JP2009061448A - Molecular sieve carbon and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon molecular sieve which is obtained by carbonizing a phenol resin and the pore size of pores of the sieve is controlled so that the carbon molecular sieve exhibits selective adsorptivity to CO<SB>2</SB>and to provide a method for producing the carbon molecular sieve. <P>SOLUTION: The carbon molecular sieve adsorbs CO<SB>2</SB>selectively, has pores whose pore size is controlled and is obtained by carbonizing the phenol resin synthesized from phenols and aldehydes. The method for producing the carbon molecular sieve is provided. When the carbon molecular sieve is produced, an activator is not required. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to molecular sieve carbon and a method for producing the same, and more specifically, a phenol resin synthesized from phenols and aldehydes as a raw material, and selectively adsorbing carbon dioxide gas (CO ₂ ), controlled molecular sieve carbon having controlled pores, and It relates to the manufacturing method.

The gas separation method mainly includes a membrane separation method, a pressure swing method (hereinafter referred to as PSA method), a liquid absorption method, and the like. These gas separation methods are also applied to the separation of methane (CH ₄ ) from digestion gas. For example, JP-A 2003-320221 discloses a liquid absorption method, and JP-A 6-173119 and JP-A 8-675513 disclose a PSA method. Among them, the liquid absorption method is a method using the difference in solubility between CH ₄ and CO _{2 in} an aqueous solution of potassium carbonate or the like in the case of digestion gas, and the PSA method is CH ₄ and CO _{2 in the} case of digestion gas. This is a method that utilizes the difference in the adsorption power of the two.

In the PSA method, an adsorbent is used, but molecular sieve carbon has a sharper pore distribution than activated carbon, which is a normal adsorbent, so that the difference in adsorption power between CH ₄ and CO ₂ is large, and CH ₄ is separated. Suitable for However, it is not easy to control the pore distribution of molecular sieve carbon, and many studies have been conducted on the control method.

  For example, JP-A-11-79722 discloses spherical carbon particles obtained by firing and carbonizing phenol resin particles in an inert gas atmosphere. More specifically, the spherical carbon particles are obtained by baking and carbonizing phenol resin particles having an average particle diameter after carbonization of 100 μm or less at 800 to 1200 ° C. in an inert gas atmosphere, and selecting carbon dioxide gas. It is described as carbon particles for carbon dioxide fixation that are adsorbed on the surface. Japanese Patent Application Laid-Open No. 2006-96780 describes a carbon material that exhibits molecular sieving ability by reacting a phenol resin with a compound having a boiling point of 800 ° C. or less and then carbonizing the compound.

JP 2003-320221 A JP-A-6-173119 JP-A-8-67513 Japanese Patent Laid-Open No. 11-79722 JP 2006-96780 A

Among these gas separation methods, the liquid absorption method has a problem that the solubility difference between CH ₄ and CO ₂ in water is as small as about 25 times and the separation performance is not good. In addition, in JP-A-8-67513 and JP-A-2006-96780, molecular sieve carbon using a phenol resin or the like as a raw material is disclosed, but molecular sieve carbon described in JP-A-8-67513 is a CO. adsorbs C ₂ H ₆ in addition to _2, the molecular sieve carbon according to JP 2006-96780 have problems such as CO ₂ selective adsorptive adsorbs N ₂ in addition to CO _2.

  By the way, the present inventors have found and announced that activated carbon produced from a phenol resin has a relatively sharp pore distribution (Abstracts of the 32nd Annual Meeting of the Carbon Society of Japan: December 2005). 7th issue, p.224-225). Carbonization of phenolic resin gave molecular sieve carbon with better propane / propylene separation performance.

In the same summary, data on gas separation of propane / propylene (C ₃ H ₈ / C ₃ H ₆ ) system is shown, but at that time, adsorption capacity for CO ₂ , CH ₄ and other gases. It is not clear what kind of characteristics the gas separation ability is. In order to selectively adsorb CO ₂ , it is necessary to control the pore diameter suitable for CO ₂ adsorption.

Abstracts of the 32nd Annual Meeting of the Carbon Materials Society of Japan: Published December 7, 2005, p. 224-225

The present invention has a problem in the above-described technology, that is, a molecular sieve carbon obtained by carbonization of a phenol resin, the pore diameter is controlled so as to have a CO ₂ selective adsorption property, and a fine adsorption of CO ₂ selectively. An object of the present invention is to provide molecular sieve carbon with controlled pores and a method for producing the same.

The present invention (1) is molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And it is characterized by carbonizing the phenol resin synthesize | combined from phenols and aldehydes.

The present invention (2) is molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And it is characterized by carbonizing a phenol resin synthesized from non-graphitizable phenols and aldehydes.

The present invention (3) is molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And it is characterized by carbonizing a phenol resin synthesized from non-graphitizable phenols, graphitizable phenols and aldehydes.

According to the present invention (4), in the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (3), the non-graphitizable phenol is phenol, and the graphitizable phenol is dimethylphenol. It is characterized by being.

The present invention (5) is the molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to the present invention (4), wherein the non-graphitizable phenol and dimethylphenol are graphitizable phenols. The molar ratio is 1: 0.5 or more.

The present invention (6) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (5), wherein the non-graphitizable phenol and dimethylphenol are graphitizable phenols. The molar ratio is 1: 0.5-20.

The present invention (7) is a molecular sieve carbon in which pores are controlled by carbonizing a phenol resin synthesized from phenol (P), 3,5-dimethylphenol (X) and an aldehyde, which selectively adsorbs CO _2. is there. Then, in FIG. 6 of the attached drawings, the phenol having a P / X molar ratio that satisfies the condition in the frame of the dotted line Z is carbonized by the relationship between the P / X molar ratio on the vertical axis and the carbonization temperature on the horizontal axis. It is characterized by.

The present invention (8) is the molecular sieve carbon of the present invention (1) to (7) having a controlled pore for selectively adsorbing CO ₂ , wherein the phenol resin has a carbonization temperature of 600 to 1200 ° C. and a carbonization time of 15 It is characterized by being more than minutes.

The present invention (9) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (1) to (7), wherein the phenol resin has a carbonization temperature of 1000 ° C. or less and a carbonization time of 15 minutes. It is the above.

The present invention (10) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (1) to (7), wherein the phenol resin has a carbonization temperature of 800 ° C. and a carbonization time of 60 minutes. It is characterized by being.

The present invention (11) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (1) to (10), wherein the molecular sieve carbon with controlled pores is from a gas containing CO _2. It is a molecular sieve carbon for adsorption separation of CO ₂ .

The present invention (12) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (1) to (10), wherein the molecular sieve carbon with controlled pores contains CO ₂ and CH ₄ . It is a molecular sieve carbon for adsorption separation of CO ₂ from gas.

The present invention (13) is the molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ of the present invention (1) to (10), wherein the molecular sieve carbon with controlled pores contains CO ₂ and N ₂ . It is a molecular sieve carbon for adsorption separation of CO ₂ from gas.

The present invention (14) is a method for producing molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And the phenol resin synthesize | combined from phenols and aldehydes is carbonized, It is characterized by the above-mentioned.

The present invention (15) is a method for producing molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And the phenol resin synthesize | combined from the hardly graphitizable phenols and aldehydes is carbonized, It is characterized by the above-mentioned.

The present invention (16) is a method for producing molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ . And it is characterized by carbonizing a phenol resin synthesized from non-graphitizable phenols, graphitizable phenols and aldehydes.

The present invention (17) is the method for producing molecular sieve carbon having controlled pores for selectively adsorbing CO _{2 according} to the present invention (16), wherein the non-graphitizable phenols are phenol, The class is characterized in that it is dimethylphenol.

According to the present invention (18), in the method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to the present invention (17), the non-graphitizable phenols and the easily graphitizable phenols The molar mixing ratio of dimethylphenol is 1: 0.5-20.

The present invention (19) is a molecular sieve carbon having controlled pores formed by carbonizing a phenol resin synthesized from phenol (P), 3,5-dimethylphenol (X) and an aldehyde that selectively adsorbs CO ₂ . It is a manufacturing method. Then, in FIG. 6 of the attached drawings, the carbonization of the phenol resin having the P / X molar ratio that satisfies the condition in the dotted line Z in the relationship between the P / X molar ratio on the vertical axis and the carbonization temperature on the horizontal axis. Features.

The present invention (20) is the method of producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to the present invention (14) to (19), wherein the phenol resin is carbonized at 600 to 1200 ° C. The time is 15 minutes or more.

The present invention (21) is the method for producing molecular sieve carbon having controlled pores for selectively adsorbing CO _{2 according} to the present invention (14) to (19), wherein the carbonization temperature of the phenol resin is 1000 ° C. or less, and the carbonization time. Is 15 minutes or more.

The present invention (22) is a method of producing molecular sieve carbon having controlled pores for selectively adsorbing CO _{2 according} to the present invention (14) to (19), wherein the phenol resin has a carbonization temperature of 800 ° C. and a carbonization time of It is characterized by 60 minutes.

Molecular sieve carbon as a raw material of phenol resin described in Patent Document 5 is to express the molecular sieve ability by boiling phenol resin is carbonized after reacting a 800 ° C. The following compounds, N in addition to CO ₂ There is a problem in the selective adsorption of CO ₂ such as adsorbing ₂ . On the other hand, in the present invention, molecular sieving ability and selective adsorption of CO ₂ are expressed by carbonizing a phenol resin obtained by synthesizing each component in a specific range of mixing ratio, and only CO ₂ is expressed. Is selectively adsorbed, and CH ₄ , N _{2 and} other gases other than CO ₂ are not adsorbed.

  The phenols that are the components of the raw material resin of the molecular sieve carbon of the present invention are not particularly limited as long as they are phenols. For example, cresols such as phenol, o-cresol, m-cresol, and p-cresol, 2,3-xylenol 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, xylenol such as 3,5-xylenol, o-ethylphenol, m-ethylphenol, p-ethylphenol, etc. Alkylphenols such as ethylphenol, isopropylphenol, butylphenol, p-tert-butylphenol, p-tert-amylphenol, p-octylphenol, p-nonylphenol, p-cumylphenol, fluorophenol, chlorophenol, bromine Halogen phenols such as phenol and iodophenol, monovalent phenol derivatives such as p-phenylphenol, aminophenol, nitrophenol, dinitrophenol and trinitrophenol, monovalent phenols such as 1-naphthol and 2-naphthol, resorcin, Examples thereof include polyhydric phenols such as alkylresorcin, pigalol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, phloroglucin, bisphenol A, bisphenol F, bisphenol S, and dihydroxynaphthalene. These can be used alone or in combination of two or more.

  Here, “non-graphitizable phenols” in this specification means that a resin synthesized from phenols and aldehydes is non-graphitizing, that is, synthesized from phenols and aldehydes. When carbonized resin is carbonized, it means that the graphite structure is difficult to develop. Examples of the non-graphitizable phenols include phenol.

  In the present specification, the “graphitizable phenols” means that a resin synthesized from phenols and aldehydes is graphitizing, that is, a resin synthesized from phenols and aldehydes. This means that the graphite structure is easy to develop. Examples of graphitizable phenol include 3,5-dimethylphenol.

  The aldehydes that are components of the raw material resin of the molecular sieve carbon of the present invention are not particularly limited as long as they are aldehydes. For example, formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, polyoxyethylene, chloral, hexamethylenetetramine, Examples include furfural, glyoxal, n-butyraldehyde, caproaldehyde, allyl aldehyde, benzaldehyde, crotonaldehyde, acrolein, tetraoxymethylene, phenylacetaldehyde, o-tolualdehyde, salicylaldehyde, and the like. These can be used alone or in combination of two or more.

  In the present invention, an appropriate phenol is selected from the phenols, an appropriate aldehyde is selected from the aldehydes, the components are mixed, and heated in the presence of an acid or alkali catalyst. To synthesize phenolic resin. The polymerization method is not particularly limited, and a conventional polymerization method can be used.

  Phenolic resins are synthesized in the form of lumps, plates, spheres, and other various shapes, but in the case of lumps, plates, etc., they are crushed and granulated and then carbonized under an inert gas atmosphere such as nitrogen. . The carbonization temperature is in the range of 600-1200 ° C. The carbonization treatment may be performed at the carbonization temperature within the range from the start of carbonization to the completion of carbonization. The time, that is, the lower limit of the carbonization time is approximately 15 minutes, and the upper limit of the carbonization time is approximately 120 minutes. It is not limited to these ranges.

  In the production of carbon materials by the conventional method, an activator is necessary to develop the pore structure during carbonization. However, in the present invention, the activator is unnecessary, and the pore structure of molecular sieve carbon is controlled without an activator. Can do. From this, the means for controlling the pore structure in the “method for producing molecular sieve carbon with controlled pores” of the present invention is substantially only the carbonization temperature and carbonization time, except for the selection of phenols and aldehydes. Control of the pore structure formation is also easy. It is an important feature that an activator is unnecessary in the production of the molecular sieve carbon of the present invention.

  Hereinafter, the molecular sieve carbon of the present invention and the production method thereof will be described in more detail based on examples (experimental examples), but the present invention is of course not limited to these examples.

3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) are mixed at a predetermined ratio (indicated by molar ratio) and heated in a N ₂ atmosphere in a sealed container to obtain a phenol resin (hereinafter referred to as “XPF”). Abbreviated as “resin”). The heating temperature was 95 ° C. The XPF resin thus produced was carbonized in an electric furnace in a nitrogen atmosphere at a predetermined temperature and for a predetermined time to manufacture molecular sieve carbon (hereinafter abbreviated as “XPF molecular sieve carbon”).

  In the following adsorption experiments, the measurement of gas adsorption amount and adsorption time constant by XPF molecular sieve carbon and PF molecular sieve carbon (= Example 9) was performed using a magnetic floating balance: Model FMS-BG-H, Gas adsorption amount measuring device: Model BELSORP -HP, gas adsorption amount measuring apparatus: Model BELSORP-28 (all manufactured by Nippon Bell Co., Ltd.) was used. The adsorption amount was measured with a magnetic suspension balance, the gas adsorption amount and the adsorption time constant were measured with BELSORP-HP and BELSORP-28 at 25 ° C. using each adsorption gas.

<Example 1: XPF molecular sieve carbon>
The XPF molecular sieve carbon of Example 1 is obtained by mixing 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) at a molar ratio of 1: 1: 4 (P / X = 1). The powdered molecular sieve carbon produced by carbonizing the XPF resin in an electric furnace in an N ₂ atmosphere at 900 ° C. for 30 minutes. This molecular sieve carbon is described as “Example 1: XPF molecular sieve carbon”. The same applies to the XPF molecular sieving carbon in Example 2 and later.

  1 and 2 are graphs showing the characteristics of Example 1: XPF molecular sieve carbon (indicated as XPF-MSC in FIGS. 1 and 2).

FIG. 1 is a graph showing the adsorption amounts of CO ₂ and CH ₄ with respect to adsorption pressure by Example 1: XPF molecular sieve carbon. As shown in FIG. 1, CH ₄ is not adsorbed, CO ₂ is adsorbed, and the amount of adsorption increases with increasing pressure. Thus useful because it selectively adsorbs CO ₂ in the separation of CO ₂ from gas containing CO _2, from a gas containing CH _4, CO _2, etc. as digestion gas CH ₄ selectively to Can be used to separate.

FIG. 2 is a graph showing the equilibrium ratio (Equilibrium ratio) of CO ₂ with respect to the adsorption time by XPF molecular sieving carbon, and the horizontal axis shows the adsorption time s (seconds) on a logarithmic scale. As shown in FIG. 2, CO ₂ begins to be adsorbed after about 2 × 10 ¹ s has elapsed from the start of measurement, and requires about 2 × 10 ⁴ s from the start of measurement to saturation. This is 2209 seconds in terms of the adsorption time constant.

<Example 2: XPF molecular sieve carbon>
Except that the shape of the XPF resin was granulated, Example 1: The same conditions as the carbonization conditions of the XPF molecular sieve carbon, that is, carbonized for 30 minutes at 900 ° C. in an N ₂ atmosphere in an electric furnace, gave an XPF molecular sieve carbon. FIG. 3 is a graph showing the adsorption amounts of CO ₂ and CH ₄ with respect to the adsorption pressure by Example 2: XPF molecular sieve carbon.

As shown in FIG. 3, carbonization temperature = 900 ° C. and carbonization time = 60 minutes. Example 2: In XPF molecular sieve carbon, CH ₄ is not adsorbed and CO ₂ is adsorbed. The amount of CO ₂ adsorbed increases as the pressure is increased, but it is less than the amount of CO ₂ adsorbed by Example 1: XPF molecular sieve carbon.

<Example 3: XPF molecular sieve carbon>
The point that the shape of the XPF resin was granulated was the same as that of Example 2: XPF molecular sieving carbon, but carbonization was performed in an electric furnace in an N ₂ atmosphere at 800 ° C. for 30 minutes to obtain XPF molecular sieving carbon. FIG. 4 is a graph showing the adsorption amounts of CO ₂ and CH ₄ with respect to the adsorption pressure by Example 3: XPF molecular sieve carbon. Example 3: The adsorption time constant of CO _{2 on} molecular sieve carbon was 648 seconds.

As shown in FIG. 4, the carbonization temperature = 800 ° C. and the carbonization time = 30 minutes. In Example 3: XPF molecular sieve carbon, the adsorption amount of CO ₂ was improved as compared with Example 2: XPF molecular sieve carbon. The adsorption amount of ₄ is slightly increased.

<Example 4: XPF molecular sieve carbon>
The point that the shape of the XPF resin was granulated was the same as that of Example 2: XPF molecular sieving carbon, but carbonization was performed in an electric furnace in an N ₂ atmosphere at 800 ° C. for 60 minutes to obtain an XPF molecular sieving carbon. FIG. 5 is a graph showing the adsorption amounts of CO ₂ and CH ₄ with respect to the adsorption pressure by Example 4: XPF molecular sieve carbon.

As shown in FIG. 5, carbonization temperature = 800 ° C. and carbonization time = 60 minutes. In Example 4: XPF molecular sieving carbon, CO ₂ adsorbs the same amount as in Example 3: XPF molecular sieving carbon, and CH ₄ Was adsorbed only slightly at 650 mmHg or more, and was not substantially adsorbed. Moreover, compared with Example 1: XPF molecular sieve carbon, Example 4: XPF molecular sieve carbon has the same amount of adsorption of CO ₂ , and CH ₄ is not adsorbed.

Furthermore, when the adsorption time constant of CO ₂ of Example 4: XPF molecular sieve carbon was measured, it was 1369 seconds, which was improved as compared to the adsorption time constant of 2209 seconds of Example 1: XPF molecular sieve carbon.

<Consideration of the above experimental progress and experimental results>
From the above experimental results, it was possible to obtain molecular sieve carbon for separation and adsorption of CO ₂ from gas containing CO ₂ and CH ₄ in all Examples. In addition, when the experimental results are considered based on Example 1, diffusion of tar generated in the carbonization process takes time by increasing the particle size of the molecular sieve carbon as in Example 2: Molecular Sieve Carbon. It seems to have re-polymerized and closed the pores before being released out of the system.

Therefore, as in Example 3: XPF molecular sieving carbon, the carbonization temperature was lowered to 800 ° C., but due to insufficient heat shrinkage, the pore diameter was increased and CH ₄ was adsorbed although it was slight. Thus, as in Example 4: XPF molecular sieve carbon, the carbonization temperature is the same as that in Example 3: XPF molecular sieve carbon. Carbon was produced.

Further, since the adsorption rate increases as the pore diameter increases, there are pores having an optimal size that do not adsorb CH ₄ but have a relatively high CO ₂ adsorption rate. Example 4: It seems that XPF molecular sieve carbon is almost equivalent to this.

Furthermore, the adsorption time constant of Example 1: Molecular Sieve Carbon is 2209 seconds, whereas the adsorption time constant of Example 3: Molecular Sieve Carbon is 648 seconds, and Example 4: The adsorption time constant of Molecular Sieve Carbon is 1369 seconds. Since the adsorption rate of CO ₂ is increased, the efficiency of the separation operation can be improved.

  From the results of the above examples (experimental examples), it is suggested that high-performance molecular sieve carbon can be produced by further lowering the carbonization temperature and extending the holding time.

<Examples 5 to 10>
The following is about the XPF molecular sieve carbon produced by expanding the molar ratio P / X of phenol (P), which is a non-graphitizable phenol, and dimethylphenol (X), which is a graphitizable phenol, to 0.5-20. This is an example (experimental example) in which the adsorption amount of CO ₂ and CH ₄ and the adsorption time constant were evaluated to clarify the molecular sieve performance.

  In the following, the adsorption amount is the gas adsorption amount at 760 mmHg obtained by interpolating or extrapolating the adsorption isotherm data, and the adsorption time constant reaches the first equilibrium adsorption amount of the adsorption isotherm. The time required to reach the adsorption amount of 1/2 of the equilibrium adsorption amount from the start of adsorption, that is, the time required to reach 1/2 of the saturated adsorption amount for each gas to be adsorbed was obtained. It's time. These points are the same for the first to fourth embodiments.

In Tables 1 to 5 below, symbols such as x, Δ, ○, ◎, etc. are attached to the right column of the sample column. It is the code | symbol attached | subjected in order to show typical evaluation. Taking the CO ₂ adsorption amount as an example, the x mark has a selective adsorption performance for CO ₂ , and the Δ mark has a selective adsorption performance for CO ₂ superior to the x mark (the x mark and the circle mark). The selective adsorption performance of CO ₂ between the marks ◯ indicates that the selective adsorption of CO ₂ is superior to the △ marks (the selective adsorption of CO ₂ between the marks △ and ◎. ) Signifies that it has particularly excellent CO ₂ selective adsorption performance. For example, with respect to the amount of adsorption of CO ₂ with respect to the amount of adsorption of CH ₄ , there is no change in that it has a selective adsorption performance of CO ₂ even with a cross. This also applies to the adsorption time constant.

<Example 5: XPF molecular sieve carbon>
Example 5: XPF molecular sieving carbon has a molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) of (1) 1: 0.5: 3, (2) 1: 1: 4, (3) 1: 2: 6, (4) 1: 3: 8, XPF resin obtained by mixing and synthesizing each in an electric furnace in an N ₂ atmosphere, It is a granular molecular sieve carbon produced by carbonization at 600 ° C. for 60 minutes. The obtained molecular sieve carbons are designated as XPF molecular sieve carbons (1) to (4).

For each XPF molecular sieve carbon of (1) to (4), the adsorption amount and adsorption time constant of CO ₂ and CH ₄ were measured. Table 1 shows the measurement results and characteristics of each XPF molecular sieve carbon of (1) to (4). In Table 1, in each XPF molecular sieve carbon of (1) to (4), the upper part is the adsorption amount, and the lower part is the adsorption time constant.

As shown in Table 1, each of the XPF molecular sieve carbons (1) to (4) has a larger amount of CO ₂ adsorption than the amount of CH ₄ adsorption, and the amount of CO ₂ adsorption is larger than the amount of CH ₄ adsorption. 2.5 to 2.7 times the value. The adsorption time constant ratio of CH ₄ / CO ₂ for both (2) XPF molecular sieve carbon (P / X = 1) and (3) XPF molecular sieve carbon (P / X = 2) is 16; It shows that the adsorption rate of CO ₂ is 16 times faster than the adsorption rate of ₄ .

<Example 6: XPF molecular sieve carbon>
Example 6: XPF molecular sieving carbon has a molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) of (1) 1: 0.5: 3, (2) 1: 1: 4, (3) 1: 2: 6, (4) 1: 3: 8, (5) 1: 4: 10, (6) 1: 5: 12, (7) 1: It is a granular molecular sieving carbon produced by carbonizing XPF resin obtained by mixing with each of 10:22 in an electric furnace in an N ₂ atmosphere at 700 ° C. for 60 minutes. The obtained molecular sieve carbons are designated as XPF molecular sieve carbons (1) to (7).

The adsorption amounts and adsorption time constants of CO ₂ and CH ₄ were measured for each XPF molecular sieve carbon of (1) to (7). Table 2 shows the measurement results and characteristics of each XPF molecular sieve carbon of (1) to (7). In Table 2, in each XPF molecular sieve carbon of (1) to (7), the upper part is the adsorption amount, and the lower part is the adsorption time constant.

As shown in Table 2, each of the XPF molecular sieve carbons (1) to (7) has a larger amount of CO ₂ adsorption than the amount of CH ₄ adsorption, and the amount of CO ₂ adsorption is larger than the amount of CH ₄ adsorption. The value is 2.2 to 3.2 times. Further, (1) XPF molecular sieve carbon (P / X = 0.5) of CH ₄ / CO ₂ adsorption time constant ratio is 25, CH of XPF molecular sieve carbon in (2) (P / X = 1) 4 / adsorption time constant ratio of CO ₂ is 32, with respect to XPF adsorption time constant ratio of CH ₄ / CO ₂ of molecular sieve carbon (P / X = 2) is 39, the adsorption rate of CH ₄ in (3), CO It shows that the adsorption speed of ₂ is 25 to 39 times faster.

<Example 7: XPF molecular sieve carbon>
Example 7: XPF molecular sieving carbon has a molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) of (1) 1: 0.5: 3, (2) 1: 1: 4, (3) 1: 2: 6, (4) 1: 3: 8, (5) 1: 4: 10, (6) 1: 5: 12, (7) 1: 6:14, (8) 1:10:22, XPF resin obtained by mixing and synthesizing each was carbonized in an electric furnace in an N ₂ atmosphere at 800 ° C. for 75 minutes [(8) only for 60 minutes]. The granular molecular sieving carbon produced in this way. The obtained molecular sieve carbons are designated as XPF molecular sieve carbons (1) to (8).

The adsorption amounts of CO ₂ and CH ₄ were measured for each XPF molecular sieve carbon of (1) to (8). Table 3 shows the measurement results and characteristics of the XPF molecular sieve carbons (1) to (8).

As shown in Table 3, each of the XPF molecular sieve carbons (1) to (8) has a larger amount of CO ₂ adsorption than the amount of CH ₄ adsorption, and the amount of CO ₂ adsorption is larger than the amount of CH ₄ adsorption. The value is 7 to 180 times.
Among them, XPF molecular sieve carbon (P / X = 0.5) is the ratio of CO ₂ / CH ₄ 175, the CO ₂ / CH ₄ of (2) XPF molecular sieve carbon of the (P / X = 1) (1) The adsorption amount ratio is 180, and the adsorption amount ratio of CO ₂ / CH ₄ of XPF molecular sieve carbon (P / X = 2) in (3) is 113, indicating that the selective adsorption characteristic of CO ₂ is particularly excellent. Yes.

<Example 8: XPF molecular sieve carbon>
Example 8: XPF molecular sieving carbon has a molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) of (1) 1: 0.5: 3, (2) 1: 1: 4 <Example 2: XPF molecular sieve carbon>, (3) 1: 2: 6, (4) 1: 3: 8, (5) 1: 4: 10, (6) 1: 5:12, (7) 1: 6: 14, (8) 1:10:22, (9) 1:20:42, and mixing the XPF resin obtained by mixing them in an electric furnace in an N ₂ atmosphere Below, it is a granular molecular sieve carbon produced by carbonization at 900 ° C. for 30 minutes [(3) to (4) are for 60 minutes]. The obtained molecular sieve carbons are designated as XPF molecular sieve carbons (1) and (3) to (9).

The adsorption amounts of CO ₂ and CH ₄ were measured for each XPF molecular sieve carbon of (1) and (3) to (9). Table 4 (a) shows the measurement results and characteristics of the XPF molecular sieve carbons (1) and (3) to (9). In Table 4 (a), the data of FIG. 3 in the above-mentioned <XPF molecular sieve carbon of Example 2> is transcribed as the XPF molecular sieve carbon of (2).

As shown in Table 4 (a), each of the XPF molecular sieve carbons (1) to (9) has a larger CO ₂ adsorption amount than the CH ₄ adsorption amount, and the CO ₂ adsorption amount is the CH ₄ adsorption amount. The value is 53 to 250 times the amount.
Among them, XPF molecular sieve carbon (P / X = 0.5) is the ratio of CO ₂ / CH ₄ 107, the CO ₂ / CH ₄ of (2) XPF molecular sieve carbon of the (P / X = 1) (1) The adsorption amount ratio and the adsorption amount ratio of CO ₂ / CH ₄ of XPF molecular sieve carbon (P / X = 2) in (3) are infinite, that is, only CO ₂ / is adsorbed, and XPF molecular sieve carbon (P / X = 5) CO ₂ / CH ₄ adsorption ratio is 213, (7) XPF molecular sieve carbon (P / X = 7) CO ₂ / CH ₄ adsorption ratio is 250, (8) The XPF molecular sieve carbon (P / X = 10) has a CO ₂ / CH ₄ adsorption ratio of 185, which indicates that the selective adsorption characteristic of CO ₂ is particularly excellent.

<Example 9: PF molecular sieve carbon>
Example 9: PF molecular sieve carbon is the same as in Example 8 except that the molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) is 0: 1: 2. That is, a resin obtained by mixing only phenol (P) and formaldehyde (F) without using 3,5-dimethylphenol (X) as a resin component (abbreviated as PF resin) was used in Example 8. Is a granular molecular sieve carbon produced by carbonization under the same carbonization conditions. Each obtained molecular sieve carbon is defined as PF molecular sieve carbon of (10).

The adsorption amount of CO ₂ and CH ₄ was measured for the PF molecular sieve carbon of (10). Table 4 (b) shows the measurement results and characteristics. Table 4 As (b), the adsorption amount of CO ₂ in comparison with the adsorption amount of PF molecular sieve carbon CH ₄ is large and the amount of adsorption of CO ₂ is 23 times as compared with the amount of adsorption of CH ₄ (10) The value is shown. Thus, PF molecular sieve carbon obtained by carbonizing a PF resin not containing the component (X) can also be effectively used as molecular sieve carbon.

The PF molecular sieve carbon (P / X = ∞) of (10) is zero by further reducing the amount of 3,5-dimethylphenol (X) component compared to the XPF molecular sieve carbon (P / X = 20) of (9). The PF molecular sieve carbon (P / X = ∞) in (10) and the XPF molecular sieve carbon (P / X = 20) in (9) show good CO ₂ selective adsorption characteristics. Therefore, the amount of the 3,5-dimethylphenol (X) component is an amount between the XPF molecular sieve carbon (P / X = 20) of (9) and the PF molecular sieve carbon (P / X = ∞) of (10). Similarly, certain XPF molecular sieve carbons are understood to have good CO ₂ selective adsorption characteristics.

<Example 10: XPF molecular sieve carbon>
Example 10: XPF molecular sieving carbon has a molar ratio “X: P: F” of 3,5-dimethylphenol (X), phenol (P) and formaldehyde (F) of (1) 1: 1: 4, (2 ) 1: 2: 6, (3) Granular molecular sieves produced by carbonizing XPF resin obtained by mixing each mixture in an electric furnace in an N ₂ atmosphere at 1000 ° C. for 30 minutes. Carbon. The obtained molecular sieve carbons are designated as XPF molecular sieve carbons (1) to (3).

With respect to the XPF molecular sieve carbons (1) to (3), the adsorption amount and adsorption time constant of CH ₄ of CO ₂ were measured. Table 5 shows the characteristics of the XPF molecular sieve carbons (1) to (3). In Table 5, in each XPF molecular sieve carbon of (1) to (3), the upper part is the adsorption amount, and the lower part is the adsorption time constant.

As shown in Table 5, (1) ~ (3 ) XPF adsorption amount of CO ₂ in comparison with the amount of adsorption of molecular sieve carbon are both CH ₄ is large and the adsorption amount of CO _2, compared to the amount of adsorbed CH ₄ The value is 4.1 to 11.1 times. Further, (1) the adsorption time constant ratio of CH ₄ / CO ₂ of XPF molecular sieve carbon of the (P / X = 1) 2.82 , CH of XPF molecular sieve carbon in (2) (P / X = 2) 4 / The adsorption time constant ratio of CO ₂ is 63.6, and the adsorption time constant ratio of CH ₄ / CO ₂ of XPF molecular sieve carbon (P / X = 3) of (3) is 35.9, (2) to (3 ) XPF molecular sieve carbon shows that the adsorption rate of CO ₂ is 36 to 63 times faster than the adsorption rate of CH ₄ .

<About the experimental results of Examples 5-10>
FIG. 6 illustrates the presence or absence of the gas separation effect for the gas containing CO ₂ and CH ₄ by combining these data based on the experimental results of Examples 5 to 10. In FIG. 6, the horizontal axis represents the carbonization temperature, and the vertical axis represents the molar ratio (P / X molar ratio) between the component P (= phenol) and X (= 3,5-dimethylphenol) during the synthesis of the phenol resin. is there. 6 corresponds to the PF molecular sieve carbon of Example 9.

As shown in FIG. 6, a phenol resin having a P / X molar ratio that satisfies the conditions within the dotted line Z in FIG. 6 is used in relation to the P / X molar ratio and the carbonization temperature. Among them, CO ₂ can be selectively adsorbed and separated from a gas containing CO ₂ and CH ₄ by XPF molecular sieve carbon produced by carbonization at a temperature satisfying the carbonization temperature in the frame of the dotted line Z.

<Example 11: XPF molecular sieve carbon>
As part of the above experiment, the XPF molecular sieving carbon according to the present invention selectively adsorbs CO ₂ , and is not limited to CH ₄ , but what kind of adsorption performance is provided for gas components such as N ₂ Tested. FIG. 7 is a graph showing adsorption amounts of CO ₂ , CH _4, and N ₂ with respect to the adsorption pressure by the XPF molecular sieve carbon of Example 7 (1) (see (1) of Table 3) as an example of the result. It is.

As shown in FIG. 7, CH ₄ and N ₂ are not adsorbed, CO ₂ is adsorbed, and the amount of adsorption increases with increasing pressure. Both CH ₄ and N ₂ were only slightly adsorbed at 95 kPa or more and were not substantially adsorbed. Thus, the XPF molecular sieve carbon according to the present invention can selectively adsorb CO ₂ from a gas containing CH ₄ , N _{2 and the} like.

<Consideration of Experimental Results of Examples 5 to 11>
In addition to the above, the experimental results of Examples 5 to 11 and the performance of XPF molecular sieve carbon and PF molecular sieve carbon clarified by observation in the experimental process are as follows.
(1) In PF resin and XF resin, which are raw materials for XPF molecular sieve carbon, XF resin is generally more easily carbonized and has smaller pores. Thereby, the pore size of XPF molecular sieve carbon increases as the P / X molar ratio increases. Further, when carbonized at a high temperature, the pores shrink due to heat, and the pore diameter becomes small. However, as in Example 9, even PF resin has effective CO ₂ and selective adsorption performance.
(2) When the carbonization temperature is 600 ° C., molecular sieve carbon that can be used for separation due to the difference in adsorption rate is obtained due to the difference in adsorption time constant at P / X = 1 and P / X = 2. However, it is considered that the temperature is somewhat lower than the optimum carbonization temperature, and the pores are not developed, so that the molecular sieve performance was not exhibited in the range where P / X was larger than this.
(3) When the carbonization temperature is 700 ° C., the carbonization temperature is slightly lower as in the case of the carbonization temperature of 600 ° C., but due to the difference in the adsorption time constant, the molecular sieve suitable for the selective adsorption of CO ₂ due to the difference in adsorption rate Carbon was obtained.
(4) A carbonization temperature of 800 to 900 ° C. is an optimal carbonization temperature. Carbonization time was also suitable, and molecular sieve carbon particularly suitable for equilibrium separation was obtained in a wide range.
(5) Since carbonization temperature is slightly higher at 1000 ° C., it is considered that carbonization further proceeds and CO ₂ and CH ₄ are adsorbed together. Depending on the carbonization time, both molecular sieve carbon for equilibrium separation and molecular sieve carbon for velocity separation can be produced.
(6) Although the experimental results of Examples 5 to 10 relate to the selective adsorption of CO ₂ from the gas containing CO ₂ and CH ₄ , considering the results of Example 11 and the like, the selective CO ₂ is selected. It is understood that adsorption separation can be determined by the type of gas and the size of gas molecules.

Example 1: Diagram showing characteristics of XPF molecular sieve carbon Example 1: Diagram showing characteristics of XPF molecular sieve carbon Example 2: Graph showing the adsorption amount of CO ₂ and CH ₄ with respect to adsorption pressure by XPF molecular sieve carbon Example 3: Graph showing the adsorption amount of CO ₂ and CH ₄ with respect to adsorption pressure by XPF molecular sieve carbon Example 4: A graph showing adsorption amounts of CO ₂ and CH ₄ with respect to adsorption pressure by XPF molecular sieve carbon Based on the experimental results of Examples 5-10 showed the existence of the gas separation effect to the gas containing CO ₂ and CH ₄ by comprehensively their data Figure Example 11: A graph showing the amount of adsorption for each gas by XPF molecular sieve carbon

Claims (22)

Molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ , which is formed by carbonizing a phenol resin synthesized from phenols and aldehydes, and that selectively adsorbs CO ₂ Controlled molecular sieve carbon. Selectively adsorbs CO _2, a molecular sieve carbon having a controlled pore selectively the CO _2, characterized in that formed by carbonizing the synthesized phenolic resin from non-graphitizable phenols and aldehydes Molecular sieve carbon with controlled pores adsorbed. Molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ and is characterized by carbonizing a phenol resin synthesized from non-graphitizable phenols, graphitizable phenols and aldehydes. Molecular sieve carbon with controlled pores that selectively adsorb CO ₂ . The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to claim 3, wherein the non-graphitizable phenol is phenol and the graphitizable phenol is dimethylphenol. Molecular sieve carbon with controlled pores that selectively adsorb CO ₂ . 5. The molecular sieve carbon having controlled pores for selectively adsorbing CO _{2 according} to claim 4, wherein the molar ratio of phenol as the non-graphitizable phenol and dimethylphenol as the graphitizable phenol is 1: 0. Molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ , characterized by being 5 or more. 5. The molecular sieve carbon having controlled pores for selectively adsorbing CO _{2 according} to claim 4, wherein the molar ratio of phenol as the non-graphitizable phenol and dimethylphenol as the graphitizable phenol is 1: 0. Molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ , characterized in that it is 5-20. A molecular sieve carbon in which pores formed by carbonizing a phenol resin synthesized from phenol (P), 3,5-dimethylphenol (X) and an aldehyde, which selectively adsorbs CO ₂ , are shown in the attached drawings. In FIG. 6, the pores are characterized by carbonizing a phenol having a P / X molar ratio that satisfies the conditions in the dotted line Z in relation to the P / X molar ratio on the vertical axis and the carbonization temperature on the horizontal axis. Controlled molecular sieve carbon. The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 1 to 7, wherein the phenol resin has a carbonization temperature of 600 to 1200 ° C and a carbonization time of 15 minutes or more. Molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ characterized by the above. The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 1 to 7, wherein the phenol resin has a carbonization temperature of 1000 ° C or less and a carbonization time of 15 minutes or more. Molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ characterized by The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 1 to 7, wherein the phenol resin has a carbonization temperature of 800 ° C and a carbonization time of 60 minutes. Molecular sieve carbon with controlled pores. In the molecular sieve carbon having controlled pores selectively adsorb CO ₂ according to any one of claims 1 to 10, the adsorption molecular sieve carbon that is controlling the pores of CO ₂ from gas containing CO ₂ A molecular sieve carbon having controlled pores for selectively adsorbing CO ₂ , which is a molecular sieve carbon for separation. The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 1 to 10, wherein the molecular sieve carbon with controlled pores is CO from a gas containing CO ₂ and CH _{4. A} molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ , characterized in that it is a molecular sieve carbon for adsorption separation of ₂ . The molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 1 to 10, wherein the molecular sieve carbon with controlled pores is CO from a gas containing CO ₂ and N _{2. A} molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ , characterized in that it is a molecular sieve carbon for adsorption separation of ₂ . Selectively adsorbs CO _2, a method for producing a molecular sieve carbon having a controlled pore, fine to selectively adsorb CO _2, characterized by carbonizing a synthetic phenolic resin from phenol and aldehydes A method for producing molecular sieve carbon with controlled pores. Selectively adsorbs CO _2, a method for producing a molecular sieve carbon having a controlled pore, selectively CO _2, characterized by carbonizing a synthetic phenolic resin from non-graphitizable phenols and aldehydes For producing molecular sieve carbon with controlled pores adsorbed on the surface. A method of producing molecular sieve carbon with controlled pores that selectively adsorbs CO ₂ , characterized by carbonizing a phenol resin synthesized from non-graphitizable phenols, graphitizable phenols and aldehydes. A method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ . The method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to claim 16, wherein the non-graphitizable phenols are phenol and the graphitizable phenols are dimethylphenol. A method for producing molecular sieve carbon with controlled pores that selectively adsorb CO ₂ . 18. The method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to claim 17, wherein the molar mixture of phenol as the non-graphitizable phenols and dimethylphenol as the graphitizable phenols. A method for producing molecular sieve carbon with controlled pores that selectively adsorb CO ₂ , wherein the ratio is 1: 0.5-20. A method for producing molecular sieve carbon with controlled pores obtained by carbonizing phenol resin synthesized from phenol (P), 3,5-dimethylphenol (X) and aldehyde, which selectively adsorbs CO _2. In FIG. 6 of the drawing, a phenol resin having a P / X molar ratio that satisfies the conditions in the frame of the dotted line Z is carbonized by the relationship between the P / X molar ratio on the vertical axis and the carbonization temperature on the horizontal axis. A method for producing molecular sieve carbon with controlled pores. The method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 14 to 19, wherein the phenol resin has a carbonization temperature of 600 to 1200 ° C and a carbonization time of 15 minutes. A method for producing molecular sieve carbon with controlled pores characterized by the above. The method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO _{2 according} to any one of claims 14 to 19, wherein the phenol resin has a carbonization temperature of 1000 ° C or less and a carbonization time of 15 minutes or more. A method for producing molecular sieve carbon with controlled pores for selectively adsorbing CO ₂ , wherein: The method of manufacturing a molecular sieve carbon having controlled pores selectively adsorb CO ₂ according to any one of claims 14 to 19, the carbonization temperature 800 ° C. of the phenolic resin, the carbonization time and 60 minutes A method for producing molecular sieve carbon with controlled pores characterized by the above.

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