Process for dehumidifying moist gas mixtures

• US 10,512,883 B2
• Filed: 06/12/2017
• Issued: 12/24/2019
• Est. Priority Date: 06/14/2016
• Status: Expired due to Fees

• Current Assignee: Evonik Operations GmbH (Rag-Stiftung)
• Original Assignee: Evonik Degussa GmbH (Rag-Stiftung)
• Inventors: Zehnacker, Olivier, Willy, Benjamin, Wang, Xinming, Schneider, Rolf
• Primary Examiner(s): McCormack, John P
• Application Number:
  US15/619,573
• Publication Number:
  US 20170354923A1
• Time in Patent Office: 925 Days
• Field of Search: 34 72, 34 76- 78, 34 80, 34 82
• CPC Class Codes: B01D 2251/61 Phosphates
• CPC Class Codes: B01D 2251/80 Organic bases or salts
• CPC Class Codes: B01D 2252/20473 containing an imidazole-ring
• CPC Class Codes: B01D 2252/30 Ionic liquids and zwitter-ions
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2258/06 Polluted air
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: B01D 53/26 Drying gases or vapours
• CPC Class Codes: B01D 53/263 by absorption
• CPC Class Codes: B01D 53/265 by refrigeration (condensation)
• CPC Class Codes: B01D 53/268 by diffusion
• CPC Class Codes: B01D 53/28 Selection of materials for use as drying agents
• CPC Class Codes: C02F 1/281 using inorganic sorbents
• CPC Class Codes: C08K 2003/321 Phosphates
• CPC Class Codes: C08K 3/32 Phosphorus-containing compounds

Abstract

The invention relates to a process for dehumidifying a moist gas mixture. The invention further relates to an apparatus for dehumidifying a moist gas mixture and to the use of said apparatus in the process according to the invention.

Claims

1. A process for dehumidifying a moist gas mixture G, in an apparatus (V₁), comprising the steps of:

(a) contacting the moist gas mixture G with a liquid absorption medium A_VE comprising a mixture of at least one trialkyl phosphate of structure (I);

2. The process of claim 1, wherein the gas mixture G is moist air.

3. The process of claim 1, wherein:

a) Q⁺ is a dialkylimidazolium cation in which the alkyl groups each independently of one another have 1 to 10 carbon atoms;

b) R*, R′

, R″

, R^A, R^B, R^C, R¹, R², R³ are each independently of one another an alkyl group having 1 to 10 carbon atoms; and

c) M⁺=Li⁺, K⁺ or Na⁺.

4. The process of claim 1, wherein:

a) the salt S is selected from the group consisting of;

Q⁺A⁻

, and Q⁺(R¹O)₂PO₂⁻

;

b) Q⁺ is a dialkylimidazolium cation in which the alkyl groups each independently of one another have 1 to 6 carbon atoms;

c) A⁻

is an anion selected from the group consisting of R*COO⁻

, R′

SO₃⁻

, and R″

SO₄⁻

; and

d) R*, R¹, R′

, R″

, R^A, R^B, R^C are each independently of one another an alkyl group having 1 to 6 carbon atoms.

5. The process of claim 1, wherein R^A, R^B, and R^C are independently of one another either methyl, or ethyl.

6. The process of claim 1, wherein the liquid absorption medium A_VE is an aqueous solution.

7. The process of claim 6, wherein, in the liquid absorption medium A_VE, the total weight of all trialkyl phosphates of structure (I) and all salts S is in the range from 65 wt % to 95 wt % based on the total weight of the aqueous solution.

8. The process of claim 1, wherein, in the liquid absorption medium A_VE, the ratio of the total weight of all trialkyl phosphates of structure (I) to the total weight of all salts S is in the range 1:

9999 to 1;

9.

9. The process of claim 3, wherein R^A, R^B, and R^C are independently of one another, either methyl or ethyl.

10. The process of claim 9, wherein the liquid absorption medium A_VE is an aqueous solution, and the total weight of all trialkyl phosphates of structure (I) and all salts S is in the range 65 wt % to 95 wt % based on the total weight of the aqueous solution.

11. The process of claim 10, wherein, in the liquid absorption medium A_VE, the ratio of the total weight of all trialkyl phosphates of structure (I) to the total weight of all salts S is in the range 1:

9999 to 1;

9.

12. An apparatus (V₂) for dehumidifying a moist gas mixture, comprising the components:

(i) a liquid absorption medium A_VO comprising a mixture of at least one trialkyl phosphate of structure (I);

13. The apparatus (V₂) of claim 12, wherein:

a) Q⁺ is a dialkylimidazolium cation in which the alkyl groups each independently of one another have 1 to 10 carbon atoms;

b) R*, R′

, R″

, R^A, R^B, R^C, R¹, R², and R³ are each independently of one another an alkyl group having 1 to 10 carbon atoms; and

c) M⁺=Li⁺, K⁺ or Na⁺.

14. The apparatus (V₂) of claim 12, wherein:

a) the salt S is selected from the group consisting of;

Q⁺A⁻

, and Q⁺(R¹O)₂PO₂⁻

;

b) Q⁺ is a dialkylimidazolium cation in which the alkyl groups each independently of one another have 1 to 6 carbon atoms;

c) A⁻

is an anion selected from the group consisting of R*COO⁻

, R′

SO₃⁻

, and R″

SO₄⁻

; and

d) R*, R¹, R′

, R″

, R^A, R^B, and R^Care each independently of one another an alkyl group having 1 to 6 carbon atoms.

15. The apparatus (V₂) of claim 12, wherein R^A, R^B, and R^C are independently of one another either methyl or ethyl.

16. The apparatus V₂) of claim 12, wherein the liquid absorption medium A_VO is an aqueous solution.

17. The apparatus (V₂) of claim 12, wherein the liquid absorption medium A_VO is an aqueous solution, and the total weight of all trialkyl phosphates of structure (I) and all salts S is in the range from 65 wt % to 95 wt % based on the total weight of the aqueous solution.

18. The apparatus (V₂) of claim 12, wherein in the liquid absorption medium A_VO , the ratio of the total weight of all trialkyl phosphates of structure (I) to the total weight of all salts S is in the range 1:

9999 to 1;

9.

19. The apparatus (V₂) of claim 18, wherein the liquid absorption medium A_VO is an aqueous solution, and the total weight of all trialkyl phosphates of structure (I) and all salts S is in the range from 65 wt % to 95 wt % based on the total weight of the aqueous solution.

20. An absorption heat pump, comprising the apparatus (V₂) of claim 12, and further comprising a condenser, an evaporator and a coolant, wherein the coolant is water.