Q & A > Question Details
What would be a typical product distribution of Coker light gas oil (diesel range) on an FCC Unit when the Coker light gas oil has gone through a VGO Hydrotreater?
15/10/2010 A: Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
There are many elements with respect to yield pattern which can be anticipated when co-processing light coker gas oil in a VGO FCC Unit.
It is vitally important to have the following information:
# Organic Hydrogen Content [measured or predicted] for LCGO BEFORE & AFTER hydrotreating
# Organic Sulphur and Organic Nitrogen Contents for LCGO also before & after hydrotreating
# FCC Riser Reactor Outlet Temperature [measured typical]
# Current Typical Calculated FCC Cat-To-Oil Ratio
# Current 'Carbon-On-Regenerated Catalyst' for regenerated fluid catalyst [measured]
# Key qualities of Heavy Distillate [Vacuum Gas Oil, Etc.] primary cat feed
# Typical yield pattern [including 430F- volumetric conversion and wt% 'coke'] on primary cat feed
Once these are known, it becomes feasible to predict whether hydrotreated light coker gas oil will crack similar to but at higher conversion than the primary cat feed or LCGO will be inhibited from cracking into higher octane FCC Gasoline and Olefinic C3 + C4 LPG.
IF the particular VGO FCC Unit is operating 'cold' at ROT =940F to 968F with high CRC values, low MAT, and low Cat-To-Oil Ratio, THEN the prediction of what happens to LCGO becomes more challenging.
IF the particular VGO FCC Unit is operating 'hot & catalytic'; THEN cracking of HT LCGO may be quite attractive in terms of high octane FCC Gasoline and Olefinic C3 + C4 LPG production.