A new catalyst regenerator technology was developed to improve Δcoke operations. Since improved equipment technology and catalyst offerings have resulted in progressive decreases in Δcoke, refiners have continued to debottleneck unit constraints within the capacity of existing major equipment. Usually with the constraint of not replacing main vessels or large rotating equipment, i.e., main air blowers (MABs), wet gas compressors (WGCs), regenerator shells, reactor shells, stripper shells and catalyst circulation standpipes. Maintaining this philosophy through several technology upgrades can result in several operational and reliability concerns:
• Excessive catalyst loading to regenerator cyclones
    – Cyclone erosion, fines generation
• High catalyst circulation and catalyst flux
    – Insufficient regenerator and stripper residence time
    – Hydraulic instability or limitation in the catalyst standpipes
• Excessive catalyst fines to the flue gas system
    – Increased particulate matter (PM) emissions.