petrochemical, and solvent industries, and it will continue to be so. Measures to enhance light production in non-hydro- processing applications, such as FCC units, visbreaker units (VBU), and delayed coking units (DCU), include both short- term and operational adjustments. However, these utili- ties may deliver more branched paraffins and naphthenic compounds, as the refinery operation is optimised for these types of naphtha molecules to keep high resistance to knocking, with the focus on road gasoline production. Nevertheless, there are options for modifying kerosene hydrotreaters, aromatics saturation, gasoil hydrotreat- ers and beyond by using a layered approach. This can be achieved by applying Clariant’s proprietary Hysopar and Hydex technologies in combination with HDMax slim cata- lyst layers, to enhance the desired naphtha portion in the product slate without a major revamp and (most appropri- ately) hydrogen management. A Edward Tay, Head Refinery Technology, Technologies & Solutions Management, Sulzer Chemtech, edward. tay@sulzer.com The most cost-effective strategy to increase naphtha pro- duction lies in revamping existing capacity-constrained fractionation towers using enhanced mass-transfer com- ponents. This approach leverages existing infrastructure, minimises capital expenditure, and accelerates implemen- tation timelines. For example, to boost straight-run naphtha production, targeted upgrades can be made to the fractionation or pumparound sections of the crude distillation tower, naph- tha splitter, and naphtha stabiliser. These upgrades may include high-performance structured packing, advanced tray technologies, or ultra-capacity trays. Similarly, to increase FCC naphtha production, refiners can enhance FCC unit throughput by consistently recov- ering more atmospheric gas oil (AGO) and vacuum gas oil (VGO). This can be achieved by upgrading the fractionation and wash sections in the crude and vacuum towers, respec- tively. Depending on the severity of the service, a tailored selection of structured packing, high-performance trays, or grid packing can be deployed. Q Can you discuss how HEFA co-processing can safely be increased from 5% to 10% or higher? A Rainer Rakoczy, Technology Advisor Fuels, Clariant International Ltd, rainer.rakoczy@clariant.com Co-processing of fats and oils (biogenic triglycerides [BTG]) has been a high-interest topic since the early 2000s. Besides encountering substantial hydrogen demand and the release of heat and unwanted small molecules, there are options to increase the co-processing level below 15-20 wt% under certain circumstances. In particular, for more complex fossil gas oil hydrotreaters that handle large quantities of cracked feed components, which negatively affect density, blending with BTG can be beneficial. This blending can help in hydrogen and heat management, as deep (mono-) aromatics saturation is not required, with the contribution of low-density normal paraffins sourced from
BTG hydrodeoxygenation (HDO). For shaping the distilla- tion curve and adjusting cold flow properties, there is an appropriate catalyst layer solution from Clariant’s propri- etary Hydex or Hysopar families. A Joris Mertens, Principal Consultant, KBC (A Yokogawa Company), joris.mertens@kbc.global The risks associated with processing vegetable oils and/or animal fats relate to the following: • Catalyst deactivation, primarily caused by phosphor pres- ent in biofeed (irreversible) and the formation of CO during the decarboxylation reaction (reversible). • Corrosion, resulting from acids in the feed and water formed during decarbonylation, reverse water-gas shift, and methanation reaction. • Hydrogen consumption and reaction exotherm. The specific hydrogen consumption when hydrotreating bio-oils tends to be higher than full conversion VGO hydrocracking. • Product cold flow property (freeze-, cloud point, cold filter plugging point [CFPP]) deterioration due to the paraffining nature of hydrotreated triglyceride biofeeds. Industry experience shows that up to 5% of bio-oils and fats can be processed relatively easily without modifica - tions to the unit, except for catalyst changes and possi- bly minor modifications to quench systems, provided the unit is equipped with an effective feed filter system. Co-processing up to 5% may be feasible without a full- blown feed pretreatment unit (PTU) that removes phos- phorus (P), metals, and other contaminants. However, this requires a strict selection of the biofeeds purchased and monitoring of P, metals, solids, chloride, and acidity. Therefore, even 5% co-processing is often done using pretreated feeds, which adds cost but ensures better and more stable feed quality. Co-processing of more than 20% biofeed has been dem- onstrated. However, it requires significant investments in new reactors, recycle gas compressor debottlenecking, metallurgy changes, liquid recycling requirements, and other significant changes to the design of the preheat and separation/fractionation sections. A move from 5% to 10% co-processing should aim at avoiding these high capital investments. The first step in this process is to assess the performance at 5% compared to operation without co-processing. Extrapolation of the move to 5% will give an indication of constraints and risks, such as mechanical bottlenecks, reaction exotherms, and cold flow property deterioration. If 5% co-processing has been sustained for a sufficiently long period, the extrapola - tion will clarify impacts on catalyst performance and pos- sibly corrosion. This analysis helps establish the co-processing limit and define actions to overcome these, such as: • Feed adjustment : Keep the acidity (TAN) of the feed mix below approximately 1 mg KOH/g. Processing of feeds with high levels of free fatty acids, such as palm oil mill effluent (POME) and palm fatty acid distillate (PFAD), will therefore need to be limited, even if pretreated, which may increase the cost of the feed blend.
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PTQ Q1 2026
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