Novel Adsorbents for Desulfurization of High Sulfur Battlefield Fuels

The major drawback to using fuel cells as auxiliary power units (APUs) is their inability to directly use battlefield fuels. Polymer electrolyte membrane (PEM) systems require clean, essentially sulfur-free hydrogen, and ppm levels of sulfur degrade even solid-oxide fuel cells. Battlefield fuels (i.e., NATO-76, JP8) contain high levels of refractory sulfur specie, which must be removed before entering the fuel processor. TDA Research, Inc. developed a low-cost, high-capacity regenerable sorbent that can directly remove organic sulfur from high sulfur military fuels, demonstrating the technical feasibility of a desulfurization process using this sorbent. An engineering analysis showed that a 3 kWe APU running on JP8 with 10,000 ppm sulfur would need under 2 kg of sorbent. We have already completed five consecutive adsorption/regeneration cycles; at least 40 cycles are planned during the remainder of the project. In Phase II, we will further improve our sorbent and scale up production. We will demonstrate our desulfurization sorbent’s performance integrated with a fuel cell system in a full-scale factory allowance test, and complete a detailed engineering analysis to assess the impact of our sorbent on the overall fuel cell system. The Phase II results will demonstrate the technical and economic feasibility of the technology.