Study on Hydroisomerization and Upgrading of Diesel Oil

Abstract

From previous work in this institute as well as from other research communities we have chosen the metal oxide couple containing NiO and Mo03 which work effectively in catalytic operations of hydrisomerization and hydrocracking. It is also well established that group VIII metal oxides comprises 20-25% of the combination including group VI plus group VIII metal oxides, hence, in all our catalysts under study, NiO comprises 3wt% while Mo03 comprises 12wt% besides 85 wt% of the supporting material. This support includes HY-zeolite in a matrix of y-alumina prepared in the form of aluminium hydroxide gel in different proportions, namely; 12.75% zeolite + 72.25% alumina (catalyst 15Y); 25.5% zeolite+ 59.5% alumina (catalyst 30Y); 51.0% zeolite + 34% alumina (catalyst 60 Y). Also, two catalysts containing 85% HY-zeolite (catalyst 100 Y) and 85% alumina (catalyst 100 A) were prepared as another two extremes. All of these catalysts have been sulfided in the reactor unit before the catalytic tests have been carried out (in situ).

The reaction conditions tested are as follows: Temperatures range between 350 and 450oC; pressures range between 1.5 and 6.0 MPa and LHSV range between 1.5 and 6.0 h-1, at a fixed H2/oil ratio of 200 vol. per vol.. The reactor is a fixed-bed stainless steel high-pressure once­ through operation system. The gaseous products have been collected through cooling and analyzed gas-chromato­ graphically wheeas the liquid products have been fractionally distilled to separate light fraction (b.r. I.B.P-200°C) and a gas oil product (b:r. 200-380oC).

The light fraction has been gas-chromatographically