Activated carbon for odor control and method for making same
View Patent ↗An activated carbon/metal oxide filter element is disclosed. The filter element may be prepared by blending an activated carbon, a metal oxide, and a binder to form a filter media mixture, shaping the filter media mixture into a filter body. The filter body may be calcined to form a filter element. The activated carbon/metal oxide filter element may be used to remove odorous compounds, acidic gases, and volatile organic compounds from a gas.
1. A method for preparing a filter element comprising:
blending an activated carbon, a metal oxide, and a binder to form a filter media mixture;
shaping the filter media mixture into a filter body; and
calcining the filter body to form a filter element.
2. The method of claim 1 , further comprising mixing a solvent with the binder to form a slurry prior to blending the activated carbon and metal oxide.
3. The method of claim 2 , further comprising dry blending the activated carbon and metal oxide.
4. The method of claim 2 , wherein the binder is magnesium aluminosilicate.
5. The method of claim 2 , wherein the binder is silica sol.
6. The method of claim 2 , wherein the binder is alumina sol.
7. The method of claim 3 , wherein shaping the filter media mixture comprises extruding the filter media mixture to form a first extrudate.
8. The method of claim 7 , further comprising extruding the first extrudate to form a second extrudate.
9. The method of claim 8 , further comprising extruding the second extrudate to form a third extrudate.
10. The method of claim 2 , wherein the solvent is water.
11. The method of claim 8 , wherein the filter body is calcined at about 300° C.
12. The method of claim 11 , wherein the activated carbon is a granulated activated carbon.
13. The method of claim 11 , wherein the activated carbon is a powdered activated carbon.
14. The method of claim 11 , wherein the activated carbon is a reactivated activated carbon.
15. The method of claim 13 , wherein the metal oxide is magnesium oxide.
16. The method of claim 13 , wherein the metal oxide is calcium oxide.
17. The method of claim 13 , wherein the metal oxide is barium oxide.
18. The method of claim 3 , further comprising calcining the metal oxide prior to blending with the activated carbon and the binder.
19. The method of claim 18 , wherein the metal oxide is high density metal oxide.
20. The method of claim 3 , wherein the metal oxide is a powder.
21. The method of claim 20 , wherein the metal oxide is about 3% to about 15%, by weight, of the filter media mixture.
22. The method of claim 21 , wherein the metal oxide is about 5% to about 10%, by weight, of the filter media mixture.
23. The method of claim 22 , wherein the binder is about 10%, by weight, of the filter media mixture.
24. The method of claim 2 , wherein the binder is a fiber with an aspect ratio of between about 500:1 and about 700:1.
25. A method for reducing a concentration of an odorous compound in a gaseous stream comprising:
forming an activated carbon/metal oxide filter element, wherein the filter element is constructed and arranged to exhibit a structural failure when saturated with the odorous compound;
contacting the gaseous stream with the filter element such that the odorous compound is sorbed on the filter element to purify the gaseous stream; and
removing the purified gaseous stream from the filter element.
26. The method of claim 25 , wherein forming the activated carbon/metal oxide filter element comprises blending an activated carbon, a metal oxide, a binder.
27. The method of claim 26 , wherein forming the activated carbon/metal oxide filter element further comprises shaping the filter media mixture into a filter body.
28. The method of claim 27 , wherein forming the activated carbon/metal oxide filter element further comprises calcining the filter body.
29. The method of claim 26 , wherein the metal oxide is magnesium oxide.
30. The method of claim 29 , wherein the metal oxide is calcined.
31. The method of claim 26 , wherein blending an activated carbon, a metal oxide, and a binder comprises mixing a solvent with a binder to form a slurry prior to blending the activated carbon and metal oxide.
32. The method of claim 31 , wherein activated carbon and metal oxide are dry blended.
33. The method of claim 31 , wherein the binder is magnesium alumino silicate.
34. The method of claim 33 , wherein the binder has a fiber with an aspect ratio of about 500:1 to about 700:1.
35. The method of claim 31 , wherein the activated carbon is a powdered activated carbon.
36. The method of claim 32 , wherein the activated carbon is a reactivated activated carbon.
37. A method for reducing a concentration of hydrogen sulfide present in a gaseous discharge comprising:
contacting the gaseous discharge with an activated carbon-metal oxide filter element, wherein the filter element is constructed and arranged to exhibit a structural failure when saturated with sulfur, thereby producing a product stream having a reduced hydrogen sulfide concentration; and
removing the product stream from the activated carbon/metal oxide filter element.
38. The method of claim 37 , wherein the metal oxide is magnesium oxide.
39. The method of claim 38 , wherein the metal oxide is calcined.
40. The method of claim 38 , wherein the filter element comprises a binder.
41. The method of claim 40 , wherein the binder is magnesium aluminosilicate.
42. The method of claim 40 , wherein the binder has a fibrous aspect ratio of between about 500:1 and about 700:1.
43. The method of claim 37 , wherein the activated carbon is a powdered activated carbon.
44. The method of claim 37 , wherein the activated carbon is a reactivated activated carbon.
45. A filter media comprising:
an activated carbon;
a metal oxide; and
a fibrous binder having an aspect ratio of between and including about 500:1 and about 700:1.
46. The filter media of claim 45 , wherein the activated carbon is a reactivated activated carbon.
47. The filter media of claim 45 wherein the binder is magnesium aluminosilicate.
48. The filter media of claim 45 , wherein the metal oxide is magnesium oxide.
49. The filter media of claim 45 , further comprising a hydrogen sulfide breakthrough capacity of at least about 0.27 gH.sub2S/ccC.
50. The filter media of claim 45 , further comprising a moisture content of about 5 weight percent to about 15 weight percent.
51. The filter media of claim 50 , further comprising a moisture content of about 10 weight percent.
52. A method for preparing a filter element comprising:
blending an activated carbon, metal oxide, and binder to form a filter media mixture;
shaping the filter media mixture to form a filter body;
drying the filter body to form a filter element having a moisture content of about 5 weight percent to about 15 weight percent.
53. The method of claim 52 , wherein the filter element has a moisture content of about 10 weight percent.
54. The method of claim 52 , further comprising mixing a solvent with the binder to form a slurry prior to blending the activated carbon and metal oxide.
55. The method of claim 54 , further comprising dry blending the activated carbon and metal oxide.
56. The method of claim 55 , wherein the binder is magnesium aluminosilicate.