Systems and methods of storing combustion waste products

Patent metadata

Field	Value
Publication number	US-9309161-B2
Application number	US-201314423986-A
Country	US
Kind code	B2
Filing date	Aug 30, 2013
Priority date	Aug 30, 2012
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

In one aspect, methods of storing one or more combustion waste products are described herein. Combustion waste products stored by a method described herein can include solid combustion waste products such as coal ash and/or gaseous combustion products such as carbon dioxide. In some embodiments, a method of storing carbon dioxide comprises providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure and flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete.

First claim

That which is claimed is:

1. A method of storing carbon comprising:
providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure; and
flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete,
wherein the porous concrete has a porosity of about 10 percent to about 70 percent and comprises macropores having a diameter between about 200 μm and about 800 μm and micropores having a diameter between about 100 nm and about 20 μm.

2. The method of claim 1 , wherein the porous concrete comprises a mixture of coal ash and cement.

3. The method of claim 1 , wherein the carbon dioxide is sorbed by the porous concrete at a rate of at least 0.01 grams of carbon dioxide per gram of porous concrete per minute.

4. The method of claim 1 , wherein the carbon dioxide is chemisorbed and physisorbed by the porous concrete.

5. The method of claim 1 , wherein the concentration of carbon dioxide flowed into the pore structure of the porous concrete is greater than the atmospheric concentration of carbon dioxide.

6. The method of claim 1 , wherein flowing carbon dioxide into the pore structure of the porous concrete comprises disposing the carbon dioxide in the porous concrete in an amount of 5 to 33 weight percent, based on the total weight of the porous concrete.

7. The method of claim 1 , wherein the porous concrete is at least partially uncured.

8. The method of claim 1 , wherein the porous concrete is substantially cured.

9. The method of claim 1 , wherein flowing carbon dioxide into the pore structure of the porous concrete comprises:
providing an uncured porous concrete composition; and
curing the uncured porous concrete composition in the presence of the carbon dioxide.

10. The method of claim 9 , wherein the uncured porous concrete composition comprises coal ash, cement, water, and a blowing or foaming agent.

11. The method of claim 9 , wherein the uncured porous concrete composition has an acidic pH.

12. The method of claim 9 , wherein curing is carried out at a pressure of 30 psi to 500 psi.

13. The method of claim 9 , wherein curing is carried out at a constant temperature.

14. The method of claim 9 , wherein curing is carried out at ambient temperature.

15. A method of backfilling comprising disposing a backfill material in a void to at least partially fill the void, the backfill material comprising:
porous concrete having a macroporous and microporous pore structure and carbon dioxide residing within the porous concrete in an amount greater than 1 weight percent of the porous concrete,
wherein the porous concrete has a porosity of about 10 percent to about 70 percent and comprises macropores having a diameter between about 200 μm and about 800 μm and micropores having a diameter between about 100 nm and about 20 μm.

16. The method of claim 15 , wherein the porous concrete comprises a mixture of coal ash and cement.

17. The method of claim 1 , wherein the carbon dioxide is present in the carbon dioxide storage medium at a depth of more than 5 cm from the surface of the porous concrete.

18. The method of claim 1 , wherein flowing carbon dioxide into the pore structure of the porous concrete comprises flowing compressed carbon dioxide into the porous concrete.

19. The method of claim 1 , wherein the coal ash is present in the porous concrete in an amount between 5 weight percent and 90 weight percent, based on the total weight of the porous concrete.

Assignees

• Univ North Carolina
• Univ China Mining

Inventors

• Chen Shen-En
• Wang Peng
• Miao Xiexing
• Feng Qiyan
• Zhu Qianlin

Classifications

• C04B2111/00017

  Aspects relating to the protection of the environment · CPC title

• B01J20/28078

  Pore diameter · CPC title

• C04B40/0231

  Carbon dioxide hardening · CPC title

• C04B28/10

  Lime cements or magnesium oxide cements · CPC title

• B01J20/041

  Oxides or hydroxides · CPC title