Modifications to model IV fluid catalytic cracking units to improve dynamic performance

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · AIChE Journal

DOI:https://doi.org/10.1002/aic.690410613· OSTI ID:80035

Huq, I; Morari, M ^[1]; Sorensen, R C ^[2]

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1. California Inst. of Tech., Pasadena, CA (United States)
2. Chevron Research and Technology Co., Richmond, CA (United States)

Model IV fluid catalytic cracking units (FCCUs) differ from other cracking units in that model IV FCCUs do not have slide valves in the catalyst circulation lines to enable direct control of catalyst circulation rate through the unit. Reducing fluctuations in catalyst circulation rate is found to significantly improve closed-loop performance of the FCCU. Some design and operational modifications that can be made to model IV FCCUs to improve closed-loop performance at the regulatory level based on this insight are modeled and compared. Closed-loop performance of a model IV FCCU operated with the weir and standpipe always flooded is examined. The achievable performance is significantly better than that of the standard model IV FCCU. The closed-loop performance of the model IV FCCU modified to incorporate slide valves in the catalyst circulation lines is also examined. The performance of the FCCU with slide valves is better than the performance achievable by the FCCU with the weir flooded. It is found that model IV FCCUs are ill-conditioned owing to the use of the weir and standpipe arrangement in the regenerator section. Both the operational and design modifications studied reduce plant ill-conditioning appreciably.

• OSTI ID: 80035
• Journal Information: AIChE Journal, Journal Name: AIChE Journal Journal Issue: 6 Vol. 41; ISSN 0001-1541; ISSN AICEAC
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CATALYSTS
CATALYTIC CRACKING
CHEMICAL REACTORS
COKE
DEPOSITION
GAS OILS
GASOLINE
MASS TRANSFER
MODIFICATIONS
PERFORMANCE
PETROLEUM REFINERIES
REGENERATION
SYNTHESIS