JPH06100309A - Production of carbon of molecular sieve - Google Patents

Abstract

PURPOSE:To obtain high-performance molecular sieve carbon having excellent equilibrium separation type molecular sieve to methane, etc., by heating optically isotropic pitch in an inert gas containing an aromatic hydrocarbon, etc., and depositing thermally decomposed carbon on microholes of a porous carbon base material in a given condition. CONSTITUTION:Optically isotropic pitch having >=150 deg.C softening temperature and <=5,000ppm ash content is infusibilized, activated in an inert gas atmosphere containing a carbon dioxide gas and/or steam to give porous carbon (carbonaceous base material) having 300-1,000 specific surface area. Then in a treating furnace heated to 650-850 deg.C, an inert gas containing an aromatic hydrocarbon and/or an alicyclic hydrocarbon is supplied to the carbon base material having 5.5-12A average micropore diameter and thermally decomposed carbon is deposited on the micropores. After the completion of the deposition treatment, the carbon base material is successively maintained in an inert gas atmosphere at the deposition temperature to 1,100 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing molecular sieving carbon used in gas separation technology such as air separation by PSA method, hydrogen purification from off-gas, separation of methane from fermentation gas and the like. .

[0002]

2. Description of the Related Art In recent years, technological development for separating and refining specific components from various mixed gases has been active. Among them, the method called PSA is expected to be applied to many applications because the device is compact and the running cost is low. In particular, air separation that separates and recovers nitrogen from air using hydrophobic molecular sieving carbon is accompanied by an increase in the demand for nitrogen.
Rapid market expansion is expected. The characteristic of molecular sieving carbon is that ordinary activated carbon has micropores of 10 to 30Å, whereas micropores have a small and narrow distribution of 3 to 5Å. Various methods have been proposed as a method for producing molecular sieving carbon, and a pyrolytic carbon vapor deposition method is one of them.

In this pyrolytic carbon deposition method, a carbonaceous base material and a hydrocarbon gas are brought into contact with each other at a high temperature, and the pyrolytic carbon released from the hydrocarbon is deposited near the entrance of the micropores of the carbonaceous base material. , A method for controlling micropores in a carbonaceous substrate, and there have been various proposals for this method.

In Japanese Patent Publication No. 52-18675, a coke having a low volatile component is used as a carbonaceous base material, and a hydrocarbon (for example, benzene, toluene, ethane, hexane, methanol) which releases carbon by thermal decomposition. Such)
Is added and treated at a temperature of 600 to 900 ° C. for 1 to 60 minutes or longer to deposit the released carbon in the pores of the course, thereby obtaining about 4Å
The following methods of making carbon-containing molecular sieves have been proposed for use in the separation of gases with small molecular dimensions.

This proposal is epoch-making and highly evaluated in that it first proposed a method for producing a carbon molecular sieve for separating small molecules, but in order to obtain a high-quality carbon molecular sieve excellent in reproducibility. Further improvement is needed.

Further, in the specification of Japanese Patent Publication No. 1-502743, a dry distillate containing a small amount of volatile components is 800 to 900.
The mixture was introduced into a vibrating furnace, which was supplied with an inert gas having a water vapor concentration of 20 to 95% by volume in countercurrent at a temperature of ℃ for 5 to 30 minutes, and was weakly activated, and then 5 in countercurrent. Disclosed is a method for producing a molecular sieve having an excellent ability to separate oxygen and nitrogen and having a uniform quality by introducing the same into a vibrating furnace to which an inert gas having a benzene concentration of ˜12% by volume is supplied.

This proposal is excellent in that a product having a more uniform quality can be obtained, but the method of contacting in a countercurrent makes the process a little complicated, and depending on the dry distillate used, a high quality product is obtained. You may not get things.

As another proposal, Japanese Patent Laid-Open No. 60-17121
In the specification No. 2, (i) high temperature (800 to 900 ° C)
Degassing the carbon substrate with (ii) cooling the degassed carbon substrate to a temperature of 300 to 500 ° C., bringing it into contact with a gas phase hydrocarbon, and adsorbing this hydrocarbon inside , (Iii) a step of degassing the adsorbed carbon base material under reduced pressure to remove physically retained hydrocarbons, and (iv) heating the hydrocarbons adhering to the pores of the carbon base material at a high temperature (800 to 90
A method for producing molecular sieving carbon has been proposed which comprises a combination of the steps of (i) to (iv), which is a step of decomposing at 0 ° C. to deposit carbon in pores, and carbonization to be adsorbed on a carbon substrate. A case of using propylene as hydrogen is disclosed, and the minimum dimension of propylene is 0.5 to 0.55 nm.
It is said that it is most suitable for treating a carbon base material having pores of (5-5.5Å).

According to this proposal, pyrolytic carbon is deposited only in the openings of the carbon substrate, and molecular sieving carbon having a controlled pore structure can be produced, but the production process is complicated and complicated as a whole. Become.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method for producing molecular sieving carbon by such a pyrolytic carbon deposition method. More specifically, it is an object of the present invention to provide a method for producing a high-performance molecular sieving carbon easily, inexpensively and with good reproducibility.

[0011]

Means for Solving the Problems The inventors of the present invention have made earnest studies on the relationship between the micropore size of a carbonaceous substrate and the kind of a hydrocarbon that is a source of pyrolytic carbon, using pitch as a starting material. , A carbonaceous base material with an average micropore diameter of 5.5 to 12Å and aromatic hydrocarbons or alicyclic hydrocarbons as hydrocarbons are used, a high-performance molecular sieving carbon can be reproducibly produced by a very simple process. They have found that they can be manufactured, and have completed the present invention.

That is, according to the general concept of the present invention,
A carbonaceous substrate having an average micropore diameter of 5.5 to 12Å is heated to 650 to 850 ° C., and an inert gas containing aromatic hydrocarbons and / or alicyclic hydrocarbons is supplied in the treatment furnace. Provided is a method for producing molecular sieving carbon, which comprises depositing pyrolytic carbon in micropores.

Also, in an inert gas atmosphere, 650-85
A carbonaceous substrate heated to 0 ° C. and having an average micropore diameter of 5.5 to 12 Å is heated in a treatment furnace heated to 650 to 850 ° C. in an aromatic hydrocarbon and / or alicyclic system. Provided is a method for producing molecular sieving carbon, which comprises supplying an inert gas containing a hydrocarbon to perform a vapor deposition process.

Here, the carbonaceous substrate has a softening point of 150.
Manufactured using optical isotropic pitch having a ash content of 5000 ° C or more and an ash content of 5000 ppm or less as a raw material, a softening point of 150 ° C or more and an ash content of 50
Optically isotropic pitch of 00 ppm or less is crushed or made into fibers, made infusible, then molded, and further activated in an inert gas atmosphere containing carbon dioxide and / or steam to give a specific surface area of 300 to It is preferable to use 1000 m ² / g of porous carbon and use this as the carbonaceous substrate.

Further, after the completion of the vapor deposition process, it is preferable that the temperature is continuously maintained at a temperature of the vapor deposition process temperature or more and 1100 ° C. or less in an inert gas atmosphere.

[0016]

[Structure] The structure of the present invention will be described in detail below, but more preferable embodiments and advantages based thereon will be apparent.

Carbonaceous Substrate The average micropore size of the carbonaceous substrate used in the present invention is 5.5.
It is in the range of 12 to 12Å, preferably 5.5 to 9Å, particularly 5.5 to 8Å. When the distribution of the micropore size of the carbonaceous substrate is narrow, the distribution of the micropore size of the obtained molecular sieving carbon is also narrowed, and a suitable result is obtained. Average micropore size is 5.5
In the case of a carbonaceous substrate of less than Å, the rate of narrowing the micropore size (change of the micropore size with time) is too fast during vapor deposition treatment with carbon generated by thermal decomposition of aromatic hydrocarbons.
It is not appropriate because it is difficult to control the diameter of the micropores. Further, if the average diameter exceeds 12Å, the micropores themselves are likely to be blocked during the vapor deposition process, which is not suitable.

The term "micropore" used in the present invention means 20
Å The following pores are shown. The average micropore diameter means the 50% average diameter of the micropore volume in the distribution curve of the micropore diameter. A carbonaceous base material having an average micropore diameter within the range of 5.5 to 12Å can be extremely easily obtained by using a coal-based or petroleum-based pitch as a starting material according to the method described in detail below.

The method for obtaining the carbonaceous substrate will be described below. Softening point is 150 ° C. or higher, preferably 150-250
Ash content is less than 5000ppm, preferably 500p
Optically isotropic pitches of pm or less are mechanically pulverized into fine powder. Alternatively, an optically isotropic pitch is heated to form a fiber by a melt spinning method.

A pitch having a softening point of 150 ° C. or lower is not suitable as a starting material because it takes a long time to infusibilize. Further, pitch having an ash content of 5000 ppm or more, as the ash content acts as a catalyst, causes the activation reaction described below to run away, or the average micropore diameter of the resulting carbonaceous base material easily exceeds 12Å as a starting material. not appropriate. This fine powdery pitch or fibrous pitch is heated to 300 ° C. in an oxidizing atmosphere such as air to make it infusible.

The infusible fine powder or fibrous material is mixed with a binder and molded. Here, the binder has a function of holding a molded shape by binding fine powdery substances or fibrous substances together, and has a softening point of 80.
Pitch, phenol resin, furan resin, epoxy resin and the like at about 120 ° C. can be exemplified. The binder is preferably used in an amount of 2 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the fine powdery substance and the fibrous substance infusibilized as residual carbon content. If it is more than 30 parts by weight, the activation treatment will not be easy, and the pore distribution will be widened, which is not preferable as a raw material for molecular sieving carbon. When the amount is less than 2 parts by weight, the effect as the above-mentioned binder does not appear.

By this molding step, the finely powdered infusibilized material is molded into particles by the extrusion granulation method or the rolling granulation method. The fibrous infusibilized material is formed into a granular form as in the case of the fine powder form, and is also formed into paper by a wet papermaking method or felt by a needle punch method.

This molded product is then subjected to activation treatment. In the activation treatment, carbon crystals forming the carbonaceous material (activating raw material) or carbon forming the fine pores are consumed by reaction, and pores are formed in a complicated and systematic manner due to the carbon structure,
The specific surface area increases.

The activation treatment is carried out at a temperature of 800 to 1100 ° C. under a carbon dioxide gas atmosphere or an inert gas atmosphere such as carbon dioxide gas and / or nitrogen gas containing water vapor at 0 to 4 ° C.
It is carried out by leaving it for 80 minutes. Before activation, 500-1 in an inert gas atmosphere such as nitrogen gas in advance.
You may carbonize at the temperature of 500 degreeC.

With this activation treatment, the specific surface area of the treated product is 30
By controlling the treatment temperature and time so as to be 0 to 1000 m ² / g, a carbonaceous substrate having an average micropore diameter in the range of 5.5 to 12Å can be easily produced. If activation is performed to this extent, the activation yield (the ratio of the weight of the activated product to the weight of the molded product of the fine powder or fibrous material) is as high as 50 to 70%, and the molecular sieving carbon can be obtained at a low cost.

Hydrocarbons Aromatic hydrocarbons or alicyclic hydrocarbons are used as the hydrocarbons that serve as the carbon source in the pyrolytic carbon deposition method of the present invention. As aromatic hydrocarbons, benzene, toluene,
Alkylbenzene such as ethylbenzene and xylene, naphthalene, methylnaphthalene, and the like, and cyclohexane and the like as an alicyclic hydrocarbon can be given, but generally, those having 1 to 2 carbon rings are preferable.

In the present invention, the above-mentioned carbonaceous base material is first subjected to an inert gas atmosphere at 650 to 850 ° C., preferably 700 to 800.
Heated to ℃. This heating may be performed in a treatment furnace described later, or may be performed in another furnace and the heated carbonaceous substrate may be continuously supplied to the treatment furnace.

The vapor deposition process is carried out in a processing furnace heated to 650 to 850 ° C., preferably 700 to 750 ° C. The above-mentioned heated carbonaceous substrate is present in the treatment furnace, to which aromatic hydrocarbon or alicyclic hydrocarbon is added in an amount of 0.1 to 2
An inert gas represented by nitrogen gas containing 0% by volume, preferably 3 to 10% by volume, is supplied.

If the temperature of the processing furnace is lower than 650 ° C., the amount of pyrolytic carbon generated is small, and a huge amount of time is required for vapor deposition.
If the temperature exceeds 850 ° C., the amount of pyrolytic carbon generated is too large, and the speed at which the micropore diameter becomes narrow becomes fast, making control uncontrollable.

The time for vapor deposition treatment is 10 in industrial production.
Minutes to 480 minutes, more preferably 10 minutes to 120
It is preferable that the amount is not more than a minute because of the stability of quality. The flow rate of the inert gas containing hydrocarbon during the vapor deposition process is 1 cm /
It is preferably s or more and 200 cm / s or less. The vapor deposition treatment can be performed on a fixed bed or a moving bed such as a rotary furnace, but a method of producing on a fluidized bed is preferable because the treatment temperature can be made uniform. The gas at the time of the vapor deposition treatment can be circulated, but a method in which the precipitated fine carbon particles are removed by a filter or the like and then circulated is preferable.

After such a vapor deposition process, the molecular sieving carbon can be obtained by cooling in an inert gas atmosphere.

By the above treatment method, pyrolytic carbon released from an aromatic hydrocarbon or an alicyclic hydrocarbon is vapor-deposited in the vicinity of the micropore inlet of the carbonaceous substrate, and the treatment temperature, treatment time, aromatic hydrocarbon Alternatively, by appropriately controlling the concentration of alicyclic hydrocarbons within the above range, it is possible to inexpensively produce molecular sieving carbon having 3-4 Å or more micropores and narrow Miroku pore size distribution with good reproducibility. .

Even better results can be obtained if the temperature is kept above the vapor deposition temperature and below 1100 ° C. in an inert gas atmosphere after the vapor deposition treatment. The effect is to firmly fix the micropore size distribution obtained by the vapor deposition process. Further, holding at high temperature also has the effect of narrowing the diameter of the micropores exceeding 4Å, and therefore has the effect of making the distribution of micropores generated by the vapor deposition treatment sharper. This effect cannot be obtained below the vapor deposition treatment temperature. Also, the temperature is 1100 ℃
When it exceeds, the micropores disappear rapidly, which is not preferable. According to the method explained above, the micropore diameter is 3 to 4Å
Strong and narrow molecular sieving carbon can be produced easily, inexpensively and with good reproducibility.

[0034]

EXAMPLES The present invention will be described below with reference to examples. (Example 1) Coal tar pitch was heat-treated to obtain an optically isotropic pitch having a softening point of 210 ° C and an ash content of 350 ppm or less. This pitch was extrusion-spun to obtain pitch fibers having a diameter of 14 μm. This pitch fiber is heated in a furnace from room temperature to 300 ° C. over 5 hours while blowing air,
It was further held for 1 hour to obtain pitch infusible fiber. The pitch infusibilized fiber was crushed with an impeller mill (INP250 type, manufactured by Seishin Enterprise Co., Ltd.), and the average fiber length was 0.35 m.
m pitch infusible fiber. Next, 100 parts by weight of the crushed pitch infusible fiber was mixed with 15 parts by weight of coal tar pitch having a softening point of 110 ° C. This mixed raw material was tumbled and granulated with a 1000 mmφ dish type granulator while adding water to obtain a granulated product having a diameter of 3.35-4.8 mm.
The granules were dried at 200 ° C. to remove water. Hereinafter, this granule will be referred to as a fiber granule. The fiber granules are classified to have particle sizes of 3.35 to 4 mm and 4 to 4.
It was separated into two types of 8 mm.

A fibrous granule having a particle size of 3.35 to 4 mm is heated in a furnace to 300 ° C. while feeding nitrogen gas, and then heated to 5 ° C./min while feeding nitrogen gas containing 50% carbon dioxide gas. After heating up to 1000 ° C. at a speed and holding at this temperature for 2 hours for activation treatment, it was cooled in nitrogen gas to obtain a carbonaceous substrate I. The activation yield of the carbonaceous substrate I was 56%. The micropores are in the range of 5 to 11Å as shown in FIG. 1, and the average micropore diameter is 7.
The specific surface area was ² m and the specific surface area was 800 m ² / g.

The micropore size distribution is represented by the relationship between the integrated micropore volume and the micropore size. The micropore volume of 6 Å or less is carbon tetrachloride (minimum molecular diameter 6 Å), isobutane (5.0 Å), n-butane (4.3 Å), ethane (4.0 Å), carbon dioxide (3.0 Å). The adsorption isotherm of 3Å) was measured, the maximum adsorption volume W ₀ of each was determined from the Dubinin-Astakhov plot, and the value was represented. Also, 6Å
The volume of micropores having a larger diameter was obtained by analyzing the adsorption isotherm of nitrogen at the liquid nitrogen temperature by the MP method. W / W ₀ = exp {-(A / E) ⁿ } W: Micropore volume [cm ³ / g] filled when relative pressure is P / P ₀ W ₀ : Maximum adsorption volume [cm ³ / g ] A: Adsorption potential [mol / joul] E: Adsorption characteristic energy [joul / mol] n: Constant of 1 to 6 P ₀ : Saturated vapor pressure of adsorbed gas at measurement temperature [torr] P: Vapor pressure of adsorbed gas [Torr]

Next, the carbonaceous substrate I was heated to 725 ° C. while feeding nitrogen gas in the furnace. Subsequently, while feeding a nitrogen gas containing 7.8% of benzene at this temperature, it was held for 90 minutes to perform a pyrolytic carbon vapor deposition treatment, and then cooled with a nitrogen gas to prepare a molecular sieving carbon I-1 as a prototype.

Similarly, a molecular sieving carbon I-2 was prepared by using the carbonaceous substrate I and setting the pyrolytic carbon vapor deposition treatment time to 120 minutes. FIG. 1 shows the micropore size distribution of I-1 and I-2. It can be seen that the pyrolysis carbon vapor deposition treatment narrows the micropores to a little over 3 to 4 Å with almost no reduction in the micropore volume. Next, in order to evaluate the molecular sieving property, oxygen of I-1 and I-2 (minimum molecular diameter 2.8
Å), nitrogen (3.0 Å), carbon dioxide (3.3 Å),
The adsorption isotherm for methane (same as 4.0Å) was measured.
For the measurement, an adsorption isotherm measuring device Bell Soap 18 (high pressure measurement specification, Nippon Bell Co., Ltd.) by a constant volume method was used. The results are shown in FIGS. 2 and 3. Both I-1 and I-2
There is a large difference in the adsorption amount of methane and carbon dioxide (Fig. 2), which shows excellent equilibrium separation type molecular sieving property.
I-2 also shows some equilibrium separation type molecular sieving property with respect to oxygen and nitrogen (FIG. 3). FIG. 4 shows I-
1 is a comparison of adsorption rates of nitrogen and oxygen of I-2. The measurement method is a method in which a molecular sieving carbon sample is placed in a container of known volume, the system is evacuated, gases to be adsorbed (nitrogen, oxygen) are introduced, and the time and pressure after introduction are measured. As the device, the same bell soap 18 as that used for measuring the adsorption isotherm was used. From FIG. 4, it can be seen that the adsorption of oxygen is completed within a very short time, while the time required for the completion of adsorption of nitrogen is very long. That is,
It is clear that I-1 and I-2 have very good velocity separation type molecular sieving properties.

(Example 2) Particle size produced in Example 1
A fibrous granule having a size of 35 to 4 mm was activated by the same method as in Example 1 to obtain a carbonaceous base material G. However, the holding time at 1000 ° C. was 1 hour. The activation yield of the carbonaceous substrate G was 65%. As shown in FIG. 5, the micropores are in the range of 5 to 10Å, and the average micropore diameter is 6.
The specific surface area was 2Å and 590 m ² / g.

Next, the carbonaceous substrate G was heated to 725 ° C. in a furnace while feeding nitrogen gas. Subsequently, at this temperature, nitrogen gas containing 7.8% or 12.6% of benzene was fed, and after holding for 60 minutes to carry out the pyrolytic carbon vapor deposition treatment, 750 while feeding nitrogen gas further.
Hold at 60 ° C for 60 minutes, then cool with nitrogen gas, and use two types of molecular sieving carbon G-1 (benzene: 7.8%), G-
2 (benzene: 12.6%) was prototyped.

FIG. 5 shows the micropore size distribution of G-1 and G-2. It can be seen that the pyrolysis carbon deposition treatment narrows the micropores to 3 to 4 Å without reducing the micropore volume.

Next, in order to evaluate the molecular sieving property, adsorption isotherms of carbon dioxide, methane, oxygen and nitrogen were measured. The results are shown in FIGS. 6 and 7. From this FIG. 6, G-1, G
It can be seen that -2 has excellent equilibrium separation type molecular sieving performance against methane and carbon dioxide gas. Further, it can be seen from FIG. 7 that G-2 has equilibrium separation type molecular sieving performance against oxygen and nitrogen.

FIG. 8 shows the results of comparing the adsorption rates of nitrogen and oxygen of G-1 and G-2. From this figure, G-1, G
It can be seen that both -2 have excellent speed separation type molecular sieving performance for nitrogen and oxygen.

(Example 3) The particle size of 4 to 4 produced in Example 1
A 4.8 mm fiber granule was activated by the same method as in Example 2 to obtain a carbonaceous substrate H. The activation yield of the carbonaceous substrate H was 69%. The micropores, as shown in FIG.
It is in the range of 5 to 9Å and the average micropore size is 6.0Å
The specific surface area was 470 m ² / g.

Next, the carbonaceous substrate H was heated to 725 ° C. in a furnace while feeding nitrogen gas. Subsequently, while feeding nitrogen gas containing 7.8% of benzene at this temperature and holding it for 90 minutes to perform a pyrolytic carbon vapor deposition treatment, cooling with nitrogen gas was carried out, and molecular sieving carbon H-1 was produced as a trial.

FIG. 9 shows the micropore size distribution of H-1.
It can be seen that the pyrolysis carbon deposition treatment narrows the micropores to 3 to 4 Å without reducing the micropore volume.

Next, in order to evaluate the molecular sieving property, adsorption isotherms of carbon dioxide gas, methane, oxygen and nitrogen were measured. The results are shown in FIGS. From FIG. 10 and FIG.
It can be seen that H-1 has excellent equilibrium separation type molecular sieving performance against methane and carbon dioxide gas as well as against oxygen and nitrogen.

FIG. 12 shows the results of comparing the adsorption rates of nitrogen and oxygen of H-1. From this figure, it is understood that H-1 has not only equilibrium separation type nitrogen and oxygen, but also excellent velocity separation type molecular sieving performance.

[0049]

According to the method for producing molecular sieving carbon of the present invention, molecular sieving carbon having a micropore size of 3 to 4 Å and a narrow micropore size distribution can be produced easily and with good reproducibility. . The molecular sieving carbon obtained by the present invention is particularly excellent in equilibrium separation type molecular sieving performance for methane and carbon dioxide, and rate separation type molecular sieving performance for nitrogen and oxygen.

[Brief description of drawings]

FIG. 1 Carbonaceous substrate I and molecular sieve carbon I-
It is the figure which represented the micropore diameter distribution of 1 and I-2 by integrated distribution. The vertical axis represents integrated micropore volume, and the horizontal axis represents micropore diameter.

FIG. 2 is a diagram showing adsorption isotherms of carbon dioxide and methane of molecular sieve carbons I-1 and I-2, respectively.

FIG. 3: Nitrogen of molecular sieve carbons I-1 and I-2,
It is a figure which shows the adsorption isotherm of oxygen.

FIG. 4 is a diagram expressing the adsorption rates of nitrogen and oxygen of molecular sieving carbon I-1 by the change in adsorption amount with time.

FIG. 5: Carbonaceous substrate G and molecular sieving carbon G-
It is the figure which represented the micropore diameter distribution of 1 and G-2 by integrated distribution.

FIG. 6 is carbon dioxide gas of molecular sieving carbons G-1 and G-2,
It is a figure which shows the adsorption isotherm of methane.

FIG. 7 is a diagram showing adsorption isotherms of nitrogen and oxygen on molecular sieving carbons G-1 and G-2.

FIG. 8 is a diagram in which the adsorption rates of nitrogen and oxygen on molecular sieving carbons G-1 and G-2 are expressed by changes in the adsorption amount with respect to time.

FIG. 9: Carbonaceous substrate H and molecular sieving carbon H-1
It is the figure which expressed the micropore diameter distribution of this with integrated distribution.

FIG. 10 is a diagram showing adsorption isotherms of carbon dioxide and methane of molecular sieving carbon H-1.

FIG. 11 is a diagram showing adsorption isotherms of nitrogen and oxygen of molecular sieving carbon H-1.

FIG. 12 is a diagram in which the adsorption rates of nitrogen and oxygen on molecular sieving carbon H-1 are expressed by the change in adsorption amount with time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location C04B 41/85 F (72) Inventor Miyoshi Fumihiro 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Technology Co., Ltd.Technology Research Headquarters (72) Inventor Hiroyuki Osugi 1 Kawasaki-cho, Chuo-ku, Chiba, Chiba Prefecture Kawasaki Steel Co., Ltd. Technology Research Headquarters (72) Inventor Yoshio Nakano Akamatsu, Chigasaki-shi, Kanagawa 2-10-10 of town 7

Claims (5)

[Claims] 1. An inert gas containing an aromatic hydrocarbon and / or an alicyclic hydrocarbon in a treatment furnace in which a carbonaceous substrate having an average micropore diameter of 5.5 to 12Å is heated to 650 to 850 ° C. A method for producing molecular sieving carbon, which comprises supplying gas to deposit pyrolytic carbon on micropores. 2. A carbonaceous substrate heated to 650 to 850 ° C. under an inert gas atmosphere and having an average micropore diameter of 5.5 to 12 Å in a treatment furnace heated to 650 to 850 ° C. A method for producing molecular sieving carbon, which comprises supplying an inert gas containing an aromatic hydrocarbon and / or an alicyclic hydrocarbon to a reaction furnace and performing a vapor deposition process. 3. The carbonaceous substrate has a softening point of 150 ° C. or higher,
The method for producing molecular sieving carbon according to claim 1 or 2, which is produced using an optically isotropic pitch having an ash content of 5000 ppm or less as a raw material. 4. A softening point of 150 ° C. or higher and an ash content of 5000 ppm
The following optical isotropic pitch is crushed or fiber,
This is made infusible, then molded, and further activated in an inert gas atmosphere containing carbon dioxide gas and / or steam to obtain porous carbon having a specific surface area of 300 to 1000 m ² / g, which is the carbonaceous group described above. 1 to use as a material
3. The method for producing molecular sieving carbon according to any one of 3 above. 5. The production of molecular sieving carbon according to any one of claims 1 to 4, wherein after the completion of the vapor deposition treatment, the temperature is kept above the vapor deposition treatment temperature and below 1100 ° C. in an inert gas atmosphere. Method.