摘要: |
Supercritical water is a synergistic, non-catalytic media for the reformation of crude ethanol feedstocks into hydrogen. The kinetics of the supercritical water reformation of ethanol was experimentally studied in a tabular reactor made of Inconel 625 alloy. The high enthalpy level of supercritical water and the extraordinary solubility of reaction components in supercritical water allow the reformation reaction to proceed without the presence of a heterogeneous catalyst. The principal reactions are pyrolytic decomposition and reformation of ethanol, which are competing in nature. The products of both reactions are quite similar yielding both hydrogen and carbon oxides, except that the former reaction also generates methane which undergoes further reformation in the supercritical water medium. The competitive nature of the reformation and pyrolytic decomposition reactions along with the water gas shift reaction in the supercritical reformation process was elucidated from a mechanistic standpoint. Kinetic rate information as well as the optimal process operating conditions was obtained for the supercritical water reformation process. |