Mixed salt CO;sorbent, process for making and uses thereof

• US 9,539,541 B2
• Filed: 01/18/2013
• Issued: 01/10/2017
• Est. Priority Date: 01/20/2012
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia), Research Triangle Institute
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia), Research Triangle Institute
• Inventors: Shen, J. P., Hamad, Esam Zaki, Al-Sadat, Wajdi Issam, Coleman, Luke, Gupta, Raghubir
• Primary Examiner(s): Smith, Jennifer A
• Assistant Examiner(s): NASSIRI MOTLAGH, ANITA
• Application Number:
  US13/744,992
• Publication Number:
  US 20130195742A1
• Time in Patent Office: 1,453 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B01D 2251/30 Alkali metal compounds
• CPC Class Codes: B01D 2251/302 of lithium
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/306 of potassium
• CPC Class Codes: B01D 2251/402 of magnesium
• CPC Class Codes: B01D 2251/60 Inorganic bases or salts
• CPC Class Codes: B01D 2251/602 Oxides
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2253/112 Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106
• CPC Class Codes: B01D 2253/1124 Metal oxides
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 2259/4566 for use in transportation means
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/82 with stationary reactants
• CPC Class Codes: B01D 53/92 of engine exhaust gases exhaust or silencing apparatus for internal combustion engines, machines or engines in general, having means for purifying, rendering innocuous or otherwise treating exhaust gases F01N3/00
• CPC Class Codes: B01D 53/94 by catalytic processes
• CPC Class Codes: B01J 20/04 comprising compounds of alkali metals, alkaline earth metals or magnesium
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/043 : Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/3085 : Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
• CPC Class Codes: B01J 20/3433 : of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• CPC Class Codes: B01J 20/3483 : by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: B01J 2220/42 : Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32
• 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: Y02C 20/40 : of CO2

Abstract

The invention relates to a mixed salt composition which is useful as a CO₂ sorbent. The mixed salt composition comprises a Mg salt, and at least one Group IA element salt, where the Mg and Group IA element are present at a molar ratio of from 3:1 to 8:1. The resulting composition can adsorb about 20% or more of CO2 in a gas. Via varying the molar ratios of the components, and the Group IA element, one can develop compositions which show optional functionality at different conditions. The composition is especially useful in the adsorptive capture of CO₂ on mobile sources, such as transportation vehicles, where it can be recovered during regeneration of the adsorbent composition and the CO₂ used as a coolant gas, as a reactant in manufacture of fuel, and so forth.

Claims

1. A method for removing CO₂ from a gas or gas mixture produced by combustion of hydrocarbon fuel by an internal combustion engine on a mobile source comprising contacting a mixed salt composition which consists of:

(i) MgCO₃, (ii) at least one carbonate salt of Na, Li, K, or Rb, and (iii) at least one nitrate salt of Na, Li, K, or Rb, wherein the Mg of (i) and the Na, Li, K, or Rb of (ii) and (iii) are present in a molar ratio of from about 6;

1 to about 4;

1, with said gas or gas mixture produced by said internal combustion engine at a temperature of from about 100°

C. to about 450°

C. for a time sufficient for said mixed salt composition to remove a portion of CO₂ therefrom and releasing adsorbed CO₂ to regenerate said composition by heat exchange with hot exhaust gas discharged from said internal combustion engine.

3. The method of claim 1, wherein (i) is MgO.

4. The method of claim 1, wherein said mixed salt composition is MgO:

Na₂CO₃;

NaNO₃.

5. The method of claim 1, wherein said temperature is from about 250°

C. to about 350°

C.

6. The method of claim 1, further comprising contacting said mixed salt composition with an inert gas to remove any CO₂ adsorbed therein.

7. The method of claim 6, wherein said inert gas is N₂.

8. The method of claim 6, comprising contacting said inert gas to said mixed salt composition at a temperature of about 500°

C.

9. The method of claim 1, wherein said mobile source is a transportation vehicle.

10. The method of claim 9, wherein said transportation vehicle is an automobile, truck, bus, train, or boat, and the hydrocarbon fuel is gasoline or diesel fuel.

2. A method for removing CO₂ from a gas or gas mixture produced by combustion of hydrocarbon fuel by an internal combustion engine on a mobile source comprising contacting a mixed salt composition which consists of:

(i) a magnesium salt, (ii) at least one carbonate salt of Na, Li, K, or Rb, and (iii) at least one nitrate salt of Na, Li, K, or Rb, wherein the molar ratio of Mg and said Na, Li, K, or Rb is from about 6;

1 to about 4;

1, with said gas or gas mixture produced by said internal combustion engine at a temperature of from about 100°

C. to about 450°

C. for a time sufficient for said mixed salt composition to remove a portion of CO₂ therefrom and releasing adsorbed CO₂ to regenerate said composition by heat exchange with hot exhaust gas discharged from said internal combustion engine.

11. The method of claim 2, wherein (i) is MgO.

12. The method of claim 2, wherein said temperature is from about 250°

C. to about 350°

C.

13. The method of claim 2, further comprising contacting said mixed salt composition with an inert gas to removed any CO₂ adsorbed therein.

14. The method of claim 13, wherein said gas is N₂.

15. The method of claim 14, comprising contacting said inert gas to said mixed salt composition at a temperature of about 500°

C.

16. The method of claim 2, wherein said mobile source is a transportation vehicle.

17. The method of claim 16, wherein said transportation vehicle is an automobile, truck, bus, train, or boat, and the hydrocarbon fuel is gasoline or diesel fuel.