Refinery catalysts gasoline pool

From the inspection of the gasoline pool of a conversion type refinery, it is clear that major contributions with respect to octane optimization, may be expected from the fluid catalytic cracker and the downstream upgrading of its products. The development of zeolites contributes very substantially to these goals, both by their introduction into FCC catalysts and their use in the upgrading of some of the side streams. 

Environmental limits on the aromatic content of gasoline and diesel fuel have led to a further application of supported nickel hydrogenation catalysts. Benzene can be completely removed from light Ce reformate or other similar streams by liquid phase hydrogenation, before blending into the refinery gasoline pool. 

In the chapter on olefms plants, in the section on propylene, a route to making propylene involved butene-2. In this process, called metathesis, ethylene and butene-1 are passed over a catalyst, and the atoms do a musical chair routine. When the music stops, the result is propylene. The conversion of ethylene to propylene is an attraction when the growth rate of ethylene demand is not keeping up with propylene. Then the olefins plants produce an unbalanced product slate, and producers wish they had an on-purpose propylene scheme instead of just a coproduct process. The ethylene/butene-2 metathesis process is attractive as long as the supply of butylenes holds out. Refineries are big consumers of these olefins in their alkylation plants, and so metathesis process has, in effect, to buy butylene stream away from the gasoline blending pool. 

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