innovative technologies is essential. By leveraging these pathways, the petrochemical industry can enhance the yield of these valuable products while improving both economic and environmental sustainability. The future of naphtha and LPG production lies in the integration of these strategies to meet the growing demand for petrochemical feedstocks in an environmentally responsible manner. A Carl Keeley, Head of Key Accounts, Global, Catalyst Technologies, carl.keeley@matthey.com, Marie Goret- Rana, Market Manager Additives, Catalyst Technologies, marie.goret-rana@matthey.com, and Jason Goodson, Regional Sales Manager Additives, Catalyst Technologies, jason.goodson@matthey.com, Johnson Matthey Naphtha is a fraction derived from crude oil and can also be obtained from natural gas condensates, petroleum dis- tillates, and other less common routes. It is primarily used to produce gasoline and as a feedstock for petrochemical products. LPG is commonly used for heating and cooking and includes products like propane, butane, and propane- butane blends. In addition to propane and butane, crude oil refining produces LPG olefins; these olefins are used to enhance gasoline quality and serve as feedstocks for pet- rochemical production. While gasoline demand is projected to decline as the US, Europe, and China adopt fuel alternatives and move towards a net zero economy, demand for naphtha and LPG for petrochemical production is expected to continue to grow ( source: bp Energy Outlook 2024 ). Crude oil is produced in many locations, with physical properties unique to the location from which it is extracted. Certain types of crude oil provide a higher yield of straight- run naphtha and LPG after distillation. By carefully selecting the crude oil blend to process, oil refineries can maximise naphtha and LPG production. In addition to crude oil distil- lation, oil refineries can use conversion process technolo - gies such as FCC to increase naphtha and LPG production. By optimising feedstock selection, equipment, process conditions, catalyst formulations, and additives, the FCC units can maximise naphtha and LPG yields depending on refinery economics. In general, FCC feeds are predomi - nantly paraffinic. Paraffinic feeds are easier to crack and normally provide the highest naphtha and LPG yields. Enhancements in feed injection, feed-catalyst mixing, and product and catalyst separation can boost naphtha yields. In addition, routing naphtha to a second reaction zone or dedicated riser can significantly increase LPG yields. Each FCC unit has its own operating window based on its available equipment and other constraints. Generally, high operating severity drives both thermal and catalytic cracking reactions. However, thermal cracking produces low-value byproducts like dry gas. Optimising FCC catalyst selection and incorporating additives enables the opera- tor to reduce operating severity and significantly increase naphtha and LPG production. Commercial FCC catalysts are engineered materials to optimise yields within unit constraints. The matrix materials perform the precracking of large molecules. The smaller, inter- mediate products produced can then enter the ultra-stable Y
(USY) zeolite, where they are further converted into naph- tha, LPG, dry gas, and coke. In addition to the FCC catalyst, specialist additives can be added to enhance LPG yield and increase propylene and butylenes production. Other addi- tives are available that enable operators to boost LPG olefins when FCC gasoline olefinicity is low. Utilising reliable and accurate catalyst and additive addi- tion systems is essential for optimising the addition of FCC catalyst and additives. Frequent, small additions are prefer- able to infrequent, large ones, as larger additions can upset FCC circulation and catalyst retention, leading to sub- optimal performance. Likewise, regular, small withdrawals of spent catalyst are recommended. Expertise in the cata- lyst and additive addition system design is crucial, as poorly designed systems can result in compromised safety and reliability, as well as reduced production of FCC naphtha and LPG. As refining markets continue to evolve, the operational flexibility of FCC units adapts accordingly, enabling refiners to remain competitive and profitable. The primary product streams consist of naphtha for gasoline production, along with naphtha and propylene for petrochemical production. Additional downstream naphtha and LPG olefins process - ing requires hydrogen and purification steps, requiring catalyst and absorbents. Q What type of flexibility can be built into a hydrocracker to quickly shift from naphtha to diesel output? A Heather Gilligan, Sr Hydroprocessing Engineer, heather.gilligan@imubit.com, Imubit Closed-loop artificial intelligence optimisation (AIO) technol - ogies, such as manipulated available handles (for example, reactor temperature and fractionator targets), drive towards a pre-computed optimal product mix based on a provided price set. This can occur for a single-unit or multi-unit sys- tem. The AIO model looks at economic objectives and con- straints, manipulating the handles to the optimal position to maximise the profit of the unit or the system as a whole. Moving from naphtha mode to diesel mode can have two transition points. The first is deconverting the tower to maxi - mise naphtha into the diesel cut, often to a flash constraint, once diesel is the more valued product. However, reduc- ing conversion/reactor temperatures to make more diesel frequently comes with a loss of liquid value gain, so diesel needs to have an even greater price advantage over naphtha before reducing reactor temperatures becomes attractive. Imubit’s AIO models are built on deep neural networks that ‘learn’ the nonlinear liquid volume gain and conversion curves associated with changing the reactor temperatures. This occurs not just at a single point in time but across the catalyst cycle as the catalyst deactivates, so the reactor stays optimised whether this transition occurs with fresh catalyst or just before the next changeout. A Peter Nymann, Senior Solution Specialist, Hydro- cracking, Clean Fuels, pan@topsoe, Topsoe In general, changes to the operation of a hydrocracker should never be made quickly due to safety concerns. It is
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PTQ Q1 2025
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