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 (< 20 ppm CO) by low temperature (∼ 490 ^{{ring operator}} 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 K₂ CO₃ promoted hydrotalcite in a single unit. The chemisorbent is periodically regenerated by steam purge at ∼ 590 ^{{ring operator}} 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 H₂ 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 H₂ O : CH₄ ratio) are carried out.