Sulfur tolerant noble metal containing aromatics hydrogenation catalyst and a method of making and using such catalyst
View Patent ↗An aromatics hydrogenation catalyst composition which comprises a noble metal component and a support comprising zirconia, silica, and, optionally, alumina. The catalyst composition is manufactured by co-mulling silica, a zirconium compound, and, optionally, alumina to form a mixture that is formed into a shape, such as by extrusion to form an extrudate, with the shape being calcined and noble metal being incorporated into the shape. The catalyst composition may be used in the saturation of aromatic compounds.
1. A process for hydrogenating aromatics of a hydrocarbon feedstock containing a concentration of sulfur in the range of from 10 to 1000 ppmw and a concentration of aromatics, wherein said process comprises:
contacting said hydrocarbon feedstock, under suitable aromatics hydrogenation conditions, with a sulfur tolerant aromatics hydrogenation catalyst, comprising:
from 0.01 to 5 wt % of a platinum component and from 0.01 to 5 wt % of a palladium component in a weight ratio of elemental palladium-to-platinum of 1:10 to 10:1, which platinum and palladium components have been incorporated into a catalyst support comprising a calcined mixture of from 1 to 30 wt % zirconia and from 60 to 99 wt % inorganic oxide, wherein said calcined mixture, before calcination, comprises a zirconium compound that has been co-mulled with an inorganic oxide selected from the group consisting of silica, alumina, silica-alumina and any combination of two or more thereof; and
yielding a product having a reduced aromatics concentration.
2. The process as recited in claim 1 , wherein said calcined mixture comprises silica and alumina in relative amounts such that the molar ratio of silica-to-alumina is in the range of from 1:10 to 10:1.
3. The process as recited in claim 1 , wherein said zirconium compound is present in said calcined mixture in an amount in the range of from 0.5 to 20 wt. % with the weight percent being based on the total weight of the aromatics hydrogenation catalyst and calculated as elemental metal.
4. The process as recited in claim 1 , wherein said platinum component and said palladium component are present in a weight ratio of elemental palladium-to-platinum in the range of 1:2 to 5:1.
5. The process as recited in claim 1 , wherein said platinum component and said palladium component are present in a weight ratio of elemental palladium-to-platinum in the range of 1:1 to 3:1.
6. The process as recited in claim 5 , wherein said aromatics hydrogenation catalyst has a surface area in the range of from 300 m 2 /gm to 600 m 2 /gm.
7. The process as recited in claim 6 , wherein said hydrocarbon feedstock contains a concentration of sulfur in the range of from 15 to 500 ppmw and wherein the amount of dearomatization provided by said process exceeds 50 molar percent of the aromatics contained in said hydrocarbon feedstock.
8. The process as recited in claim 1 , wherein said calcined mixture has a silica-to-alumina molar ratio of greater than 10:1.
9. The process as recited in claim 8 , wherein said zirconium compound is present in said calcined mixture in an amount in the range of from 3 to 30 wt. % with the weight percent being based on the total weight of the aromatics hydrogenation catalyst and calculated as elemental metal.
10. The process as recited in claim 9 , wherein said platinum component and said palladium component are present in a weight ratio of elemental palladium-to-platinum in the range of 1:2 to 5:1.
11. The process as recited in claim 10 , wherein said platinum component and said palladium component are present in a weight ratio of elemental palladium-to-platinum in the range of 1:1 to 3:1.
12. The process as recited in claim 11 , wherein said aromatics hydrogenation catalyst has a surface area in the range of from 200 m 2 /gm to 500 m 2 /gm.
13. The process as recited in claim 7 , wherein said aromatics hydrogenation catalyst has a pore volume in the range of from 0.7 ml/gm to 1.3 ml/gm and a median pore diameter in the range of from 50 angstroms to 250 angstroms.
14. The process as recited in claim 1 , wherein said zirconium compound is selected from the group consisting of oxides, nitrates, sulfates, silicates, carbonates, acetates, chlorides, hydroxides, and hydrates of zirconium.
15. The process as recited in claim 1 , wherein said palladium and platinum components are incorporated into said catalyst support in a weight ratio of elemental palladium to platinum of 1:1 to 3:1 using an impregnating solution containing tetraamine platinum (II) nitrate and tetraamine palladium (II) nitrate.
16. The process recited in claim 13 , wherein the amount of dearomatization provided by said process exceeds 80 molar percent of the aromatics contained in said hydrocarbon feedstock.