A Novel Technology for Low-Carbon Hydrogen from H2S: A Large-Scale Techno-Economic and Environmental Assessment

Abstract H2S, a waste gas in oil & gas industry is usually incinerated in the Claus process. H2S-methane reforming (H2SMR) is a new technology developed at KU-RICH for producing low-cost and low-carbon hydrogen, key for the hydrogen economy. This work provides a comparative techno-economic and environmental assessment for alternative hydrogen-production via H2S methane reforming where H2S substitutes water in the conventional Steam methane reforming process (SMR). A large-scale H2SMR process is developed and benchmarked against SMR with CO2 capture (SMR+CC) in addition to methane thermal decomposition (CH4Pyrol). The study reveals the comparable energy intensity of H2SMR and SMR+CC at 148-149 MJ.kgH2-1 while CH4Pyrol has the least energy intensity of 75 MJ.kgH2-1. The added-value of process by-products of H2SMR and CH4Pyrol improved their levelized cost of hydrogen (LCOH) to $-1.00 and $1.93 per Kg, respectively compared to SMR+CC with $4.13 per kg and $2.41 per kg excluding and including CO2 selling credits. The carbon footprint of the three pathways is demonstrated via a gate-to-gate lifecycle assessment obtained in the order of H2SMR < CH4Pyrol< SMR+CC.