FCC (FCC reactor / regernerator)

Our FCC model begins with general calculations around the reactor. These inferences can be used as APC control variables or simply as engineering indicators

• Coke make – from regenerator conditions.
• Cat to oil ratio – from reactor and regenerator heat balances.
• Strippable coke make – from catalyst stripper conditions.
• Feed Watson Kw factor – from vacuum unit inference models.
• Reaction coke make – from Kw and reactor conditions.
• Estimate of the feed Con Carbon.
• Conversion, corrected to 221ºC (430ºF) – from reactor and fractionator conditions.
• Crackability (ease of cracking of the feed).
• Estimate of catalyst activity.
• Estimate of olefinic LPG.
• Estimate of Octane.
• Estimate of slurry density.

The FCC inferential model technology has proven to:

Model many useful indicators in open loop.

• Trending of the inferences provides clues as to the feed properties and catalyst conditions. Especially these indicators are powerful in a lube refinery where the feed properties variations are large.

Predict important constraints for closed loop control.

• Use of the above calculations as disturbance variables helps controlling the unit well near it maximum capacity: conversion, gas make, coke make, LPG production, etc.

Model product properties for closed loop optimization.

• Slurry density, olefin content, octane number, etc, must be determined if one is to perform optimization of the unit.

Respond to feed changes.

• When the unit is at constraints it is very important for APC applications to quickly respond to new feed properties.

Be easily understood.

• The model follows standard process engineering procedures