Product

Hydrotreated kerosene is straight-run or cracked kerosene that has been upgraded through catalytic hydrotreating — a refinery process in which the kerosene fraction is contacted with hydrogen over a fixed-bed catalyst (typically cobalt-molybdenum or nickel-molybdenum on alumina) at moderate temperature (280–370 °C) and pressure (20–60 bar) to remove contaminants and improve product quality.

What hydrotreating does to kerosene

The process simultaneously achieves several quality improvements:

• Desulphurisation (HDS): Converts sulphur-containing compounds — particularly mercaptans (thiols), sulphides, and thiophenes — to hydrogen sulphide, which is stripped out. This is critical for meeting the low-sulphur requirements of jet fuel specifications.

• Denitrogenation (HDN): Removes nitrogen compounds that cause colour degradation and oxidative instability in storage.

• Dearomatisation: Partially saturates polycyclic aromatic compounds, improving the smoke point — a key Jet A/Jet A-1 specification (minimum 25 mm) that governs combustion cleanliness and resistance to soot formation in turbine combustors.

• Olefin saturation: Hydrogenates unstable olefinic compounds present in cracked kerosene feedstocks, improving thermal and oxidative stability.

• Mercaptan sweetening / colour improvement: Eliminates corrosive mercaptans that would otherwise fail the silver strip corrosion and Doctor tests required for jet fuel certification.

Feedstock and output

The feed to a kerosene hydrotreater can be straight-run kerosene drawn directly from the atmospheric distillation unit, or cracked kerosene from a fluidised catalytic cracker (FCC) or coker — the latter typically containing higher levels of olefins and aromatics requiring more severe treatment. The product is a specification-grade, colourless to pale yellow kerosene with ultra-low sulphur, improved smoke point, and excellent thermal stability — meeting ASTM D1655 (Jet A/Jet A-1), DEF STAN 91-091, or equivalent national specifications.

Hydrotreated kerosene is the standard production route for Jet A-1 in the majority of the world's refineries. It is chemically and commercially indistinguishable from hydrocracked kerosene once both meet the same finished-fuel specification; the distinction lies entirely in feedstock origin (light straight-run or cracked kerosene vs. heavy gas oil) and unit configuration (hydrotreater vs. hydrocracker).