Sorbent comprising activated carbon, process for making same and use thereof

• US 20090111690A1
• Filed: 10/26/2007
• Published: 04/30/2009
• Est. Priority Date: 10/26/2007
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Kuang, Peiqiong Q., Johnson, Benedict Y., Shi, Youchun, Liu, Anbo, Gadkarec, Kishor Purushottam
• Granted Patent: US 7,998,898 B2
• Time in Patent Office: Days
• US Class Current: 502/417
• CPC Class Codes: B01J 20/0266 Compounds of S
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28026 Particles within, immobilised, dispersed, entrapped in or on a matrix, e.g. a resin
• CPC Class Codes: B01J 20/28042 Shaped bodies; Monolithic structures
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

A sorbent body adapted for abating toxic elements from a fluid stream, such as a carbon combustion flue gas stream or a syngas stream produced in coal gasification process, and process for making such sorbent. The sorbent body comprises an activated carbon matrix defining a plurality of pores, sulfur and an additive adapted for promoting the abatement of toxic elements from the fluid stream. At least one of the additive is formed into the sorbent body by in-situ forming such as in-situ extrusion. The sorbent is useful for abatement of, e.g., arsenic, cadmium, mercury and selenium from gas streams.

Claims

1. A sorbent body comprising:

an activated carbon matrix defining a plurality of pores;

sulfur; and

an additive adapted for promoting the abatement of at least one of As, Cd, Hg and Se from a fluid stream,

wherein;

the additive is distributed throughout the activated carbon matrix.

2. A sorbent body according to claim 1, which is a monolith.

3. A sorbent body according to claim 1, wherein sulfur is distributed throughout the activated carbon matrix.

4. A sorbent body according to claim 1, wherein the additive is essentially homogeneously distributed in the activated carbon matrix.

5. A sorbent body according to claim 1, wherein sulfur is essentially homogeneously distributed in the activated carbon matrix.

6. A sorbent body according to claim 1, wherein at least part of sulfur is present in a state capable of chemically bonding with Hg, and wherein at least 10% of the sulfur on the surface of the walls of the pores is essentially at zero valency when measured by XPS.

7. A sorbent body according to claim 1, wherein the additive is selected from:

(i) halides, oxides and hydroxides of alkali and alkaline earth metals;

(ii) precious metals and compounds thereof;

(iii) oxides, sulfides, and salts of vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, tungsten and lanthanoids; and

(iv) combinations and mixtures of two or more of (i), (ii) and (iii).

8. A sorbent body according to claim 1, wherein the additive is selected from:

(i) oxides, sulfides and salts of manganese;

(ii) oxides, sulfides and salts of iron;

(iii) combinations of (i) and KI;

(iv) combinations of (ii) and KI; and

(v) mixtures and combinations of any two or more of (i), (ii), (iii) and (iv).

9. A sorbent body according to claim 1, wherein the sorbent body comprises an alkaline earth hydroxide.

10. A sorbent body according to claim 1, comprising at least 91% by weight of activated carbon, sulfur and the additive.

11. A sorbent body according to claim 1, comprising from 50% to 97% by weight of activated carbon.

12. A sorbent body according to claim 1, comprising at least 60% by weight of activated carbon.

13. A sorbent body according to claim 1, comprising less than 40% by weight of inorganic filler.

14. A sorbent body according to claim 1, comprising from 1% to 20% by weight of sulfur.

15. A sorbent body according to claim 1, comprising from 1% to 25% by weight of the additive.

16. A process for making a sorbent body comprising an activated carbon matrix, sulfur, and an additive adapted for promoting the abatement of a toxic element from a fluid stream, wherein the additive is distributed throughout the activated carbon matrix,

comprising the following steps:

(A) providing a batch mixture body formed of a batch mixture material comprising a carbon-source material, a sulfur-source material, an additive-source material and an optional filler material, wherein the additive-source material is substantially homogeneously distributed in the mixture;

(B) carbonizing the batch mixture body by subjecting the batch mixture body to an elevated carbonizing temperature in an O₂-depleted atmosphere; and

(C) activating the carbonized batch mixture body at an elevated activating temperature in a gaseous atmosphere selected from CO₂, H₂O, a mixture of CO₂ and H₂O, a mixture of CO₂ and nitrogen, a mixture of H₂O and nitrogen, and a mixture of CO₂ and another inert gas.

17. A process according to claim 16, wherein in step (A), the carbon-source material comprises:

synthetic carbon-containing polymeric material;

activated carbon powder;

charcoal powder;

coal tar pitch;

petroleum pitch;

wood flour;

cellulose and derivatives thereof;

wheat flour;

nut-shell flour;

starch;

coke;

coal;

or mixtures or combinations of any two or more of these.

18. A process according to claim 16, wherein in step (A), the sulfur-source material comprises:

sulfur powder;

sulfur-containing powdered resin;

sulfides;

sulfates; and

other sulfur compounds;

or mixtures or combination of any two or more of these.

19. A process according to claim 16, wherein in step (A), the additive-source material is selected from:

(i) precious metals and compounds thereof;

(ii) alkali and alkaline earth halides, oxides and hydroxides;

(iii) oxides, sulfides, sulfates, acetates and salts of vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, silver, tungsten and lanthanoids; and

(iv) combinations and mixtures of two or more of (i) to (iii).

20. A process according to claim 16, wherein in step (A), the additive-source material is selected from:

(i) oxides, sulfides and salts of manganese;

(ii) oxides, sulfides and salts of iron;

(iii) combinations of (i) and KI;

(iv) combinations of (ii) and KI; and

(v) mixtures and combinations of any two or more of (i), (ii), (iii) and (iv).

21. An extruded batch mixture body comprising:

(I) a carbon-source material comprising an uncured, curable polymeric resin;

(II) particles of sulfur-containing material;

(III) an additive adapted for promoting the abatement of a toxic element from a fluid stream;

wherein the additive is distributed substantially homogeneously in the material forming the extruded batch mixture body.

22. An extruded batch mixture body according to claim 21, wherein the particles of sulfur-containing material are distributed substantially homogeneously in the material forming the extruded batch mixture body.

23. An extruded batch mixture body according to claim 22, comprising less than 20% by weight of inorganic material other than water, carbon, sulfur-containing inorganic material, and the additive.

24. An extruded batch mixture body according to claim 38, comprising from 20% to 50% by weight of inorganic material other than carbon, sulfur-containing inorganic material, water and the additive.

25. A process for abating As, Cd, Se and/or Hg from a fluid stream, comprising placing a sorbent body in the fluid stream, wherein the sorbent body comprises:

an activated carbon matrix defining a plurality of pores;

sulfur; and

an additive adapted for promoting the abatement of at least one of As, Cd, Hg and Se from a fluid stream,

wherein;

the additive is distributed throughout the activated carbon matrix.