Selective hydrogenation catalyst for a C3 hydrocarbon cut

Patent metadata

Field	Value
Publication number	US-10695748-B2
Application number	US-201715824310-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Nov 29, 2016
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A catalyst comprises an active phase constituted by palladium, and a porous support comprising at least one refractory oxide selected from the group constituted by silica, alumina and silica-alumina, in which:
the palladium content in the catalyst is in the range 0.0025% to 1% by weight with respect to the total weight of catalyst; at least 80% by weight of the palladium is distributed in a crust at the periphery of the porous support, the thickness of said crust being in the range 25 to 450 μm; the specific surface area of the porous support is in the range 70 to 160 m 2 /g; the metallic dispersion D of the palladium is less than 20%.

First claim

The invention claimed is:

1. A catalyst consisting of palladium, and a porous support comprising at least one refractory oxide that is silica, alumina or silica-alumina, in which:
the palladium content in the catalyst is in the range 0.0025% to 1% by weight with respect to the total weight of catalyst;
at least 80% by weight of the palladium is distributed in a crust at the periphery of the porous support, the thickness of said crust being in the range 125 to 225 μm;
the specific surface area of the porous support is in the range 70 to 150 m 2 /g;
the metallic dispersion D of the palladium is less than 20%.

2. The catalyst as claimed in claim 1 , in which the metallic dispersion D of the palladium is 18% or less.

3. The catalyst as claimed in claim 1 , in which the palladium content in the catalyst is 0.025% to 0.8% by weight with respect to the total weight of catalyst.

4. The catalyst as claimed in claim 1 , Therein the specific surface area of the porous support is 70 to 150 m 2 /g.

5. The catalyst as claimed in claim 1 , wherein at least 80% by weight of the palladium is distributed in a crust at the periphery of the porous support, the thickness of said crust being 50 to 450 μm.

6. The catalyst as claimed in claim 1 , wherein the porous support is alumina.

7. The catalyst as claimed in claim 1 , wherein the total pore volume of the support is in the range 0.1 to 1.5 cm 3 /g.

8. The catalyst as claimed in claim 1 , wherein the porous support comprises in the range 0.0050% to 0.25% by weight of sulphur with respect to the total weight of catalyst.

9. The catalyst as claimed in claim 1 , wherein the palladium is in the form of particles with a mean size in the range 4 to 10 nm.

10. A process for the preparation of a catalyst as claimed in claim 1 , comprising:
a) preparing a colloidal suspension of palladium oxide or palladium hydroxide in an aqueous phase by mixing an aqueous solution (I) comprising at least one alkali hydroxide or alkaline-earth hydroxide and an aqueous solution (II) comprising at least one precursor of palladium;
b) impregnating said solution obtained from a) onto a porous support comprising at least one refractory oxide that is silica, alumina or silica-alumina;
c) optionally, maturing the impregnated porous support obtained in b) in order to obtain a catalyst precursor;
d) drying the catalyst precursor obtained in b) or c) at a temperature in the range 70° C. to 200° C.;
e) optionally, calcining the dried catalyst obtained in d) at a temperature in the range 250° C. to 900° C.;
f) carrying out a hydrothermal treatment of the dried catalyst obtained in d) or of the calcined catalyst obtained in e) at a temperature in the range 500° C. to 900° C., in air comprising in the range 150 to 5000 grams of water per kg of air;
g) optionally, carrying out a reduction treatment on the catalyst obtained at the end off) by contact with a reducing gas.

11. The preparation process as claimed in claim 10 , in which in a), the palladium precursor is palladium chloride, palladium nitrate or palladium sulphate.

12. The process as claimed in claim 10 , in which in f), a hydrothermal treatment of the dried catalyst obtained in d) or of the calcined catalyst obtained in e) is carried out at a temperature in the range 600° C. to 800° C., in air comprising 300 to 4500 grams of water per kg of air.

13. A process for selective hydrogenation, comprising bringing a C3 cut from steam cracking and/or catalytic cracking into contact with the catalyst as claimed in claim 1 , in which the temperature is in the range 0° C. to 300° C., at a pressure in the range 0.1 to 10 MPa, with a molar ratio of hydrogen/(polyunsaturated compounds to be hydrogenated) in the range 0.1 to 10 and at an hourly space velocity, HSV, in the range 0.1 to 100 h −1 for a process carried out in the liquid phase, with a molar ratio of hydrogen/(polyunsaturated compounds to be hydrogenated) in the range 0.5 to 1000 and at an hourly space velocity, HSV, in the range 100 to 40000 h −1 for a process carried out in the gas phase.

Assignees

• Ifp Energies Now

Inventors

• Boualleg Malika
• Avenier Priscilla

Classifications

• B01J35/45

  Nanoparticles · CPC title

• B01J35/51

  Spheres · CPC title

• B01J21/12

  Silica and alumina · CPC title

• B01J37/0236

  Drying, e.g. preparing a suspension, adding a soluble salt and drying · CPC title

• B01J37/16

  Reducing · CPC title