METHOD AND SYSTEM OF DESTRUCTION OF VOLATILE COMPOUNDS IN WASTEWATER

• US 20100219132A1
• Filed: 05/13/2010
• Published: 09/02/2010
• Est. Priority Date: 03/07/2005
• Status: Active Grant

• Current Assignee: Elcon Recycling Center (2003) Ltd.
• Original Assignee: Elcon Recycling Center (2003) Ltd.
• Inventors: LEVIN, Alexander
• Granted Patent: US 8,282,837 B2
• Time in Patent Office: Days
• US Class Current: 210/664
• CPC Class Codes: B01D 3/343 the substance being a gas

Abstract

The invention proposes a method of destruction of volatile organic and inorganic compounds in wastewater, this method includes following stages: stripping the aforementioned volatile compounds in a stripping-chemisorption column; preliminary heating the gaseous medium containing these volatile compounds in a first heat regenerator; thermal, flare or thermo-catalytic oxidation of the volatile compounds in circulating gaseous medium; cooling the gaseous medium in a second heat regenerator; chemisorption of acidic gases from the gaseous medium in the stripping-chemisorption column with stripping at the same time additional amount of the volatile compounds from the wastewater. After specific period, direction of the gaseous medium flow is alternated. The proposed method can be executed at elevated temperature. The invention includes as well systems realizing the proposed method.

Claims

1-16. -16. (canceled)

17. A system for processing water contaminated with volatile compounds, comprising:

a stripping unit including a first inlet for contaminated water, a second inlet for a circulating gaseous medium, and an outlet;

wherein the stripping unit is operative to strip volatile compounds from the contaminated water and into said circulating gaseous medium, and for extraction of oxidation products from said circulating gaseous medium;

an oxidation unit having an inlet coupled to said stripping unit outlet, to oxidize the volatile compounds in said circulating gaseous medium, and to form oxidation products in said circulating gaseous medium;

an outlet from the oxidation unit for the oxidation product-carrying gaseous medium coupled to the second inlet of said stripping unit; and

a heat regeneration system to preheat said volatile compound-containing circulating gaseous medium entering said oxidation unit from said stripping unit, and to cool the oxidation product-carrying gaseous medium exiting the oxidation unit.

18. A system according to claim 17, wherein said heat regeneration system comprises:

a first and a second heat exchange unit and a heat flow reversal unit,

wherein the heat flow reversal unit is operative to change a direction of heat flow from a first state in which the first heat exchange unit cools the circulating oxidation product-carrying gaseous medium exiting the oxidation unit and the second heat exchange unit preheats the volatile compound-carrying circulating gaseous medium entering said oxidation unit, to a second state in which the second heat exchange unit cools the oxidation product-carrying gaseous medium exiting the oxidation unit and the first heat exchange unit preheats the oxidation product-carrying circulating gaseous medium entering said oxidation unit.

19. A system according to claim 18, wherein said heat flow reversal unit reverses the flow direction of said circulating gaseous medium.

20. A system according to claim 19, wherein the heat flow reversal unit includes a blower.

21. A system according to claim 19, wherein the heat flow reversal unit includes a system of shutters.

22. A system according to claim 18, wherein said heat flow reversal unit is responsive to an average temperature in the one of said first or said second heat exchange units then being used for cooling said circulating gaseous medium exiting said oxidation means reaching a certain level.

23. A system according to claim 17, wherein said oxidation unit is a thermal oxidation unit.

24. A system according to claim 17, wherein said oxidation unit is a flare oxidation unit.

25. A system according to claim 17, wherein said oxidation unit is a thermo-catalytic oxidation unit.

26. A system according to claim 17, further comprising a heating unit operative to heat the wastewater before entry thereof into said stripping unit.

27. A system according to claim 17, further comprising an inlet for adding an additional gas to said volatile compound-carrying gaseous medium entering said oxidation unit from said stripping unit, said additional gas inlet being so located that the additional gas is preheated together with said volatile compound-carrying gaseous medium entering said oxidation unit.

28. A system according to claim 17, wherein the stripping unit includes a chemisorption bed.

29. A method of processing water contaminated with volatile organic and inorganic compounds, the method comprising:

delivering the contaminated water and a circulating gaseous medium to a stripping unit;

stripping the volatile compounds from the contaminated water and into the circulating gaseous medium;

oxidizing the volatile compounds in said circulating gaseous medium, the resulting oxidation products being carried in said circulating gaseous medium;

preheating said circulating gaseous medium before oxidation of the volatile compounds;

cooling said oxidation product-carrying circulating gaseous medium, said preheating and cooling being performed in a heat regeneration system; and

removing said oxidation products carried in said circulating gaseous medium in said stripping unit.

30. The method of claim 29, wherein the heat regeneration system includes a first and a second heat exchange unit, and

wherein the method further includes reversing a direction of heat flow from a first state in which the first heat exchange unit cools the oxidation product-carrying circulating gaseous medium, and the second heat exchange unit preheats the circulating gaseous medium before oxidation, to a second state in which the second heat exchange unit cools the oxidation product-carrying circulating gaseous medium, and the first heat exchange unit preheats the volatile compound-containing circulating gaseous medium before oxidation.

31. A method according to claim 30, wherein the direction of said heat flow is reversed by reversing the flow direction of said circulating gaseous medium.

32. A method according to claim 30, wherein the direction of said heat flow is reversed by a blower.

33. A method according to claim 30, wherein the direction of said heat flow is reversed by a system of shutters.

34. The method of claim 30, wherein the direction of said heat flow is reversed when average temperature is elevated up to a certain level in said first or in said second heat exchange unit being used for cooling said oxidation product-carrying circulating gaseous medium.

35. A method according to claim 29 further comprising adding an additional gas into said volatile compound-carrying gaseous medium before oxidation, said additional gas being added at a location such that said additional gas is preheated together with said volatile compound-carrying gaseous medium.

36. A method according to claim 35, wherein said additional gas includes oxygen.

37. The method of claim 35, wherein the amount of said additional gas added into said circulating gaseous medium is determined in accordance with an amount of oxygen consumed by said oxidation.

38. A method according to claim 29, wherein oxidation products are removed from said circulating gaseous medium by chemisorption.

39. A method according to claim 38, wherein said chemisorption is performed in said stripping unit.

40. A method according to claim 29, wherein said oxidation is performed by thermal oxidation.

41. A method according to claim 29, wherein said oxidation is performed by flare oxidation.

42. A method according to claim 29, wherein said oxidation is performed by thermo-catalytic oxidation.

43. A method according to claim 29, further comprising measuring a concentration of the volatile compounds in said contaminated water or in said circulating gaseous medium after stripping, and/or measuring temperatures in different locations in said circulating gaseous medium.

44. A method according to claim 29, further comprising changing a temperature of the contaminated water before stripping.

45. A method according to claim 44, wherein the temperature of the contaminated water is changed to achieve a desired rate of evaporation of the volatile compounds and, to prevent danger of explosion of said circulating gaseous medium.

46. A method according to claim 43, wherein the temperature of the contaminated water is changed to maintain a concentration of the volatile compounds in said circulating gaseous medium significantly lower than a dangerous level which can cause explosion of said circulating gaseous medium.

47. A method according to claim 29, wherein said contaminated water is delivered to the stripping unit in a continuous stream, and wherein stripping, oxidation, and chemisorption are performed in a plurality of processing subunits, each comprised of a stripping unit, an oxidation unit and a chemisorption unit arranged in series.

48. A method according to claim 47, wherein a temperature of said contaminated water is gradually elevated in a direction starting from first said processing sub-units to maintain a concentration of volatile compounds in the gaseous medium in processing sub-unit lower than a dangerous level.

49. A method according to claim 29, wherein said contaminated water is processed in batches.