Approaching complete CO conversion and total H 2 recovery for water gas shift reaction in a high-temperature and high-pressure zeolite membrane reactor

Abstract Water gas shift reaction of syngas and subsequent H 2 /CO 2 separation are key operations for large-scale H 2 production from fossil fuels and agricultural and forestry biomass with CO 2 capture. In this study, a tubular zeolite membrane reactor has been demonstrated for the first achievement of nearly complete CO conversion and total H 2 recovery with simultaneous production of a high pressure pure CO 2 stream for water gas shift reaction at high temperature and high pressure. When operated at 500 °C and 20 bar, the membrane reactor attained CO conversion > 99.9% and H 2 recovery > 99.9% with a high pressure pure CO 2 retentate under practically meaningful gas hourly space velocity of 15,000 h −1 and steam-to-CO ratio of 3.5. The zeolite membrane reactor with proven long-term stability is promising for further development and practical considerations.