HYDROCARBON FUEL GAS REFORMER ASSEMBLY FOR A FUEL CELL POWER PLANT

A fuel gas reformer assembly for use in a fuel cell power plant includes fuel gas passages, some of which contain a particulate alumina packing in which a vaporized steam-hydrocarbon fuel stream mixture is heated. The walls of the fuel gas passages are provided with an alumina coating which protects the walls of the passages from corrosion. The alumina coating of the walls, and alumina packing are both overlain by an alkaline earth metal oxide layer, such as a calcium oxide layer, that acts to limit carbon build-up on the surfaces of the coated passage walls. Limiting of carbon build-up in the reformer passages prevents premature clogging of the passages. The carbon build-up-limiting layer is formed on components of the reformer passages by applying a water-based slurry of alkaline earth metal compounds to the reformer passage surfaces, and then drying the slurry so as to solidify it. The formation of the desired crystalline phase of the coating occurs in situ on the coated passage surfaces during initial operation of the reformer. The coated packing material is operative to convert any free carbon remaining in the gas stream to carbon dioxide, or carbon monoxide, thereby further limiting carbon deposition in the assembly.