Carbon material manufacturing process

FIELD: carbon materials.

SUBSTANCE: powderlike catalyst is continuously fed into tubular reactor and displaced along reactor axis. Following composition of catalyst can be used: 70-90% Ni and 10-30% MgO or 40-60% Co and 40-60% Al2O3, or Mo, Co, and Mg at molar ratio 1:5:94, respectively. Process is carried out continuously at countercurrent catalyst-hydrocarbon contact. In the first zone(s) catalyst is activated by gases leaving hydrocarbon pyrolysis at 450-600°C. Residence time of catalyst ranges from 5 to 180 min. Activated catalyst is passed into pyrolysis zone(s) at 550-1000°C. Into the same zone(s), hydrocarbons, e.g. methane, are countercurrently passed. Residence time of catalyst in pyrolysis zone(s) ranges from 0.5 to 180 min. Invention can be used in sorbent, catalyst, and composite manufacturing processes.

EFFECT: enabled continuous manufacture of layered nanotubes or bent hollows fibers, reduced number of stages and consumption of reagents.

4 cl, 2 dwg, 7 ex

 

The invention relates to the field of chemical industry, in particular to catalytic method for the production of carbon materials from hydrocarbons. It can be used in the production of sorbents, catalysts, composites.

A method of obtaining a carbon material by pyrolysis of ethylene in the mixture with hydrogen on the catalyst Fe-SiO2in the fluidized-bed reactor [D.Venegoni et al. Carbon, 40, 2002, 1799-1808]. The pyrolysis is carried out at temperatures 550-1050°C. the Disadvantages of this method are the need for preliminary recovery of the catalyst in a stream of H2or its mixtures with other gases, a strong increase of the initial particle size and the volume of a layer that impedes continuous process, not a counter-current movement phases in simple reactors.

A method of obtaining a carbon material by pyrolysis of hydrocarbons at temperatures in the range of 400-3000°in the presence of 0.01-5 wt.% volatile ORGANOMETALLIC catalyst [US Patent 4816289, class D 01 C 5/00]. The resulting product is a carbon fiber with a diameter of 0.1-4.0 μm. The disadvantages of this method is the low value of the specific yield (the number of carbon product formed per unit mass of catalyst) at high cost, some original to the components.

The closest in technical essence and the achieved result is a method that considered further as a prototype [RF Patent №2146648, IPC701 In 31/02].

In accordance with the prototype process for the production of carbon nanotubes are, decomposing methane in vibramicina layer of granular iron-cobalt catalyst, at a temperature not higher than 650°C. the Catalyst contains 25-85 wt.% iron, 5-75 wt.% cobalt, the rest is aluminum oxide. The process is carried out for 17 h to completely deactivate the catalyst. Vibrosignal the catalyst bed to create in order to prevent agglomeration, leading to deactivation of the catalyst, the heterogeneity of the carbon particles and to improve the uniformity of the heating of the catalyst. The main disadvantages of the described method of producing carbon nanotubes following:

1) the periodicity of the way, due to the need to load portions of fresh catalyst and removing from the reactor the resulting product.

2) a multi-stage, which is caused by the need for prior activation of the catalyst prior to use.

3) Increased consumption of reagents due to the need to pre-activate the catalyst.

The present invention is the production of carbon materials in continuous mode, the reduction of the number of stages of the process and reagent consumption.

The problem is solved by a method of obtaining a carbon material by pyrolysis of hydrocarbons at elevated temperatures in the catalyst containing transition metals, in continuous countercurrent moving catalyst layer and a gas stream in two or more temperature zones in one or more of which at a temperature of 450-600°conduct activating catalyst exhaust after pyrolysis gases, when the residence time of the catalyst 5-180 min, and the other or the other zones at a temperature of 550-1000°To carry out the pyrolysis of hydrocarbons, when the residence time of the catalyst in this or these areas 0.5-180 minutes added advantage in organization backflow is that partial heating of the catalyst is carried out of the exhaust after pyrolysis gases. The simplification lies in the exclusion of the pre-activated catalyst with hydrogen, because hydrogen is a product of pyrolysis and countercurrent contacting the exhaust gases with fresh catalyst activates the catalyst in the zone where the required temperature and maintain the necessary residence time of the catalyst. Reducing the consumption of reagents is achieved by special exception the pre-activated catalyst. An additional advantage is one the Xia, when countercurrent contacting and organizing multiple temperature zones achieved a higher degree of use of the original hydrocarbons.

The morphology obtained in the reactor, the carbon material mainly depends on the choice of catalyst, the conditions of the pyrolysis temperature, flow rate, gas phase and its composition).

The method can be implemented in a horizontal or inclined at a small angle to the horizon reactors, where the movement of solid material can be effected by vibration of the retort reactor, using auger or conveyor belt. An additional advantage of the last method move is that it can be used for growing the carbon material on the finished substrate. The method can be implemented in a vertical shelf reactors when applying the above catalyst and hydrocarbon from the bottom, and partitioned fluidized bed reactors.

The invention is illustrated by the following examples.

Example 1. At the end of the tubular reactor inner diameter of 54 mm and a length of 1000 mm continuously with a speed of 0.6 g/h serves a powdery catalyst composition Nickel 90 wt.%, magnesium oxide 10 wt.%, which move along the axis of the reactor. The original catalyst restore in the zone is activated at a temperature of 00° With in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 10 minutes Activated catalyst is fed to the pyrolysis zone at a temperature of 600°where the other end of the reactor countercurrent to a flow rate of 750 cm3/min serves methane, which is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 30 minutes, the Degree of conversion of methane to 40-45%. Unreacted methane and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously withdrawn from the reactor and separated from the catalyst by dissolving the catalyst in dilute nitric acid. Performance on the purified material to 10 g/H. the resulting product is a curved hollow fiber with a diameter of 20-60 nm with a tapered walls and a specific surface area of about 100 m2/year

Example 2. The conditions of the experiment are different from the conditions in the example 1 in that the pyrolysis zone is divided into two zones with a temperature of 600 and 700°C, the temperature increases in the direction of the current of gas. The degree of conversion of methane 55-60%. Performance on the purified material up to 15 g/H. the resulting product is a curved hollow fiber with a diameter of 20-60 nm with a tapered walls and a specific surface area of about 100 m2/year

Example 3. In the context of the t tubular reactor with an inner diameter of 54 mm and a length of 1000 mm continuously served powdery catalyst composition of cobalt 60 wt.%, aluminum oxide 40 wt.%, which move along the axis of the reactor. The original catalyst restore in the zone is activated at a temperature of 550°in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 10 minutes Activated catalyst is fed to the pyrolysis zone to a temperature of 700°where the other end of the reactor countercurrent to a flow rate of 900 cm3/min serves methane, which is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 30 minutes Unreacted methane and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously withdrawn from the reactor and separated from the catalyst by dissolving the catalyst in dilute hydrochloric acid. The resulting product is a multilayer nanotube diameter 12-25 nm (figure 1).

Example 4. At the end of the tubular reactor inner diameter of 54 mm and a length of 1000 mm continuously served powdered catalyst with a molar ratio of Mo:Co:Mg=1:5:94, which moves along the axis of reactor. The original catalyst restore in the zone is activated at a temperature of 600°in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 10 minutes Activated catalyst is fed to the pyrolysis zone with the pace of what atural 1000° With where the other end of the reactor countercurrent to a flow rate of 750 cm3/min serves a mixture of hydrogen and methane in a ratio of 4:1. Methane is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 5 minutes Unreacted methane and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously withdrawn from the reactor and separated from the catalyst by dissolving the catalyst in dilute hydrochloric acid. The resulting product is a mixture of carbon nanotubes (single-, two-, three - and four-layer) and nanofibers (figure 2). The outer diameter of the double-layer nanotubes varies between 1.8-6.7 nm, outer diameter of three - and four-layer nanotubes, respectively in the range 2.6-6.2 and 4.0-7.7 nm. The specific surface of the product is about 400 m2/year

Example 5. At the end of the tubular reactor inner diameter of 54 mm and a length of 1000 mm continuously served powdery catalyst composition of cobalt 60 wt.%, aluminum oxide 40 wt.%, which move along the axis of the reactor. The original catalyst restore in the zone is activated at a temperature of 550°in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 20 minutes Activated catalyst is fed to the pyrolysis zone to a temperature of 750°where from the other end the reactor countercurrent to a flow rate of 750 cm 3/min serves ethylene, which is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 30 minutes Unreacted ethylene and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously withdrawn from the reactor and separated from the catalyst by dissolving the catalyst in dilute hydrochloric acid. The resulting product is a multilayer nanotubes with a diameter of 15-25 nm.

Example 6. At the end of the tubular reactor inner diameter of 54 mm and a length of 1000 mm continuously served powdery catalyst composition of cobalt 60 wt.%, aluminum oxide 40 wt.%, which move along the axis of the reactor. The original catalyst restore in the zone is activated at a temperature of 550°in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 15 minutes Activated catalyst is fed to the pyrolysis zone to a temperature of 700°where the other end of the reactor countercurrent to a flow rate of 750 cm3/min serves a mixture of acetylene (10%) with argon. Acetylene is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 30 minutes Unreacted acetylene, argon and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously output of treactor and separated from the catalyst by dissolving the catalyst in dilute hydrochloric acid. The resulting product is a multilayer nanotubes with a diameter of 10-15 nm.

Example 7. At the end of the tubular reactor inner diameter of 54 mm and a length of 1000 mm continuously served powdery catalyst composition of cobalt 60 wt.%, aluminum oxide 40 wt.%, which move along the axis of the reactor. The original catalyst restore in the zone is activated at a temperature of 550°in a stream of hydrogen produced in the pyrolysis zone, the residence time of the catalyst in the zone is activated 15 minutes Activated catalyst is fed to the pyrolysis zone to a temperature of 900°where the other end of the reactor countercurrent to a flow rate of 750 cm3/min serves a mixture of benzene (10 vol.%) with argon. Benzene is partially decomposed to carbon and hydrogen, when the residence time of the catalyst in the pyrolysis zone 15 minutes Unreacted benzene, argon and hydrogen is removed from the reactor. The resulting carbon material together with the catalyst is continuously withdrawn from the reactor and separated from the catalyst by dissolving the catalyst in dilute hydrochloric acid. The resulting product is a multilayer nanotubes with a diameter of 20-30 nm.

1. A method of obtaining a carbon material by pyrolysis of hydrocarbons when heated catalyst containing transition metals, wherein the process is conducted continuously privatisation the contacting of the catalyst and hydrocarbons in two or more temperature zones, in one or more of which at a temperature of 450÷600°conduct activating catalyst exhaust after pyrolysis gases at the time of catalyst 5÷180 min, and the other or the other zones at a temperature of 550÷1000°To carry out the pyrolysis of the hydrocarbon residence time of the catalyst in this or these areas of 0.5÷180 minutes

2. A method of obtaining a carbon material according to claim 1, characterized in that the use of a catalyst containing, wt.%:

Nickel70÷90
Magnesium oxide10÷30

3. A method of obtaining a carbon material according to claim 1, characterized in that the use of a catalyst containing, wt.%:

Cobalt40÷60
Aluminium oxide40÷60

4. A method of obtaining a carbon material according to claim 1, wherein the used catalyst with a molar ratio Mo:Co:Mg=1:5:94.



 

Same patents:

FIELD: electrode making industry branch, metallurgy.

SUBSTANCE: method comprises steps of baking hard carbon- containing material such as thermoanthracite, anthracite, coke, breaking them and treating in vapors of coal tar separated from liquid phase of heavy coal-tar products whose mass consists 25 -30 % of mass of hard carbon- containing materials; sieving treated carbon-containing materials, metering them and mixing with binder for 3 - 5 min at 140-180°C; shaping briquettes of melt electrode mass. Self-firing electrodes made of composition according to invention features next characteristics: density, 1.71 - 1.98 g/cm3; specific electric resistance, 73.3 - 81.4 Ohm mm2/m, compression strength, 34.1 - 35.2 MPa.

EFFECT: enhanced properties of electrodes.

3 cl, 1 tbl, 6 ex

FIELD: carbon materials.

SUBSTANCE: reaction space is evacuated and filled with helium to pressure 0.1-0.4 atm, coaxial graphite electrodes are brought together to ignite electric arc between them, and graphite is evaporated at voltage 40-60 v and current intensity 250-400 A. Simultaneously, electrodes are continuously affected by video pulse packets characterized by duration 2·10-4-2·10-3 s, relative pulse duration in packet 10-100, and power 1-15 W. Resulting products are moved in helium flow and precipitated in carbon black collector in the form of fullerene-containing carbon black. To remove carbon black from inner surfaces of working chamber and carbon black collector, the surfaces are affected by alternate-polarity pulses with repetition frequency 50-500 Hz and power 1-10 W. To remove fragments of destroyed graphite rods and cathode deposit scoria from chamber space to bottom part of working chamber, pulse magnetic field with frequency 3-15 Hz and magnetic induction 0.05-0.1 Tl.

EFFECT: increased content of fullerenes in carbon black and reduced power consumption.

3 cl

FIELD: metallurgy.

SUBSTANCE: solid carbon materials are calcined at 1200-1300°C, crushed, riddled, dosed, and mixed with binder for 3-5 min at 140-180°C. Following amounts of ingredients are employed: 23-57% thermoanthracite, 25-55% iron coke, and coal-tar pitch in balancing amount. Molten electrode mass is treated to mold briquettes. Carbon electrodes made from mass according to invention show resistance 83.9-96.4 Ohm*mm2/m and conductivity 2.6-4.8 W/m*deg.

EFFECT: improved performance characteristics.

2 tbl

FIELD: aircraft industry, power production.

SUBSTANCE: carbon-carbonic material is impregnated with mixture, containing potassium hydrophosphate, manganese hydrophosphate, phosphoric acid and water in mass ratio of (0.5-0.7):(1.0-2.8):(1.8-2.2):(10-50), respectively. Then material is dried and heat treated with temperature rising rate of 15-20°C/h up to 650-700°C to produce 2.0-5.0 mass % of ultraphosphate as calculated to starting material weight. Dried material is cooled, impregnated with mixture of furfuryl alcohol and phenol-phormaldehyde resin in mass ratio of (8.0-9.0):(1.2-2.0), respectively, heat treated again with temperature rising rate of 8-20°C/h up to 280-350°C to produce solid residual content of 0.5-5.0 mass %. Method of present invention makes it possible to reduce oxidative losses when heating at 600°C in air up to 0.1-0.25 %/h and to obtain material with compressive resistance of 120-150 MPa and long-term serviceability at 520-550°C.

EFFECT: decreased oxidation losses; material with increased compressive resistance and serviceability.

1 tbl, 5 ex

FIELD: metallurgy, aircraft industry, power engineering, semiconductor technique.

SUBSTANCE: plate tar cake is ground to produce fractional makeup having at least 97 mass % of <0.09 mm-fraction and at least 91 % of <0.045 mm-fraction. Grinded cake is mixed with 35-40 % of coal-tar asphalt and 0.015-1.5 mass % of organic additive at 120-130°C. As organic additive space-hindered phenols and/or phenylphosphites are used. Obtained mass is formed, cooled and crushed followed by pressing to produce semimanufactured article with density of1.01-1.06 g/cm3. Said articles are sintered at 800-1300°C and black-leaded at 3000°C. Finished black-leaded material has bulk density of 1760-1950 kg/cm3, compression strength of 90-105 MPa and blending strength of 60-75 MPa. Material of present invention is useful in production of electrodes, seal assembly and material of high purity.

EFFECT: black-leaded material with improved physical characteristics.

1 tbl, 10 ex

The invention relates to the field of technologies for producing fullerenes - cluster compounds of carbon that are used to develop new drugs, obtaining diamond films, new, clean, power sources, composite materials, etc
The invention relates to a method of granulating carbon-containing materials, in particular fullerensoderzhashchikh songs
The invention relates to the field of production of fullerene - new allotropic modifications, is a hollow spherical clusters of carbon atoms with the number of atoms in the molecule from 28 to 540

FIELD: production of new materials.

SUBSTANCE: proposed nanocomposite can be used as component contributing to charges of consumer properties of materials made on its base. Nanocomposite includes fibrils of filler-chitin individualized to nanosizes with distance between fibrils from 709 to 20-22 nm and water-soluble polymeric matrix in interfibril space. Degree of filling of nanocomposite is 0.05-0.25% mass. Fibrils are arranged in parallel and they have cross size of 4 nm. Method of production of nanocomposite comes to the following: free-radical polymerization in water medium of at least one monomer of row of acrylic acid, salt of acrylic acid, acrylamide is carried out in presence of filler. Initiator is chosen from the row of water-soluble peroxides, hydroperoxides or their salts, potassium persulfate. Individualization to nanosizes of fibrils is done simultaneously with process of polymerization and/or with combination of said process with mechanical disintegrating action by disintegrating or pressing, or pressing with abrasion shift. Nanocomposite is obtained in form of film, being pervaporation membrane.

EFFECT: enlarged range of filling, ease of production.

22 cl, 1 tbl, 9 ex, 2 dwg

FIELD: carbon materials.

SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.

EFFECT: increased proportion of diamond structure in product and increased its storage stability.

2 cl

The invention relates to methods and devices for forming images in the form of undulating terrain with a period of about 100 nm and less on the surface of the wafer ion flows and apparatus for polishing wafers

The invention relates to nanoelectronics and nanoelectromechanical and can be used in microelectromechanical systems as sensors, in the manufacture of capacitors and inductors for cellular telephone communication means, and for optical fiber communication matrix of semiconductor lasers

The invention relates to a technology of coating of nanometer size, and can find application in electronics in the production of various integrated circuits
The invention relates to the production of a film of polymer nanocomposite containing inorganic magnetic component, and can be used to create a magnetic recording media with high recording density, and magnetic sensors

The invention relates to the field of coordination chemistry, including physical chemistry of nanostructures and colloidal systems, lies in the fact that education uglerodvodorodsoderzhaschih nanostructures is carried out by dehydropolycondensation and carbonization using thermochemical methods

The invention relates to the field of coordination chemistry, including physical chemistry of nanostructures and colloidal systems, lies in the fact that obtaining a metal-containing carbon nanostructures (mobilenow) is carried out by dehydration and subsequent oxidative dehydropolycondensation polyvinyl alcohol in the presence of chlorides of copper (I) or (II)

FIELD: carbon materials.

SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.

EFFECT: increased proportion of diamond structure in product and increased its storage stability.

2 cl

Up!