Fluor's proprietary hydrogenation/amine tail gas treating process is a proven process widely employed in the industry. The hydrogenation/hydrolysis section converts SO2, COS, CS2, elemental S and other sulfur species in the Claus tail gas to H2S. The hydrogenated gas is then sweetened by a selective amine to remove H2S. This add on process follows a two or three stage Claus SRU to achieve overall sulfur recovery of up to 99.99%.
Fluor's proprietary Tail Gas Treating technology features the state of the art Low Temperature CoMo catalyst, which operates at lower temperature than conventional CoMo catalyst. The lower operating temperature eliminates the requirement of the fired heater, Reducing Gas Generator, and thus, simplifies operating and enhances performance and catalyst life. For certain applications, conventional CoMo catalyst using a Reducing Gas Generator can be offered if desired.
A two stage quench tower (de-superheater/contact condenser) is employed in Fluor's proprietary design. The lower section contains a circulating stream of caustic solution to guard against any SO2 breakthrough from the upstream reactor, which would otherwise degrade the downstream treating solvent.
Generic or formulated MDEA can be used in the amine section of the tail gas treating unit to achieve up to 99.99% overall sulfur recovery. Fluor also offers the proprietary Flexsorb® solvent which is a hindered amine with extremely high selectivity toward H2S to provide significant reduction in solvent circulation and ultra high treating performance.
Depending on the solvent used, H2S level in the treated gas from the tail gas treating unit can be as low as 10 ppm which can be discharged directly into the atmosphere. Therefore, eliminating the requirement of a thermal oxidizer.