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Title:
NOVEL CARBON MATERIALS FOR USE IN GAS STORAGE
Document Type and Number:
WIPO Patent Application WO/2018/009688
Kind Code:
A1
Abstract:
An adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m2/g and a gas. An adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m2/g and a gas wherein the carbonaceous material has a chemical functionality associated with from about 2% to about 80% of the surface area of the carbonaceous material. A method comprising contacting a carbonaceous material with a first gas composition to produce an adsorbed gas construct and desorbing at least a portion of the first gas composition from the adsorbed gas construct to regenerate at least a portion of the carbonaceous material.

Inventors:
BARNES JEFF (US)
MOYERS ROB (US)
RAE CAROL A (US)
Application Number:
PCT/US2017/040932
Publication Date:
January 11, 2018
Filing Date:
July 06, 2017
Export Citation:
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Assignee:
IMMUTRIX THERAPEUTICS INC (US)
International Classes:
B01J20/02; B01D53/02; B01J20/28
Foreign References:
US20140294701A12014-10-02
US20160136613A12016-05-19
Other References:
LOZANO-CASTELLO, D. ET AL.: "Advances in the study of methane storage in porous carbonaceous materials", FUEL, vol. 81, no. 14, 2002, pages 1777 - 1803, XP004378465
MORRIS, RUSSE LL E. ET AL.: "Gas storage in nanoporous materials", ANGEWANDTE CHEMIE INTERNATIONAL EDITION, vol. 47, no. 27, 2008, pages 4966 - 4981, XP055451153
LOZANO-CASTELLO, D. ET AL.: "Influence of pore size distribution on methane storage at relatively low pressure: preparation of activated carbon with optimum pore size", CARBON, vol. 40, no. 7, 2002, pages 989 - 1002, XP004352455
Attorney, Agent or Firm:
HARRIS, JR., Jerry C. et al. (US)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. An adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m2/g and a gas.

2. The construct of claim 1 wherein the carbonaceous material has a multimodal pore size distribution.

3. The construct of claim 1 wherein the carbonaceous material has at least two distributions of mesoporous pore sizes with a first population having a mesoporous pore size denoted x and a second population having a mesoporous pore size denoted y where the carbonaceous material provides a mixture having a ratio of x/y of about 1.

4. The construct of claim 3 wherein the pore size of the first population is approximately twice the pore size of the second population.

5. The construct of any of claims 1 through claim 4 wherein the gas comprises ethane, isomers of xylene, methane, nitrogen, hydrogen, carbon monoxide, carbon dioxide, argon, oxygen, tetrafluorocarbon, sulfur hexafluoride or combinations thereof.

6. The construct of any of claims 1 through 5 having a gas gravimetric storage density of greater than about 2 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C.

7. The construct of any of claims 1 through 5 having a gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C, alternatively less than wherein the light gas comprises hydrogen.

8. The construct of any of claims 1 through 5 having a light gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C wherein the light gas comprises methane.

9. The construct of any of claims 1 through 5 having a light gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C wherein the light gas comprises carbon dioxide.

10. A battery component comprising the construct of any of claims 1 through 5.

11. A gas purification system comprising the construct of any of claims 1 through 5.

12. An adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m2/g and a gas wherein the carbonaceous material has a chemical functionality associated with from about 2% to about 80% of a surface area of the carbonaceous material.

13. The construct of claim 12 wherein the chemical functionality is selected from the group consisting of a hydroxy 1 group, an amine group, a carboxyiate, an ester, an ether, an aldehyde and a ketone.

14. A gas separation system comprising the construct of claim 12.

15. A method comprising contacting a carbonaceous material with a first gas composition to produce an adsorbed gas construct and desorbing at least a portion of the first gas composition from the adsorbed gas construct to regenerate at least a portion of the carbonaceous material.

16. The method of claim 15 wherein the first gas composition comprises a mixture of two or more gases.

17. The method of claim 16 wherein desorbing releases at least a portion of one of the mixture of gases.

18. The method of claim 16 wherein desorbing releases from about 10 wt.% to about 99 wt.%) of the one of the mixture of gases based on the total weight of the one of the mixture of gases absorbed.

19. The method of claim 15 wherein desorbing at least a portion of the first gas composition comprises thermally treating the construct to a temperature of equal to or greater than about 25 °C.

20. The method of claim 15 wherein desorbing at least a portion of the first gas composition comprises reducing the pressure on the construct to less than about 100 psi.

Description:
NOVEL CARBON MATERIALS FOR USE IN GAS STORAGE

TECHNICAL FIELD

[0001] Generally, the present disclosure is directed to the use of carbonaceous materials. Particularly, the present disclosure is directed to carbonaceous material for storage and/or transport of gas and/or gas components.

BACKGROUND

[0002] As a cleaner, cheaper and more globally evenly distributed fuel, natural gas has considerable environmental, economic, and political advantages over petroleum as a source of energy for the transportation sector. Despite these benefits, its low volumetric energy density at ambient temperature and pressure presents substantial challenges, particularly for light-duty vehicles with little space available for on-board fuel storage. There are practical challenges involved in designing systems with high capacities and in managing the thermal fluctuations associated with adsorbing and desorbing gas from an adsorbent.

[0003] Further in adsorbent-based gas storage and dispensing systems materials that provide increased working capacity are desirable. Herein "working capacity" refers to the amount of gas that can be stored ("loaded") on the sorbent medium and desorptively removed from such sorbent medium for use. An ongoing need exists for compositions and methodologies that can provide constructs for the storage and/or transport of gases that have high working capacities.

SUMMARY

[0004] Disclosed herein is an adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m 2 /g and a gas.

[0005] Also disclosed herein is an adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m 2 /g and a gas wherein the carbonaceous material has a chemical functionality associated with from about 2% to about 80% of a surface area of the carbonaceous material.

[0006] Also disclosed herein is a method comprising contacting a carbonaceous material with a first gas composition to produce an adsorbed gas construct and desorbing at least a portion of the first gas composition from the adsorbed gas construct to regenerate at least a portion of the carbonaceous material. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a depiction of an adsorbed gas construct of the type disclosed herein.

DETAILED DESCRIPTION

[0008] Disclosed herein are compositions and methodologies for the production of an adsorbed gas construct (AGC) a depiction of which is presented in Figure 1. Referring to Figure 1, in one aspect the AGC comprises an adsorbent material such as for example a carbonaceous material 100, which is associated with a gas 200 to form the AGC 300. Although the term "adsorbent material" is used in the present disclosure, it is contemplated that adsorption may be one of multiple mechanisms that contribute to the formation of an AGC of the type disclosed herein. Consequently, formation of an AGC of the type disclosed herein may involve mechanisms such as adsorption, absorption, chemical binding, and the like.

[0009] In an aspect, the adsorbent material of the AGC comprises a carbonaceous material containing micro-, meso- and macropores from porous phenolic resins. As used herein, the term "micropore" refers to a pores with diameter <2 nm, as measured by nitrogen adsorption and mercury porosimetry methods and as defined by RJPAC. As used herein, the term "mesopore" refers to pores with diameter from ca. 2 nm to ca. 50 nm, as measured by nitrogen adsorption and mercury porosimetry methods and as defined by RJPAC. As used herein, the term "macropore" refers to pores with diameters larger than 50 nm, as measured by nitrogen adsorption and mercury porosimetry methods and as defined by RJPAC. In macroporous beads they are located within beads and formed by pore-formers. Their size is generally 50-200 nm, typically 70-200 nm. Typically a precursor resin formulation is used which comprises a large proportion of pore former, e.g. 250 parts ethylene glycol or other pore former to 100 parts of resin-forming components.

[0010] Herein a mesoporous resin may be formed by condensing a nucleophilic component which comprises a phenolic compound or a phenol condensation prepolymer with at least one electrophilic cross-linking agent selected from formaldehyde, paraformaldehyde, furfural and hexamethylene tetramine in the presence of a pore-former selected from the group consisting of a diol (e.g. ethylene glycol), a diol ether, a cyclic ester, a substituted cyclic ester, a substituted linear amide, a substituted cyclic amide, an amino alcohol and a mixture of any of the above with water to form a resin. The pore-former is present in an amount effective to impart meso- or macroporosity to the resin (e.g. at least 120 parts by weight of the pore former being used to dissolve 100 parts by weight of the total resin forming components, i.e. nucleophilic component plus electrophilic component), and it is removed from the porous resin after condensation by cascade washing with water or by vacuum drying. The resulting resin may be carbonized by heating in an inert atmosphere to a temperature of at least 600°C to give a material having a multimodal distribution of pores, the pore structure as estimated by nitrogen adsorption porosimetry comprising micropores and mesopores or macropores. The value for the differential of pore volume with respect to the logarithm of pore radius (dV/dlogR) for the mesopores is greater than 0.2 for at least some values of pore size in the range 20-500 A. The mesoporous carbon may have a BET surface area of 250-800 m 2 /g without activation. It may be activated by heating it at high temperature in the presence of carbon dioxide, steam or a mixture thereof, e.g. by heating it in carbon dioxide at above 800 °C, or it may be activated by heating it in air at above 400 °C. It may then have surface areas of up to 2000 m 2 /g and even higher e.g. 1000-2000 m 2 /g. As used herein the term "BET surface area" is determined by the Brunauer, Emmett, and Teller (BET) method according to ASTM D1993-91, see also ASTM D6556-04.

[0011] Resins for making carbonaceous material can be prepared from any of the starting materials such that the nucleophilic components may comprise phenol, bisphenol A, alkyl phenols, e.g. cresol, diphenols, e.g. resorcinol and hydroquinione, and aminophenols, e.g. m- amino-phenol.

[0012] It is preferred to use as nucleophilic component a phenolic novolac or other similar oligomeric starting material which because it is already partly polymerized makes polymerization to the desired resin a less exothermic and hence more controllable reaction. The preferred novolacs have average molecular weights (AMW) in the range of from about 300 to about 3000 prior to cross-linking (corresponding to a DP with respect to phenol of about 3-30). Where novolac resins are used, they may be solids with melting points in the region of 100 °C. novolac resins of AMW less than 2000 and preferably less than 1500 form resins which on carbonization tend to produce carbons with desired pore size distributions using lower amounts of pore former. Novolacs are thermally stable in that they can be heated so that they become molten and cooled so that they solidify repeatedly without structural change. They are cured on addition of cross- linking agents and heating. Fully cured resins are infusible and insoluble. Whilst commercial novolacs are largely produced using phenol and formaldehyde, a variety of modifying reagents can be used at the pre-polymer formation stage to introduce a range of different oxygen and nitrogen functionalities and cross-linking sites. These include but are not limited to: (a) dihydric phenols e.g. resorcinol and hydroquinone ( (i)both are more reactive than phenol and can lead to some cross-linking at the pre-polymer production stage, (ii) it is also possible to introduce these compounds at the cross-linking stage to provide different cross- linking paths, (iii) these also increase the oxygen functionality of the resins); and (b) nitrogen containing compounds that are active in polycondensation reactions, such as urea, aromatic (aniline, m-amino phenol) and heteroaromatic (melamine) amines ((i) these allow the introduction of specific types of nitrogen functionality into the initial polymer and final carbon and influence the development of the mesoporous structure of both the resins and the final carbons, (ii) like hydroquinone and resorcinol, all the nitrogen containing nucleophilic modifying reagents which can be used possess two or more active sites and are more reactive in condensation reactions than phenol or novolacs, (iii) it means that they are first to react with primary cross-linking agents forming secondary cross-linking agents in situ).

[0013] The nucleophilic component may be provided alone or in association with a polymerization catalyst which may be a weak organic acid miscible with the novolac and/or soluble in the pore former e.g. salicylic acid, oxalic acid or phthalic acid. The concentration of novolac in the pore former may be such that when combined with the solution of cross-linking agent in the same pore former the overall weight ratio of pore former to (novolac+cross-linking agent) is at least 125: 100 by weight. The actual ratios of novolac:pore former and cross-linking agent pore former are set according to convenience in operation by the operational requirements of a bead production plant and are controlled by the viscosity of the novolac:pore former solution such that it remains pumpable and by the ratio of cross-linking agent pore former such that the cross-linking agent remains in solution throughout the plant.

[0014] The cross-linking agent is normally used in an amount of from about 5 to about 40 parts by weight (pbw) per 100 parts by weight of the nucleophilic components e.g. novolac. It may be, for example, an aldehyde e.g. formaldehyde or furfural, it could be hexamethylenetetramine (hexamine), or hydroxymethylated melamine. [0015] Hexamine is preferably used as cross-linking agent. In aspects requiring a completely cured resin, it is preferably used for cross-linking novolac resin at a proportion of about 10 to about 25 pbw e.g. about 15 to about 20 pbw hexamine per 100 pbw of novolac. This ensures formation of the solid resin with maximal cross-linking degree and ensures the stability of the mesopore structure during subsequent removal of the pore former.

[0016] The pore former also acts as solvent. Thus, the pore former is preferably used in sufficient quantities to dissolve the components of the resin system, the weight ratio of pore former to the total components of the resin system resin being preferably at least 1.25: 1.

[0017] The pore former may be, for example, a diol, a diol-ether, a cyclic ester, a substituted cyclic or linear amide or an amino alcohol e.g. ethylene glycol, 1 ,4-butylene glycol, diethylene glycol, triethylene glycol, γ-butyrolactone, propylene carbonate, dimethylformamide, N- methyl- 2-pyrrolidinone and monoethanolamine, ethylene glycol being preferred, and where the selection is also limited by the thermal properties of the solvent as it should not boil or have an excessive vapor pressure at the temperatures used in the curing process. It is thought that the mechanism of meso- and macropore generation is due to a phase separation process that occurs during the cross-linking reaction. In the absence of a pore former, as the linear chains of pre-polymer undergo cross-linking, their molecular weight initially increases. Residual low molecular weight components become insoluble in the higher molecular weight regions causing a phase separation into cross-linked high molecular weight domains within the lower molecular weight continuous phase. Further condensation of light components to the outside of the growing domains occurs until the cross-linked phase becomes essentially continuous with residual lighter pre-polymer trapped between the domains. In the presence of a low level of pore former the pore former is compatible with, and remains within, the cross-linked resin domains, (e.g., <120 parts/100 parts novolac for the novolac-Hexamine-Ethylene Glycol reaction system), whilst the remainder forms a solution with the partially cross-linked polymer between the domains. In the presence of higher levels of pore former, which exceed the capacity of the cross-linked resin, the pore former adds to the light polymer fraction increasing the volume of material in the voids between the domains that gives rise to the mesoporosity and/or macroporosity. In general, the higher the pore former content, the wider the mesopores, up to macropores, and the higher the pore volume. [0018] This phase separation mechanism provides a variety of ways of controlling the pore development in the cross-linked resin structures. These include chemical composition and concentration of the pore former; chemical composition and quantity of the cross-linking electrophilic agents, presence, chemical nature and concentration of modifying nucleophilic agents, chemical composition of phenolic nucleophilic components (phenol, novolac), the presence of water within the solvent and concentration of any curing catalyst if present.

[0019] A carbonaceous material suitable for use in the present disclosure may have any shape compatible with the compositions and methodologies disclosed herein. For example the shape of the carbonaceous material may be that of an irregular granule, a low angularity shape, spherical (e.g., bead), pellet, minilith, monolith, etc. For simplicity, the present disclosure may refer to the use of beads of the carbonaceous material however it is to be understood the carbonaceous material may be of any suitable shape.

[0020] Production of the bead form may be by pouring a solution of a partially cross-linked pre-polymer into a hot liquid such as mineral oil containing a dispersing agent and stirring the mixture. The pre-polymer solution forms into beads which are initially liquid and then, as curing proceeds, become solid. The average bead particle size is controlled by several process parameters including the stirrer type and speed, the oil temperature and viscosity, the pre- polymer solution viscosity and volume ratio of the solution to the oil and the mean size can be adjusted between 5 μιη and 2000 μιη. The beads can then be filtered off from the oil. In a preparative example, industrial novolac resin is mixed with ethylene glycol at an elevated temperature, mixed with hexamine and heated to give a viscous solution which is poured into mineral oil containing a drying oil, after which the mixture is further heated to effect curing. On completion of curing, the reaction mixture is cooled, after which the resulting porous resin is filtered off, and washed with hot water to remove pore former and a small amount of low molecular weight polymer. The cured beads are carbonized to porous carbon beads which have a pore structure as indicated above, and may be activated as indicated above. It is stated that the beads can be produced with a narrow particle size distribution e.g. with a D90/D10 of better than 10 and preferably better than 5. However, the bead size distribution that can be achieved in practice in stirred tank reactors is relatively wide, and the more the process is scaled up the worse the homogeneity of the mixing regime and hence the particle size distribution becomes wider.

[0021] Discrete solid beads of polymeric material e.g. phenolic resin having a porous structure may be formed, which process may produce resin beads on an industrial scale without aggregates of resin building up speedily and interrupting production. The process comprises the steps of: (a) combining a stream of a polymerizable liquid precursor e.g. a novolac and hexamine as cross-linking agent dissolved in a first polar organic liquid e.g. ethylene glycol with a stream of a liquid suspension medium which is a second non-polar organic liquid with which the liquid precursor is substantially or completely immiscible e.g. transformer oil containing a drying oil; (b) mixing the combined stream to disperse the polymerizable liquid precursor as droplets in the suspension medium e.g. using an in-line static mixer; (c) allowing the droplets to polymerize in a laminar flow of the suspension medium so as to form discrete solid beads that cannot agglomerate; and (d) recovering the beads from the suspension medium.

[0022] For bead production, the pore former comprises a polar organic liquid e.g. ethylene glycol chosen in combination with dispersion medium which is a non-polar organic liquid so as to form a mainly or wholly immiscible combination, the greater the incompatibility between the pore former which forms the dispersed phase and the dispersion medium, the less pore former becomes extracted into the dispersion medium. The pore former desirably has a greater density than the dispersion medium with which it is intended to be used so that droplets of the pore former containing dissolved resin-forming components will pass down a column more rapidly than a descending flow of dispersion medium therein. Both protic and aprotic solvents of different classes of organic compounds match these requirements and can be used as pore formers, both individually and in mixtures. In addition to dissolving the reactive components and any catalyst, the pore former should also, in the case of phenolic resins, be compatible with water and/or other minor condensation products (e.g. ammonia) which are formed by elimination as polymerization proceeds, and the pore former is preferably highly miscible with water so that it can be readily removed from the polymerized resin beads by washing.

[0023] The dispersion medium is a liquid which can be heated to the temperature at which curing is carried out e.g. to 160 °C without boiling at ambient pressure and without decomposition and which is immiscible with ethylene glycol and with the dissolved components therein. It may be hydrocarbon-based transformer oil which is a refined mineral oil and is a byproduct of the distillation of petroleum. It may be composed principally of C 15 - C40 alkanes and cycloalkanes, have a density of 0.8 g/cm 3 -0.9 g/cm 3 depending upon grade and have a boiling point at ambient pressure of 260-330 °C, also depending upon grade. Transformer oil has a viscosity of about 0.5 poise at 150 °C which is a typical cure temperature. Transformer oil or other dispersion medium may be used in volumes 3-10 times the volume of the combined streams of nucleophilic precursor and crosslinking agent e.g. about 5 times.

[0024] Preferred dispersing agents which are dissolved in the dispersion medium before that medium is contacted with the reaction mixture to be dispersed therein to retard droplet coalescence are either sold as drying oils e.g. Danish oil or are produced by partially oxidizing naturally occurring precursors such as tung oil, linseed oil, etc. The dispersing agents are consumed as the process proceeds, so that if the dispersion medium is recycled, dispersing agent in the recycled oil stream should be replenished. The dispersing agent is conveniently supplied as a stream in solution in the dispersion medium e.g. transformer oil and e.g. in an amount of 5% v/v - 10% v/v where Danish oil is used which contains a low concentration of the active component to give final concentration of the dispersant in the dispersion medium 0.2% v/v -1% v/v. Higher dispersant concentrations would be used in the case of oxidized vegetable oils.

[0025] The resin beads formed as described above may be carbonized and optionally activated. For example, carbonization and activation may comprise supplying the material to an externally fired rotary kiln maintained at carbonizing and activating temperatures, the kiln having a downward slope to progress the material as it rotates, the kiln having an atmosphere substantially free of oxygen provided by a counter-current of steam or carbon dioxide, and annular weirs being provided at intervals along the kiln to control progress of the material.

[0026] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a mesoporous/macroporous structure.

[0027] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a microporous/mesoporous structure.

[0028] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a microporous/macroporous structure. [0029] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a microporous/microporous structure.

[0030] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a mesoporous/mesoporous structure.

[0031] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a macroporous/macroporous structure.

[0032] Herein a carbonaceous material suitable for use in the present disclosure may comprise a carbonaceous material having at least two pore size distributions, e.g., the pore sizes of the two distributions may differ by < 5%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or > 100%.

[0033] In an aspect, the carbonaceous material may comprise a first population having a pore size denoted x and a second population having a pore size denoted y where the carbonaceous material provides a mixture having a ratio of x/y of about 1; alternatively about 5, alternatively about 10, alternatively about 20; alternatively about 50, or alternatively about 100. In some aspects, the carbonaceous material comprises a mixture of two populations wherein the pore size of the first population is approximately twice the pore size of the second population. The pore sizes may be microporous, mesoporous, macroporous or combinations thereof.

[0034] In an aspect, a carbonaceous material suitable for use in the present disclosure is characterized by a microporous/macroporous structure. In an aspect, the carbonaceous material has a macroporous pore size of from about 75 nm to about 1000 nm, alternatively the carbonaceous material has a macroporous size of from about 100 nm to about 750 nm, or alternatively from about 100 nm to about 500 nm. In an aspect, the carbonaceous material may comprise a first population having a microporous pore size denoted x and a second population having a macroporous pore size denoted y where the carbonaceous material provides a mixture having a ratio of x/y of about 1; alternatively about 5, alternatively about 10, alternatively about 20; alternatively about 50, or alternatively about 100.

[0035] Herein a carbonaceous material suitable for use in the present disclosure may comprise a carbonaceous material having at least two pore size distributions such that the carbonaceous material is a mixture of carbon beads having at least two distributions of pore sizes such as microporous/macroporous, alternatively mesoporous/macroporous. In another aspect, the carbonaceous material can have at least two types of mesopores differing in pore size. In another aspect, the carbonaceous material comprises a trimodal distribution having micropores, mesopores, and macropores.

[0036] In some aspects, the carbonaceous material comprises a mixture of three populations where the pore size of a first population is approximately twice the pore size of the second population and the pore size of the third population is approximately two and a half times the pore size of the second population. The pore sizes may be microporous, mesoporous, macroporous or combinations thereof.

[0037] An AGC of the type disclosed herein further comprises a gas. In an aspect, the gas may be a hydrocarbon molecule such as one or more of C2H2, C2H4, or one of the isomers of xylene. In another aspect, the gas comprises methane, nitrogen, hydrogen, carbon monoxide, carbon dioxide, argon, oxygen, tetrafluorocarbon, sulfur hexafluoride or combinations thereof. An AGC of the type disclosed herein may display a surface area of equal to or greater than about 500 m 2 /g, alternatively from about 500 m 2 /g to about 2000 m 2 /g, alternatively from about 800 m 2 /g to about 2000 m 2 /g or alternatively from about 1000 m 2 /g to about 2000 m 2 /g. In an aspect, an AGC of the type disclosed herein may exhibit a gravimetric storage density for light gases (e.g., H 2 , C2H4) of equal to or greater than about 2 wt.%, alternatively from about 2 wt.% to about 15 wt.%), alternatively from about 5 wt.%> to about 10 wt.%> or alternatively from about 5 wt.%) to about 10 wt.%) based on the total weight of the AGC at pressures equal to or less than about 500 psi and temperatures equal to or greater than about 77K.

[0038] In an aspect, a carbonaceous material of the type disclosed herein is modified to be associated with one or more chemically functionalities such that the material is selectively adsorbent and is hereinafter designated a selectively adsorbent carbon (SAC). A SAC of the present disclosure may be functionalized to include one or more chemical groups that promote association of the material with one or more specified gaseous materials. In an aspect, a method of preparing the SAC comprises (i) contacting a carbonaceous material of the type disclosed herein with a reaction medium containing a solvent and a functional group (hydroxyl) to form a reaction mixture (ii) exposing the reaction mixture to ultrasonic energy under conditions sufficient associate the functional group with the carbonaceous material forming a reaction product comprising a SAC; and (iii) recovering the reaction products. As will be understood by one of ordinary skill in the art, the reaction mixture subjected to acoustic cavitation in liquids may associate with the carbonaceous material.

[0039] In an aspect, the reaction medium is exposed to ultrasonic energy having a frequency of equal to or greater than about 20 kilo Hertz (kHz), alternatively greater than about 25 kHz, alternatively greater than about 30 kHz, alternatively greater than about 35 kHz, alternatively greater than about 40 kHz, alternatively greater than about 40 kHz, alternatively greater than about 45 kHz, or alternatively greater than about 50 kHz.

[0040] In an aspect, the molecules/moieties may be associated with the SAC (such that these moieties are distributed throughout the surface and/or interior of the SAC. Without wishing to be bound by theory the presently disclosed methodology contemplates the ultrasonic production of areas of high and low pressure on the surface of the carbonaceous material resulting the deformation of pores in response to the acoustic energy (e.g., an accordion effect) in the affected dimensions and geometries of substrate surface. Simultaneously the mass transfer momentum of the acoustic energy wave moves the precursor molecules in a wave-like fashion toward the carbon surface essentially driving the precursor molecules toward the pores of the carbonaceous material. Subsequently, the precursor molecule experiences local micro-level compression and distortion from dynamically-deforming synthetic carbon particles that produce a high probability of chemical bonding between the surface of the carbonaceous material and precursor molecules as the reaction distances are dramatically reduced during the compression cycles. Additionally, other reactive sites on the surface of the carbonaceous material become exposed during the expansion cycles. Trapped and bounded precursor molecules experience redistribution of electron densities within a molecule, as some of the inner-molecule shared electrons become involved in covalent bounding with the surface of the carbonaceous material. This distortion of the inner molecules' electronic field opens opportunities for a variety of additional chemical bonding with external molecules in relation to the surface of the carbonaceous material where bound precursor perform the function of an anchored interface between external functional molecules and the surface of the carbonaceous material.

[0041] In an aspect, the moieties associated with the SAC are chemically reactive. Herein "chemically reactive" refers to the ability of the moieties associated with the SAC to be further chemically modified to include one or more functional groups and generate a functionalized reaction product that associates with some user and/or process-desired molecule. By

"functionalized reaction product" is meant that the reaction product is contacted with a functional group, and optionally a catalyst, heat, initiator, or free radical source to cause all or part of the functional group to incorporate, graft, bond to, physically attach to, and or chemically attach to the SAC. The functional group may be a compound containing a heteroatom, such as nialeic anhydride. Nonlimiting examples of functional groups include organic acids, organic amides, organic amines, organic esters, organic anhydrides, organic alcohols, organic acid halides (such as acid chlorides, acid bromides, etc.) organic peroxides, Examples of suitable functional groups include unsaturated carboxylic acids, esters of the unsaturated carboxylic acids, acid anhydrides, di-esters, salts, amides, imides, aromatic vinyl compounds hydrolyzable unsaturated siiane compounds and unsaturated halogenated hydrocarbons. Other nonlimiting examples of unsaturated carboxylic acids and acid derivatives include, but are not limited to maleic anhydride, citraconic anhydride, 2 -methyl maleic anhydride, 2-chloromaleic anhydride, 2,3-dimethyimaleic anhydride, bicyclo[2,2,l]-5-heptene-2,3-dicarboxylic anhydride and 4- methyl-4-cyclohexene-l,2-di carboxylic anhydride, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, crotonic acid, bicyclo(2.2.2)oct-5- ene-2,3-dicarboxylic acid anhydride, l,2,3,4,5,&g, lo-octahydronaphthalene-2,3-dicarboxylic acid anhydride, 2-oxa- 1 ,3-diketospiro(4.4)non-7-ene, bicycio(2.2. l)hepl~5~ene~2,3- di carboxylic acid anhydride, maleopimaric acid, tetrahydrophtalic anhydride, norbom-5-ene- 2,3-dicarboxylie acid anhydride, nadic anhydride, methyl nadic anhydride, himic anhydride, methyl himic anhydride, and x-methyl-bicycio(2.2.1)hept-5-ene-2,3-dicarboxylic acid anhydride (XMNA). Nonlimiting examples of the esters of the unsaturated carboxylic acids include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate and the like.

[0042] I an aspect, a SAC of the type disclosed herein has chemical functionalities associated with greater than about 2 percent of the surface area of the carbonaceous material, based on the total surface area of the carbonaceous material, alternatively greater than about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, or 75%. In an alternative aspect, a SAC of the type disclosed herein has chemical functionalities associated with from about 2 % to about 80% of the surface area of the carbonaceous material, alternatively from about 5 % to about 70% or alternatively from about 10% to about 25%. In an aspect, the chemical functionality is selected from the group consisting of a hydroxy! group, an amine group, a carboxyiate, an ester, an ether, an aldehyde and a ketone.

[0043] In some aspects, the SAC is formulated to provide a gas storage density of from about 5 wt.%) to about 50 wt.%> , alternatively from about 5 wt.%> to about 40 wt.%> or alternatively from about 5 wt.%> to about 20 wt.%> for gases such as methane, hydrogen, ethane, carbon monoxide, carbon dioxide, propane, or combinations thereof wherein the weight percent is based on the total weight of the AGC.

[0044] An AGC once prepared comprises the carbonaceous material and at least one gas. An aspect of the present disclosure contemplates the production of an AGC wherein a carbonaceous material has adsorbed a gas (e.g., a hydrocarbon gas, such as for example methane). In some aspects, the adsorption is selective such that the carbonaceous material selectively adsorbs the gas of interest. For example, a method of the present disclosure can be practiced by contacting a gas mixture (e.g., carbon dioxide and methane) and the adsorbent material which selectively adsorbs one of the gases to form an AGC of the type disclosed herein. Subsequently, the AGC may be treated (e.g., exposed to reduced pressure) to release one or more of the gases.

[0045] It is to be understood that although a carbonaceous material of the type disclosed herein adsorbs differing gases, the strengths of interaction between any particular gas and adsorbent material may vary. It is contemplated that in some aspects, the strength of interaction of a gas with the adsorbent material is sufficient to allow the adsorbent material to "capture" an amount of gas that meets some user/process goal but also affords low isoteric heats of adsorption, thereby reducing the amount of energy required to drive off the captured gas and regenerate the vacated adsorbent material. The weak interaction between a carbonaceous material of the type disclosed herein and a gas is thus advantageous when compared to the formation of chemical bonds which would require a substantial amount of energy to vacate the gas from the adsorbent material. In some aspects, there may be applications for the adsorbent materials and AGCs of this disclosure in industrial scale capture and separation of gases due to the potentially significant energy savings available. The present disclosure also contemplates a SAC where the strengths of the interactions between the carbonaceous material and gas may be increased as a result of modification of the carbonaceous material to include functionalities that selectively adsorb a particular gas or type of gas.

[0046] In an aspect, a method of the present disclosure comprises the capture of one or more gases of interest by carbonaceous materials of the type disclosed herein to form an AGC and subsequent release of the captured gases by the AGC. In such methods, release of the captured gases from the AGC results in regeneration of the adsorbent material which may be used for capture of additional gases and thus formation of another AGC. For purposes of further illustration and not limitation, the method disclosed herein can be practiced to carry out the a pressure swing adsorption (PSA) process wherein a component of a mixture comprising at least one gas is selectively adsorbed by the carbonaceous material at relatively high pressure followed by a reduction in pressure for desorption to regenerate the material and release the gas. In some aspects, the released gas can be compressed for storage or transport. In an alternative aspect, release of a gas present in an AGC may be triggered by thermal changes. For example, absorption of a gas to form an AGC may occur at temperatures of equal to or less than about 25 °C and release of said gas from the AGC may result from increasing the temperature to temperatures of greater than about 25 °C.

[0047] For purposes of illustration and not limitation, the AGC can be used to separate carbon dioxide from a gas mixture that includes carbon dioxide and methane, propane and/or propylene. Substantially reversible carbon dioxide adsorption on and desorption from the AGC can occur in practice of the PSA process and others. Thus, the present disclosure provides compositions (i.e., AGC) and methods that may be advantageous for the selective removal of carbon dioxide from natural gas, landfill gas, and other gas mixtures of C0 2 and CH4.

[0048] Release of the gas from the AGC may be carried out using any suitable methodology. In one aspect, at least a portion of the gas is released from an AGC using a pressure differential such that a gas is associated with the AGC at pressures of equal to or greater than about 14 psi, alternatively greater than about 100 psi, alternatively greater than about 500 psi and is released when the pressure is lowered to less than about 100 psi, alternatively less than about 50 psi, less than about 14 psi or alternatively less than about 10 psi. In an alternative aspect, gas release from an AGC may be the result of a thermal treatment such that an AGC comprising a gas at a temperature of equal to or less than about 25 °C, alternatively less than about 0 °C or alternatively less than about -10 °C releases at least a portion of the gas at a temperature of equal to or greater than about 25 °C, alternatively equal to or greater than about 0 °C, or alternatively equal to or greater than about -10°C. In any of the aspects disclosed herein, release of a gas from an AGC can be carried out to provide release of from about 10% to about 99% of the gas stored by the AGC, alternatively from about 25% to about 99% of the gas stored by the AGC or alternatively from about 50% to about 75% of the gas stored by the AGC.

[0049] Nonlimiting examples of processes that may employ an AGC of the type disclosed herein include power generation, iron and steel production, ammonia production, battery electrodes, cement production, natural gas sweetening, syngas gas purification, and gas separation.

[0050] AGCs of the present disclosure may also be formed to capture Volatile Organic

Compounds (VOCs). For example, anaesthetic systems utilize a rebreather system in which C0 2 is scrubbed from the anaesthetic gas during the cycling of the gas. Currently soda lime is used in this process. An adsorbent material of the present disclosure may be used for scrubbing the

C0 2 from the recycled gas and thus may facilitate the reduction of medical/chemical waste as soda lime has a finite life and, once depleted, it is disposed of as contaminated waste.

[0051] The AGC may also find utility in diving rebreathers (i.e. SCUBA); personal protective equipment (PPE), gas masks etc. (acidic gas scrubbing); military applications (PPE, gas scrubbing air in closed environments e.g. bunkers, submarines etc.), and driving the water gas shift to completion for more efficient production of hydrogen from CO and water.

[0052] The following enumerated aspects are provided as non-limiting examples:

[0053] A first aspect which is an adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m 2 /g and a gas.

[0054] A second aspect which is the construct of the first aspect wherein the carbonaceous material has a multimodal pore size distribution.

[0055] A third aspect which is the construct of any of the first through second aspects wherein the carbonaceous material has at least two distributions of mesoporous pore sizes with a first population having a mesoporous pore size denoted x and a second population having a mesoporous pore size denoted y where the carbonaceous material provides a mixture having a ratio of x/y of about 1. [0056] A fourth aspect which is the construct of the third aspect wherein the pore size of the first population is approximately twice the pore size of the second population.

[0057] A fifth aspect which is the construct of any of the first through fourth aspects wherein the gas comprises ethane, isomers of xylene, methane, nitrogen, hydrogen, carbon monoxide, carbon dioxide, argon, oxygen, tetrafluorocarbon, sulfur hexafluoride or combinations thereof.

[0058] A sixth aspect which is the construct of any of the first through fifth aspects having a gas gravimetric storage density of greater than about 2 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C.

[0059] A seventh aspect which is the construct of any of the first through fifth aspects having a gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C wherein the light gas comprises hydrogen.

[0060] An eighth aspect which is the construct of any of the first through fifth aspects having a light gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C wherein the light gas comprises methane.

[0061] A ninth aspect which is the construct of any of the first through fifth aspects having a light gas gravimetric storage density of from about 2 wt,% to about 15 wt.% based on the total weight of the construct at pressures of equal to or less than about 100 psi and temperatures equal to or greater than about 25 °C wherein the light gas comprises carbon dioxide.

[0062] A tenth aspect which is a battery component comprising the construct of any of the first through sixth aspects.

[0063] An eleventh aspect which is a gas purification system comprising the construct of any of the first through sixth aspects.

[0064] A twelfth aspect which is an adsorbed gas construct comprising a carbonaceous material having a surface area of equal to or greater than about 500 m 2 /g and a gas wherein the carbonaceous material has a chemical functionality associated with from about 2% to about 80%) of a surface area of the carbonaceous material. [0065] A thirteenth aspect which is the construct of the twelfth aspect wherein the chemical functionality is selected from the group consisting of a hydroxyl group, an amine group, a carboxylate, an ester, an ether, an aldehyde and a ketone.

[0066] A fourteenth aspect which is a gas separation system comprising the construct of the twelfth aspect.

[0067] A fifteenth aspect which is a method comprising contacting a carbonaceous material with a first gas composition to produce an adsorbed gas construct and desorbing at least a portion of the first gas composition from the adsorbed gas construct to regenerate at least a portion of the carbonaceous material.

[0068] A sixteenth aspect which is the method of the fifteenth aspect wherein the first gas composition comprises a mixture of two or more gases.

[0069] A seventeenth aspect which is the method of any of the fourteenth through fifteenth aspects wherein desorbing releases at least a portion of one of the mixture of gases.

[0070] An eighteenth aspect which is the method of the sixteenth aspect wherein desorbing releases from about 10 wt.% to about 99 wt.% of the one of the mixture of gases based on the total weight of the one of the mixture of gases absorbed.

[0071] A nineteenth aspect which is the method of any of the fifteenth through eighteenth aspects wherein desorbing at least a portion of the first gas composition comprises thermally treating the construct to a temperature of equal to or greater than about 25 °C .

[0072] A twentieth aspect which is the method of any of the fifteenth through nineteenth aspects wherein desorbing at least a portion of the first gas composition comprises reducing the pressure on the construct to less than about 100 psi.

[0073] In addition to the various aspects depicted and claimed, the disclosed subject matter is also directed to other aspects having any other possible combination of the features disclosed and claimed herein. As such, the particular features presented herein can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter includes any suitable combination of the features disclosed herein. Thus, the foregoing description of specific aspects of the disclosed subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those aspects disclosed. [0074] It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed subject matter without departing from the spirit or scope of the disclosed subject matter. Thus, it is intended that the disclosed subject matter include modifications and variations that are within the scope of the appended claims and their equivalents. For the purpose of any U.S. national stage filing from this application, all publications and patents mentioned in this disclosure are incorporated herein by reference in their entireties, for the purpose of describing and disclosing the constructs and methodologies described in those publications, which might be used in connection with the methods of this disclosure. Any publications and patents discussed above and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

[0075] Unless indicated otherwise, when a range of any type is disclosed or claimed, for example a range of the number of carbon atoms, molar ratios, temperatures, and the like, it is intended to disclose or claim individually each possible number that such a range could reasonably encompass, including any sub-ranges encompassed therein. Moreover, when a range of values is disclosed or claimed, which Applicants intent to reflect individually each possible number that such a range could reasonably encompass, Applicants also intend for the disclosure of a range to reflect, and be interchangeable with, disclosing any and all sub-ranges and combinations of sub-ranges encompassed therein. Accordingly, Applicants reserve the right to proviso out or exclude any individual members of any such group, including any sub-ranges or combinations of sub-ranges within the group, if for any reason Applicants choose to claim less than the full measure of the disclosure, for example, to account for a reference that Applicants are unaware of at the time of the filing of the application.

[0076] In any application before the United States Patent and Trademark Office, the Abstract of this application is provided for the purpose of satisfying the requirements of 37 C.F.R. § 1.72 and the purpose stated in 37 C.F.R. § 1.72(b) "to enable the United States Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure." Therefore, the Abstract of this application is not intended to be used to construe the scope of the claims or to limit the scope of the subject matter that is disclosed herein. Moreover, any headings that can be employed herein are also not intended to be used to construe the scope of the claims or to limit the scope of the subject matter that is disclosed herein. Any use of the past tense to describe an example otherwise indicated as constructive or prophetic is not intended to reflect that the constructive or prophetic example has actually been carried out.




 
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