Activated carbon sorbent including nitrogen and methods of using the same

1. A method of reducing the mercury content in a pollutant-containing gas, the method comprising:

heating a carbon precursor comprising indole, quinoxaline, isoquinoline, piperazine, quinolone, diazabicyclo[2.2.2]octane (DABCO), polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer, vinylpyrrolidone-acrylic acid copolymer, vinylpyrrolidone-maleic acid copolymer, or a combination thereof, to about 200° C. to about 10,000° C., to provide an activated carbon sorbent comprising activated carbon sorbent particles comprising nitrogen in a surface layer of the sorbent particles;

contacting a mercury-containing gas with the activated carbon sorbent, to form a mercury-sorbent composition; and

separating at least some of the mercury-sorbent composition from the mercury-containing gas, to give a separated gas.

2. The method of claim 1 , wherein the mercury-containing gas further comprises a concentration of sulfur(VI) and the concentration of sulfur(VI) in the mercury-containing gas is greater than about 3 ppm by mole and the activated carbon sorbent forms a mercury-sorbent composition at a higher absorption rate relative to a corresponding activated carbon sorbent comprising at least one of a) less or substantially no nitrogen in a corresponding particle surface layer, b) less or substantially no halide- or halogen-promotion, wherein the activated carbon sorbent comprising the activated carbon sorbent particles is halide- or halogen-promoted, and c) less or substantially no inorganic matrix support, wherein the activated carbon sorbent comprising the activated carbon sorbent particles is inorganic matrix-supported.

3. The method of claim 1 , wherein the concentration of nitrogen in the surface layer of the sorbent particles is higher than the concentration of nitrogen in a core of the sorbent particles.

4. The method of claim 1 , wherein the mercury-containing gas further comprises a concentration of sulfur(VI) and the concentration of sulfur(VI) in the mercury-containing gas is about 3 ppm-2000 ppm.

5. The method of claim 1 , wherein the nitrogen in the surface layer at least one of decreases neutralization of carbocations in the activated carbon by at least one of SO 3 2 and HSO 3 1− , and at least partially blocks carbocations in the activated carbon from at least one of SO 3 2 and HSO 3 1− , as compared to a corresponding activated carbon sorbent comprising less or substantially no nitrogen in a corresponding particle surface layer.

6. The method of claim 1 , further comprising:

obtaining or providing an unpromoted carbon sorbent;

obtaining or providing a promoter; and

promoting at least a portion of the unpromoted sorbent by contacting the portion of the unpromoted sorbent with the promoter to form the activated carbon sorbent.

7. The method of claim 6 , wherein the promoter comprises a halogen or halide promoter.

8. The method of claim 1 , wherein the core of the activated carbon sorbent particles comprise about 0 wt %-about 99 wt % nitrogen.

9. The method of claim 1 , wherein the surface layer of the activated carbon sorbent particles comprises about 0.001 wt %-about 99 wt % nitrogen.

10. The method of claim 1 , wherein the surface layer of the activated carbon sorbent comprises a layer at the surface of the particle having a thickness of about 0.001% to about 99% of the radius of the particles.

11. The method of claim 1 , wherein the activated carbon sorbent particles have an average diameter of about 0.1 μm to about 1000 μm.

12. The method of claim 1 , wherein obtaining or providing the activated carbon sorbent comprises:

obtaining or providing a carbon precursor comprising nitrogen; and

processing the carbon precursor with at least one of heating, microwaving, and irradiating, to provide the activated carbon sorbent.

13. The method of claim 12 , wherein the carbon precursor comprises a carbonaceous material comprising carbon and a nitrogenous material comprising nitrogen.

14. The method of claim 12 , further comprising:

obtaining or providing a substrate material;

contacting the carbon precursor and the substrate material, to provide a sorbent starting material; and

processing the sorbent starting material with at least one of heating, microwaving, and irradiating, to provide the activated carbon sorbent.

15. The method of claim 14 , wherein the substrate comprises at least one of diatomaceous earth, a clay, a zeolite, or a mineral.

16. The method of claim 14 wherein the activated carbon sorbent comprises a carbon nanocomposite sorbent.

17. The method of claim 1 , wherein at least one of the contacting and the separating occurs in an aqueous scrubber.

18. A method of making an activated carbon sorbent, comprising:

contacting a carbonaceous material comprising brown sugar, barley sugar, caramel, cane sugar, corn syrup, starch, molasses, molasses raffinate, glucans, galactans, xylans, a sugar waste product, activated carbon, granular activated carbon, carbon black, carbon fiber, carbon honeycomb or plate structure, aerogel carbon film, or a combination thereof, and a nitrogenous material that is indole, quinoxaline, isoquinoline, piperazine, quinolone, diazabicyclo[2.2.2]octane (DABCO), polyacrylonitrile, polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer, vinylpyrrolidone-acrylic acid copolymer, vinylpyrrolidone-maleic acid copolymer, or a combination thereof, to provide a carbon precursor comprising nitrogen; and

heating the carbon precursor to about 200° C. to about 10,000° C. to form an activated carbon sorbent comprising activated carbon sorbent particles comprising nitrogen in a surface layer of the sorbent particles, wherein the concentration of nitrogen in the sorbent particles is higher than the concentration of nitrogen in the carbonaceous material.