Ali Fazeli - College of Engineering, University of Tehran, Tehran, Iran

Hydrogen can be used as a green fuel in an automobile for reducing air pollutions in crowded cities. Storing hydrogen in a heavy pressure vessel for the automobile is dangerous. Therefore, the idea of generating hydrogen onboard in a small-scale reactor called a microchannel reformer wasdeveloped to overcome this problem. Using steam reforming of methane (MSR), partial oxidation (POX), and auto-thermal reforming (ATR) of methane (the main component of natural gas) can be used for these purposes. The design of the reforming microchannel reactors and heat integrations needs thecomputational fluid dynamics (CFD) approach. In the microchannel reactors, the surface-to-volume ratio is high, and hence the temperature gradient and heat and mass transfer limitation will be reduced. Also, using the coating of the catalyst on the channel walls can bold these advantages of themicrochannel reactors and reduce the pressure drop in comparison to the packed bed reactors. Catalytic wall-coated microchannel reformers for portable hydrogen production were modeled using CFD to study the improved heat transfer on a very small-scale. In this review, recent progress in the CFDmodeling of microchannel reformers for hydrogen production using natural gas or methane as a feedstock was briefly discussed. Using straight or zigzag channel, feed distribution along the channels, heat integration in co, counter and cross-flow configurations were also reviewed.

Microchannel Reformer; Hydrogen Production; Computational Fluid Dynamic (CFD); Natural Gas; Methane Steam Reforming (MSR).