High surface area carbon and process for its production

Patent metadata

Field	Value
Publication number	US-9517445-B2
Application number	US-201313790831-A
Country	US
Kind code	B2
Filing date	Mar 8, 2013
Priority date	Nov 8, 2006
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

First claim

What is claimed is:

1. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising contacting a char with KOH for one hour at an activation temperature ranging from 700° C. to 900° C. and a KOH:C ratio ranging from 3 to 4.5, wherein the activated carbon adsorbent has a total pore volume of at least 1.5 cc/g and a surface area of at least about 2700 m 2 /g.

2. The process of claim 1 , wherein the activation temperature is 700° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 40% to about 50%.

3. The process of claim 1 , wherein the activation temperature is 800° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 40%.

4. The process of claim 1 , wherein the activation temperature is 900° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 30%.

5. The process of claim 1 , wherein the KOH is an amount of KOH flakes or a KOH solution.

6. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising contacting a char with KOH flakes or solution for one hour at an activation temperature of 700° C. and a KOH:C ratio ranging from 2.5 to 3.5, wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 80% to about 40%.

7. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising contacting a char with KOH solution for one hour at an activation temperature of 800° C. and a KOH:C ratio ranging from 2.5 to 3.5, wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 55% to about 40%.

8. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising contacting a char with KOH solution for one hour at an activation temperature of 900° C. and a KOH:C ratio ranging from 2.5 to 3.5, wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 50% to about 30%.

9. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising:
providing a char comprising an acid-activated, charred biomass feedstock; and
contacting the char with an amount of KOH flakes or solution for one hour at an activation temperature ranging from 700° C. to 900° C. and a KOH:C ratio ranging from 3 to 4.5; wherein the activated carbon adsorbent has a total pore volume of at least 1.5 cc/g and a surface area of at least about 2700 m 2 /g.

10. The process of claim 9 , wherein the activation temperature is 700° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 40% to about 50%.

11. The process of claim 9 , wherein the activation temperature is 800° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 40%.

12. The process of claim 9 , wherein the activation temperature is 900° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 30%.

13. A process for making an activated carbon adsorbent having a predetermined pore size distribution and surface area, the process comprising:
soaking a biomass feedstock in phosphoric acid at about 45° C. for about 12 hours to form an acid-activated feedstock;
washing the acid-activated feedstock to adjust the pH of the acid-activated feedstock to about 7;
charring the washed acid-activated feedstock at about 480° C. under a nitrogen atmosphere to form a char; and
contacting the char with an amount of KOH flakes or solution for one hour at an activation temperature ranging from 700° C. to 900° C. and a KOH:C ratio ranging from 3 to 4.5;
wherein the activated carbon adsorbent has a total pore volume of at least 1.5 cc/g and a surface area of at least about 2700 m 2 /g.

14. The process of claim 13 , wherein the activation temperature is 700° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less ranging from about 40% to about 50%.

15. The process of claim 13 , wherein the activation temperature is 800° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 40%.

16. The process of claim 13 , wherein the activation temperature is 900° C., wherein the KOH:C ratio is 3.5, and wherein the activated carbon adsorbent has a % volume of pores of 10 Å diameter or less of about 30%.

Assignees

• Univ Missouri

Inventors

• Romanos Jimmy
• Burress Jacob
• Pfeifer Peter
• Rash Tyler
• Shah Parag
• Suppes Galen

Classifications

• C01B32/318

  characterised by the starting materials · CPC title

• C01B3/0021

  Elemental carbon, e.g. active carbon, carbon nanotubes or fullerenes · CPC title

• B01J20/00

  Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof · CPC title

• C02F1/283

  using coal, charred products, or inorganic mixtures containing them · CPC title

• B01J20/28085

  being more than 50 nm, i.e. macropores · CPC title