NITROGEN-CONTAINING ACTIVATED CARBON MATERIAL

• US 20130168321A1
• Filed: 01/03/2013
• Published: 07/04/2013
• Est. Priority Date: 01/03/2012
• Status: Active Grant

• Current Assignee: Penn State Research Foundation (Pennsylvania State University)
• Original Assignee: Penn State Research Foundation (Pennsylvania State University)
• Inventors: Cannon, Frederick Scott, Brown, Nicole Robitaille, Byrne, Timothy M., Hou, Pin, Parette, Robert, Gu, Xin, Cash, Colin C., Delgado, Cesar Nieto, Hong, Siqi
• Granted Patent: US 9,095,840 B2
• Time in Patent Office: Days
• US Class Current: 210/684
• CPC Class Codes: B01J 20/20 comprising free carbon; comprising carbon obtained by carbonising processes
• CPC Class Codes: B01J 20/28011 Other properties, e.g. density, crush strength
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3248 the functional group or the linking, spacer or anchoring group as a whole comprising at least one type of heteroatom selected from a nitrogen, oxygen or sulfur, these atoms not being part of the carrier as such
• CPC Class Codes: C02F 1/281 using inorganic sorbents
• CPC Class Codes: C02F 1/283 using coal, charred products, or inorganic mixtures containing them
• CPC Class Codes: C02F 2101/101 Sulfur compounds
• CPC Class Codes: C02F 2101/103 Arsenic compounds
• CPC Class Codes: C02F 2101/12 Halogens or halogen-containing compounds
• CPC Class Codes: C02F 2101/163 Nitrates
• CPC Class Codes: C02F 2101/22 Chromium or chromium compounds, e.g. chromates
• CPC Class Codes: C02F 2101/30 Organic compounds
• CPC Class Codes: C02F 2103/06 Contaminated groundwater or leachate
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

An activated carbon material for removing a contaminant from a liquid. The activated carbon material can be a plurality carbon grains that have a pore volume of approximately 0.1 milliliters per gram (mL/g) in the range of less than about 15 angstroms in width. The carbon grains can also have or contain a nitrogen-containing species having a concentration of more than 2 atomic percent nitrogen. A plurality of the carbon grains can be used to make a contactor that is operable to remove or reduce perchlorate having a concentration of 20 parts per billion (ppb) to less than 4 ppb from 4,500 bed volumes of water with the nitrogen-containing species leaching off of the carbon grains less than 0.1 mg/L. The activated carbon material can also be electrochemically regenerated.

Claims

22. An activated carbon material for removing a contaminant from a liquid, said activated carbon material comprising:

a contactor made from a plurality of carbon grains, said contactor operable to remove about 10,000 bed volumes or greater of perchlorate down to below about 4 parts per billion from native ground water having an alkalinity more than about 90 mg/L as calcium carbonate and more than about 0.4 mg/L total organic carbon and about 20 parts per billion or more of perchlorate, as monitored per a Standardized Proportional Mini-Column Perchlorate Adsorber protocol, and provided that nitrogen-containing species do not leach off of the activated carbon grains above a concentration of about 0.2 mg/L, as monitored by a Tsubouchi Two-phase Titration method.

23. A process for removing a contaminant from a liquid comprising:

providing a contactor made from a plurality of carbon grains made from coal or wood, said contactor operable to exhibit a current change span of from more than 1 amp per gram of carbon grains from the highest-to-lowest points in a voltammogram cycle when the electric potential changes by less than about 2.3 volts from the most positive to the most negative, as measured by a Cyclic Voltammetry protocol for oxyanion; and

provided that following said positive voltage oxidation per this protocol, the activated carbon exhibits an oxyanion-to-nitrogen ratio that exceeds about 0.04-to-1, whereas following said negative voltage reduction per this protocol, the activated carbon exhibits an oxyanion-to-nitrogen ratio that is less than about 0.005 to-1, as measured by an X-ray Photoelectron Spectroscopy protocol; and

flowing water contaminated water with oxyanions into contact with the contactor, the contactor removing at least part of the oxyanions and purifying the water.

24. A process for removing a contaminant from a liquid, the process comprising:

providing a plurality of carbon grains derived from coal or wood, the plurality of carbon grains having;

an average pore volume per gram of more than about 0.08 mL per gram in the width range below about 500 angstroms, as measured per a Argon Adsorption Density Functional Theory protocol;

a nitrogen-containing species with more than 1.0 atomic percent nitrogen content, as measured per a X-ray Photoelectron Spectroscopy protocol which cannot detect hydrogen;

fabricating a contactor made from the plurality of carbon grains, the contactor operable to remove about 4,500 bed volumes or greater of perchlorate down to below about 4 parts per billion from native ground water having an alkalinity more than about 90 mg/L as calcium carbonate and more than about 0.4 mg/L total organic carbon and about 20 parts per billion or more of perchlorate, as monitored per a Standardized Mini-Column Proportional Adsorber protocol for perchlorate and the nitrogen-containing species does not leach off of the contactor above a concentration of about 0.2 mg/L, as monitored by the Tsubouchi Two-phase Titration protocol;

flowing perchlorate contaminated water into contact with the contactor, the contactor removing at least part of the perchlorate and purifying the water.

1. An activated carbon material comprising:

a plurality of carbon grains, where said plurality of carbon grains are operable to exhibit a current change that spans more than about 0.5 amps per gram of carbon grains from the highest-to-lowest points in a voltammogram cycle, while the electric potential spans less than 2.3 volts from the most positive to most negative points, as measured by a Cyclic Voltammetry protocol; and

provided that the said plurality of carbon grains will sorb more than about 2.5 mg of oxyanion per gram of said carbon grains when the initial concentration is 10 mg/L of the oxyanion in deionized water, and 0.02 grams of said carbons grains are mixed in 23 mL water, per an Adapted Batch Adsorption Isotherm protocol.

2. The activated carbon material of claim 1, wherein the oxyanion used in an Adapted Batch Adsorption Isotherm protocol is perchlorate or sulfate, and wherein said carbon grains will sorb more than about 20 mg of oxyanion per gram of said carbon grains.

3. The activated carbon material of claim 1, wherein said plurality of carbon grains are operable to exhibit a current change that spans more than about 1.0 amps per gram of carbon material when the electric potential spans less than about 2.3 volts, as measured by a Cyclic Voltommetry protocol.

4. The activated carbon material of claim 1, wherein said activated carbon material is used for removing a contaminant from a liquid, and wherein said activated carbon material has:

an average mean pore volume per gram of more than about 0.10 mL per gram in the pore width range below about 15 angstroms wherein the average pore volume for a given pore widths is measured per an Argon Adsorption Density Functional Theory protocol;

nitrogen-tailored carbon grains having more than 2 atomic percent of a nitrogen-containing species; and

at least about 0.15;

1 atomic fraction of the nitrogen-containing species are at least one selected from the group NQ and N5, as measured per an X-ray Photoelecton Spectroscopy protocol which cannot detect hydrogen.

5. The activated carbon material of claim 1, wherein when fabricating a contactor from the nitrogen-tailored carbon grains, the contactor is operable to remove perchlorate to below 4 ppb for at least about 4,500 bed volumes of water, when the water has a perchlorate concentration of at least about 20 parts per billion (ppb) and the water also has an alkalinity greater than about 90 mg/L as calcium carbonate and a total organic carbon content of greater than about 0.4 mg/L, the perchlorate removal monitored per a Standardized Proportional Mini-Column Perchlorate Adsorber protocol.

6. The activated carbon material when fabricating a contactor of claim 5, wherein the nitrogen-containing species leaches off of the carbon grains to an amount of less than about 0.2 mg/L while perchlorate is removed from perchlorate-containing water flowing through the contactor, the leaching of the nitrogen-containing species monitored by a Tsubouchi Two-phase Titration protocol.

7. The activated carbon material of claim 1, wherein the carbon grains is derived from at least one material selected from the group consisting of lignite coal, subbituminous coal, bituminous coal, anthracite coal, coconut shells, lignin, hemicellulose, cellulose, kraft black liquor, cotton, softwood, hardwood, fruit pits, graphite, exfoliated graphite, switch grass, peat, carbonaceous textiles, and agricultural silage.

8. The activated carbon material of claim 1, wherein said material that has become activated carbon has been heat treated at a temperature greater than 250°

C., and wherein the activated carbon material of claim 1, wherein the carbon grains have not been made into a solid by means of chemical vapor deposition of organic gases.

9. The activated carbon material of claim 1, wherein the carbon grains contain at least 0.3 atomic percent of a halogen selected from the group consisting of chloride, bromide, fluoride, iodide, and mixtures thereof.

10. The activated carbon material of claim 1, wherein the contactor is operable to remove anionic species, oxyanions, perchlorate, arsenate, arsenite, chromate, sulfate, sulfite, thiosulfate, polysulfides, sulfide, polythionates, hexathionate, pentathionate, tetrathionate, trithionate, dithionate, nitrate, bromate, bromide, chloride, fluoride bicarbonate, carbonate, uranyl carbonate, vanadate, selenate, silicate, selenite, and/or mixtures thereof.

11. The activated carbon material of claim 1, wherein the contactor removes organic species, natural organic matter, endocrine disrupting compounds, pharmaceutical and personal care products, acetate, methylene blue dye, congo red dye, geosmin, methylisoborneol, methyl tert butyl ether, chlorinated organic compounds, aliphatic organic compounds, aromatic organic compounds, ibuprofen, sulfamethoxazole, iopromide, dilantin, meprobabmat, diclofenac, naproxen, gemfibrozil, atrazine, N,N-Diethyl-meta-toluamide (DEET), acetaminophen, hodrocodone, carbamazepine, diazepam, caffeine, pentoxifyline, trimethoprim, striol, erythromycin, ethynylestradiol, testosterone, androstenedione, fluoxetine, stradiol, estrone, triclosan, tris(2-carboxeyethyl)phosphine (TCEP), progesterone, perfluorooctanoic acid, perfluorodecanoic acid, perfluorooctanesulfonic acid, and/or mixtures thereof.

12. The activated carbon material of claim 1, wherein the carbon grains contain nitrogen functionality and/or moieties that are selected from the group consisting of pyridine, pyridinium, quaternary ammonium, pyrrole, amines, imines, amides, imides, pyrrolic nitrogen, pyridinic nitrogen, primary amine, carboxamide, secondary amine, tertiary amine, primary ketimine, secondary ketimine, primary aldimine, secondary aldimine, azide, azo compounds, cyanate, isocyanate, nitrate, nitrile, isonitrile, nitrosooxy, nitro, nitroso, pyridyl, viologen, aniline, poly(aniline-co-o-aminophenol), hemoglobin, porphyrin, and/or mixtures thereof.

13. The activated carbon material of claim 1, wherein the carbon grains have a positive surface charge greater than about 0.05 milliequivalents/gram at pH 7, as measured by a Surface Charge Titration protocol.

14. The activated carbon material of claim 1, wherein the individual carbon grains have an average mean grain-width dimension that is between 5 microns and 3 millimeters with an aspect ratio less than or equal to 10, and wherein the carbon grains that have been wetted and confined horizontally, will then compress less than 20% when a water pressure of about 300 kPa is applied thereto.

15. The activated carbon material of claim 1, wherein the carbon grains are aggregated with other carbon grains via one or more biomaterial-derived binders.

16. The activated carbon material of claim 1, wherein the contactor is operable to remove at least 14,000 bed volumes of perchlorate down to below about 4 ppb from a native groundwater having at least 30 ppb perchlorate, an alkalinity greater than 90 mg/L as calcium carbonate and a total organic carbon concentration greater than 0.4 mg/L, as determined by a Standardized Proportional Mini-Column Adsorber protocol.

17. The activated carbon material of claim 1, provided that following said positive voltage oxidation per this protocol, the activated carbon exhibits an oxyanion-to-nitrogen ratio that exceeds about 0.04-to-1, whereas following said negative voltage reduction per this protocol, the activated carbon exhibits an oxyanion-to-nitrogen ratio that is less than about 0.005-to-1, as measured by an X-ray Photoelectron Spectroscopy protocol, and wherein said oxyanion does not contain nitrogen.

18. The activated carbon material of claim 1, wherein the nitrogen content is achieved by first exposing the parent carbon to an oxidizing agent that is selected from the group consisting of nitric acid, sulfuric acid, phosphoric acid, ozone, hydrogen peroxide, oxygen;

provided that the activated carbon is then exposed to a hot ammonia gas at a temperature above about 300°

C.;

provided the activated carbon is then exposed to an alkyl halide wherein the alkyl group contains 1 to 20 carbons, and the halide is at least one selected from the group of;

chloride, bromide, fluoride, and iodide.

19. The activated carbon material of claim 12, wherein the nitrogen functionality and/or moieties are achieved by adsorbing organic compounds onto the activated carbon that contain both a functional group that will undergo an epoxide reaction in high-pH conditions plus nitrogen functionality and/or moieties.

20. The activated carbon material of claim 1, wherein following an initial loading of oxyanion onto said activated carbon material, more than about 50 percent of the initial oxyanion sorption capacity can be restored by an electrochemical regeneration protocol that sequentially involves a reduction and oxidation step, wherein said oxyanion sorption capacity is measured by either an Adapted Batch Adsorption Isotherm Protocol or a Standardized Proportional Mini-Column Adsorber protocol.

21. The activated carbon material of claim 1, where said plurality of carbon grains are operable to exhibit a current change that spans more than about 0.5 amps per gram of carbon grains from the highest-to-lowest points in a voltammogram cycle, while the electric potential spans less than 2.3 volts from the most positive to most negative points, as measured by a Cyclic Voltammetry protocol, provided that such exhibition of current change can be maintained through at least 50 cycles of a Cyclic Voltammetry protocol.

25. The process of claim 24, wherein the nitrogen functionality and/or moieties are achieved by adsorbing organic compounds onto the activated carbon that contain both a functional group that will undergo an epoxide reaction in high-pH conditions plus nitrogen functionality and/or moieties.

26. The process of claim 24, wherein the contactor exhibits a positive surface charge that is more than about 0.1 milliequivalents per gram at a pH of 10, when measured by a Surface Charge Titration protocol.

27. The process of claim 24, wherein the plurality of carbon grains is derived from at least one material selected from the group consisting of lignite coal, subbituminous coal, bituminous coal, anthracite coal, coconut shells, lignin, hemicellulose, cellulose, craft black liquor, cotton, softwood, hardwood, fruit pits, graphite, exfoliated graphite, switch grass, peat, carbonaceous textiles, and agricultural silage.

28. The process of claim 24, wherein the material that has become activated carbon has experienced heat treatment at a temperature that exceeds 250°

C., and wherein the plurality of carbon grains has not been made into a solid by means of chemical vapor deposition of organic gases, and wherein the individual carbon grains have an average mean grain-width dimension that is between 5 microns and 3 millimeters with an aspect ratio less than or equal to 10.

29. The process of claim 24, wherein the contactor removes anionic species, oxyanions, perchlorate, arsenate, arsenite, chromate, sulfate, sulfite, thiosulfate, polysulfides, sulfide, polythionates, hexathionate, pentathionate, tetrathionate, trithionate, dithionate, nitrate, bromate, bromide, chloride, fluoride, bicarbonate, carbonate, uranyl carbonate, vanadate, selenate, silicate, selenite, and/or mixtures thereof.

30. The process of claim 24, wherein the contactor removes organic species, natural organic matter, endocrine disrupting compounds, pharmaceutical and personal care products, acetate, methylene blue dye, congo red dye, geosmin, methylisoborneol, methyl tert butyl ether, chlorinated organic compounds, aliphatic organic compounds, aromatic organic compounds, ibuprofen, sulfamethoxazole, iopromide, dilantin, meprobabmat, diclofenac, naproxen, gemfibrozil, atrazine, N,N-Diethyl-meta-toluamide (DEET), acetaminophen, hodrocodone, carbamazepine, diazepam, caffeine, pentoxifyline, trimethoprim, striol, erythromycin, ethynylestradiol, testosterone, androstenedione, fluoxetine, stradiol, estrone, triclosan, tris(2-carboxeyethyl)phosphine (TCEP), progesterone, perfluorooctanoic acid, perfluorodecanoic acid, perfluorooctanesulfonic acid, and/or mixtures thereof.

31. The process of claim 24, wherein the plurality of carbon grains contain nitrogen functionality and/or moieties that are selected from the group consisting of pyridine, pyridinium, quaternary ammonium, pyrrole, amines, imines, amides, imides, pyrrolic nitrogen, pyridinic nitrogen, primary amine, carboxamide, secondary amine, tertiary amine, primary ketimine, secondary ketimine, primary aldimine, secondary aldimine, azide, azo compounds, cyanate, isocyanate, nitrate, nitrile, isonitrile, nitrosooxy, nitro, nitroso, pyridyl, viologen, aniline, poly(aniline-co-o-aminophenol), hemoglobin, porphyrin, and/or mixtures thereof.

32. The process of claim 24, wherein the contactor removes at least 10,000 bed volumes of perchlorate down to below 4 parts per billion from native ground water having an alkalinity more than about 100 mg/L as calcium carbonate and more than about 0.4 mg/L total organic carbon and about 30 parts per billion or more of perchlorate, as monitored per a Standardized Proportional Mini-Column Adsorber protocol for perchlorate.

33. The process of claim 24, wherein the plurality of carbon grains compress less than 20% when a water pressure of 300 kPa is applied thereto after the activated carbon material has been wetted and confined horizontally.

34. The process of claim 24, wherein a proportion of C—

Cl bonds is less than about 0.1 atomic percent, as measured per an X-ray Photoelectron Spectroscopy Protocol.

32-1. The process of claim 24, wherein the contactor removes at least 20,000 bed volumes of perchlorate down to below 4 parts per billion from native ground water having an alkalinity more than about 100 mg/L as calcium carbonate and more than about 0.4 mg/L total organic carbon and about 30 parts per billion or more of perchlorate, as monitored per a Standardized Proportional Mini-Column Adsorber protocol for perchlorate.