AM-00-08 New Developments in FCC Feed Injection and Stripping

Description:

The feed injection and catalyst stripping systems of an FCC play key roles in the unit’s product selectivities and properties. Recently commercialized developments in these areas have shown significant impact on overall FCC unit performance and profitability. Feed injection systems must be designed to atomize the feedstock into small droplets and disperse it into the riser. Mobil (now part of ExxonMobil) and KBR have applied state of the art technologies, such as Laser Phase Dopplerimetry, to develop and commercialize a new feed injection system technology. This paper describes the development and presents recent commercial data demonstrating yield improvements worth more than $0.24/Bbl of feed. For a 50 TBD unit this results in over $4 million per year in increased product value. Poor stripper operation can result in loss of recoverable product, excessive regenerator temperatures, reduced conversion and increased catalyst deactivation. We will review common operating problems in commercial catalyst strippers such as flooding, channeling, poor mixing, and local defluidization. Examples of diagnostic methods used to detect these problems are provided. A new Mobil-KBR stripper technology, known as DynaFlux™, has recently been developed to eliminate such problems and improve stripper performance. Results from large-scale cold flow tests and commercial installations are provided. The commercial results include hydrodynamic and yield improvements, mechanical reliability histories, and a discussion of ways to take full advantage of improved stripping within typical unit constraints.