Thermal matching characteristics in an autothermal methanol reforming microchannel reactor for hydrogen production

Abstract

To ensure efficient operation of an onboard hydrogen production reactor, it is essential to synchronize heat generation and consumption in the channels. A computational fluid dynamics study is conducted to simulate a base case of the microchannel reactor that couples hydrogen catalytic combustion with methanol steam reforming in response to this problem. Our results show poor thermal matching of the reactor under the base case, with hydrogen combustion concentrated in the first half of the channel, creating a hot spot (796.09 K) and incomplete catalyst utilization (89% and 60% for reforming and combustion, respectively). Compared to the base case, when reducing the combustion side’s pre-exponential factors to 1.5×106, the local hot spots are eliminated, and the catalysts in the reforming and combustion channels are fully utilized. Furthermore, the maximum temperature of the reactor decreases to 691 K, producing more hydrogen while less hazardous carbon monoxide.