PTQ Q3 2024 Issue

gasoline octane with minimal LPG increase is Johnson Matthey’s Isocat HP additive. Standard ZSM-5 additives have a low silica:alumina (Si:Al) ratio. By increasing the alumina content of the ZSM-5 particle, there are more acid sites for catalytic cracking reactions. Independent of the alumina content, the shape selectivity of the ZSM-5 crystal also promotes isomerisation reactions to increase branch- ing and, hence, octane in the gasoline stream. Isocat HP additive is designed to have a very high Si:Al ratio, so it has a lower activity for cracking but maintains the shape selectivity of the ZSM-5 crystal to promote isomerisation and increase gasoline octane. This additive is used in FCCs where LPG processing is limited, but an increase in gaso - line octane is still required. SUPER Z, ZMX-B-HP, and ISOCAT HP are marks of Johnson Matthey . Q What opportunities do you see for the integration of biorefineries with steam crackers? A Yoeugourthen Hamlaoui, Global Market Manager, Axens, Yoeugourthen.HAMLAOUI@axens.net By integrating refineries and steam crackers, it becomes possible to take advantage of several sources of feedstock and increase the plants’ profitability. Refinery off-gases (ROGs) are used as feedstocks in the steam cracker after being treated in the different steps required to remove contaminants and maximise olefins recovery. Such a configuration allows for enhancing ethyl - ene and propylene yield by valorising low-value byproducts. On the same principle, naphtha produced by the refinery can be used in the steam cracker as a feedstock. This naph - tha maximises profitability. The hydrogen produced by the steam cracker can be valorised on the refinery side by any unit consuming it. On the one hand, for any existing integrated refinery with steam cracking, it could be relevant to consider switching from fossil naphtha to bio-naphtha, as the integrated scheme is already in place. The main counterpart standing in the way is economics, as currently the cost of bio-naphtha does not look attractive without appropriate regulation. On the other hand, the biorefinery is mainly oriented towards sustainable aviation fuel (SAF) production. Bio- naphtha is then a byproduct, which could be valorised but produced at quite low quantities. However, opportunities for integration of biorefineries with steam crackers seem quite limited. A Hans-Christoph Schwarzer, Head of Business Development Ethylene, Clariant Catalysts Although we do not foresee the true integration of biore- fineries with steam crackers, bio-based oil could be co-fed into a steam cracker after purification and stabilisation, like what is currently being established in chemical plastic recycling. Instead of being incinerated or ending up in land - fills, mixed plastic waste can be converted to pyrolysis oils, which can be used as feedstock for the sustainable produc- tion of chemicals. In this emerging field, producers are faced with continu - ously changing contaminants and contaminant levels in a

A ction A ction +

8.5

7.5

6.5

Ecat FST C= (wt%)

Figure 3 Maximising alky barrels with Action+

and partnering with a catalyst technology provider will pro- vide the best outcomes in terms of achieving the desired yield and product quality shifts while maximising overall unit profitability. Various catalytic handles are available with advances in catalyst technology, and a partnership approach is the key to sustained success in a dynamic environment. DENALI and ACTION are marks of Ketjen. A Heather Blair, Senior Technical Service Engineer at Johnson Matthey There are a few operational methods available to increase higher-octane gasoline components. The first is to increase FCC riser temperature; an increase of ~13-15°F yields an octane increase of 1.0 RON, and a 25°F riser increase yields a MON increase of 1.0. Decreasing FCC feed gravity will also increase gasoline octane; a decrease of -1.7 API (+0.1 g/cc density) will increase gasoline RON by 0.6. Reducing the rare earth content of the base catalyst will also increase gasoline octane, but it comes at the expense of gasoline yield. The ability to change feed quality, adjust riser tem - perature, or change catalyst properties is not always pos- sible. An alternative method to increase gasoline octane is to utilise a ZSM-5-type additive. ZSM-5 additives increase the octane first by cracking C6 to C 10 straight-chain gasoline olefins into LPG olefins. This increases the propylene and butylene feed to the alkylation unit, increasing alkylate as a high-octane blending compo- nent. The cracking of the lower-octane gasoline species also concentrates the gasoline stream to higher-octane material. ZSM-5 has a secondary effect of increasing the gasoline octane. As ZSM-5 deactivates and loses cracking activity, older ZSM-5 particles isomerise straight-chain gasoline molecules to more highly branched molecules, increasing the octane of the gasoline stream. When ZSM-5 is used long term a significant boost in gasoline octane is observed. Johnson Matthey provides multiple types of ZSM-5, such as the standard Super Z family that cracks into both propyl- ene and butylene, with more selectivity towards propylene. The second family is ZMX-B-HP, which has more selectivity towards butylene than a standard ZSM-5 product. propyl - ene processing or sales outlets, but there is a significant economic benefit for butylene. The last ZSM-5 product with the unique ability to increase

PTQ Q3 2024