(548d) Development of a Novel Flexible Fuel Reformer with Sulfur Tolerant Catalyst

A novel flexible fuel reformer (FFR) acting as a closed loop heat exchanger that combines mechanical and catalytic innovation to extend the conventional reformer performance is being developed by Catacel Corporation, in partnership with the University of Toledo. The FFR is built using the foundation of a simple, low cost heat exchanger module that can produce hydrogen from heavy fuels, i.e. diesel fuels and jet fuels for commercial bulk hydrogen production through steam reforming.

The FFR concept is based on catalyst coated corrugated metal foils which form channels inside an accordion-folded heat exchanger. Reforming and combustion reactions are separated by a single layer of metal foil. A simple manifold distributes gas flow to the appropriate corrugation channels. The mechanical advantages of the FFR include compactness, robustness, durability, flexible design to fit a variety of fuel cell applications, lightness of weight and low cost to manufacture. The chemical advantages of this reformer involve continuous hydrogen production without plugging or deactivating the catalyst due to a back and forth periodic switching action designed in the FFR unit.

Diesel fuels contain large amount of sulfur, i.e > 500 ppm. Deactivation due to coke formation and sulfur poisoning limit the effectiveness of traditional reforming catalysts. Carbon and sulfur deposits that form during the reforming reaction are burned off in FFR during the combustion reaction, resulting in continuous regeneration and hydrogen production. The complete removal of 100-1000 ppm sulfur is still a challenge by this process. Hence, the development of a sulfur tolerant catalyst is attempted in this study in order to produce a continuous flow of hydrogen.

Performance of the FFR has been analyzed using a two-dimensional numerical model that was built using commercially available CFD software. The model successfully predicted steady-state temperature and concentration profiles in two dimensions. A lumped system model has been used to describe the various reaction steps on the catalyst surface. Dual mechanisms of FFR operation with novel sulfur tolerant catalyst will be demonstrated in detail and the CFD model pertaining to the transient analysis in FFR will also be presented.