Method for preparing a selective hydrogenation catalyst

Patent metadata

Field	Value
Publication number	US-10946370-B2
Application number	US-201716305772-A
Country	US
Kind code	B2
Filing date	Apr 24, 2017
Priority date	May 30, 2016
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A process for the preparation of a catalyst comprising palladium, a porous support with a specific surface area in the range 140 to 250 m 2 /g, said catalyst being prepared by a process comprising the following steps:
a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase; b) adding said solution obtained from step a) to said porous support at a flow rate in the range 1 to 20 litre(s)/hour; said porous support being contained in a rotary impregnation device functioning at a rotational speed in the range 10 to 20 rpm; c) optionally, submitting the impregnated porous support obtained from step b) to a maturation; d) drying the catalyst precursor obtained from step b) or c); e) calcining the catalyst precursor obtained from step d).

First claim

The invention claimed is:

1. A process for the preparation of a catalyst comprising palladium, a porous support comprising at least one refractory oxide selected from the group consisting of silica, alumina and silica-alumina, said porous support having a specific surface area of 140 to 250 m 2 /g, wherein at least 80% by weight of the palladium is distributed in a crust at the periphery of said support, the thickness of said crust being 20 to 100 μm, said process comprising:
a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase;
b) adding said solution obtained from step a) to said porous support at a flow rate of 1 to 20 liter(s)/hour; said porous support being contained in a rotary impregnation device functioning at a rotational speed of 10 to 20 rpm;
c) optionally, submitting the impregnated porous support obtained from step b) to a maturation in order to obtain a catalyst precursor;
d) drying the catalyst precursor obtained from step b) or c) at a temperature of 70° C. to 200° C.;
e) calcining the catalyst precursor obtained from step d) at a temperature of 300° C. to 500° C.

2. The process as claimed in claim 1 , wherein said porous support is in the form of a bead.

3. The process as claimed in claim 1 , wherein said porous support is in the form of an extrudate.

4. The process as claimed in claim 3 , wherein said porous support is in the form of an extrudate with a length h of 2 to 10 mm.

5. The process as claimed in claim 3 , wherein said porous support comprises a section comprising at least three lobes.

6. The process as claimed in claim 5 , wherein the number of lobes of the extrudate, n, is an integer 3, 4, 5, 6, 7, 8, 9 or 10.

7. The process as claimed in claim 6 , wherein the number of lobes of the extrudate, n, is an integer 4, 5, 6, 7, 8, 9 or 10.

8. The process as claimed in claim 5 , wherein the number of lobes, n, is an integer 3 or 4.

9. The process as claimed in claim 3 , wherein the extrudate is in the form of a cylinder.

10. The process as claimed in claim 1 , wherein the palladium content in the catalyst is 0.01% to 2% by weight with respect to the total catalyst weight.

11. The process as claimed in claim 1 , wherein said catalyst further comprises silver at a content of 0.02% to 3% by weight of silver with respect to the total catalyst weight.

12. The process as claimed in claim 1 , wherein the metallic dispersion D of the palladium is 15% to 70%.

13. The process as claimed in claim 1 , wherein the support has a pore diameter of 2 to 50 nm.

14. The process as claimed in claim 1 , wherein a maturation step c) is carried out for a period of 0.5 to 40 hours.

15. The process as claimed in claim 1 , wherein said dried catalyst obtained from step e) undergoes a reduction treatment by contact with a reducing gas at a temperature of 80° C. to 180° C.

16. The process as claimed in claim 1 , wherein the rotary impregnation device of step b) is a revolving drum.

17. The process as claimed in claim 1 , wherein the process results in palladium crust size of 20 to 100 μm.

18. The process as claimed in claim 1 , wherein the process results in a catalyst with an activity of at least 0.75 (moles H 2 )/[min×(grams of palladium) as measured for the hydrogenation of a styrene-isoprene mixture in the presence of Sulphur.

Assignees

• Ifp Energies Now

Inventors

• Petit-Clair Carine
• Avenier Priscilla
• Martin Michel
• Boualleg Malika

Classifications

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• B01J35/51

  Spheres · CPC title

• B01J23/50

  Silver · CPC title

• C07C2521/04

  Alumina · CPC title

• B01J2523/00

  Constitutive chemical elements of heterogeneous catalysts · CPC title