Systems and methods for acid gas removal from a gaseous stream

• US 9,968,883 B2
• Filed: 01/16/2015
• Issued: 05/15/2018
• Est. Priority Date: 01/17/2014
• Status: Active Grant

• Current Assignee: Carbonfree Chemicals Holdings, LLC
• Original Assignee: Carbonfree Chemicals Holdings, LLC
• Inventors: Yablonsky, Al, Stola, Alexander, Germain, Adam, Jones, Joe
• Primary Examiner(s): Chorbaji, Monzer R
• Application Number:
  US14/599,137
• Publication Number:
  US 20150202568A1
• Time in Patent Office: 1,215 Days
• Field of Search: 422 4, 422 5, 96275, 261 75
• CPC Class Codes: B01D 2251/108 Halogens or halogen compounds
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/60 Inorganic bases or salts
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2257/2045 Hydrochloric acid
• CPC Class Codes: B01D 2257/2047 Hydrofluoric acid
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/502 characterised by a specific solution or suspension
• CPC Class Codes: B01D 53/526 Mixtures of hydrogen sulfide and carbon dioxide
• CPC Class Codes: B01D 53/56 Nitrogen oxides B01D53/60 takes precedence
• CPC Class Codes: B01D 53/60 Simultaneously removing sulfur oxides and nitrogen oxides
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/75 Multi-step processes
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: C01B 11/062 Hypochlorites of alkali metals
• CPC Class Codes: C01D 7/07 Preparation from the hydroxides
• CPC Class Codes: C01D 7/10 : Preparation of bicarbonates from carbonates ammonia soda process C01D7/18
• CPC Class Codes: C25B 1/34 : Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
• CPC Class Codes: C25B 15/08 : Supplying or removing reactants or electrolytes; Regeneration of electrolytes
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

Apparatuses, systems, and methods for removing acid gases from a gas stream are provided. Gas streams include waste gas streams or natural gas streams. The methods include obtaining a hypochlorite and a carbonate or bicarbonate in an aqueous mixture, and mixing the aqueous mixture with the gas stream to produce sulfates or nitrates from sulfur-based and nitrogen-based acidic gases. Some embodiments of the present disclosure are directed to produce the carbonate and/or bicarbonate scrubbing reagent from CO₂ in the gas stream. Still others are disclosed.

Claims

1. A system for effectively reducing pollutants from a gas stream comprising:

a first set of mixing equipment adapted to admix a hydroxide with the gas stream to create a first admixture in which carbon dioxide in the gas stream can react with a hydroxide to produce a bicarbonate product or a combination of bicarbonate and carbonate products in a first liquid outflow and

a second set of mixing equipment adapted to admix a hypochlorite and the bicarbonate product or the combination of bicarbonate and carbonate products with the gas stream to create a second admixture in which nitrogen-based or sulfur-based acid gases can react with the hypochlorite and the bicarbonate product or the combination of bicarbonate and carbonate products to produce nitrate or sulfate products in a second liquid outflow,

wherein the gas stream flows through the second set of mixing equipment before at least a portion of the gas stream flows through the first set of mixing equipment.

2. The system of claim 1, further comprising a conduit adapted to transfer the liquid outflow to the second set of mixing equipment to create the second admixture.

3. The system of claim 1, further comprising a chlor-alkali cell adapted to electrochemically produce the hydroxide with a protonated brine solution, wherein the chlor-alkali cell is in fluid communication with the first set of mixing equipment.

4. The system of claim 3, further comprising a third set of mixing equipment adapted to admix hydroxide from the chlor-alkali cell with chlorine gas from the chlor-alkali cell, wherein the chlor-alkali cell is in fluid communication with the third set of mixing equipment and wherein the third set of mixing equipment is in fluid communication with the second set of mixing equipment.

5. The system of claim 4, wherein at least a portion of the hydrochloric acid is in communication with the chlor-alkali cell to protonate a brine solution.

6. The system of claim 3, further comprising a fourth set of mixing equipment adapted to admix hydroxide from the chlor-alkali cell with the gas stream before at least a portion of the gas stream flows through the first set of mixing equipment.

7. The system of claim 3, further comprising a burner adapted to combust hydrogen gas and chlorine gas from the chlor-alkali cell to produce hydrochloric acid.

8. The system of claim 1, wherein the acid gases are selected from NO_x, SO_x, SO_x and H₂S.

9. The system of claim 8, further comprising a fifth set of mixing equipment adapted to convert the sulfate or nitrate products to ammonium sulfate or ammonium nitrate.

10. The system of claim 1, wherein the acid gases are selected from SO_x and H₂S.

11. The system of claim 10, further comprising a fifth set of mixing equipment adapted to separate the sulfate products from the second liquid outflow and form calcium sulfate in solid form.

12. The system of claim 1, wherein the second admixture comprises about 0.5% by weight to about 5% by weight of hypochlorite and about 0.5% by weight to about 5% by weight of bicarbonate.

13. The system of claim 12, wherein the molar ratio of hypochlorite to bicarbonate is about 1:

1 to about 5;

1.

14. The system of claim 1, wherein the first set of mixing equipment comprises two phases:

a first phase adapted to admix the hydroxide with a portion of the gas stream exiting the second set of mixing equipment to produce carbonate products in a first phase liquid outflow and

a second phase adapted to admix the first phase liquid outflow with another portion of the gas stream exiting the second set of mixing equipment to produce bicarbonate products in the first liquid outflow.

15. The system of claim 1, wherein the hypochlorite is in the form of sodium hypochlorite and the hydroxide is in the form of sodium hydroxide.