Catalyst to Improve Small-Scale Claus Plants

70493S02-II Although the Claus process is the dominant process for recovering sulfur from natural gas, sulfur conversion is limited by equilibrium, and two or three Claus stages are needed to recover most of it. In addition, expensive tail-gas treatment processes are needed to bring large Claus plants under environmental compliance. This project will develop a novel catalyst that provides a higher conversion of sulfur compounds in the Claus reactor. The use of this catalyst would decrease emissions of sulfur compounds in Claus processes, significantly reducing the amount of investment and operating funds needed for gas processors to meet their emissions requirements. Phase I synthesized and tested a series of catalysts that resulted in an improvement in the conversion of sulfur compounds in the Claus reactor. A detailed process and economic analysis was conducted to determine the benefits of the technology to the gas industry. Phase II will continue testing promising catalysts, and the most promising will be selected for long term testing to determine the stability of the catalyts. A bench-scale unit will be designed and fabricated, and the catalyst will be tested using a slip-stream from a Claus plant in Oklahoma. Commercial Applications and Other Benefits as described by awardee: The increased recovery efficiency from the use of the new catalyst should benefit existing Claus plants and eliminate the need to install costly tail-gas cleanup technology. The improved catalyst should also find use in new grass roots Claus plant installations.