from naphtha to resid boiling-point range hydrocarbons and contain atypically high levels of contaminant met- als, such as K, P, Ca, Fe, Mg, and Si. To address the chal- lenges associated with these new feeds to the FCC unit will require the co-development of reactor and catalyst tech- nologies. Biogenic oils such as vegetable and used cooking oils (FOG-oils) and biomass pyrolysis oils (bio-oils) contain high levels of oxygenates and alkali metals. Additionally, bio-oils may feature elevated levels of water/TAN, thermally unstable and insoluble in conven- tional FCC feeds. Other feedstocks, such as waste plastic- derived oils, can contain high levels of contaminant metals, halides, and olefins and can have a large portion of the oil in naphtha and LCO boiling range, more than typical FCC feeds. Viable catalyst solutions must address the require- ment for high metals tolerance, deoxygenation activity, and acceptable coke selectivity while maintaining desired prod- uct selectivities. Managing enhanced corrosion risks during storage and transportation of highly oxygenated feedstocks with lower pH associated is also important Handling and storage can also be problematic, poten- tially requiring stabilisers and/or emulsifiers due to the reactivity of olefins in plastic oils or the poor solubility of bio-oils in conventional feeds. Separate feed storage and new injection strategies, particularly for bio-oils, may be required. Managing enhanced corrosion risks during stor- age and transportation of highly oxygenated feedstocks with lower pH associated is also important. Injection of thermally unstable feeds with high free water content may require separate injection nozzles to account for lower feed injection temperatures and volume expansion associated with free water in bio-oils or lower boiling compositions of plastic oils. FCC unit licensors continue to develop technology solutions in these areas to support feed flexibility. As part of decarbonising the FCC unit, technology pro- viders are developing new reactor technologies, includ- ing increased flue gas feed atomisation to reduce steam demand, oxy-combustion coupled with CO₂ capture from the regenerator, and reactor designs with improved thermal efficiencies. These enhancements in reactor design have a direct impact on catalyst requirements. Oxy-combustion may result in higher severity in the regenerator, which will require highly stable catalytic materials, while the integra- tion of conventional CO₂ capture technologies may require improved catalytic materials for sulphur management within the FCC unit. Additionally, improvements in thermal efficiencies and reduced steam for feed atomisation will require low coke-selective catalyst technologies to fully take advantage of reactor improvements.
Co-development of innovative process and catalyst solu- tions is necessary to fully address challenges associated with increasing feedstock and product slate flexibility for the FCC unit. Collaboration between technology providers, process chemical providers, catalyst vendors, and the refin - ery is required to navigate the energy transition success- fully and profitably. Q What cost-effective strategies are available to allow diversification of fuels refineries towards the petrochemi - cal value chain? A Pierre-Yves Le-Goff, Global Market Manager Reforming and Paraffin isomerisation, Pierre-Yves.LE-GOFF@axens. net , Arnaud Cotte, Aromatics Product Line Manager, Arnaud.COTTE@axens.net , Axens Considering the potential reduction of gasoline consump- tion, linked to the growth of car electrification, while there is a still growing demand for petrochemicals, some refiners may consider shifting part of their reformate production to petrochemicals. Among the various options available, some necessitate marginal capital expenditure. The first option, if the reforming unit has some activity and cycle length margin or coke burning extra capacity, is to lower the naphtha initial boiling point to maximise the number of benzene precursors and increase the reactor temperature to increase aromatics production. This being done, it is possible to implement an aromatic extraction unit to produce petrochemical-grade benzene, while the raf- finate can be sent as chemical naphtha to a steam cracker to generate olefins or dropped to the gasoline pool for vol - ume or specification requirements. If the toluene can be removed from the gasoline pool while maintaining the gasoline pool specification, a toluene disproportionation unit can be considered. Depending on the catalyst choice, a mixed xylene stream or a paraxylene- rich stream can be produced, together with petrochemical- grade benzene. If the gasoline demand and specifications can be met with only a C₉+ cut, the mixed xylene-rich stream can be eventually extracted and sold on a petrochemical basis. This short introduction only gives a flavour of the pos - sibilities a refiner may consider when evaluating a move to petrochemicals. A Andrew Richardson, Johnson Matthey, andrew.rich - ardson@matthey.com A range of strategies exist to allow diversification of fuels at refineries toward petrochemicals cost-effectively. Johnson Matthey’s ZSM-5 additive products can be used to convert gasoline-range molecules into propylene and C₄s, both valuable chemical intermediates. Other strategies include the deployment of technologies to produce blending com- ponents for decarbonised fuels, which can drop into exist- ing refinery process streams without modification, allowing diversification toward decarbonised fuel products. JM’s proprietary FT CANS and BioForming technologies can produce drop-in low-CI molecules suitable for use across the gasoline, kerosene, diesel, and BTX markets.
16
PTQ Q4 2023
www.digitalrefining.com
Powered by FlippingBook