Understanding Unit Pressure Balance Key to Cost-effective FCC Revamps
SUMMARY
FCC pressure balance is one of the key operating parameters that set catalyst circulation, unit charge rate, and conversion. Quantifying the individual system component pressure drops and the relative cost of reducing them allows cost-effective revamps to be implemented. Several examples present the benefits from actual revamps, which have increased unit capacity by 12%-40%.
TEXT
Understanding how system-component pressure losses influence compressor capacity is essential for cost-effective revamps in FCC units.
Depending on the specific limitations of a particular FCC unit, capacity increases of 12-40% have been achieved without modifications to major vessels or rotating equipment. This article presents three case studies in which a manipulated pressure balance has materially reduced revamp investment by eliminating or minimizing compressor changes.
Pressure drop from the FCC air blower discharge to wet-gas compressor suction has a large influence on the performance of both compressors. Because paralleling or replacing these compressors increases revamp costs significantly, once should only consider these high-cost options as a last resort...