feedstock increasing hydrocracking profitability. While the objectives and the chem - istry differ, HC-PT and high-pressure distillate hydrotreating share the same key kinetic functionality, namely hydrogenation (HYD). Figure 5 , anal - ogous to Figure 1 for high-pressure distillate hydrotreating, illustrates the operating zones in an HC-PT unit below the guard bed section. Four main zones are identified. In Zone 1, metals (Ni, V, Fe, P, Si, As) and asphaltenes are removed. This requires a NiMo catalyst with mod - erate HYD activity and an open pore structure to control coke formation and distribution throughout the cata -
Spent Quasar catalyst
Spent type II Nimo reference catalyst
Figure 3 STEM-EDX mapping showing the significantly reduced agglomeration of nickel into nickel sulphide crystals for Quasar compared to an earlier generation type II NiMo reference catalyst
leading to longer operating cycles and increased volume swell. Performance advantages in terms of RVA HDS and additional volume swell are illustrated in Figure 4 . KF 882 is typically applied in loading configurations with other NiMo catalysts designed using Ketjen’s propri - etary STAX kinetic engine. Due to its excellent capacity to remove nitrogen, it is also regularly used to enhance the performance of Celestia and Nebula BMCs loaded in reac - tor Zones 2 or 3. Despite its recent introduction to the mar - ket, KF 882 already has several commercial references in all major regions. Hydrocracking pretreat (HC-PT) The primary objectives of the HC-PT catalyst system are to remove metals and other contaminants, organic sulphur and nitrogen (particularly basic nitrogen), and to convert aromatics to naphthenes, while increasing volume swell. By enhancing feedstock quality for the cracking section, the HC-PT catalyst system boosts the efficiency and longevity of the hydrocracking catalysts. This allows for the produc - tion of higher-quality fuels such as ULSD from low value
lyst bed. Transitioning to Zone 2, PNAs are partially hydro - genated, and the bulk of sulphur and nitrogen is removed, starting with the easier species. In Zone 2, a catalyst with higher HYD activity is typically applied. Good pore accessi - bility remains important, especially in the presence of deep tails of cracked material or de-asphalted oil (DAO). Zone 3 is defined as the zone where difficult sulphur and nitrogen are removed, analogous to Zone 2 for distillate hydrotreating. Additionally, PNAs are further converted to di- and mono-aromatics in Zone 3. This zone requires a cat - alyst with maximum HYD activity to boost HDN, HDS, and HDA reactions. Finally, Zone 4 is the bottom part of the reactor where residual extremely difficult nitrogen can be removed. In Zone 4, provided the catalyst is sufficiently active, the inhi - bition by nitrogen on the HDA reaction is low enough to allow the saturation of mono-aromatics to naphthenes, fur - ther increasing volume swell. A major advantage of converting mono-aromatics to naphthenes is that the latter are easier to crack in the hydrocracking section. The same type of HC-PT catalyst
SRGO/HGO (254 ppm N)
HGO (440 ppm N)
HGO/LCO (560 ppm N)
SRGO/HGO (254 ppm N)
HGO (440 ppm N)
HGO/LCO (560 ppm N)
0.6 ∆˚ API
∆ g/l
120
3.0
0.5
115
0.4
2.0
0.3
110
0.2
1.0
105
0.1
0.0
100
0.0
800
950
1080
1230
800
950
1080
1230
55
65
75
85
55
65
75
85
Pressure (psig/bar)
Pressure (psig/bar)
Figure 4 Performance advantage of KF 882 Quasar compared to the previous-generation ultra-high activity type II NiMo for ULSD distillate hydrotreating. The additional volume swell reported is for the same operating temperature
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PTQ Q4 2025
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