AM-13-01 Best Practices for Achieving Maximum ZSM5 Value in the FCC

Description:

Mobil Oil launched “ZSM5” as a revolutionary new catalyst in 1984. ZSM5 is a small pore zeolite which catalytically cracks higher molecular weight olefins boiling within the gasoline range into propylene and butylene (Figures 1-2). Within the FCC nomenclature ZSM5 has been classed as an “additive” since typical addition rates are less than 10% of the base catalyst addition rate. The advent of ZSM5 initiated one of the major step changes in FCC technology. Not long afterwards many units began to be operated in maximum propylene mode. In extreme cases, the FCC has been transformed from a motor fuels production process into a petrochemical feedstock platform. Marathon first started using ZSM5 additives to improve its FCC operations in the 1990’s. As FCC technology has advanced since that time, Marathon Petroleum Company (MPC) has used its in house experience in this area to develop a set of best practices, incorporating both its laboratory testing skills and operational expertise. This paper combines the best practices developed by both Marathon Petroleum Company and IntercatJM into one set of guidelines useful to all FCC process engineers.