JPS5815175B2 - Encasisogasnojiyokiyozai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an agent for removing hydrogen chloride gas, and particularly to an agent for removing hydrogen chloride gas mixed in the atmosphere.

According to Japan's Basic Law on Pollution Control, representative pollution is specified as air pollution, bad odors, water pollution, soil pollution, noise, vibration, and ground subsidence.

Among the various harmful gases that are one of the causes of air pollution and bad odors mentioned above, hydrogen chloride gas in particular has an unpleasant pungent odor, smokes strongly in humid air, and is corrosive in the presence of moisture. It not only has a negative effect on the human body, but also
It corrodes and damages machinery, equipment, and buildings, and is generated during dye manufacturing, hydrochloric acid manufacturing, chloride manufacturing, pickling of steel, etc., and mixed in the atmosphere.

Traditionally, hydrogen chloride gas has been removed using alkali neutralization washing method, water washing method, etc., but these methods require the use of large-scale equipment, making it difficult to purify the environment on a small scale. The problem is that it is not suitable for

The present invention was completed as a result of various research conducted in order to find an effective remover for hydrogen chloride gas in order to eliminate these difficulties. This is a hydrogen chloride gas remover characterized by being made by molding and drying a mixture of the hydrogen chloride gas and activated carbon.

The allophane used in the hydrogen chloride gas remover of the present invention is also called colloid, and is composed of nSiO2゜Al20
It has a composition of A1203O [n=1-2], for example, Si
About 40% by weight of O2, about 40% by weight of Al2O3.

Contains about 17% by weight of H20 and has a specific surface area of about 300m/
g and true specific gravity of about 2.7.

This allophane is preferably purified and used, for example, by elutriation or other purification methods.

The size of allophane powder when used is generally 20
A range of 0 to 500 meshes, particularly 300 to 400 meshes is preferred.

The activated carbon used in the hydrogen chloride gas remover of the present invention may be commercially available activated carbon, such as coconut shell charcoal or oil-based activated carbon for repelling insects that burn hydrocarbons.

The particle size of activated carbon when used is generally in the range of 300 to 500 mesh, particularly preferably 30D mesh or less.

The ratio of allophane to activated carbon is generally 80:20.
60:40. In particular, it is preferable to set the ratio to 70:30.

To produce the hydrogen chloride gas remover of the present invention, allophane and activated carbon are mixed, the mixture is formed into a spherical size of approximately 0.3 to 6 mm, and heated at a temperature of approximately 150 to 160°C. It is sufficient to dry it for about 2 to 3 hours.

In the hydrogen chloride gas remover of the present invention, in addition to allofene and activated carbon, conventionally known adsorbents such as silica gel,
Alumina gel, activated clay, etc. can be mixed, but it is important to use small amounts.

The hydrogen chloride gas remover according to the present invention is filled in a certain container, for example, an iron container, a duct is provided in this container, and air mixed with hydrogen chloride gas is forced to pass through the filled bed to remove hydrogen chloride gas. Used for gas removal.

Next, the present invention will be specifically described with reference to production examples and examples.

70% by weight of allophane with a size of 300 to 400 meshes and 30% by weight of activated carbon (commercially available oil-based activated carbon) with a size of 300 meshes or less are mixed to form a homogeneous mixture, and this mixture is The pellets are granulated into approximately spherical shapes of 6 mm and dried at 160° C. for 2 hours to obtain a product (hydrogen chloride gas removal agent).

Production Example 2 Allophane and activated carbon used in Production Example 1 were each
A homogeneous mixture is obtained by mixing 0% by weight and 40% by weight, and this mixture is granulated and dried in the same manner as in Production Example 1 to obtain a product (hydrogen chloride gas removing agent).

Production Example 3 Allophane and activated carbon used in Production Example 1 were each
A homogeneous mixture is obtained by mixing 0% by weight and 20% by weight, and this mixture is granulated and dried in the same manner as in Production Example 1 to obtain a product (hydrogen chloride removal agent).

Examples Products shown in Production Examples 1 and 2 (hydrogen chloride gas removal agent)
was tested as follows using the testing apparatus shown in FIG.

The test results are shown in Figure 2. The main parts of the test equipment are:
It consists of a hydrogen chloride gas generator 1, a humidity control device 2, and a hydrogen chloride gas adsorption device 3.

In the test, the hydrogen chloride gas generator 1 was configured such that a concentrated hydrochloric acid solution 4 was placed in a glass container and heated by a heating device 5, and water 6 was placed in a humidity control device 2 and kept warm by a heating device 7. It is possible to do so.

Open the cock 9 of the nitrogen cylinder 8 and take out the nitrogen gas.
This is divided into two parts: one passes through a flow meter 10 and then a hydrogen chloride gas generator 1, with hydrogen chloride gas flowing through a gas reservoir 1;
1, and the other one goes through the flow meter 12 to the humidity controller 2.
There, the gas is appropriately heated and humidified by the heating device 7, and the two flows are combined at the three-way pipe 13 to form an appropriately humidified mixed gas of hydrogen chloride gas and nitrogen gas.

This is because actual hydrogen chloride gas mixtures usually involve a certain degree of humidity, so the test was conducted by preparing a gas mixture to match this natural condition.

The mixed gas of hydrogen chloride gas and nitrogen gas that has been appropriately humidified in this manner is sent to the hydrogen chloride gas adsorption device 3, which uses a glass tube with an inner diameter of 16 mm to remove the hydrogen chloride gas. Add 5g of Agent 14.

The concentration of hydrogen chloride gas introduced into the hydrogen chloride gas adsorption device 3 was 15 to 30 ppm, the flow rate was 2.41/min, and the relative humidity was 40 to 50%.

The removal rate of hydrogen chloride gas is determined by the concentration of hydrogen chloride in the sample (before adsorption) taken from the sample collection tube 15 installed between the hydrogen chloride gas adsorption device 3 and the three-way pipe 13, and the outflow from the hydrogen chloride gas adsorption device 3. The concentration of hydrogen chloride in the sample (after adsorption) taken from the sample collection tube 16 provided on the side was measured and determined from the difference in the concentration of hydrogen chloride.

The test results are shown in the curve diagram of FIG. 2 (the horizontal axis represents time in hours, and the vertical axis represents hydrogen chloride gas removal rate).

In the curve diagram of FIG. 2, 5 g each of activated carbon alone (100%) or allophane alone (100%) was filled in place of the hydrogen chloride removing agent 14 shown in Production Examples 1 and 2, and under the same conditions as above ( That is, hydrogen chloride gas concentration 15-30p
pm, flow rate 2.41/min, and relative humidity 40-50%). The removal rate of hydrogen chloride gas is also shown.

As is clear from the curve diagram in Figure 2, allophane 100%
Those made of 100% activated carbon also show a high removal performance, but those made of 100% activated carbon only show a considerably low performance.

However, when activated carbon is added to allophane, a synergistic effect appears, and the removal performance and performance duration are greatly improved compared to those containing 100% allophane.

That is, although activated carbon itself has a low ability to remove hydrogen chloride gas, it is presumed that the large specific surface area of activated carbon has an effective effect in bringing hydrogen chloride gas molecules closer to the active surface of allophane.

According to experiments, increasing the addition rate of activated carbon from 30% to 40% by weight seems to improve the removal rate and removal duration, but the difference is small and there is almost no difference in practical performance. I cannot go so far as to admit that.

That is, the error in the average value for each time is about ±5% (32 degrees of freedom).

Furthermore, as the amount of activated carbon is increased from 30% by weight to 40% by weight, the degree of pulverization of the granulated material increases, so it is estimated that approximately 30% by weight is practically appropriate.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the outline of a test device for the performance of the hydrogen chloride gas remover of the present invention, and Fig. 2 is a curve diagram showing the test results of the performance of the hydrogen chloride gas remover of the present invention. be. 1... Hydrogen chloride gas generator, 2...
Humidity control device, 3...Hydrogen chloride gas adsorption device,
4... Concentrated hydrochloric acid solution, 5... Heating device,
6...Water, 7...Heating device, 8...
...Nitrogen cylinder, 9...Cock, 10...
...Flowmeter, 11...Gas reservoir, 12...
...Flowmeter, 13...Three-way pipe, 14...
・Hydrogen chloride gas removal agent, 15... Sample collection tube, 16... Sample collection tube, 17...
・Flowmeter, 18, 19, 20, 21 and 22...
··cock.

Claims (1)

[Claims] 1. A hydrogen chloride gas removal agent characterized by forming and drying a mixture containing allophane as a main component and mixed with activated carbon.