Plasma treatment of a heated diesel/steam mixture for use in ship service fuel cell systems

Fuel Cell Energy (FCE), Inc. is a leading manufacturer of high-temperature internal reforming fuel cells for distributed power generation. FCE is currently developing a 625kW power module fueled by naval logistics fuels for ship service applications. The design of this power generator includes provisions for desulfurization of NATO F-76 marine diesel fuel and preparation of methane-rich gas for use in the internal reforming Direct Fuel Cell® (DFC®). Non-thermal plasma technology provides an attractive alternative to conventional catalytic routes for steam reforming of high molecular weight hydrocarbon fuels such as diesel and naval distillates. The prospects for the development of the compact non-thermal plasma technology for the ship service fuel cell application are currently under investigation. We are using a plasma reactor with a large number of micro-rods, each of which generates a surface discharge that is simlar to a dielectric barrier discharge. Each micro-rod consists of an inner conductor of small diameter, which is connected to the discharge-sustaining high voltage. The inner conductor is surrouded by an insulating dielectric material. A bare wire, tightly wrapped around the insulated conductor, serves as the second electrode, which is typically grounded. A large number of these micro-rods are packed inside the plasma reactor. The surface discharges from the individual micro-rods overlap and form a more or less homogeneous plasma volume. The heated fluel/steam mixture is passed through the plasma reactor either in the direction of the microrods (parallel flow) or perpendicular to it (cross flow). Preliminary experiments indicate that this plasma reactor is capable of converting a significant fraction of the complex aromatic hydrocarbons in the diesel vapor into small, aliphatic hydrocarbons (methane, ethane, propane). Further details will be presented at the Conference.