Increase FCCU processing capacity with debottlenecking revamp

摘要

Fluid catalytic cracking units (FCCUs) are still the main units for modern refineries to obtain high-efficiency profits thanks to their low construction investment and ability to convert heavy oil into clean transportation fuels and high-grade petrochemical feedstocks.1'2 Recently, maximizing the production of gasoline products with low olefin content and liquefied petroleum gas (LPG) with high propylene content3 has become the main purpose for FCCUs. For many old units, technical modifications or new process packages are often adopted to overcome production bottlenecks to achieve the goal of changing production. The FCCU at CNPC's Karamay Petrochemical Co. refinery in China was built in 1994 with a processing capacity of 0.5 MMtpy; a recent revamp in 2001 increased its capacity to 0.8 MMtpy. The reactor and regenerator scheme is shown in FIG. 1. In recent years, with the change of feedstock properties, higher processing capacity and different product yields favoring a lower thesel-to-gasoline ratio, this unit has been overloaded and operations have been unstable. For example, the particle separation efficiency of the riser termination separator was reduced due to serious wear at its inlet cylinder.