FCC operational changes to boost gasoline octane

摘要

The fluid catalytic cracking unit (FCCU) is one of the main units providing gasoline with high-octane numbers to the refinery gasoline pool. The objective of FCC operations is primarily to maximize octane barrels. Catalyst selection and operating parameters are usually optimized accordingly. Refiners require the flexibility to produce a wide range of products and within a variable quality. Any high-octane and low-sulfur gasoline components from a unit are a surplus for the gasoline pool, since any decrease in gasoline pool octane will be compensated by gasoline octane boosters. Therefore, pretreating FCC feeds to produce high-octane and low-sulfur gasoline can be an ideal option, but it can also be costly. Conversely, post-treating FCC gasoline to decrease sulfur will lead to a decrease in octane. If FCC gasoline is post-treated, then feed aromaticity and operating parameters are key factors to impede any octane loss downstream.