simulación FCC hysys

4.1 FCC Unit Simulation Configurations The FCC primary feeds are atmospheric and vacuum gas oil from the crude and vacuum distillation system. In FCC units, the reactions take place on the surface of the cracking catalyst. A carbonaceous deposit is left on the catalyst surface and must be removed by oxidation in a regenerator. The catalyst is of such particle size that it may be “fluidized” in the reactor regenerator. FCC block is used to model the FCC process.

Figure 1. FCC Model in HYSYS The FCC setup and calibration configurations are shown in the flowing files.

FCC Configration.doc

FCC Calibration.xls

4.2 Main Fractionator Simulation Configuration The column submodel is shown in Figure 2.

Figure 2. Main Fractionator column submodel in HYSYS 17 theoretical trays are used to represent the actual trays and sheds in column T201. Model the LCO as show in submodel. The steam stripper T202 is solved with the main fractionator column by HYSYS. The LCO stream that returns to the main column from T205 reboiler is modeled as a “net” pumparound circuit. The LCO that flows to T204 is represented as a side draw from T201. The HCO circuit is handled as two streams within the column sub-model. The HCO Recycle stream that returns to the reactor is modeled as a product draw. The portion of the HCO draw that flows to T206 reboiler is modeled as a “net” pumparound circuit. For modeling purpose the CSO is handled as three streams. The CSO product is drawn from the column as the bottom flow. The cool CSO used for quench is modeled as a “net” pumparound from tray 17 to tray 15. The cool CSO to the boot is modeled as a “net” pumparound from tray 17 to tray 17. Tray 17 is sub-cooled and produces no vapor. For continuous distillation calculation there must be both liquid and vapor streams leaving each tray. To overcome this problem, a dummy feed comprised of a few moles of H2 is fed to tray 17. The specifications are needed to solve this column are shown as table 2.

Table 2. Specifications for T201 Variable

Value

Reflux Rate (m3/h)

47.4

Btms Prod Rate (m3/h)

14.24

LCO to T204 Rate (m3/h)

16.56

HCO Recycle Rate (m3/h)

6.29

T202 Prod Flow (m3/h)

20.86

LCO "Net" P/A _Rate (m3/h)

165.6

LCO "Net" P/A_Duty (kJ/h)

-2.37e+07

HCO P/A_Rate (m3/h)

198.7

HCO P/A_Duty (kJ/h)

-2.74e+07

CSO Qch P/A _Rate (m3/h)

198.7

CSO Subcool P/A _Rate (m3/h)

39.74

Condenser Temp ( C )

37.7

Bottom Temp ( C )

357.2

1.3 Gas Plant Columns Simulation Configurations The specifications for the rest 4 columns are shows as table 3 Table 3. Specifications for T203-T206 Columns

Configuration

Primary Absorber T203

 Absorber model 11 theoretical stages

Sponge Absorber T204

 Absorber model 4 theoretical stages

Stripper Column T205

Reboiled Absorber model 12 theoretical stages

Stabilizer Column T206

Distillation model 30 theoretical stages