Steam reforming of the crude glycerol by-product of a biodiesel production plant has been evaluated experimentally at atmospheric pressure, with and without in situ CO2 sorption, in a continuous flow fixed-bed reactor between 400 degrees C and 700 degrees C. The process outputs were compared to those using pure glycerol. Thermodynamic equilibrium calculations were used to assess the effect on the steam reforming process of the main crude impurities (methanol and four fatty acid methyl esters). The crude glycerol and steam conversions and the H-2 purity reached 100%, 11% and 68%, respectively at 600 degrees C. No CH4 was found at and above 600 degrees C. Steam reforming of crude glycerol with in Situ CO2 removal is shown to be an effective means of achieving hydrogen purity above 88% in pre-CO2 breakthrough conditions. (C) 2009 Elsevier Ltd. All rights reserved.