Production of Hydrogen by Methane Steam Reforming Coupled with Catalytic Combustion in Integrated Microchannel Reactors

This paper addresses the issues related to the rapid production of hydrogen from methane steam reforming by means of process intensification. Methane steam reforming coupled with catalytic combustion in thermally integrated microchannel reactors for the production of hydrogen was investigated numerically. The effect of the catalyst, flow arrangement, and reactor dimension was assessed to optimize the design of the system. The thermal interaction between reforming and combustion was investigated for the purpose of the rapid production of hydrogen. The importance of thermal management was discussed in detail, and a theoretical analysis was made on the transport phenomena during each of the reforming and combustion processes. The results indicated that the design of a thermally integrated system operated at millisecond contact times is feasible. The design benefits from the miniaturization of the reactors, but the improvement in catalyst performance is also required to ensure the rapid production of hydrogen, especially for the reforming process. The efficiency of heat exchange can be greatly improved by decreasing the gap distance. The flow rates should be well designed on both sides of the reactor to meet the requirements of both materials and combustion stability. The flow arrangement plays a vital role in the operation of the thermally integrated reactor, and the design in a parallel-flow heat exchanger is preferred to optimize the distribution of energy in the system. The catalyst loading is an important design parameter to optimize reactor performance and must be carefully designed. Finally, engineering maps were constructed to design thermally integrated devices with desired power, and operating windows were also determined.