Compact wastewater concentrator and pollutant scrubber

• US 8,790,496 B2
• Filed: 07/29/2010
• Issued: 07/29/2014
• Est. Priority Date: 03/13/2007
• Status: Active Grant

• Current Assignee: Heartland Water Technology, Inc.
• Original Assignee: Heartland Technology Partners, LLC
• Inventors: Duesel, Bernard F. Jr., Rutsch, Michael J., Clerkin, Craig
• Primary Examiner(s): Bhat, Nina
• Assistant Examiner(s): Miller, Jonathan
• Application Number:
  US12/846,337
• Publication Number:
  US 20110083556A1
• Time in Patent Office: 1,461 Days
• Field of Search: 203/29, 203/32, 203/36, 203/37, 203/12, 202/182, 202/197, 210/702, 210/712, 210/723, 210/724, 210/725, 210/737, 210/749, 210/757, 210/765, 210/766, 951/49, 951/56, 951/58, 951/59, 951/60, 951/61, 951/65, 951/66, 951/69, 951/87, 951/88, 951/89, 96234-242, 261/78.1, 261/108, 261/110, 261/11, 261/111, 261/128
• US Class Current: 203/12
• CPC Class Codes: B01D 1/14 with heated gases or vapours or liquids in contact with the liquid
• CPC Class Codes: B01D 1/305 Demister (vapour-liquid separation)
• CPC Class Codes: C02F 1/048 Purification of waste water by evaporation
• CPC Class Codes: C02F 1/10 by direct contact with a particulate solid or with a fluid, as a heat transfer medium
• CPC Class Codes: C02F 1/12 Spray evaporation
• CPC Class Codes: C02F 1/16 using waste heat from other processes
• CPC Class Codes: C02F 1/20 by degassing, i.e. liberation of dissolved gases degasification of liquids in general B01D19/00; arrangement of degassing apparatus in boiler feed supply F22D
• CPC Class Codes: C02F 1/70 by reduction C02F1/4676 takes precedence
• CPC Class Codes: C02F 2101/101 Sulfur compounds
• CPC Class Codes: C02F 2103/06 Contaminated groundwater or leachate
• CPC Class Codes: C02F 2103/18 from the purification of gaseous effluents
• CPC Class Codes: C02F 2201/008 Mobile apparatus and plants, e.g. mounted on a vehicle for biological treatment C02F2203/008
• CPC Class Codes: C02F 2209/03 Pressure

Abstract

A compact and portable liquid concentrator includes a gas inlet, a gas exit and a flow corridor connecting the gas inlet and the gas exit, wherein the flow corridor includes a narrowed portion that accelerates the gas through the flow corridor. A liquid inlet injects liquid into the gas stream at a point prior to the narrowed portion so that the gas-liquid mixture is thoroughly mixed within the flow corridor, causing a portion of the liquid to be evaporated. A demister or fluid scrubber downstream of the narrowed portion removes entrained liquid droplets from the gas stream and re-circulates the removed liquid to the liquid inlet through a re-circulating circuit. Fresh liquid to be concentrated is also introduced into the re-circulating circuit at a rate sufficient to offset the amount of liquid evaporated in the flow corridor.

Claims

1. A process for concentrating wastewater with a heated gas comprising oxides of sulfur (SOx) and reducing SO_x therein, the process comprising:

(a) combining the heated gas and a liquid flow of wastewater under pressure to form a mixture thereof at a first location upstream of a narrowed portion of a mixing corridor;

(b) drawing the mixture through the mixing corridor, and reducing the static pressure of the mixture in the narrowed portion to vaporize a portion of the liquid in the mixture yielding a partially vaporized mixture comprising entrained concentrated liquid;

(c) contacting with the partially vaporized mixture an alkaline agent to reduce the oxides of sulfur in the partially vaporized mixture;

(d) removing a portion of the entrained concentrated liquid and reduced oxides of sulfur from the vaporized mixture to provide a demisted gas, and

(e) returning a portion of the concentrated liquid to the mixing corridor at a second location, downstream of the first location.

2. The process of claim 1 further comprising re-circulating and combining with the liquid flow of wastewater the removed entrained concentrated liquid.

3. The process of claim 1, wherein removing a portion of the entrained concentrated liquid and reduced oxides of sulfur from the partially vaporized mixture comprises passing the partially vaporized mixture through a cross flow scrubber operable to remove a portion of the entrained concentrated liquid and reduced oxides of sulfur from the partially vaporized mixture.

4. The process of claim 1, wherein the partially vaporized mixture has a temperature of about 150°

F. to about 190°

F. (about 66°

C. to about 88°

C.).

5. The process of claim 1, wherein the heated gas comprises an exhaust gas from the combustion of a fuel.

6. The process of claim 5, wherein the fuel is selected from the group consisting of landfill gas, natural gas, propane, and combinations thereof.

7. The process of claim 6, wherein the fuel is landfill gas.

8. The process of claim 6, wherein the fuel is natural gas.

9. The process of claim 1, wherein the heated gas has a temperature of about 900°

F. to about 1200°

F. (about 482°

C. to about 649°

C.).

10. The process of claim 1, wherein the wastewater is selected from the group consisting of leachate, flowback water, produced water, and combinations thereof.

11. The process of claim 10, wherein the wastewater is leachate.

12. The process of claim 1, wherein the removed entrained concentrated liquid comprises about 1 wt. % to about 5 wt. % solids based on the total weight of the removed entrained concentrated liquid.

13. The process of claim 12, wherein the removed entrained concentrated liquid comprises at least about 10 wt. % solids, based on the total weight of the removed entrained concentrated liquid.

14. The process of claim 13, wherein the removed entrained concentrated liquid comprises at least about 20 wt. % solids, based on the total weight of the removed entrained concentrated liquid.

15. The process of claim 14, wherein the removed entrained concentrated liquid comprises at least about 30 wt. % solids, based on the total weight of the removed entrained concentrated liquid.

16. The process of claim 15, wherein the removed entrained concentrated liquid comprises at least about 50 wt. % solids, based on the total weight of the removed entrained concentrated liquid.

17. The process of claim 1, wherein the partially vaporized mixture in step (b) comprises about 5 wt. % to about 20 wt. % liquid, based on the total weight of the partially vaporized mixture.

18. The process of claim 17, wherein the partially vaporized mixture in step (b) comprises about 10 wt. % to about 15 wt. % liquid, based on the total weight of the partially vaporized mixture.

19. The process of claim 1, wherein the alkaline agent is selected from the group consisting of sodium hydroxide, calcium carbonate, and mixtures thereof.

20. The process of claim 19, wherein the alkaline agent further comprises a solution of sodium hydroxide.

21. The process of claim 19, wherein the alkaline agent further comprises a slurry of calcium carbonate.

29. The process of claim 8, wherein the natural gas is unrefined and supplied directly from a well head.

30. The process of claim 8, wherein the natural gas is refined.

22. A process for concentrating wastewater with a heated gas comprising oxides of sulfur (SOx) and reducing SO_x therein, the process comprising:

(a) combining the heated gas and a liquid flow of wastewater comprising an alkaline agent under pressure at a first location upstream of a narrowed portion of a mixing corridor to form a mixture of heated gas and liquid thereof and to reduce the oxides of sulfur;

(b) drawing the mixture through the mixing corridor, and reducing the static pressure of the mixture in the narrowed portion to vaporize a portion of the liquid in the mixture yielding a partially vaporized mixture comprising entrained concentrated liquid;

(c) removing a portion of the entrained concentrated liquid and reduced oxides of sulfur from the vaporized mixture to provide a demisted gas; and

,

(d) returning a portion of the concentrated liquid to the mixing corridor at a second location, downstream of the first location.

23. A process for concentrating wastewater with a heated gas comprising oxides of sulfur (SOx) and reducing SO_x therein, the process comprising:

(a) combining the heated gas and a liquid flow of wastewater under pressure at a first location upstream of a narrowed portion of a mixing corridor;

(b) passing the combined heated gas and liquid flow of wastewater through the mixing corridor to form a gas-liquid mixture having a liquid concentration of about 5 weight percent (wt. %) to about 20 wt. %, based on the total weight of the mixture, and accelerating the gas and liquid flow within the narrowed portion, causing a portion of the liquid to evaporate;

(c) contacting with the gas-liquid mixture an alkaline agent to reduce the oxides of sulfur in the gas-liquid mixture;

(d) separating a portion of the liquid from the gas-liquid mixture to provide a gas mixture entrained with liquid droplets, wherein one of the liquid and the liquid droplets comprises reduced oxides of sulfur;

(e) removing liquid droplets entrained in the gas mixture obtained in step (d) to provide a concentrated liquid and a substantially liquid-free and substantially SO_x-free gas; and

,

(f) returning a portion of the concentrated liquid to the mixing corridor at a second location, downstream of the first location.

24. The process of claim 23, further comprising re-circulating and combining with the liquid flow of wastewater in step (a) the concentrated liquid obtained in step (e).

25. A process for removing ammonia from wastewater and concentrating the wastewater with a heated gas, the process comprising:

(a) combining with a liquid flow of the wastewater a pH-raising agent to form a flow of increased-pH wastewater;

(b) contacting with the flow of increased-pH wastewater an air stream under conditions sufficient to remove ammonia from the wastewater yielding an ammonia-rich air exhaust stream and an ammonia-lean, increased-pH wastewater;

(c) combining the heated gas and a flow of the ammonia-lean, increased-pH wastewater under pressure to form a mixture thereof at a first location upstream of a narrowed portion of a mixing corridor;

(d) drawing the mixture through the mixing corridor, and reducing the static pressure of the mixture in the narrowed portion to vaporize a portion of the liquid in the mixture yielding a partially vaporized mixture comprising entrained concentrated liquid; and

,

(e) removing a portion of the entrained concentrated liquid from the vaporized mixture to provide a demisted gas; and

(f) returning a portion of the concentrated liquid to the mixing corridor at a second location, downstream of the first location.

26. The process of claim 25 further comprising combining the ammonia-rich air exhaust stream obtained in step (b) with a combustion air stream, and combusting a fuel in the presence of the combined air stream to form an exhaust gas comprising the heated gas employed in step (c).

27. The process of claim 25, wherein the pH-increasing agent is a caustic.

28. The process of claim 27, wherein the caustic is one of sodium hydroxide and lime.