Advances in feed conditioning for heavy hydroprocessing feeds
Media architecture and surface interactions for catalyst protection align with feed variability, providing a way to condition contaminant systems upstream of the reactor
Leontina Tompea, Mac McGuire, Carolyn Heyse, and Jimmy Wallum Filtration Group
H eavy-feed hydroprocessing units, ranging from atmospheric residue desulphurisation (ARDS), vac- uum residue desulphurisation (VRDS), resid hydro- treaters, and hydrocrackers running on atmospheric gas oil (AGO), heavy vacuum gas oil (HVGO), deasphalted oil (DAO), and cracked fractions are being pushed to process heavier, more contaminated, and more variable feeds as refiners increase opportunity crude exposure and deepen bottom-of-the-barrel upgrading.1 This shift has been accompanied by sustained expansion in hydrocracking and deep-conversion capacity, with global hydrocracking throughput now broadly estimated in the range of 10-15 million barrels per day, reflecting the industry’s focus on upgrading heavier fractions and maximising distillate yield. In many complex refineries, a substantial share of the crude barrel is routed through deep-conversion trains where high Conradson carbon residue (CCR), elevated metals, and asphaltenic fractions concentrate. Under these conditions, the practical constraint is often not intrinsic catalyst activity but the ability of the system to tolerate swings in contam- inant systems without losing reactor pressure-drop head- room or filtration stability. Fouling studies show that even low precursor levels can have measurable consequences. Deposition on the order of 1 ppmw corresponds to significant accumulation of carbo - naceous material in refinery systems, while HVGO systems exhibit substantially higher fouling rates in the absence of effective filtration.2 , 3 These bespoke observations emphasise that both the amount and the form of precursors reaching feed condi- tioning, guard beds, and catalyst are critical. Conventional feed filtration remains fundamentally size-based and does not explicitly address the mixed organic-inorganic agglom - erates now recognised as dominant fouling precursors. The work presented in the following discussion is based on an interaction-based approach, in which media pack construction and fibre surface energy are treated as design variables to control contaminant behaviour. Implemented through pleated, lofted media such as the proprietary Jonell Systems SynGuard platform, this approach promotes depth-loading of semi-deformable agglomerates rather than surface accumulation. Bench-scale characterisa- tion and field observations show that this shift in capture
mechanism translates into stable pressure drop behav- iour, extended service life, and measurable operating cost reduction under variable heavy-feed conditions. Heavy hydroprocessing under variable bottom-of-the-barrel feeds Heavy hydroprocessing feeds are inherently composite, comprising AGO, HVGO, ARDS, and VRDS effluent, res - idues, DAOs, and delayed coker gas oils. The contami - nant burden of these feeds is directly tied to crude slate. Opportunity crudes typically exhibit CCR in the 8-18 wt% range and nickel and vanadium (Ni+V) contents from sev- eral hundred up to more than 1,000 ppm in the heaviest fractions compared with conventional crudes, where CCR is often below 5 wt% and Ni+V well below 100 ppm. As crude slates, cut points, and secondary unit opera- tions evolve, each change shifts metals, CCR, aromaticity, and wax content, and so does the contaminant system presented to feed conditioning, guard beds, and catalyst.1 In practice, these feeds do not behave as a fixed system. Under identical hardware, shifts in blending and upstream operation generate different contaminant populations with distinct fouling behaviour. In representative heavy-feed hydroprocessing services, three consecutive runs on the same unit processed blends of paraffinic bottoms gas oil (PBGO), intermediate coker gas oil (ICGO), heavy coker gas oil (HCGO), medium vac- uum gas oil (MVGO), heavy atmospheric gas oil (HAGO), and lube extract fractions. Each run shifted by several per - centage points, generating three distinct contaminant pop- ulations under identical hardware (internal Jonell technical data). This variability is reflected in both laboratory charac - terisation and field filtration performance, reinforcing that contaminant behaviour, not just concentration, must be treated as a primary design input. Contaminant systems in heavy hydroprocessing feeds Contaminant systems encountered in heavy hydroprocess- ing are not well represented by rigid particulate models. Suspended inorganics, including corrosion products and catalyst fines, act as nucleation sites for hydrocarbon asso - ciation. These inorganic nuclei interact with oxidised gums,
23
PTQ Q3 2026
www.digitalrefining.com
Powered by FlippingBook