The characteristics of a sorption-enhanced steam-methane reaction for the production of hydrogen using CO2 sorbent

The objective of the present study is to characterize the production of hydrogen with a sorption-enhanced steam-methane reaction process using Ca(OH)(2) as the CO2 adsorbent. Theoretical equilibrium compositions at different operation conditions were calculated using an iterative method. It was found that with Ca(OH)(2) as the CO2 sorbent, the concentration of CO2 adsorption was reduced in the product stream, that gave rise to higher methane conversion and higher H-2 concentration. An experimental setup was built to test the theoretical calculation. The effects of sorbents and the particle size of Ca(OH)(2) on the concentration of CO2 and H-2 were investigated in detail. Results showed that the reactor packed with catalyst and Ca(OH)2 particles produced H-2 concentration of 94%. It was nearly 96% of the theoretical equilibrium limit, much higher than H-2 equilibrium concentration of 67.5% without CO2 sorption under the same conditions of 500 degrees C, 0.2 MPa pressure and a steam-to-methane ratio 6. In addition, the residual mole fraction of CO2 was less than 0.001.