Preparation of high activity silica-supported hydrotreating catalysts and catalysts thus prepared

Claim 2

Process for preparing silica-supported catalysts containing 10-25 %w molybdenum and from 1-5 %w nickel and/or cobalt as hydrogenation metals which comprises impregnating a dried silica support with an aqueous solution or an aqueous mixture obtained by contacting a hydrogenation metal compound with a nitrogen-containing organic ligand in the presence of water.

Claim 3

Process according to claim 1, wherein the dried silica support is impregnated at elevated temperature with the solution from step (d) which has been obtained by:-(a) preparing a slurry of about equal quantities of MoO 3 and EDTA in water to provide from 10 to 25 %w of Mo on said support; (b) adding from at least said equal quantity up to about a double quantity of (NH 4 ) 2 CO 3 to the slurry and mixing same; (c) adding about half as much hydrazine to the mixture as the quantity of (NH 4 ) 2 CO 3 added; (d) heating the mixture from step (c) to a temperature sufficient to form (NH 4 ) 2 [Mo 2 O 4 (EDTA)] in a reasonable time; followed by drying the Mo-impregnated silica at elevated temperature; whilst the dried silica support is impregnated with a desired quantity of aqueous nickel and/or cobalt salt solution either before or after the impregnation with the solution from step (d), and drying the Ni- and/or Co-impregnated silica at elevated temperature.

Claim 4

Process according to claim 1, wherein the dried silica support is impregnated at elevated temperature with the solution from step (b) which has been obtained by:- (a) preparing a slurry of an amount of MoO 3 and diethylene triamine in water to provide from 10 to 25 %w M on said support; (b) heating and mixing the slurry in sufficient water to dissolve the MoO 3 ; followed by drying the Mo-impregnated silica at elevated temperature; whilst the dried silica support is impregnated with a desired quantity of aqueous nickel and/or cobalt salt solution either before or after the impregnation with the solution from step (b), and drying the Ni-Mo or Co-Mo impregnated silica at elevated temperature.

Claim 5

Process according to claim 1, wherein the dried silica support is impregnated at elevated temperature with the aqueous mixture from step (d) which has been obtained by:- (a) dissolving an appropriate amount of nitrilotriacetic-acid in anmonium hydroxide; (b) adding to the mixture from step (a) an amount of MoO x to provide from 10 to 25 %w Mo on said support; (c) heating the mixture in step (b) until the reaction is substantially complete; (d) cooling the mixture from step (c) and adding an amount of nickel and/or cobalt salt to provide from about 1-5 %w Ni and/or Co on said support; and drying the Ni-Mo- and/or Co-Mo-impregnated silica at elevated tamperature.

Claim 6

Process according to one or more of the preceding claims, wherein the catalyst is heated to about 200 °C and sulphided before being used in a hydrotreating process.

Claim 7

Process according to one or more of the preceding claims, wherein the impregnation mixtures contain sufficient catalytically active metals to provide from 10-20 %w molybdenum and about 2-4 %w nickel on said support.

Claim 8

Process according to claim 3, wherein the molybdenum impregnation mixture is heated at about reflux temperature of said mixture.

Claim 9

Process according to one or more of the preceding claims, wherein the MoO x is MoO 3 , and the volume of the solution/mixture obtained is adjusted to about the pore volume of the silica support before impregnating same.

Claim 10

Process according to claim 5, wherein the impregnated silica is dried at about 200 °C and sulphided before being used in a hydrotreating process.

Claim 11

Process according to any one of the preceding claims, wherein use is made of silica spheres as support.

Claim 12

Process according to any one of the preceding claims, substantially as described herein with particular reference to the Examples.

Claim 13

A hydrotreating catalyst comprising from 10-25 %w molybdenum and from 1-5 %w nickel and/or cobalt as hydrogenation metals supported on silica whenever prepared according to a process as claimed in one or more of the preceding claims.

Claim 14

A hydrotreating catalyst comprising from 10-20 %w molybdenum and from 2-4 %w nickel as hydrogenation metals supported on silica, which catalyst has been prepared by the process according to claim 8.

Claim 15

A sulphided hydrotreating catalyst comprising from 10-20 %w molybdenum and from 2-4 %w nickel as hydrogenation metals and from about 10-20 %w sulphur, which catalyst has been prepared by the process according to claim 5.