Deviations between actual and calibrated cases
Item
UOM
Actual case 105,748.6 312,645.9 30,682.5
Calibrated case
Deviation, %
Hydrogen make-up flow Quench flow B-1/R-1 Quench flow B-2/R-1 Quench flow B-3/R-1 Quench flow B-1/R-2 Quench flow B-2/R-2
Nm3 /hr Nm3 /hr Nm3 /hr Nm³/hr Nm3 /hr Nm3 /hr Nm3 /hr
104,909.3 308,025.5 31,340.7 53,340.1 100,592 96,172.5 10,706.7
0.8 1.5 2.1 1.8
54,300.2 98,982.5 97,326.6 10,674.6
-1.6
1.2 0.3 0.1
Purge gas flow
Conversion
wt% kg/hr kg/hr kg/hr kg/hr kg/hr
67.8
67.7
Naphtha
27,829
27,383.7 7,066.7 84,563.9
-1.6
LPG
6,976
1.3
Kerosene
85,591 74,727 99,176
-1.2 -1.1 -0.5
Diesel
73,905
Unconverted oil
98,680.1
Table 2
is to solve a calibration case to get activity factors that will be used to predict product yields, product specifications, and conversion at different operating parameters and dif- ferent feedstocks rates and properties. The model is firstly built using design operating parame - ters considering feedstock and product properties at start- of-run (SOR). Building this case enables obtaining the fresh catalyst activity by extracting calculated and calibrated global control parameters and individual reaction activities. These values are the core of the simulation model that will be modified to simulate the studied feed mixtures over cat - alyst beds on an industrial scale. Hydrocarbon streams resulting from oil and gas process units can easily be described and defined using software already launched to simulate oil and gas process units, so it was an easy task to configure and define VGO, HCGO, and recycle oil process streams. The WLO stream is a hydro- carbon stream that results from oil and gas process units in origin but has some changes in chemical and physical prop- erties resulting from its industrial use. This makes its con- figuration in a simulation environment easy to some extent, especially using an oil characterisation tool while transfer- ring the same composition to the HCU RefSYS model fluid package called HCRSRK.
WCO is defined as a simple mixture of pure components such as linoleic acid, stearic acid, and oleic acid using the NRTL fluid package, then transferring this composition to HCRSRK. It was noticed that the HCU RefSYS model was not considered as a deoxygenation reaction of fatty acids in WCO, so the deoxygenation reaction is added as a sep - arate reaction set to the HYSYS environment. The resulting heat of reaction and products is compensated to the HCU RefSYS model through a spreadsheet. This spreadsheet is used to modify the composition of the WCO stream with HCRSRK through component mapping. Correlation and deviation between the converged calibra - tion case and the real case are established to determine if the calibrated hydrocracking case is accepted or not. Based on the data reported in Table 2 , the deviation in the main parameters is accepted. The use of a custom model for the hydrocracking reac- tor has allowed for an interesting analysis that illustrates the influence of operating parameters and feed properties on overall reactant conversion and product quality. The pre-calibrated case is used for providing expected data when processing feed mixtures experimentally to evaluate technically and economically the industrial processing of these mixtures. As performed in experimental work, each
101 100
Conversion wt%
93 92 91 95 94 97 96 99 98
Mix 1 Pred. (VGO 80% + WCO 20%)
Mix 3 Pred. (VGO 80% + WLO 10% + WCO 10%) Mix 1 act. (VGO 80% + WCO 20%) Mix 3 act. (VGO 80% + WLO 10% + WCO 10%) Mix 2 Pred. (VGO 80% + WLO 20%) Mix 4 Pred. (VGO 70% + WLO 20% + WCO 10%) Mix 2 act. (VGO 80% + WLO 20%) Mix 4 act. (VGO 70% + WLO 20% + WCO 10%)
370
380
390
400
410
420
430
440
450
Temp. (˚C)
Figure 2 Predicted and actual reaction conversion
72
PTQ Q4 2023
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