Regenerating the catalytic activity of a spent catalyst

Patent metadata

Field	Value
Publication number	US-12515210-B2
Application number	US-202118000570-A
Country	US
Kind code	B2
Filing date	Jun 23, 2021
Priority date	Jul 6, 2020
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

The invention relates to a method of regenerating the catalytic activity of a spent catalyst comprising nickel on a refractory oxide support, said method comprising the steps of contacting the spent catalyst with a nitric acid solution, heat-treating the spent catalyst, calcining and reducing the catalyst.

First claim

The invention claimed is:

1 . A method of regenerating the catalytic activity of a spent catalyst comprising nickel, said spent catalyst being:
(a) a spent steam reforming catalyst comprising a support, in which the nickel content is 5-20 wt % Ni and the support is an oxide comprising aluminium, zirconium, magnesium, calcium, lanthanum, yttrium, and/or cerium, and wherein the spent catalyst is provided in the form of tablets or pellets,
or
(b) a spent steam reforming catalyst in which the nickel content is 5-20 wt % Ni, said spent steam reforming catalyst being a structured catalyst comprising a macroscopic structure, wherein said macroscopic structure is formed by a metallic material and at least partly supported by a refractory oxide support;
said method comprising the steps of:
i) contacting the spent catalyst with a nitric acid solution, in which the nitric acid solution is at least 60 wt % HNO 3 , and adding one or more organic acids;
ii) heat-treating the spent catalyst at a suitable temperature for reacting nickel with nitric acid, said suitable temperature being in the range 50-100° C., and subsequently drying the spent catalyst at 100-125° C.; and
iii) calcining and reducing the spent catalyst, in which the calcining is conducted in air at 500-1300° C. for 1-4 hours, and the reducing is conducted in the presence of hydrogen at 400-600° C. for 2-4 hours,
wherein the tablets or pellets of spent catalyst (a) are spherical, oblong, cylindrical, multilobe, ring-shaped, or any combinations thereof;
wherein the macroscopic structure of spent catalyst (b) is a monolith; and
wherein the shape of the spent catalyst (a) or the macroscopic structure of the spent catalyst (b) is preserved during the regenerating method.

2 . The method of claim 1 , wherein the one or more organic acids are selected from the group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid, 2-hydroxypropanoic acid, ethanedioic acid, propanedioic acid, 1,4-butanedioic acid, 1,3-propanedicarboxylic acid, and 2-aminopentanedioic acid.

3 . The method of claim 2 , wherein the content of the one or more organic acids in nitric acid solution is 40 wt % or less.

4 . The method of claim 1 , wherein the nitric acid solution is free of other inorganic acids.

5 . The method of claim 1 , wherein the steps of contacting and heat-treating are repeated at least once prior to said drying or calcining.

6 . The method of claim 1 , wherein nickel is the only catalytically active element in the spent catalyst.

7 . The method of claim 1 , wherein the nickel in the spent catalyst is in oxidic form.

8 . The method of claim 1 , wherein the step of contacting with the nitric acid solution is conducted at 20-25° C.

9 . The method of claim 8 , wherein the spent catalyst is heat-treated at 70-80° C. for a duration of at least 10 min.

10 . The method of claim 1 , wherein the drying is conducted at 110° C.

11 . The method of claim 1 , wherein the calcining is conducted in air at 400-500° C. for 1-2 hours, and the reducing is conducted in the presence of hydrogen at 500-550° C. for 2-4 hours.

12 . The method of claim 1 , wherein the metallic material is an alloy comprising Fe, Cr, and Al, and the support is zirconium oxide (ZrO 2 ).

13 . The method of claim 1 , wherein said method consists of the steps of:
i) contacting the spent catalyst with a nitric acid solution, in which the nitric acid solution is at least 60 wt % HNO 3 , and adding one or more organic acids; ii) heat-treating the spent catalyst at a suitable temperature for reacting nickel with nitric acid, said suitable temperature being in the range 50-100° C., and subsequently drying the spent catalyst at 100-125° C.; and iii) calcining and reducing the spent catalyst, in which the calcining is conducted in air at 500-1300° C. for 1-4 hours, and the reducing is conducted in the presence of hydrogen at 400-600° C. for 2-4 hours.

Assignees

• Topsoe As

Inventors

• Hyldtoft Jens Henrik

Classifications

• C01B3/38

  using catalysts · CPC title

• B01J35/55

  Cylinders or rings · CPC title

• B01J2235/15

  X-ray diffraction · CPC title

• C01B2203/0233

  the reforming step being a steam reforming step · CPC title

• C01B3/40

  characterised by the catalyst · CPC title