Catalysis 2022 issue

of FCC based faujasites that not only displays significantly increased porosity in the fresh zeolite but concomitantly features enhanced hydrothermal stability over stand - ard mesoporous zeolites and con - ventional stabilised USY zeolites (see Figure 6 ). Zeopore’s technologies have also been successfully applied to ZSM-5- based additives, displaying signifi - cantly increased mesopore surface area and preserved microporosity before and after steam deactiva - tion. This combination of features unlocks benefits, such as increased olefin yields (see Figure 7 ). Hydrocracking The potential of mesoporous zeolite catalysts in hydrocracking is vast. Like FCC-based faujasites, the mes - oporisation of USYs for hydropro - cessing is a core target, yet not the ultimate challenge. For the fragile high-silica faujasite zeolite frame - work, mesoporisation is easily achieved. The challenge is to com - bine the introduction of ample mes - oporosity with the preservation of intrinsic zeolite properties, such as acidity (see Figure 8 ). Zeopore’s high-quality mesop - orised zeolites enable three-way benefits in hydrocracking: gains in selectivity, activity, and stabil - ity. Other secondary benefits are lower hydrogen consumption and improved product quality (cloud point and density). Unlike other technologies, these benefits are feasible for catalysts varying from

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Figure 7 Porous properties of ZSM-5 catalyst prepared via conventional methods – parent zeolite (orange) and Zeopore mesoporised zeolite (blue)

based on the ongoing shift from fossil to sustainable feedstocks. Also, Zeopore’s catalysts have supe - rior performance for these more demanding biomass-derived feeds than conventional zeolite based catalysts. Alcohol valorisation The production of (biomass- derived) alcohols offers significant opportunities for subsequent cat - alytic upgrading towards olefins and other platform molecules. In alcohol conversions, mesoporous zeolites have proven their value based on an increased resistance towards coke formation. In a case study on methanol-to-propyl - ene with ZSM-5-based catalysts, Zeopore has demonstrated that, in addition to the known stability benefit (lifetimes doubled or more), mesoporisation enables it to gain

low-zeolite content diesel-selective catalysts to high-zeolite content naphtha-selective catalysts. Hydro-isomerisation (dewaxing) Typically, the benefits of mesop - orisation increase as the size of the substrate molecules increases and as the size of the zeolite micropores decreases. Accordingly, in diesel and lube dewaxing using uni- directional zeolites, the benefits are even more pronounced: improved cold flow properties at an unprecedented low diesel loss (see Figure 9 ). Moreover, the reduced degree of cracking con - sumes less hydrogen, the limited LPG formation allows for a higher plant capacity, and gains in hydro - genation potential enable a lowered amount of aromatics in the product. The commercial relevance of dewaxing processes is expected to significantly increase in the future,

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Figure 8 (a) Mesoporosity and acidity of USY zeolites prepared via conventional methods (orange), standard mesoporisation (grey), and Zeopore (blue) (b, c) Conversion and diesel yield benefits Zeopore brings over the conventional zeolite-based catalyst

Catalysis 2022 47

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