Higher Octane Gasoline via Olefins Management and Alkylation

摘要

As automakers devise strategies to achieve more challenging CAFE fuel economy standards, more high-octane fuels may be needed in the U.S. passenger car and light truck fleet. This paper examines the impact of incorporating paraffin isomerization and paraffin dehydrogenation to increase feed for alkylation as a strategy for refineries to accommodate increasing production of gasoline at and above 93 (R+M)/2. The major conclusions are: 1 Incorporating the Butamer and Oleflex processes into the refinery can increase total gasoline production, increase alkylate production that can be sold as a separate product, as well as increase the refinery's capacity to produce 93 AKI premium gasoline at a higher percentage should the gasoline markets change in response to the CAFE standards. These processes convert low value materials (i.e., butanes) into high value products that increase the refinery's margin, lowering the normalized cost of gasoline production. 2 Refineries with the Butamer and Oleflex processes have higher leverage and flexibility in producing higher octane gasoline without changing the operation of the reformer or other major upstream units. 3 When 95-97 AKI premium gasoline is required, depending on the desired fraction of premium gasoline, the reformer may need to operate at higher severities, which may necessitate some plant modifications. For low fractions of premium gasoline, higher octane gasoline can still be produced without modifications. 4 The cost of production of gasoline decreases as isomerization and dehydrogenation unit capacities are increased. In addition to the favorable economics of butanes vs. gasoline, refineries will also gain from economies of scale.