Oxygen-enhanced recovery of sulfur from H2S-containing gas streams. Products are bright yellow sulfur (99.9% pure) and clean tail gas for further recovery or incineration.
Description: The capacity of a Claus-type sulfur recovery unit can be increased by thermal combustion of H2S in two or more stages with an oxidant which is an oxygen-rich gas stream comprised of pure oxygen or a mixture of air and oxygen. A portion of the oxidant is fed to a first combustion zone (1) with all or a portion of the acid gas or ammonia-containing acid gas. The reacted mixture is cooled (2) and the remaining gas streams are fed to a second combustion zone (3). After condensing sulfur, the remaining gas stream is then fed to one or more Claus converters (4). Operating conditions: Pressures are near atmospheric. Oxygen concentration in oxidant is 21% to
100%. Sulfur recovery is 90% to 98%.
Economics: Replacing air with oxygen will more than double the capacity of a Claus-type sulfur plant and subsequent tail gas treating unit. Use of the Sure process is particularly attractive for revamping existing Claus and tail gas units to substantially increase the acid gas removal and for intermittent operation of such units at higher throughputs. Using the Sure process in new installations significantly reduces capital investment.
Licensors: BOC Gases and Parsons Energy & Chemicals Group, Inc.