Production of Hydrogen for Fuel Cell: Microchannel Reactor Modelling for Combustion and Reform of Ethanol in Alternate Channels

Abstract

Microchannel reactors are miniaturized reaction systems containing reaction channels with characteristic dimensions in the range of 10-500 µm. One possible application of microchannel reactors is the production of hydrogen to generate electrical power for portable equipment. In this paper, we propose to study the use of a microchannel reactor to produce hydrogen from the reaction of steam reforming of ethanol. The proposed device has the following components: (1) channels for steam reforming of ethanol containing a catalytic bed of Ni/Al2O3, (2) channels for exothermic reaction to provide the heat required for the reforming reaction, (3) cell fuel (PEMFC) that consumes the hydrogen produced by the reaction of reform. This work involved the simultaneous modelling of components (1) and (2) with the aim of showing that the catalytic oxidation of part of the exhaust gases produced in the reform of ethanol provides the heat required for the reforming reaction of ethanol, and that in this case the temperature along the microchannel (both in the reforming channel as in the oxidation channel) is kept approximately constant. Two alternatives were studied: co-currents and crosscurrents flows in the channels of endothermic and exothermic reaction. By studying these two cases it was concluded that the configuration co-current presents best result, concluding that the system can be considered isothermal.