Patent classifications
C01B32/306
Vinylidene chloride copolymer-based carbon molecular sieve adsorbent compositions and processes therefor
Novel carbon molecular sieve (CMS) compositions comprising carbonized vinylidene chloride copolymer having micropores with an average micropore size ranging from 3.0 to 5.0. These materials offer capability in separations of gas mixtures including, for example, propane/propylene; nitrogen/methane; and ethane/ethylene. Such may be prepared by a process wherein vinylidene chloride copolymer beads, melt extruded film or fiber are pretreated to form a precursor that is finally carbonized at high temperature. Preselection or knowledge of precursor crystallinity and attained maximum pyrolysis temperature enables preselection or knowledge of a average micropore size, according to the equation ?=6.09+(0.0275?C)?(0.00233?T), wherein ? is the average micropore size in Angstroms, C is the crystallinity percentage and T is the attained maximum pyrolysis temperature in degrees Celsius, provided that crystallinity percentage ranges from 25 to 75 and temperature in degrees Celsius ranges from 800 to 1700. The beads, fibers or film may be ground, post-pyrolysis, and combined with a non-coating binder to form extruded pellets, or alternatively the fibers may be woven, either before or after pre-treatment, to form a woven fiber sheet which is thereafter pyrolyzed to form a woven fiber adsorbent.
Vinylidene chloride copolymer-based carbon molecular sieve adsorbent compositions and processes therefor
Novel carbon molecular sieve (CMS) compositions comprising carbonized vinylidene chloride copolymer having micropores with an average micropore size ranging from 3.0 to 5.0. These materials offer capability in separations of gas mixtures including, for example, propane/propylene; nitrogen/methane; and ethane/ethylene. Such may be prepared by a process wherein vinylidene chloride copolymer beads, melt extruded film or fiber are pretreated to form a precursor that is finally carbonized at high temperature. Preselection or knowledge of precursor crystallinity and attained maximum pyrolysis temperature enables preselection or knowledge of a average micropore size, according to the equation ?=6.09+(0.0275?C)?(0.00233?T), wherein ? is the average micropore size in Angstroms, C is the crystallinity percentage and T is the attained maximum pyrolysis temperature in degrees Celsius, provided that crystallinity percentage ranges from 25 to 75 and temperature in degrees Celsius ranges from 800 to 1700. The beads, fibers or film may be ground, post-pyrolysis, and combined with a non-coating binder to form extruded pellets, or alternatively the fibers may be woven, either before or after pre-treatment, to form a woven fiber sheet which is thereafter pyrolyzed to form a woven fiber adsorbent.
METHOD FOR PRODUCING POROUS CARBON MATERIAL AND SPHERICAL POROUS CARBON MATERIAL
A novel method for producing a porous carbon material which makes it possible to easily produce a porous carbon material having a desired shape; and a spherical porous carbon material are provided. The method includes immersing a carbon-containing material having a desired shape and composed of a compound, alloy or non-equilibrium alloy containing carbon in a metal bath, the metal bath having a solidification point that is lower than a melting point of the carbon-containing material, the metal bath being controlled to a lower temperature than a minimum value of a liquidus temperature within a compositional fluctuation range extending from the carbon-containing material to carbon by decreasing the other non-carbon main components, to thereby selectively elute the other non-carbon main components into the metal bath while maintaining an external shape of the carbon-containing material to give a porous carbon material having microvoids.
CHEMICAL SAMPLING IN HIGH WATER ENVIRONMENTS
The system and method of using carbide derived carbon as a sorbent material in high humidity environments. In some cases, the sorbent material is used for breath analysis. In some cases, the sorbent material is used in a gas mask. In certain cases, the sorbent material is functionalized for detection or capture of particular chemicals.
Porous carbon material, composite material reinforced with carbon material, porous carbon material precursor, porous carbon material precursor production method, and porous carbon material production method
A carbon material having a continuous porous structure oriented to the stretching axis is provided, which carbon material can be used as a structural material excellent in interfacial adhesion. The porous carbon material has a continuous porous structure in at least a portion thereof, in which the continuous porous structure has an orientation degree measured by a small-angle X-ray scattering method or an X-ray CT method of 1.10 or more.
Porous carbon material, composite material reinforced with carbon material, porous carbon material precursor, porous carbon material precursor production method, and porous carbon material production method
A carbon material having a continuous porous structure oriented to the stretching axis is provided, which carbon material can be used as a structural material excellent in interfacial adhesion. The porous carbon material has a continuous porous structure in at least a portion thereof, in which the continuous porous structure has an orientation degree measured by a small-angle X-ray scattering method or an X-ray CT method of 1.10 or more.
Carbon Molecular Sieve Adsorbents Prepared From Activated Carbon and Useful For Propylene-Propane Separation
A process to prepare a carbon molecular sieve adsorbent composition comprises steps beginning with an activated carbon having specific effective micropore size. The activated carbon is impregnated with monomers or partially polymerized polymer, allowed to complete polymerization, and then carbonized such that the impregnant shrinks the micropores to another specific effective micropore size. Finally, the impregnated/polymerized/carbonized product is annealed at a temperature ranging from 1000? C. to 1500? C., which ultimately and predictably shrinks the micropores to a size ranging from 4.0 Angstroms to 4.3 Angstroms. The invention surprisingly enables fine tuning of the effective micropore size, as well as desirable selectivity, capacity and adsorption rates, to obtain highly desirable carbon molecular sieving capability particularly suited for use in, for example, fixed beds in pressure swing or temperature swing processes to enable propylene/propane separations.
Mesoporous Activated Carbon
Mesoporous activated carbon having a mesopore structure of at least about 10%. In at least some embodiments, the activated carbon may be coconut shell-based. The enhanced activated carbon may have an intraparticle diffusion constant of at least about 40 mg/g/hr.sup.1/2.
Mesoporous Activated Carbon
Mesoporous activated carbon having a mesopore structure of at least about 10%. In at least some embodiments, the activated carbon may be coconut shell-based. The enhanced activated carbon may have an intraparticle diffusion constant of at least about 40 mg/g/hr.sup.1/2.
Process for preparing a microporous carbon material and its use as absorption product
The invention relates a process for preparing a microporous carbon material comprising the following steps: i) providing a cross-linked polymer obtainable by reacting either A1) a maltodextrin deriving from starch comprising amylose in the range from 25 to 50% expressed as dry weight relative to the dry weight of the starch or A2) a cyclodextrin with an organic aromatic dianhydride in a mass ratio of either maltodextrin or cyclodextrin with respect to the organic aromatic dianhydride in the range of 1:0.50 to 1:2, ii) pyrolyzing at a range from 700 to 900 C. with a heating ramp in the range from 5 C./min to 30 C./min in a inert gas flux; and iii) cooling the obtained residue. The microporous carbon material obtainable by the process of the invention consists of micropores having pore size distribution in the range from about 6 to about 16 and is used as absorber for liquids and gases.