Research is currently inactive on the patented technology titled, "Heat Recirculating Cooler for Fluid Stream Pollutant Removal.” This technology is available for licensing and/or further collaborative research from the U.S. Department of Energy’s National Energy Technology Laboratory.
Most fuel cell systems cannot tolerate sulfur, which necessitates the removal of sulfur from syngas generated by the reformation or gasification of heavy fuels. Current sulfur removal techniques are not thermally matched to fuel processor or fuel cell system temperatures, resulting in significant heat rejection and loss of energy efficiency. In order to use these techniques, a simple and energy efficient method is needed to lower gas temperatures prior to sulfur removal.
This invention describes a process for sulfur removal in high-temperature fuel gas processing. Using a heat recirculating cooler, the process briefly lowers the temperature of a gas stream allowing conventional sulfur removal methods to be performed. The recirculated heat is used to increase the temperature of the gas back to conditions that are minimally less than the original temperature, minimizing the amount of heat rejected from the system and increasing the overall system efficiency. The process can be used whenever an intermediate step reaction requires a lower reaction temperature than the prior and next steps. Use of this technology permits the use of known pollutant removal methods while increasing thermal efficiency of the system.
Additional information about this technology is described in an article appearing in Journal of Power Sources 134 (1): 49−56, 2004.
U.S. Patent No: 7,442,353
Title: Heat Recirculating Cooler for Fluid Stream Pollutant Removal
Inventors: George Richards, David Berry
NETL Reference No: 03N-05