Two-stage PSA/VSA to produce H2 with CO2 capture via steam methane reforming (SMR)

A two-stage pressure/vacuum swing adsorption (PSA/VSA) process was proposed to produce high purity H2 from steam methane reforming (SMR) gas and capture CO2 from the tail gas of the SMR-H2-PSA unit. Notably, a ten-bed PSA process with activated carbon and 5A zeolite was designed to produce 99.99+% H2 with over 85% recovery from the SMR gas (CH4/CO/CO2/H2 = 3.5/0.5/20/76 vol%). Moreover, a three-bed VSA system was constructed to recover CO2 from the tail gas using silica gel as the adsorbent. CO2 product with 95% purity and over 90% recovery could be attained. Additionally, the effects of various operating parameters on the process performances were investigated in detail.