Use TAME and heavier ethers to improve gasoline properties

Producing oxygenates from all potential FCC tertiary olefins is one of the most economic methods for reducing olefins and Reid vapor pressure (Rvp) in motor gasoline. MTBE production based on FCC isobutylene has reached a very high level. But the amount of MTBE from a refinery sidestream MTBE unit is insufficient for producing reformulated gasoline (RFG) and additional oxygenates must be purchased. The next phase will see conversion of isoamylenes in FCC light gasoline to TAME. Very little attention has been given to the heavier tertiary olefins present in the FCC light gasoline like tert-hexenes and heptenes. This route allows higher levels of oxygenates production, thereby lowering Rvp and the proportion of olefins in the gasoline pool and maximizing the use of FCC olefins. By using all the components produced by an FCC efficiently, many gasoline problems can be solved. Isobutene is converted to MTBE, C[sub 3]/C[sub 4] olefins are converted to alkylate and C[sub 5] tertiary olefins can be converted to TAME. All of these are preferred components for gasoline quality. By producing more oxygenates like MTBE, TAME and heavier ethers, a refinery can be self-sufficient in blending reformulated gasoline and no oxygenates need to be purchased. The technologymore » for producing TAME and other ethers is described.« less