Catalysis 2026 Issue

Properties of different ZSM-5 based catalysts

Distribution in the BTX yield of several catalysts

Catalyst Standard

Benzene, %

Toluene, %

Xylene, %

Catalyst Standard

Mesoporosity

Gallium

46 79 59

43 19 36

Limited Limited

None

Standard/Ga Zeopore/Ga

2 5

Standard/Ga

Introduced via impregnation Introduced via

Zeopore/Ga

Ample: introduced

Table 2

via metal mesoporisation

metal mesoporisation

Table 1

160

effect: improved catalytic performance by either activity, selectivity, or lifetime. Yet, despite the overwhelming catalytic superiority, the industrial adaptation of accessible zeolites has thus far been underwhelming. A probable cause is the persistence of expensive ingredients and unscalable unit operations associated with the manufacture of mesoporous zeolites. For example, various undesired aspects complicate man- ufacture, such as large amounts of expensive organics, long hydrothermal stages, and hazardous combustion steps. Moreover, such processes are typically combined to sub-optimal material properties, such as strong Brønsted acidity, as was recently illustrated for hydrocracking.9 Commercially relevant, high-quality, accessible zeolites have been made available for several years. Moreover, the catalytic value of simultaneous mesoporisation with metal incorporation (see Figure 3 ) was recently discovered, yielding unique catalysts and outstanding performance in hydro-isomerisation and methanol to propylene.10 The use of this technology platform led to a superior meso- porous Ga-containing ZSM-5 zeolite used in catalytic tests described in Table 1 . High-throughput screening The tunability of Zeopore’s technologies, combined with the streamlined high-throughput testing facilities at BioBTX, enabled testing a variety of zeolites in a short amount of time. Various compositions and porosities of zeolites were made and tested on sieved fractions on the gram scale, the performance of which is summarised in Figure 4 . The standard zeolite yielded a BTX yield that was largely similar to that of the standard Ga-containing zeolite. In con- trast, the Zeopore/Ga material achieved a BTX yield that

120

Standard

Standard/Ga Zeopore/Ga

that the Ga species in this sample is of a distinct nature as compared to Ga introduced via impregnation. Scale-up, extrudates, and miniplant Based on successful results in the screening phase, the standard and Zeopore/Ga samples were converted into industrially relevant catalyst shapes; that is, binder-con- taining extrudates. These extruded catalysts were tested on a miniplant with a capacity of 200 g/h, which is a down- scaled version of a commercial plastic waste valorisation plant from a process perspective. Figure 5 reveals that the Zeopore/Ga sample yielded twice the amount of BTX. In the conversion of waste plastics, the co-processing of biomass offers some synergic opportu- nities, for example based on oxygen content. Also, in this case, the mesoporous sample offered a doubled conversion as compared to the standard material. At the miniplant, the selectivity to xylenes was significantly larger compared to the screening phase. Moreover, the presence of mesoporosity Figure 4 BTX yields obtained on catalyst powders with PE feedstock in a high-throughput reactor. Yields normalised to standard (=100)

increased by more than 50% compared to the standard catalyst. In terms of BTX spe - cies distribution, the standard zeolite showed a preferential formation of benzene and toluene, with a minor amount (11%) of xylenes formed (see Table 2 ). Upon the introduc- tion of Ga, a pronounced shift towards benzene was evidenced. For the Zeopore/ Ga sample, a similar shift can be observed, but much less pronounced. This suggests

125

200

100

150

100

Standard

Zeopore/Ga

Standard

Zeopore/Ga

Figure 5 BTX yields obtained on extruded catalysts at the miniplant for PE (left) and 50/50 PE/biomass mixture (right). Yields normalised to standard (=100)

Catalysis 2026