Mixed salt CO2 sorbent, process for making and uses thereof

Patent metadata

Field	Value
Publication number	US-9539541-B2
Application number	US-201313744992-A
Country	US
Kind code	B2
Filing date	Jan 18, 2013
Priority date	Jan 20, 2012
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

The invention relates to a mixed salt composition which is useful as a CO 2 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 CO 2 on mobile sources, such as transportation vehicles, where it can be recovered during regeneration of the adsorbent composition and the CO 2 used as a coolant gas, as a reactant in manufacture of fuel, and so forth.

First claim

What is claimed is:

1. A method for removing CO 2 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) MgCO 3 , (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 CO 2 therefrom and releasing adsorbed CO 2 to regenerate said composition by heat exchange with hot exhaust gas discharged from said internal combustion engine.

2. A method for removing CO 2 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 CO 2 therefrom and releasing adsorbed CO 2 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:Na 2 CO 3 :NaNO 3 .

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 CO 2 adsorbed therein.

7. The method of claim 6 , wherein said inert gas is N 2 .

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.

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 CO 2 adsorbed therein.

14. The method of claim 13 , wherein said gas is N 2 .

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.

Assignees

• Saudi Arabian Oil Co
• Res Triangle Inst

Inventors

• Hamad Esam Zaki
• Al-Sadat Wajdi Issam
• Coleman Luke
• Shen J P
• Gupta Raghubir

Classifications

• B01J20/041

  Oxides or hydroxides · CPC title

• B01D2258/012

  Diesel engines and lean burn gasoline engines · CPC title

• B01J20/04

  comprising compounds of alkali metals, alkaline earth metals or magnesium · CPC title

• B01D2251/402

  of magnesium · CPC title

• B01D2251/30

  Alkali metal compounds · CPC title