Ethanol steam reforming with and without the presence of CaO as a CO2 sorbent is modeled. Potential advantages of the presence of CaO as CO2 sorbent include higher energy efficiency, higher hydrogen production and lower CO content in the reformer gas exit. The presence of CaO eliminates the need of a WGS reactor for PEMFC application. Favorable operation conditions in the presence of CaO are (1) atmospheric pressure, (2) reactor temperatures around 700degreesC, and (3) water/ethanol molar ratio of 4. (C) 2004 Elsevier B.V. All rights reserved.