PTQ Q1 2024 Issue

C= Yield vs. Conversion

8.0

7.5

7.0

6.5

6.0

5.5

Base Base w/GBA

5.0

Conversion

Figure 1 Yield shifts from an FCC implementing GBA, where the FCC observed increased butylene and propylene yields of approximately 1 vol% at equivalent conversion levels

propylene and butylene production. In this case, collabora- tion with the FCC catalyst partner is required to evaluate catalytic solutions that bring another degree of freedom to solving this challenge. To target increased LPG olefin production, it is important to ensure the FCC base catalyst drives appropriate levels of gasoline yield and olefinicity. The resulting gasoline olefins are then cracked into smaller LPG olefins via the incorporation of a pentasil zeo - lite technology. While this overall approach holds for both propylene and butylene, the choice of catalyst and pentasil technology can influence whether butylene or propylene selectivity is maximised, as will be explained in more detail. Butylene Grace’s approach to increasing butylene yields is two- fold. Starting with a base catalyst that supplies sufficient conversion and gasoline olefinicity is key. Building on that foundation, Grace supports customers with both additive- based and catalyst-oriented solutions. For refiners who

require flexibility to quickly manipulate butylene yields with the backdrop of shifting constraints or feedstock avail - ability, an additive solution is recommended. GBA can be implemented to quickly increase butylene without as much propylene increase as a traditional ZSM-5 additive. Figure 1 shows yield shifts from an FCC implementing GBA, where the FCC observed increased butylene and propylene yields of approximately 1 vol% at equivalent conversion levels. When refiners consistently require higher butylene yields, Grace considers adjustments to base catalyst formulation to incorporate both Y and pentasil zeolites with its proprietary Achieve 400 platform of catalyst, which delivers impressive butylene yields and selectivity. Incorporating the pentasil zeolite functionality directly into the base catalyst with optimised active-matrix surface area, zeolite-to-matrix surface area ratio, pore distribution, and Y-zeolite stabilisation maximise butylene yield and selectivity while also improving gasoline octane and LPG olefinicity. Achieve 400 Prime is the latest development on the butylene selective catalyst platform and delivers the highest butylene yields, selectivity, and LPG olefinicity. Figure 2 demonstrates the step-out butylene yield and selectivity performance of Achieve 400 Prime relative to competitor butylene selective catalyst. Propylene As in the case of butylene maximisation catalyst systems, when selecting a catalyst for maximising propylene, the need for conversion is balanced against minimising hydro- gen transfer reactions to preserve gasoline-range olefins. Traditionally, to minimise hydrogen transfer, max propylene catalysts are designed with low unit cell size and a coke- selective matrix. Max propylene catalyst systems include a ZSM-5 technology that cracks gasoline olefins into LPG ole - fins while shifting the selectivity towards propylene. FCCs with a high propylene yield of 11 wt% or higher are not uncommon. In these cases, a high addition rate of ZSM-5 is used. Relative to a lower activity ZSM-5 additive, using the

2.0

1.5

1.0

0.5

0.0

-0.5

Competitor Grace

-1.0

-5

-4

-3

-2

-1

Conversion / wt. %

Figure 2 Butylene yield and selectivity performance of Achieve 400 Prime relative to competitor butylene selective catalyst

PTQ Q1 2024