Δ50 %TBP =300
F.
ASTM gap is +31
F which is well within the requirement for these two cuts.
Between LGO and Kero
Reflux ratio = 0.21.
Number of trays = 11 (includes credit for PA trays).
Factor = 2.3.
Δ50 %TBP = 185
F.
ASTM gap = À10
F.
This is poor, but as the Kero cut is to be used as a blend stock, it will be accepted.
In the final design, however, provision will be made to increase the overhead
reflux at the expense of the bottom pumparound to improve this separation.
Table 10 Tower overhead condenser duty
Stream
V/L
API
Wat. K
F
lb/h
Btu/lb
MMBtu/h
In
Naphtha
V
70
12
246
76,650
266
20.389
Reflux
V
70
12
246
61,230
266
16.311
Steam
V
246
37,381
1,197
44.745
Total in
175,351
81.445
Out
Naphtha
L
70
12
100
76,650
46
3.526
Reflux
L
70
12
100
61,320
46
2.821
Water
L
100
37,381
100
3.738
Cond duty
71.360
Total out
175,351
81.445
Table 11 Tower overhead heat balance
Stream
V/L
API
Wat. K
F
lb/h
Btu/lb
MMBtu/h
In
Naphtha
V
70
12
262
76,650
273
20.925
O/flow
V
53
12
262
x
249
249x
Steam
V
262
37,381
1,199
44.82
Total in
114, 031 + x
65.745 +249x
Out
Naphtha
L
70
12
100
76,650
46
3.526
O/flow
L
53
12
255
x
128
128x
Water
L
100
37,381
100
3.738
Cond duty
71.360
Total out
114.031 + x
78.624 +128x
Atmospheric and Vacuum Crude Distillation Units in Petroleum Refineries
175