Catalysis 2025 Issue

Normalised WABT

Volume swell

390

NiMo / KF 774 NiMo / KF 780

380

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360

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WABT (˚C)

NiMo / KF 774 NiMo / KF 780

HDA

340

15 10 5 20 25 30 35 40 45

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NiMo / KF 774 NiMo / KF 780

DOS

NiMo/KF 774 vs NiMo/KF 780 cycle

Feed N : 615 vs 500 ppm Feed density : 889 vs 883 g/l ( 27.7 vs 28.7 ˚API) Volume swell : 28.7 vs 26.0 g/l ( 5.3 vs 4.5 ˚API) HDA (Mono Aromatic Equivalent) : 30 vs 23 wt%

3.5˚C / 6˚F lower normalised SOR WABT, increasing further with TOS 2.7 g/l/0.8 o API higher volume swell Projected to meet 5+ year cycle

330

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390

WABT (˚C)

Figure 6 High-pressure NiMo/KF 774 commercial case: 3.5°C/6°F lower normalised SOR WABT and 2.7 g/l/0.8°API higher volume swell. The NiMo/KF 774 Stax system is running more stable than the previous catalyst and is projected to meet more than a five-year cycle

KF 774 applied in Zone 2 to boost HDN and HDS further, allowing an even higher intake of distressed feedstock. KF 774 has higher HYD selectivity compared to KF 787 and is designed for medium and medium-to-high pressure applications, processing even more difficult feed, including high-nitrogen cracked components. KF 774 can be applied standalone at medium pressure. For applications with low PPH 2 outlet or close to the yellow operating regime (Figure 1), KF 787 is typically applied under KF 774 (KF 774/KF 787) to boost DDS selectivity at the reactor bottom and, with it, reduce hydrogen consumption and increase oper- ating stability. In contrast, for medium-to-high applications with good H₂ coverage and low enough inhibition by nitro - gen and PNAs in Zone 1, KF 774 can be loaded in combi- nation with a NiMo catalyst on top. NiMo/KF 774 loading configurations can further boost overall performance, with KF 774 allowing for reduced hydrogen consumption and improved stability compared to a full NiMo loading system. Case studies Refiners are leveraging the Pulsar catalyst technology in distillate hydrotreating to achieve various objectives by lifting performance constraints. Key achievements include upgrading significantly more distressed feedstock and achieving longer cycles. As the Pulsar technology is appli- cable across a broad range of pressure and feedstocks, it also enables high operational flexibility and simplifies cat - alyst pool management. Additionally, it offers economic advantage through energy savings from lowered WABT. Three cases illustrate the benefits of the Pulsar platform for distillate hydrotreating in commercial practice. In the first one, KF 787 was loaded as the main catalyst in a particularly

challenging low-to-medium pressure ULSD operation (PPH₂ outlet = 36 bar/520 psig) targeting maximum LCO intake (see Figure 5 ). Compared to the previous cycle with earlier generation KF 757, KF 787 allowed for a reduction in the nor- malised start-of-run (SOR) WABT of 6.5°C/12°F and for an increase of the average intake of light cycle oil (LCO) from 7.9 to 11.2 wt%, leading to 42% more LCO being processed. The main operating conditions in the two cycles were the same as the quality of LCO treated (density = 950 g/l/17.4°API, T95% = 369°C/696°F). Based on its performance, KF 787 has been confirmed in the unit for three cycles. A second notable commercial case, given the signifi - cant value generated, involves a medium-pressure ULSD unit loaded with a KF 774/KF 787 system (PPH₂ outlet = 44 bar/640 psig). In this catalyst configuration, defined through Stax, Ketjen’s proprietary kinetic model and reac - tor load optimisation technology, the specific function of KF 774 is to convert nitrogen more quickly and increase HYD activity in Zone 2, allowing for more effective removal of refractory sulphur. The unit is operated to maximise cracked stock intake, including low-value thermally cracked gasoil. A specific tar - get when loading the Pulsar catalyst system was to prolong the cycle length at equal cracked stock intake from the usual two to three years, providing the refinery with the option to synchronise the change-out with that of other units. Thanks to increased catalytic activity and stability, the cycle has successfully passed more than two years on stream with the same cracked stock intake as previous cycles, but with also sufficient activity to meet the targeted three-year cycle length. In view of the excellent performance, the same catalyst system has been confirmed for the next cycle.

Catalysis 2025