Comparative numerical analysis for an efficient hydrogen production via a steam methane reforming with a packed-bed reactor, a membrane reactor, and a sorption-enhanced membrane reactor

Abstract

Following the adoption of the Paris Agreement, H-2 has come to be considered a promising alternative energy carrier owing to its eco-friendly characteristics. However, H-2 is mostly obtained via carbon-based production methods, which account for approximately 96% of the global H-2 yield and emit CO2 as a by-product. A membrane reactor (MR) was introduced to produce H-2 more efficiently via a positive chemical equilibrium shift, according to Le Chatelier's principle. CaO was employed as a CO2 adsorbent in an MR to form a sorption-enhanced membrane reactor (SEMR), in which the additional CO2 removal enhanced the equilibrium shift. Additionally, the direction of sweep gas through the membrane with respect to that of the reactants, i.e., co-current or counter-current flow, was found to affect the performance of the reactors. In this study, numerical simulations based on chemical reaction kinetics were carried out to investigate the effects of the employment of H-2 separation membrane and/or CO2 adsorbent as well as those of co-current and counter-current flows. Based on the numerical simulation results, H-2 yield rates of 0.00143, 0.00145, 0.00127, 0.00121, and 0.00852 mol s(-1) were achieved using the SEMR with counter-current flow, SEMR with co-current flow, MR with counter-current flow, MR with co-current flow, and a packed-bed reactor, respectively. This showed that an SEMR can be used to not only enhance H-2 production but also achieve this in an environment-friendly manner.