Process and apparatus for removing carbon dioxide and stripping another component from a liquid stream

• US 5,190,665 A
• Filed: 08/12/1991
• Issued: 03/02/1993
• Est. Priority Date: 08/12/1991
• Status: Expired due to Term

• Current Assignee: Eau-Viron Incorporated
• Original Assignee: James A. Titmas, Phillip J. Flauto
• Inventors: Titmas, James A., Flauto, Phillip J.
• Primary Examiner(s): Dawson, Robert A.
• Assistant Examiner(s): DRODGE, JOSEPH W
• Application Number:
  US07/743,918
• Time in Patent Office: 568 Days
• Field of Search: 423/238, 423/352, 55/46, 55/51, 55/53, 55/55, 55/70, 55/38, 55/40, 55/43, 55/44, 55/68, 210/188, 210/743, 210/761, 210/806, 210/808, 210/903, 210/750, 210/766
• US Class Current: 210/743
• CPC Class Codes: B01D 19/0015 in contact columns containing plates, grids or other filling elements
• CPC Class Codes: Y10S 210/903 Nitrogenous

Abstract

The continuous treatment of a liquid stream for removing a selected component therefrom, includes depressurizing the liquid stream to remove carbon dioxide, forming a carbon dioxide stream and a component-laden stream (17); raising the pH of the component-laden stream (17) to form a pH adjusted stream (19); gas-stripping the component-laden, pH adjusted stream (19) with a counterflow stripping gas (73) in a stripping column (20) having a plurality of deflection cones (111) over which the pH adjusted stream (19) is sprayed, to remove the component therefrom and thereby forming a relatively component-free liquid stream (50) and a gaseous component stream (21); cooling the carbon dioxide stream; neutralizing the liquid component stream (21) with the cooled carbon dioxide stream (64); cooling the gaseous component stream (21); re-heating the gaseous component stream to form a heated stream (35) and dissolving the heated gaseous component stream (35) in an acidic solution in a re-absorption column (36) forming a reduced gas stream (40) and a liquid salt complex stream (37) of the component; and utilizing the reduced component gas stream (40) to remove the component in the gas-stripping step.

Claims

1. A process for continuously treating a liquid stream and for removing a selected component therefrom, the process for treating comprising the steps of depressurizing the liquid stream to remove carbon dioxide and forming a carbon dioxide stream and a component-laden stream;

raising the pH of said component-laden stream;

gas-stripping said component-laden stream with a stripping gas to remove the component therefrom thereby forming a relatively component-free liquid stream and a gaseous component stream;

neutralizing said relatively component-free liquid stream with said carbon dioxide stream;

dehumidifying said gaseous component stream;

dissolving said gaseous component stream in an acidic solution by re-absorption forming a reduced component gas stream and a liquid salt complex of the component; and

utilizing said reduced component gas stream to remove the component in said gas-stripping step.

2. A process as in claim 1, wherein in said pH raising step the pH of said component laden stream is raised to from about 8.8 to about 9.2.

3. A process as in claim 1, wherein said carbon dioxide stream is filtered to remove volatile organic carbons, before being said step of neutralizing said relatively component-free stream.

4. A process as in claim 1, wherein said gaseous component stream is cooled to about 15°

C.

5. A process as in claim 4, wherein said gaseous component stream is reheated after said cooling step and the heat necessary for said step of re-heating said gaseous component stream is supplied by a wet oxidation process.

6. A process as in claim 1, comprising an initial step of filtering suspended solids from the liquid stream.

7. A process as in claim 1, wherein said step of gas-stripping said component-laden stream includes the step of circulating said component-laden stream in counterflow with said stripping gas.

8. A process as in claim 1, including the further step of monitoring the pH of said component-laden stream and adjusting as necessary to a pH of about 9.

9. A process as in claim 1, wherein the component is ammonia.

10. A process as in claim 9, wherein said acidic solution is selected from the group consisting of concentrated sulfuric acid solutions and concentrated nitric acid solutions.