611
Hydrocracking
22.3.11 mAkFInIng ProCess
The process uses a multiple catalyst system in multi-bed reactors that include quench and redistribution system internals (Hunter et al., 1997).
In the process (Figure 22.9), the feedstock and recycle gas are preheated and brought into contact with the catalyst in a downflow fixed-bed reactor. The reactor effluent is sent to high- and
low-temperature separators. Product recovery is a stripper/fractionator arrangement. Typical operating conditions in the reactors are 370°C–425°C (700°F–800°F) (single-pass) and 370°C–425°C
TABLE 22.7
Feedstock and Product Data for the LC-Fining Process
Feedstock
Kuwait
Atmospheric
Residuum
Gach Saran
Vacuum
Residuum
Arabian Heavy
Vacuum
Residuum
Athabasca
Bitumen
API gravity
15.0
6.1
7.5
9.1
Sulfur, % w/w
4.1
3.5
4.9
5.5
Nitrogen, % w/w
0.4
Products, % w/w
Naphtha (C 5 –205°C, C 5 –400°F)
2.5
9.7
14.3
11.9
Sulfur, % w/w
1.1
Nitrogen, % w/w
Distillate (205°C–345°C, 400°F–650°F)
22.7
14.1
26.5
37.7
Sulfur, % w/w
0.7
Nitrogen, % w/w
Heavy distillate (345°C–525°C, 650°F–975°F)
34.7
24.1
31.1
30
Sulfur, % w/w
1.1
Nitrogen, % w/w
Residuum (>525°C, >975°F)
35.5
47.5
21.3
12.9
Sulfur, % w/w
3.4
Reactor
Fuel gas
Naphtha
Feedstock
Kerosene
Diesel
Fractionator
Stripper
Separators
Hydrogen
sulfide
Fractionator
Heavy gas oil
Recycle oil
FIGURE 22.9 MAKfining process.