Techno-economic Analysis and Optimization of Water-Gas Shift Membrane Reactors for Blue Hydrogen Production

Hydrogen (H2) is an important energy carrier for transitioning into a decarbonized economy. H2-producing membrane reactors (MRs), such as those used for fuel reforming or water-gas shift reactions, can enable low-cost blue H2 production from a variety of feedstocks, e.g., biomass, coal, or natural gas. This is a consequence of the enhanced feed utilization for the MR (i.e., kg·H2 produced per kg feed) compared to conventional multi-step H2 generation/purification schemes. Furthermore, H2 MRs simultaneously separate H2 and concentrate CO2, thereby increasing the overall process efficiency and facilitating pre-combustion carbon capture. This work describes an equation-oriented, technoeconomic optimization model for a water-gas shift membrane reactor (WGS-MR) integrated within a gasification process scheme with carbon capture to produce blue H2. We find using WGS-MRs, the levelized cost of H2 (LCOH) with carbon capture was estimated to decrease by ∼10% from $3.33 kg·H2−1 to $3.01 kg·H2−1 (2016 USD), compared to the baseline LCOH using conventional WGS reactors and pressure swing adsorption (PSA). Sensitivity analysis elucidates the influence of operating conditions (e.g., temperature, pressure, space velocity) on performance (i.e., CO conversion, H2 recovery) and identifies opportunities to further reduce the LCOH below $3 kg·H2−1. This study provides a blueprint for applying MRs in blue H2 production and motivates further studies on the optimal integration of these.