A. C. Silva
Abstract
High Resolution Image Download MS PowerPoint Slide This study focuses on the development of a conceptual vacuum pressure swing adsorption process (VPSA) for green hydrogen (GH) recovery from natural gas grids (NGGs). Accordingly, the kinetics-based separation of H 2 from NGG was achieved by using a commercial carbon molecular sieve (CMS-3K-172) adsorbent. To develop the VPSA cycle, the CMS-3K-172 was characterized, single- and multicomponent breakthrough curves for H 2 and CH 4 were performed, and adsorption isotherms were collected between 195 and 273 K and pressures up to 18 bar. To separate H 2 (20%) from CH 4 (80%), three different VPSA cycle configurations were designed and simulated by using Aspen Adsorption. The operational variables, such as step times, intermediate-to-high-pressure ratio, purge-to-feed ratio, and H 2 initial concentration, were evaluated for maximum values of purity, recovery, and adsorbent productivity. The results show that the VPSA processes can enrich H 2 in the product stream by up to 68% with a recovery of 92%.