Phillip Niccum - KBR
One of the prime challenges to operation of a fluid catalytic cracking unit is keeping the catalyst circulating. Compared to the other challenges facing FCC operations, when it comes to mystery, correction of erratic catalyst standpipe operation tops the list. In this paper, fundamental equations and practical lessons learned reveal much of the mystery surrounding fluidized particle flow through standpipes.
The topics covered include a framing of the standpipe problem, knowing how to recognize standpipe performance issues, knowing the difference between actual and apparent fluidized density, awareness of where aeration goes, the importance of the standpipe inlet design, theoretical aeration requirements, the relative effectiveness of different aeration mediums, a review of available tools, and commercial examples that demonstrate the importance of each of these topics.