Page 95 - Fluid Catalytic Cracking Handbook

72 Fluid Catalytic Cracking Handbook

The UOP method uses CABP which, for all practical purposes, is
the same as VABP as shown in Appendix 2. The K factor is more
popular than K w because the VABP data are readily available. The use
of MeABP in the Watson method generally results in a lower K value
than that of UOP. Example 2-1 illustrates steps to calculate the K
and K,,, factors.

Example 2-1

Determine K UOP and Watson K w using the following FCC feed
properties:

Feed Properties
°API Gravity @ 60°F 23.5
SG @ 60°F 0.913
Density @ 20°C (68°F) 0.90
Refractive Index @ 67°C 1.4810
Viscosity @ 130°F, SUS 137.0
@ 210°F, SUS 50.0
Sulfur, wt% 0.48
Aniline Point, °F(°C) 192.0 (88.9)

D-1160 @ 1 atm
Vol% Temp. °F
10 652
30 751
50 835
70 935
90 1080

Procedure
1. Calculate VABP from distillation data.
2. Calculate the 10%-90% slope.
3. Calculate MeABP and CABP by adding corrections from Appendix 2
to VABP.

Step 1: VABP = 1/5(652 + 751 + 835 + 935 + 1080)

VABP = 851°F = 455°C = 728.2°K