PTQ Q4 2023 Issue

(generally called Jet fuel or dual-purpose kerosene (DPK)), diesel (ultra-low sulphur diesel according to Euro 5 specs), and unconverted oil (UCO). Among these seven products, we will focus on LPG, gas- oline, kerosene, and diesel because they account for more than 95 wt% of the overall production. The figures and tables to be discussed show the comparison between the model predictions and actual values of these product yields. Averaging the absolute deviations (AADs) of the 16 runs expressed in the following graphs for product property value 8,9 is calculated by the following equation: These AAD values help in evaluating the degree of varia- tion between actual and simulation cases, representing the prediction of the model on each product yield rather than the overall yield, which is the revenue key of the refinery. In contrast, absolute deviation indicates how the model affects the estimation of the profit of the refinery by con - sidering the deviations in the same scale toward overall production. Figure 3 illustrates the comparison between predicted gasoline yield (dash lines) and actual gasoline yield (solid lines) from studied test runs. It is noticed that the predicted values are very close to actual values in the range of 380 to 400°C, which is the recommended operating window of the commercial catalyst used in this study. This recom- mended operating window is stated by the catalyst man- ufacturer and process unit licensor. Table 5 illustrates the

Reaction temperature and feed composition of each run case

Abbreviation

Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9 Case 10 Case 11 Case 12 Case 13 Case 14 Case 15 Case 16

T380-WLO10-WCO10-VGO80 T380-WLO20-WCO10-VGO70 T380-WLO20-WCO00-VGO80 T380-WLO00-WCO20-VGO80 T400-WLO10-WCO10-VGO80 T400-WLO20-WCO10-VGO70 T400-WLO20-WCO00-VGO80 T400-WLO00-WCO20-VGO80 T420-WLO10-WCO10-VGO80 T420-WLO20-WCO10-VGO70 T420-WLO20-WCO00-VGO80 T420-WLO00-WCO20-VGO80 T440-WLO10-WCO10-VGO80 T440-WLO20-WCO10-VGO70 T440-WLO20-WCO00-VGO80 T440-WLO00-WCO20-VGO80

Table 4

A summary table for the input streams is shown in Table 3 and Table 4 for the 16 runs under study. Table 4 illustrates the abbreviation for each case; for example, Case 1 (T380- WLO10-WCO10-VGO80) means that for Case 1, the reac- tion temperature was 380°C and the feed mixture consists of 10% WLO, 10% WCO, and 80% VGO. There are seven products in the simulated hydrocrack- ing unit, including purge gas, fuel gas, LPG, hydrocracked naphtha (represented as gasoline in this study), kerosene

Gasoline wt%

Mix 1 Pred. (VGO 80% + WCO 20%)

AAD = 0.23 wt%

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 3 Predicted and actual gasoline yield in weight per cent

AADs values at different temperatures for each studied product yields and product property value

AAD

@380°C

@400°C

@420°C

@440°C

Gasoline yield Kerosene yield

0.43 0.99 0.79 0.06

0.18 0.98 0.41 0.03

0.28 0.98 0.68 0.06

0.38 0.98 0.94 0.12

0.32 0.98 0.71 0.07

Diesel yield

(Kerosene + diesel) yield

Table 5

PTQ Q4 2023