Method of making alkali activated carbon

Patent metadata

Field	Value
Publication number	US-10246336-B2
Application number	US-201715426358-A
Country	US
Kind code	B2
Filing date	Feb 7, 2017
Priority date	Feb 29, 2016
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A method of making activated carbon including:
compressing a mixture of carbonaceous source material and an alkali source material into a first solid form; and activating the first solid form to a form an activated carbon having a second solid form.

First claim

What is claimed is:

1. A method of making activated carbon comprising:
compressing a mixture of carbonaceous source material and an alkali source material in a press at a pressure ranging from 1,000 to 50,000 psi to produce a first solid form, wherein the mixture does not comprise a binder; and
activating the first solid form to make a second solid form comprising an activated carbon, wherein the method does not comprise a dehydration step.

2. The method of claim 1 wherein activating the first solid form comprises a first heating of the first solid form at from 600 to 1000° C. for from 5 mins to 24 hrs to form a first heated activated carbon.

3. The method of claim 2 further comprising a second heating of the first heated activated carbon at from 400 to 1000° C. for from 5 mins to 24 hrs, in an inert or reducing atmosphere to form a second heated activated carbon.

4. The method of claim 1 further comprising treating the second solid form with at least one of: dispersing the second solid form in an aqueous liquid; washing the second solid form with water; washing the second solid form with dilute acid; washing the second solid form until the waste wash water has a pH that is the same as the pH of the source wash water; washing the second solid form until the waste wash water has a pH of from 4 to 8, washing the second solid form until the waste wash water is pH neutral; drying the second solid form after washing, or a combination thereof.

5. The method of claim 1 wherein the press is chosen from a roller compactor, a hydraulic press, an isostatic press, or a combination thereof.

6. The method of claim 1 wherein the carbonaceous source material is a coke and the alkali source is KOH, and the coke and the KOH are in a powder form.

7. The method of claim 1 wherein:
the first solid form maintains its shape before and during activating; and
the second solid form: maintains its shape upon activation; substantially disintegrates and loses its shape upon activation; or a combination of maintaining and losing its shape upon activating.

8. The method of claim 1 wherein the resulting compressed first solid form, before activating, has a density of from 1.0 to 1.8 g/cc, and a form size of from 0.25 to 3 inches.

9. The method of claim 1 further comprising after activating, washing and then drying the activated carbon second solid form to afford a dry activated carbon powder having a tap density of from 0.2 to 0.8 g/cc, and a BET surface area of from 1200 to 2400 square meters per gram.

10. The method of claim 1 wherein the carbonaceous source material to the alkali source has a weight ratio of from 1:1 to 1:3.

11. The method of claim 1 wherein the carbonaceous source material to the alkali source has a weight ratio of from 1:1.5 to 1:2.5.

12. The method of claim 1 wherein the first solid form, after compressing, has a water content of from 0.1 to 15 wt % based on a 100 wt % total of the compressed first solid form.

13. The method of claim 1 wherein the first solid form, after compressing but before activation, has a volatile organic compound (VOC) content of from 0.1 to 16 wt %.

14. The method of claim 1 wherein the first solid form has a shape selected from the group consisting of: a briquette, a pellet, or a mixture thereof, and the second solid form has a shape selected from the group consisting of: a briquette, a pellet, a powder, a fragment, a crumb, or a mixture thereof.

15. The method of claim 1 wherein the carbonaceous source material is a coke selected from the group consisting of green coke, calcined coke, needle coke, petroleum coke, coal-based coke, isotropic coke, anisotropic coke, honeycomb coke, sponge coke, shot coke, fuel-grade coke, calcinable grade coke, anode grade coke, or mixtures thereof.

16. The method of claim 1 wherein the carbonaceous source material is green coke, calcined coke, or mixtures thereof.

17. The method of claim 1 wherein the first solid form disintegrates during activation to produce the second solid form having one or more shapes of: reduced size pieces, fragments, particles, or mixtures thereof.

18. The method of claim 1 wherein the second solid form has a low net vertical height expansion property in an activation container of from 0.1 to 100% vertical height expansion during activation relative to the first solid form.

19. The method of claim 1 wherein the first solid form has a fill volume in a container of from 0.1 to 100 vol %, and the second solid form has a post-activation fill volume in the container of 50 to 200 vol % based on the first solid form fill volume, with the proviso that the first solid form has a fill volume selected such that there is no overflow of the second solid form from the container.

20. The method of claim 1 wherein the first solid form has a fill volume in a container of from 25 to 80 vol % relative to the empty container volume, and the second solid form has a post-activation fill volume of 75 to 125 vol % relative to the fill volume of the first solid form.

21. The method of claim 1 wherein the first solid form has dimensions of from: height (H) 10 to 150 mm; length (L) of from 10 to 150 mm; and width (W) 10 to 150 mm.

22. The method of claim 1 wherein the first solid form has dimensions that are the same as, or different from, the dimensions of the second solid form, and the second solid form comprises a mixture of an activated carbon and a reaction product of the alkali source material.

23. A method of making activated carbon comprising:
combining a carbonaceous source material and a base of the formula MOH where M is K, Na, or combinations thereof, to form a mixture, wherein the mixture does not comprise a binder and wherein the base is in powder form;
compressing the mixture into a first solid form; and
activating the first solid form to form a second solid form comprising an activated carbon, wherein the method does not comprise a dehydration step.

Assignees

• Corning Inc

Inventors

• Liu Jia
• Ricketts Daniel Ohen
• Schweiger Christopher Mark

Classifications

• C01B32/382 Primary

  Making shaped products, e.g. fibres, spheres, membranes or foam · CPC title

• C01B32/348 Primary

  Metallic compounds · CPC title

• C01B32/342 Primary

  characterised by non-gaseous activating agents · CPC title

• C01B32/33

  from distillation residues of coal or petroleum; from petroleum acid sludge · CPC title