Mathematical Modeling of De-Hydrogenation Micro-Reactors for Vehicles Using the Liquid Carrier of Hydrogen Fuel

When the organic liquid carrier of hydrogen is used as the fuel on a vehicle, a key component is the hydrogen releasing device, which requires large surface area of catalyst, small size and light weight. Micro-reactors with internal structure of micro pin-fin array is considered due to its high area-to-volume ratio and intimate impaction-contact with the fluids. To support the design of a first experiment, a mathematical model based on laws of conservation and chemical reaction is established. A surface-reaction efficiency has also been included to consider the possible effect of surface nonwetting in the hydrogen two-phase flow. This model has been demonstrated using the N-Ethyl Carbazole as the liquid carrier and Palladium as the catalyst. Due to the large gas generation rate, the numerical modeling indicates that the system operates at high void fraction with large slip ratio. This leads to an alternative system design of using segmented reactors with a hydrogen separator located in between. This leads to reduced size of the system and less catalyst material used.