Zeolites in fluid catalytic cracking (FCC)

Abstract

Looking back at the history of industrial chemistry, it can undoubtedly be declared that the impact of the introduction of zeolites into refinery operations has been revolutionary as it resulted in a significant increase in gasoline yield from catalytic cracking, leading to more ef ficient utilization of the petroleum feedstocks. Based on this successful entry into the industrial scene, zeolites quickly found many applications in petroleum processing in subsequent years; however, catalytic cracking still by far is the largest volume of zeolite catalyst consumer worldwide. Today, fluid catalytic cracking (FCC) catalysts account for more than 95 % of the global zeolite catalyst consumption (primarily USY zeolite). Fluid catalytic cracking units (FCCUs) around the world currently process around 15 million barrels per day and constitute the main conversion process in a typical fuels refinery. Primary output from FCC units is gasoline, and due to their pivotal role in fluid catalytic cracking, it can be stated that zeolite catalysts have been fueling our industrialized society by providing majority of the transportation fuels used, thus having direct impact on the global economy. Furthermore, in order to enhance the light olefin yields from FCCUs as a result of the increasing demand for building blocks for the chemical industry such as propylene and butylene, the FCC catalyst compositions are being modified by tuning their formulations and introducing different types of zeolite structures as additives. Using these zeolite-based catalyst formulations, many new FCC units worldwide also provide the critical starting points for (petro)chemical value chains. Hence, for the global supply of both fuels and chemicals, zeolitebased FCC catalysts are of paramount strategic and commercial importance.