Catalysis 2025 Issue

chain olefins to be produced as well as even isoparaffins. More coke-resistant catalysts promise to offer less energy input for regeneration. They could even stretch to a depar- ture from the complexity of operation and energy needed in the current fluidised bed/regenerator configurations. Changes in the mode of MTO operation have revealed cer- tain unexpected benefits in product distributions and oper- ating conditions. The oligomerisation area has likewise seen catalyst devel- opment expand the selectivity envelope to home in on SAF yield maximisation. Technology to combine both oligom- erisation and hydrogenation functions in a single reactor is demonstrated in the laboratory at a minimum. In more con- ventional process flows, consolidation of hydrocracking and hydroisomerisation functions in a single step are outlined. The key enabler will be to efficiently marry the MTO and oligomerisation selectivities as a combined process that ide- ally produces the isoparaffin content and molecular chain length to meet SAF requirements. Predominant technology providers are clearly active in these efforts. A Rob Snoeijs, Communication Specialist, rob.snoeijs@ zeopore.com A variety of conversions are available to convert methanol (or other alcohols) to olefinic products, which, through fur- ther upgrading, may be used as SAF. The first option relates to methanol conversion to ethyl- ene and propylene using zeolite-based catalyst in an MTP (ZSM-5-based) or MTO-type (SAPO-34-based) configura- tion. The resulting small olefins may then be oligomerised towards larger carbon numbers suitable for the SAF boiling range, a conversion for which zeolite catalysts have shown selectivity and lifetime benefits (particularly based on ZSM- 23 zeolites). Finally, the resulting stream may be hydroge- nated using a standard hydrogenation catalyst towards the required levels to suit SAF. An alternative pathway relates to the conversion of meth- anol directly towards larger olefinic species, for example using a ZSM-5-based catalyst in an MTG-type configura- tion. Here, too, the ZSM-23 zeolite has shown remarkable selectivity and lifetime benefits. Also, after this reaction, hydrogenation is required to yield an acceptable SAF. Importantly, reactions involving small alcohols and olefins tend to coke and deactivate the zeolite catalysts rapidly, hampering selectivity and catalyst lifetime. To overcome this challenge, various solutions have been developed, such as diluting the reactive feed, adding additives to the zeolite, and importantly increasing the external surface of zeolite, giving rise to the family of more accessible (mesoporous) zeolites. Mesoporous zeolites have suffered a bad reputation when it comes to industrial applications based on the high cost commonly associated with their production. However, efforts at Zeopore have demonstrated that these cost chal- lenges can be overcome through capitalising on the synergy between conventional hydrothermal zeolite and post-syn- thetic workup. This can be seen in the associated Zeopore article in this issue of PTQ Catalysis 2025 , that sizeable ben- efits can be attained in this domain (specifically for ZSM-5

and ZSM-23 zeolites), and that combining mesoporisation with simultaneous additive addition yields sizeable benefits ( PTQ Catalysis 2023 , pp55-58). Q How is contamination of FCC catalysts being resolved to increase yields and cycle length? A Mark Schmalfeld, Global Marketing Manager, BASF Refinery Catalysts, mark.schmalfeld@basf.com FCC catalysts, specifically BASF FCC catalysts, are specifi- cally designed to enhance the operation of fluid catalytic cracking (FCC) units. Catalyst design considers the context of contamination management expected for the feed types used by the FCC unit. Here are several ways in which FCC catalysts contribute to improved FCC performance, even in the presence of catalyst feed contamination. FCC catalysts have been developed with enhanced metal tolerance, allowing them to maintain activity and selectivity even when exposed to feedstocks containing metals such as nickel and vanadium. This capability helps mitigate the negative effects of these contaminants, leading to more stable operation and improved yields, in addition to cata- lysts with near-zero levels of chlorides. Low sodium levels in FCC catalyst improve the zeolite stability. Use of an in situ manufacturing process designs the pore volume distribution to ensure a high level of iron tolerance. FCC catalysts often incorporate advanced zeolite struc- tures engineered to resist the deposition of contaminants. These optimised structures provide greater surface area and improved diffusion pathways, allowing for better hydro- carbon access and reduced accumulation of coke and other contaminants. FCC catalysts are designed to facilitate effective regen- eration as coke and hydrocarbon deposits are combusted in the FCC regenerator. Their design allows for the efficient removal of carbon deposits and some contaminants during the regeneration process, helping to restore and maintain the catalyst activity. This means that even in the presence of contamination, the catalysts can be regenerated more effectively when tailored to the specific unit constraints and targeted operating conditions. FCC catalysts may include proprietary additives and design elements that specifically target and mitigate the effects of contaminants. For example, these additives can help neutralise harmful compounds or enhance the cata- lyst’s ability to cope with specific impurities, thus maintain- ing performance levels. Enhanced catalysts and activity can help offset the impact of contamination by ensuring that the FCC unit operates efficiently, even when feed quality fluctu- ates. An optimised activity level is required based on unit constraints and economics. BASF’s FCC technical team can adjust catalyst design to provide refiners with operational flexibility to manage unexpected changes in feed quality. Additionally, catalyst design can be utilised to adjust how contaminated metals are removed from the FCC unit over time. This adaptability is crucial in maintaining stable performance and ensuring that the FCC unit can respond effectively to variations in contamination levels.

Catalysis 2025