Reactor conceptual design by optimization for hydrogen production through intensified sorption- and membrane-enhanced water-gas shift reaction

In this feasibility study, a novel industrial-scale reactor structure for continuous hydrogen production via intensified water-gas shift (WGS) reaction is proposed. It considers both trickling calcium-oxide sorbent for carbon dioxide removal (SOR) and Pd-based membrane for hydrogen separation (MEM). It is shown that WGS, SOR, MEM, and cooling can be decoupled with a special reactor superstructure mathematically represented with the pseudo-homogenous one-dimensional model. The final reactor structure and operating conditions are determined by using rigorous multi-objective optimization. Two objective functions take all main costs into account (total reactor volume and respective volumetric fractions for the catalyst, sorbent, and membrane) and the main benefit (hydrogen yield). The results show that the best cost-benefit relation can be achieved with the two-module reactor and combined WGS and SOR processes, with 95% carbon monoxide conversion (64% higher than the equilibrium conversion at the same conditions) and the outlet-stream containing only 0.7% of carbon dioxide. (C) 2019 Elsevier Ltd. All rights reserved.