JP4066907B2 - Method for removing moisture contained in activated carbon - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for removing moisture contained in activated carbon.
[0002]
[Prior art]
Activated carbon is frequently used, for example, to remove impurity components contained in gas. Normally used activated carbon contains water. Examples of the method for removing the water include a method in which a dry inert gas such as dried nitrogen gas and activated carbon are brought into contact with heating, and a method in which activated carbon is heated under reduced pressure [Non-patent Document 1]. ].
[0003]
[Non-Patent Document 1]
"Fourth Edition Experimental Chemistry Course 1 Basic Operation I" (Maruzen Co., Ltd., issued on November 5, 1990), pp. 198 to 199
[Problems to be solved by the invention]
However, such a conventional removal method has a problem that moisture cannot be sufficiently removed and may remain.
[0005]
Therefore, the present inventor has intensively studied to develop a method capable of sufficiently removing the water contained in the activated carbon, and as a result, by contacting the activated carbon with dry hydrogen chloride gas, the water contained in the activated carbon can be more sufficiently removed. The headline, the present invention has been reached.
[0006]
[Means for Solving the Problems]
That is, the present invention provides a method for removing moisture contained in the activated carbon (A), wherein the activated carbon (A) is brought into contact with dry hydrogen chloride gas (B).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Activated carbon (A) that removes moisture by the removal method of the present invention is mainly composed of carbon, and may be obtained by firing natural materials such as wood, coconut shell, and coal. Alternatively, it may be obtained by firing an artificial material such as a synthetic organic polymer compound. Such activated carbon may be commercially available, such as those marketed by Nippon Enviro Chemical Co., Ltd. under the trade names such as “Shirakaba G2c”, “Shirakaba GM2x”, “Shirakaba GH2x”, “Shirakaba WH2C”. Can be mentioned. Since such activated carbon is porous, it is contained by adsorbing moisture in the atmosphere, and its content varies depending on the storage state, but it may be contained, for example, at about 2 to 3% by mass.
[0008]
Activated carbon (A) may be directly contacted with dry hydrogen chloride gas (B) to remove moisture, but in order to reduce the amount of dry hydrogen chloride gas (B) used, dry inert gas (C ), Or after heating under reduced pressure, it is preferably contacted with dry hydrogen chloride gas (B).
[0009]
As the dry inert gas (C), a gas that does not substantially contain moisture, is in a dry state, and is non-reactive with activated carbon is used, and examples thereof include nitrogen gas, argon gas, and air. The temperature for contact with the dry inert gas is usually 50 ° C. or higher and 200 ° C. or lower. In the method of heating under reduced pressure, heating is usually performed in a state where the absolute pressure is reduced to about 0.05 MPa (0.5 atm) or less. The heating temperature is usually about 50 ° C to 200 ° C.
[0010]
In the removal method of the present invention, the activated carbon (A) is brought into contact with dry hydrogen chloride gas (B). Dry hydrogen chloride gas (B) contains almost no moisture, for example, a moisture content of about 100 ppm or less, ideally in a dry state of 0, gaseous hydrogen chloride (HCl), for example, commercially available It is supplied from a hydrogen chloride gas cylinder.
[0011]
The dry hydrogen chloride gas (B) has a hydrogen chloride content of usually 10% by volume or more, preferably 25% by volume or more, such as dry inert gas such as dry nitrogen gas and dry argon gas, and dry air. In addition, it may be diluted with a non-reactive gas in a dry state without reacting with activated carbon, hydrogen chloride or the like, or it may be a pure dry hydrogen chloride gas having a hydrogen chloride content of 100% by volume. Good.
[0012]
The temperature at which the activated carbon is brought into contact with the dry hydrogen chloride gas is not particularly limited as long as the activated carbon does not change in quality, but is practically about 0 ° C to 200 ° C. In addition, since it may generate heat | fever by making activated carbon contact dry hydrogen chloride gas, you may make it contact, cooling, so that this temperature may not be exceeded.
[0013]
FIG. 1 shows an example of a water removing device (1) for removing water contained in activated carbon (A) by the removing method of the present invention. This device (1) includes an activated carbon filling container (2), a gas introduction pipe (3), and a gas outlet pipe (4). The activated carbon filling container (2) is filled with activated carbon (A). The gas introduction pipe (3) introduces a gas component from the outside into the activated carbon filling container (2). The gas outlet pipe (4) guides the gas from the activated carbon filling container (2) to the outside. In the activated carbon filling container (2), activated carbon (A) is filled in a filling region (2A) partitioned by a separator (21) such as a wire mesh. The activated carbon filling container (2) is provided with, for example, a jacket (5), and is configured to heat and cool the filled activated carbon (A).
[0014]
Such removal device (1) has a surface in contact with the dry hydrogen chloride gas (B) that is inert to the dry hydrogen chloride gas, for example, a metal material such as stainless steel or carbon steel, a vinyl chloride resin, a fluororesin. It is preferable to be comprised with resin materials, such as inorganic glass.
[0015]
Such a removal device (1) is an activated carbon filling container (filled with activated carbon (A) used in order to remove impurity components contained in gaseous raw materials, intermediates, products, etc. in chemical plants and the like ( 2) may be connected to a gas introduction pipe (3) for introducing dry hydrogen chloride gas (B) or dry inert gas (C), whereby moisture is removed by the method of the present invention. The activated carbon (A) after complete removal can be used for removing impurities while the activated carbon filling container (2) is filled.
[0016]
In order to remove the water contained in the activated carbon (A) using such a removal device (1), for example, first, the activated carbon filling container (2) is heated by the jacket (5), and the dry inert gas (C) is removed. The gas is introduced into the activated carbon filling container (2) from the gas introduction pipe (3) and led out to the outside from the gas outlet pipe (4), so that it is aerated and brought into contact with the activated carbon (A).
[0017]
Thereafter, the introduction of the dry inert gas (C) is stopped, and the dry hydrogen chloride gas (B) is introduced from the gas introduction pipe (3) into the activated carbon filling container (2) and led out from the gas outlet pipe (4). Thus, the dry hydrogen chloride gas (B) may be passed through the activated carbon filling container (2) and brought into contact with the activated carbon (A) filled in the activated carbon filling container (2).
[0018]
The hydrogen chloride gas (B ′) led out from the gas outlet pipe (4) contains moisture removed from the activated carbon (A). It can also be recovered from B) using a cooling trap (6) or the like.
[0019]
The dry hydrogen chloride gas (B) is a space velocity represented by a volume in terms of atmospheric pressure (0.1 MPa) per hour with respect to the volume of the filling region (2A) filled with activated carbon, and usually 1 / h to 1000 / H, preferably 1 / h to 100 / h.
[0020]
In addition, after the start of ventilation, heat generation may occur due to the adsorption heat of hydrogen chloride on the activated carbon, but since moisture is removed by dry hydrogen chloride gas (B) and the heat generation gradually decreases, the presence or absence of heat generation Can also be used as a measure of moisture removal.
[0021]
Since the activated carbon from which moisture has been removed by the method of the present invention has sufficiently removed moisture, for example, hydrogen gas, nitrogen gas, oxygen gas, argon gas, air, hydrogen chloride gas, chlorine gas, hydrogen bromide gas, It can be suitably used for adsorbing and removing impurities contained in gas components such as bromine gas without the risk of mixing moisture.
[0022]
【The invention's effect】
According to the method of the present invention, water contained in activated carbon can be sufficiently removed.
[0023]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this Example.
[0024]
Comparative Example 1
4.5 kg of activated carbon (Nippon Enviro Chemical Co., Ltd., “Shirakaba WH2C 8/32”) stored in the atmosphere is used for the activated carbon filling container [SUS304, inner diameter 200 mm, high 400 mm thick cylindrical shape] (2) in an activated carbon filling region (2A). The volume of this filling area (2A) was 10 L (10 dm ³ ).
[0025]
While introducing dry nitrogen gas (C) at 170 ° C from the gas inlet pipe (3) into the activated carbon filling container (2) at an introduction rate of 1 m ³ / h in terms of atmospheric pressure, the gas outlet pipe (4) Then, steam was supplied to the jacket (5) while venting and the jacket temperature was set to 170 ° C. A cold trap (6) at −30 ° C. was attached to the gas outlet pipe (4), and water contained in the nitrogen gas after aeration was recovered. When 1 hour passed after the start of the introduction of the dry nitrogen gas (C), the nitrogen gas temperature from the gas outlet pipe (4) was 110 ° C. When 10 hours had passed after the start of introduction, the supply of steam and the introduction of dry nitrogen gas (C) were stopped, and the activated carbon filled container (2) was sealed. At this time, the water recovered in the cold trap (6) was 82 g.
[0026]
Example 1
In Comparative Example 1, the supply of steam and the introduction of dry nitrogen gas (C) were stopped, and then the activated carbon filled container (2) was sealed and allowed to cool to 30 ° C. by natural cooling. The supply of steam was stopped, and the introduction of dry hydrogen chloride gas (moisture content of 10 ppm or less) (B) from the gas inlet pipe (3) was led out from the gas outlet pipe (4) and ventilation was started. After 30 minutes, the internal temperature of the activated carbon filled container (2) became 110 ° C. In addition, water began to be collected again in the cold trap (6) attached to (4) in the gas outlet pipe. Thereafter, the internal temperature gradually decreased and reached 30 ° C. after 6 hours had passed since the start of aeration of dry hydrogen chloride gas. At this time, the amount of recovered water after starting the aeration of the dry hydrogen chloride gas (B) was 2.9 g.
[0027]
Comparative Example 2
When operated in the same manner as in Comparative Example 1, 10 hours after the start of the introduction of the dry nitrogen gas (C), the water recovered in the cold trap (6) was 82 g.
[0028]
After that, without stopping the supply of steam, the jacket temperature was kept at 170 ° C., and 170 ° C. dry nitrogen gas (C) was continuously ventilated for 10 hours, but the cold trap (6) had fresh water. It was not recovered.
[0029]
Thereafter, with the jacket temperature maintained at 170 ° C., the inside of the activated carbon filling container (5) was closed to the cold trap (6), and the absolute pressure was reduced to 5 Torr (660 Pa) and left for 10 hours, but the cold trap (6 ) No new water was recovered.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of a water removal device for removing water contained in activated carbon by the removal method of the present invention.
[Explanation of symbols]
A: Activated carbon B: Dry hydrogen chloride gas C: Dry nitrogen gas (dry inert gas)
1: Water removal device 2: Activated carbon filling container 21: Separator 2A: Filling area 3: Gas introduction pipe 4: Gas outlet pipe 5: Jacket 6: Cold trap

Claims (7)

A method for removing moisture contained in the activated carbon, wherein the activated carbon is brought into contact with dry hydrogen chloride gas. The removal method according to claim 1, wherein the hydrogen chloride content is brought into contact with a dry hydrogen chloride gas having a content of 10% by volume or more. The removal method according to claim 1, wherein the activated carbon is contacted with a dry inert gas and then contacted with a dry hydrogen chloride gas. The removal method according to claim 3, wherein the contact with the dry inert gas is performed at a temperature of 50 ° C. or more. The removal method according to claim 1, wherein activated carbon is filled in an activated carbon filling container, and dry hydrogen chloride gas is passed through the activated carbon filling container. The removal method according to claim 5, wherein dry hydrogen chloride gas is aerated at a space velocity of 1 / h to 1000 / h. An activated carbon filling container filled with activated carbon, a gas introduction pipe for introducing gas from the outside into the activated carbon filling container, and a gas outlet pipe for introducing gas from the activated carbon filling container to the outside, and introducing dry hydrogen chloride gas into the gas Included in the activated carbon, wherein the activated carbon is configured to be introduced into the activated carbon filling container from a pipe and led out from the gas lead-out pipe to bring dry hydrogen chloride gas into contact with the activated carbon in the filled container. Water removal device.

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