Rh AND Ni SUPPORTED CATALYSTS IN THE STEAM REFORMING OF GLYCEROL TO PRODUCE HYDROGEN

Glycerol steam reforming on Rh and Ni supported catalyst were investigated in view to produce syn-gas to feed a high temperature fuel cell system. Experiments revealed Rh/Al2O3 catalyst resulted to be more active and stable than Ni supported catalysts but independently from the catalyst used (Rh or Ni) and temperature investigated, the reaction is affected by coke formation mainly promoted by the large presence of olefins formed by glycerol thermal decomposition. Even if for thermodynamic reasons the hydrogen production should be favored by operating at high temperature, results obtained demonstrate that it is more convenient to operate at not higher temperature than 923 K, since higher reaction temperature promotes the formation of encapsulated carbon which negatively reflects on catalyst stability.