Efficiency penalty analysis for pure H-2 production processes with CO2 capture

The conventional steam-reforming (CSR) process is a major process for the production of pure hydrogen from natural gas with CO2 as the main by-product. In this work, based on the CSR process, several alternative H-2-producing processes with CO2 capture are simulated and analyzed. The alternative processes capture the CO2 by concentrating the CO2 through the approaches including burning some of the separated H-2 instead of CH4 in the furnace, using pure oxygen instead of air,for the combustion of fuel gas, applying a prereformer to reduce the usage of pure oxygen, and applying an H-2-membrane in the steam reformer to separate pure H-2. The reactors of the CSR process and the alternative processes with CO2 capture were simulated based on the kinetic models of the reactions. The CSR process and the alternative processes were evaluated in terms of the thermodynamic efficiency, the amount of high pressure (HP) H-2 produced per mole of CH4, the amount of CO2 produced per mole of HP H-2, and the CO2 captured per niol of HP H-2. The efficiency penalties for CO2 capture of the alternative processes were compared and discussed. (c) 2006 American Institute of Chemical Engineers.