Difference between straight-run gasoline and refined diesel in the pretreatment of hydrogenation catalysts
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The etherification unit uses straight-run gasoline for the catalyst pretreatment in its hydrogenation distillation tower, while the heavy gasoline hydrogenation desulfurization tower uses refined diesel for catalyst pretreatment. I would like to ask what the difference is between straight-run gasoline and refined diesel. Thank you!
Straight-run gasoline: Gasoline obtained from crude oil through direct distillation (the straight-run process). In atmospheric distillation, it is the liquid product obtained after condensing the oil vapor mixture that comes out of the top of the distillation tower. Its boiling point range (also known as the distillation range) is not strictly defined; it generally ranges from the straight-run boiling point to 205 (or 215)°C. It mainly consists of hydrocarbons with 4 to 12 carbon atoms, or even heavier ones, and also contains small amounts of sulfur compounds. This type of gasoline contains mainly saturated hydrocarbons, with fewer unsaturated hydrocarbons, which gives it high chemical stability. The octane rating varies depending on the origin of the crude oil, but it is not high enough to be used on its own; it can only be used as a component in gasoline blends. Produced from naphthenic oil, generally above 60 ； Produced from paraffin-based petroleum, it is generally between 40 and 50. It cannot be used as a fuel for gasoline engines on its own; it must be blended with further processed gasoline or similar substances. It can also be used as an industrial solvent oil or cleaning oil. Straight-run gasoline is the main raw material for the petrochemical production of olefins and aromatics. Refined diesel: Straight-run diesel or catalytic diesel undergoes reactions under high temperature and pressure in the presence of a catalyst to remove N, O, S-containing saturated alkenes and aromatic hydrocarbons. Straight-run gasoline is not yet a finished product; it can be considered a type of raw material rather than fuel suitable for use in engines ； Refined diesel is a qualified product that can be used directly as fuel for engines!
The bromine index of straight-run gasoline is slightly higher than that of refined diesel, but its sulfur and nitrogen contents are also higher than those of refined diesel
Straight-run gasoline has a high content of impurities, while hydrogenated diesel has a low content of impurities.