Investigation of hydrodearomatization of prehydrogenated gas oil fractions on Pt–Pd/H-USY catalysts

Abstract

Hydrodearomatization (HDA), hydrodenitrogenation (HDN) and hydrodesulphurization (HDS) of real gas oils (various sulphur, nitrogen and total aromatic content) was investigated over Pd, Pt catalysts supported on USY zeolite, whose Pd/Pt mass ratio was varied between 6:1 and 1:3, and total metal contents were between 0.90 and 0.93. The effect of Pd/Pt ratio on HDA, HDN and HDS activities is presented. The advantageous process parameters for HDA, HDN and HDS of gas oils over a selected catalyst (e.g. Pd/Pt mass ratio 3:1) were determined. Additionally, the effect of key process parameters (temperature, pressure, LHSV) on the yield and quality of products was studied. Under optimal process parameters the HDA efficiency decreased with sulphur and nitrogen content of feed. The rate of HDA enhanced with Pt content of the catalyst while HDS and HDN efficiency increased with Pd content. The maximum aromatic saturation was 85% and it decreased with sulphur and nitrogen content of the feed.

Hydroconversion of 1-methylnaphthalene over Pt/AlSBA-15–Al2O3 composite catalysts

“…During the hydrogenation of aromatics (after reaching maximum conversion) the drop in conversion value occurring as the reaction temperature is increasing, which is typical over hydrogenation catalysts,has been reported by many authors [49][50][51][52][53][54][55][56]. In general terms, the said drop may be attributed to thermodynamic or diffusion limitations or to catalyst poisoning.…”

Hydrodearomatization of Distillates and Heavy Naphtha over a Precious Metal Hydrogenation Catalyst and the Determination of Low Aromatic Content

“…Moreover, aromatics of heavier distillates such as gas oil fractions can be hydrodearomatized. The HDA of gas oil fractions on the Pt-Pd/USY zeolite catalyst was found to substantially reduce aromatic contents …”

“…The HDA of gas oil fractions on the Pt-Pd/USY zeolite catalyst was found to substantially reduce aromatic contents. 10 There are several analytical techniques available for the determination of aromatic types and content in diesel fuels and distillates. Fluorescent indicator adsorption (FIA) method, according to ASTM Standard D 1319, is the designated method for the determination of total aromatics in diesel fuels, but it does not work well for aromatics less than 4% by volume.…”

Preparation of Mesoporous Zeolite Y by Fluorine–Alkaline Treatment for Hydrocracking Reaction of Naphthalene

“…As a result, FCC diesel fuel refining catalyst must provide high aromatic hydrogenation saturation, hydrocracking, and selective ring-opening (SRO) ability. − Several works show that adding appropriate acidic constituents into the conventional Al 2 O 3 -supported hydrocracking catalysts can substantially improve the quality of the diesel fuel. Zeolite Y is considered as the most efficient acidic component due to its high activity and selectivity in middle distillates − compared with other materials in cracking catalysts. − However, zeolite Y is a microporous material with disadvantages that active site is poorly accessible and diffusion is limited. , Therefore, many modifications of zeolite Y have been developed to enhance the catalytic behavior. − …”