Thermodynamic analysis of hydrogen generation via oxidative steam reforming of glycerol

A thermodynamic analysis of the oxidative steam reforming of glycerol (OSRG) for hydrogen production has been carried out with Aspen plus (TM). The reaction was investigated at ambient pressure within the carbon-to-oxygen (C/O) ratio of 0.5-3.0, steam-to-carbon (S/C) ratio of 0.5-8.0 and temperature of 400-850 degrees C. Higher C/O and S/C ratios favor the production of hydrogen from glycerol. The highest hydrogen selectivity is obtained at 600-700 degrees C. To predict the potential technical obstacles in the glycerol reforming process, the OSRG process was compared with oxidative steam reforming of ethanol (OSRE) in terms of hydrogen production, autothermal condition and carbon deposition. The selectivity to hydrogen via OSRG is lower than that via OSRE under identical conditions. To achieve autothermal reforming, higher S/C and C/O ratios are required for reforming of glycerol than for ethanol due to the higher oxygen content in a glycerol molecule. From the viewpoint of thermodynamics, the glycerol reforming is more resistant to the carbon deposition. On the basis of the thermodynamic analysis and the preliminary experimental study, suggestions were proposed to guide the development of the glycerol reforming technique. (C) 2011 Elsevier Ltd. All rights reserved.