Authors: Sam Clark a, Ray Fletcher a, and Peter Blaser a
a CPFD Software
Source: Blaser, P.; Fletcher, R.; Clark, S. AM-17-77 Improving FCC Economics through Computational Particle Fluid Dynamics Simulation; AFPM: San Antonio, TX, 2017.
Description: Several papers have been published during the past 12 months in which the unique circumstances surrounding maldistribution in FCC regenerators has been discussed1,2,3,4. In recent years, numerous refiners have utilized Barracuda Virtual Reactor® to successfully identify the root causes surrounding long-term, persistent afterburn and emissions issues. Virtual Reactor™ has been used to substantially reduce or eliminate such afterburn. This paper describes many additional structural issues which are endemic to the FCC operation resulting in limitations in operational flexibility with subsequent negative impact on economics. These issues include items such as incomplete combustion of spent catalyst within the regenerator commonly referred to as the “salt and pepper” appearance of regenerated catalyst, erosion of reactor or regenerator hardware leading to unscheduled shutdowns or reduced cycle length, and poor aeration at the inlets of regenerated catalyst hoppers and along the length of the standpipes leading to poor fluidization and reduced catalyst circulation rates.