Comparative thermodynamic analysis of adsorption, membrane and adsorption-membrane hybrid reactor systems for methanol steam reforming

The thermodynamic analysis of steam reforming of methanol without and with fractional removal of H-2 and CO2 in adsorption, membrane and adsorption-membrane hybrid reactor systems to produce fuel cell grade H-2 with minimal carbon formation is investigated. The results indicate that the removal of undesired CO2 by CO2 adsorbent is most effective process for the production of high purity H-2 than H-2 removal by membrane. However, the membrane is effective only above 30% H-2 removal. It is possible to obtain H-2 yield of 2.6 with negligibly small amount of CO and carbon formation at T = 405 K, P = 1 atm, 80% removal of CO2 and 100% methanol conversion. Identical results are achieved even at lower temperature of 345 K in adsorption-membrane hybrid reactor system at 80% removal of H-2 and CO2. Thus high grade H-2 can be produced by single step process and further processing to reduce CO by PROX reactor is not necessary. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.