Production of fuel-cell grade hydrogen by thermal swing sorption enhanced reaction concept

The performance of a novel thermal swing sorption enhanced reaction (TSSER) concept for production of fuel-cell grade hydrogen (<20ppm CO) by low temperature (similar to 490 degrees C) catalytic steam-methane reforming (SMR) is simulated. The process simultaneously carries out the SMR reaction and removal Of CO2 from the reaction zone by chemisorption on K2CO3 promoted hydrotalcite in a single unit. The chemisorbent is periodically regenerated by steam purge at similar to 590 degrees C. The concept efficiently utilizes the CO2 sorption capacity of the chemisorbent and requires a relatively low amount of steam for its regeneration. A compact, small foot-print H-2 generator can be designed for a residential or industrial hydrogen fuel-cell unit by the concept. Recently measured equilibrium isotherms and column dynamics for ad(de)sorption of CO2 on the chemisorbent are reviewed and parametric evaluations of design variables like catalyst: sorbent ratio and feed gas conditions (pressure, temperature, and H2O: CH4 ratio) are carried out. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.