Method for purifying and biodeodorizing gas effluents

• US 5,858,768 A
• Filed: 01/06/1997
• Issued: 01/12/1999
• Est. Priority Date: 11/02/1993
• Status: Expired due to Term

• Current Assignee: Veolia Water Solutions & Technologies Support
• Original Assignee: Omnium Detraitements et Devalorisation
• Inventors: Martin, Guy, Bonnin, Christophe, Coriton, Gabriel
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US08/779,060
• Time in Patent Office: 736 Days
• Field of Search: 435/262, 435/264, 435/266, 435/282, 435/262.5
• US Class Current: 435/266
• CPC Class Codes: B01D 53/84 Biological processes
• CPC Class Codes: B01D 53/85 with gas-solid contact
• CPC Class Codes: F24F 12/006 using an air-to-air heat exchanger F24F12/002 takes precedence
• CPC Class Codes: F24F 13/22 Means for preventing condensation or evacuating condensate
• CPC Class Codes: F24F 3/1411 by absorbing or adsorbing water, e.g. using an hygroscopic desiccant
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02B 30/56 Heat recovery units

Abstract

A method for the purification and biodeodorizing of a gas effluent charged with pollutant matter is provided. The method includes the steps of passing the gas effluent through a bed of inert granular material used as a support for a biomass. The biomass includes bacteria, majority of which are autotrophic bacteria. Preferably the bacteria are in a form designed to degrade the pollutant material. The method includes the step of sprinkling the bed with a sprinkling liquid and recovering purified biodeodorized gas effluent. Preferably, nutrient elements for the biomass are supplied entirely by the sprinkling liquid, the gas effluent or a mixture thereof.

Claims

1. A method for purifying and biodeodorizing a gas effluent charged with organic pollutant matter by abating H₂ S, NH₃ and CH₃ SH;

said method including the steps of;

(a) passing gas effluent to be purified and biodeodorized through a bed of inert mineral granular material;

the bed of inert mineral granular material including thereon a biomass comprising bacteria, a majority of which are autotrophic bacteria;

(i) the autotrophic bacteria comprising bacteria which aerobically degrades organic pollutant matter;

(b) sprinkling the bed with a sprinkling liquid comprising water and optionally nutrient;

the sprinkling liquid having a pH within the range of 3 to 14;

a pH gradient being established within the bed from the sprinkling liquid gas effluent, and degradation products; and

H₂ S, NH₃ and CH₃ SH are abated;

(c) recovering purified and biodeodorized gas effluent from an outlet of the bed of inert mineral granular material;

(d) said method being conducted such that all nutrients used by the biomass are supplied by the combination of the sprinkling liquid and the gas effluent; and

,

(e) said steps of passing gas effluent to be purified and biodeodorized through a bed of inert mineral granular material including a biomass thereon abates the pollutant matter by physical/chemical and biological processes.

2. A method according to claim 1, wherein:

(a) said method is conducted such that all nutrients used by the biomass are supplied in the sprinkling liquid.

3. A method according to claim 1, wherein:

(a) said method is conducted such that all nutrients used by the biomass are supplied in the gas effluent.

4. A method according to claim 1 including steps of:

(a) removing at least a portion of sprinkling liquid from the bed and recirculating a portion of sprinkling liquid back to the bed.

5. A method according to claim 4 including a step of:

(a) regulating pH of the sprinkling liquid applied to the bed to a pH within the range of 6-14.

6. A method according to claim 5 wherein:

(a) said step of regulating pH comprises providing potassium in the sprinkling liquid.

7. A method according to claim 4 including a step of:

(a) regulating pH of the sprinkling liquid applied to the bed to a pH of less than 6.

8. A method according to claim 1 including a step of:

(a) removing at least a portion of sprinkling liquid from the bed.

9. A method according to claim 1 wherein:

(a) said step of sprinkling comprises continuously sprinkling the bed, during said step of passing gas effluent through the bed.

10. A method according to claim 1, wherein:

(a) said step of sprinkling comprises discontinuously sprinkling the bed, during said step of passing gas effluent through the bed.

11. A method according to claim 10, wherein:

(a) said step of discontinuously sprinkling comprises periods between sprinkling of no more than 24 hours.

12. A method according to claim 1, wherein:

(a) the step of passing gas effluent through the bed comprises passing gas effluent upwardly through the bed; and

(b) said step of sprinkling the bed comprises passing sprinkling liquid downwardly through the bed in a counterflow to the gas effluent.

13. A method according to claim 1, wherein:

(a) said step of passing a gas effluent to be purified comprises passing a gas effluent including at least 1 mg/m³ of ammonia and at least 1% by volume of CO₂.

14. A method according to claim 1, wherein:

(a) said step of sprinkling with sprinkling liquid comprises sprinkling with a liquid containing at least 1 mg/l nitrogen as ammonium compounds.

15. A method according to claim 1, wherein:

(a) said step of sprinkling with a sprinkling liquid comprises sprinkling with a liquid having a carbonate content of at least 10 mg/l.

16. A method according to claim 1, wherein:

(a) said step of sprinkling with a sprinkling liquid comprises sprinkling with a liquid having a phosphate content of at least 0.01 mg/l.

17. A method according to claim 1, wherein:

(a) said step of passing gas effluent through a bed of inert mineral granular material comprises passing gas effluent through a bed of inert mineral material selected from the group consisting of;

clay;

clay slates;

alumina;

activated alumina zeolites;

sand;

gravel;

anthracite; and

, activated carbon.

18. A method according to claim 17, wherein:

(a) said step of passing gas effluent through a bed of inert mineral granular material comprises passing gas effluent through a bed having a mineral grain size of greater than 1 mm.

19. A method according to claim 1, wherein:

(a) said step of passing gas effluent through a bed of inert mineral granular material comprises passing gas effluent through a bed having a mineral grain size of greater than 1 mm.

20. A method according to claim 1, wherein:

(a) said step of passing gas effluent through a bed of inert mineral granular material having a biomass thereon comprising bacteria comprises passing gas effluent through a bed including autotrophic bacteria which enables oxidation of sulfurous compounds;

said autotrophic bacteria which enables oxidation of sulfurous compounds being selected from the group consisting of;

Thiobacillus thioxydous;

Thiobacillus thioparus; and

, Thiobacillus intermedius.

21. A method according to claim 1, including the step of:

(a) removing gas effluent from the bed, after passage therethrough, and directing said gas effluent over at least one refining filtration unit.

22. A method according to claim 21, wherein:

(a) said step of directing gas effluent over at least one refining filtration unit comprises directing said gas effluent over a refining filtration unit including a bed of granular activated carbon.

23. A method according to claim 1, wherein:

(a) said step of sprinkling comprises sprinkling water selected from the group consisting of;

water from drillings;

natural water;

supplemented water; and

, outlet water from waste-water purification.

24. The method of claim 1, wherein said bed is configured and includes a sufficient amount of bacteria, of an appropriate type, to degrade pollutant matter in the gas effluent at gas effluent rate, passing through the bed, of at least 400 meters/hr.