Thermodynamics of ethanol reforming with carbon dioxide for hydrogen production has been studied by Gibbs free energy minimization method. The optimum conditions for hydrogen production are identified: reaction temperatures between 1200 and 1300 K and carbon dioxide-to-ethanol molar ratios of 1.2-1.3 at 0.1 MPa. Under the optimal conditions, complete conversion of ethanol, 94.75-94.86% yield of hydrogen and 96.77-97.04% yield of carbon monoxide can be achieved in the absence of carbon formation. The ethanol reforming with carbon dioxide is suitable for providing hydrogen-rich fuels for molten carbonate fuel cell and solid oxide fuel cell. The carbon-formed and carbon-free regions are found, which are useful in guiding the search for suitable catalysts for the reaction. Inert gases have a positive effect on the hydrogen and carbon monoxide yields. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.