Numerical simulation on non-catalytic thermal process of methane reformation for hydrogen productions

Abstract

The reformer that produces hydrogen from hydrocarbon is very important part of fuel cell system. One of the promising solutions has been recently considered as direct partial oxidation of hydrocarbon by excess enthalpy flame under rich and ultra-rich condition without a platinum catalyst. In this paper, excess enthalpy flame reforming process in the perforated silicon carbide tube reformer using a two dimensional approached with GRI mechanism 1.2 was investigated. The result shows that the stable excess enthalpy flame with temperature spike was observed in a perforated silicon carbide tube reformer under condition of higher equivalence ratio than rich flammability limit of methane. It is found that hydrogen rich gases could be produced through partial oxidation at very rich equivalence ratio by formation of excess enthalpy flame. The peak flame temperature of excess enthalpy flame was higher than the adiabatic flame temperature for a free laminar flame at identical conditions and excess enthalpy flame at ultra-rich equivalence ratio could become effective way to produce hydrogen rich gases from hydrocarbon. The conversion efficiency of hydrogen and carbon monoxide by partial oxidation of excess enthalpy flame was calculated as 37.64% and 60.62%, respectively at equivalence ratio of 2.0 and inlet velocity of 80 cm/s.