JPH0424095B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an agent for removing lower aliphatic aldehydes such as formaldehyde and acetaldehyde. As is well known, lower aliphatic aldehydes such as formaldehyde and acetaldehyde are harmful gases with a unique pungent odor, and even if they exist in the air at extremely low concentrations, such as 0.1 to 0.2 ppm, the odor will not be noticeable. Concentrations of about 5 ppm are highly irritating to the eyes and throat, and prolonged contact can cause health problems such as dermatitis and respiratory diseases, which is not desirable. Sources of these aldehydes include factories that manufacture formaldehyde, acetaldehyde, or their derivatives, factories that manufacture urea-formalin resin, and factories that manufacture adhesives, plywood, etc.; In many cases, the level is 100 ppm, and effective abatement measures are strongly desired. Conventionally, as removal agents for these aldehyde-containing gases, alumina catalysts supporting platinum metal compounds, activated carbon supporting hydrazines, activated carbon supporting aniline, etc. have been proposed. However, in the former case, the catalyst is expensive and the temperature at which catalytic oxidation occurs is as high as 200 to 300°C, so it is difficult to heat the dilute aldehyde-containing gas.
The temperature must be raised, and the latter two have the disadvantage that if the activated carbon contains water even in a normal humidity atmosphere (about 50 to 80% relative humidity), the removal performance will drop significantly, so neither is satisfactory. . In view of these points, the present inventors have conducted intensive studies and found that a removal agent in which aromatic or araliphatic primary amines or their salts are supported on clay minerals effectively captures aldehydes. However, based on this knowledge, we have completed the present invention. That is, the present invention is an agent for removing lower aliphatic aldehydes, which is prepared by supporting an aromatic or araliphatic primary amine or a salt thereof on a clay mineral having a one-dimensional or two-dimensional structure. Examples of clay minerals used in the present invention include sepiolite attapulgite, halloysite, and allofene having a one-dimensional structure (fibrous structure), montmorillonite, bentonite, and vermiculite having a two-dimensional structure (plate-like structure). Examples include talc and mica, and among these, sepiolite and attapulgite, which have a one-dimensional structure (fibrous structure), are preferred. Any shape of the clay mineral can be used, such as powder, irregularly crushed, cylindrical, spherical, etc. shaped granules. Examples of aromatic primary amines used in the present invention include aniline, O-toluidine, m-toluidine, p-toluidine, methanic acid, and sulfanilic acid, and examples of aromatic aliphatic primary amines include benzylamine. can give.
These include, for example, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid,
It may be an inorganic salt obtained by reaction with an inorganic acid such as hydrobromic acid or hydrofluoric acid, or an organic salt obtained by reaction with an organic acid such as acetic acid, oxalic acid, or citric acid. Two or more of the above amines or salts may be used as a mixture. Methods for supporting these amines or their salts on clay minerals include, for example, an immersion method in which the amine or its salt is dissolved in water in advance and the clay mineral is immersed in this aqueous solution, and a method in which the aqueous solution is sprinkled while stirring and mixing using a conventional method. Examples include a sprinkle method, or a method in which clay mineral powder and crystals of amine or its salt are mixed in advance, and then dissolved and granulated using a rolling granulator or the like while spraying water. The amount of amine or its salt supported on the clay mineral is about 1 to 40% by weight, preferably about 1 to 20% by weight, more preferably about 1 to 20% by weight, based on the weight of the clay mineral anhydride.
It is about 10% by weight. If the supported amount of amine or its salt is less than 1% by weight, the aldehyde removal effect may not be sufficiently exerted. Also, 40
If it exceeds % by weight, the removal effect will not improve in proportion to the supported amount, and the amine salt may be eliminated. Clay minerals carrying amines or their salts are
The removing agent of the present invention can be obtained by drying in an air bath at about 100° C. by a conventional static drying method or ventilation drying method. The thus obtained removing agent of the present invention can efficiently capture and remove aliphatic aldehydes having 1 to 2 carbon atoms, and the removing effect does not deteriorate even in a wet state. In addition, although the coloring mechanism of the remover of the present invention is unknown, the color changes from pale pink to yellow when formaldehyde is captured, so it can also be used as a formaldehyde detector. . EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples. Example 1 500 g each of irregularly shaped particles of 6 to 8 meshes of Spanish sepiolite were placed in a 5 capacity tabletop mixer, and 2.5 g, 5 g, and 12.5 g of aniline hydrochloride were added.
Weigh out g, 25g, 50g, 100g, 150g, 200g,
Dissolve each in 200 ml of water. While operating a tabletop mixer, the aniline hydrochloride solution was sprinkled on the mixture, and then dried using an air bath dryer at 110° C. to obtain the removing agent shown in Table 1.

[Table] The acetaldehyde removal performance of each of the removers thus obtained was measured by the method shown below, and the results shown in Table 2 were obtained. Method for Measuring Acetaldehyde Removal Performance Measurement was performed under the following conditions using the gas circulation adsorption test device shown in Figure 1. Measurement operation: Operate the gas flow switching knob to make the gas circulation system shown in Figure 1 a bypass flow path, and accurately weigh and fill approximately 5 g of sample into the sample column and set it in the apparatus. The diaphragm pump is operated, and while circulating the air at a constant humidity in the gas holder, a fixed amount of acetaldehyde is injected from the gas injection hole, and while the gas continues to circulate, the gas is sampled from the gas sampling hole, and the gas is analyzed using a gas chromatograph. Analyze the gas concentration using E. Once the gas concentration has stabilized, operate the gas flow path switching knob to switch the gas flow path to the sample column side, sample the gas at regular intervals, and measure the change in gas concentration over time. When the gas concentration in the gas holder stabilizes and reaches equilibrium, operate the gas flow path switching knob to set the bypass flow path, repeat the operations from to, and measure the gas concentration equilibrium point in the same way. The measurement results are converted to equilibrium adsorption lines using the following method. The equilibrium adsorption amount is calculated from the amount of acetaldehyde injected to reach that concentration, the amount of acetaldehyde remaining in the system after measurement, and the amount of sample used for measurement, using the following formula, assuming that the concentration at the time when the gas concentration stabilizes is the equilibrium concentration. Calculate and plot at each corresponding equilibrium concentration to obtain the equilibrium adsorption line and compare the removal performance at gas concentrations of 10 ppm and 100 ppm. All specimens used in this measurement must be saturated with moisture in an atmosphere of 95% relative humidity. Q=VCo(1-Cs/Co)/W Here Q: Equilibrium adsorption amount (mg/g) V: Total gas volume () Co: Initial gas concentration (mg/) Cs: Equilibrium gas concentration (mg/) W: Sample amount (g)

【table】

[Table] Example 2 500 g of sepiolite used in Example 1 was weighed out, and 25 g of aniline sulfate dissolved in 200 ml of water was supported in the same manner as in Example 1 to obtain a removal agent. This removing agent was treated in the same manner as in Example 1,
As a result of measuring acetaldehyde removal performance,
9.8mg/g at 10ppm concentration, 15.8mg/g at 100ppm concentration
It had the performance of g. Example 3 500 g of crushed irregularly shaped particles of 10 to 20 meshes of attapulgiaite produced in Georgia State, USA were weighed out, 25 g of aniline hydrochloride dissolved in 200 ml of water was supported in the same manner as in Example 1, and a removing agent was applied. Obtained. As a result of measuring the acetaldehyde removal performance of this removal agent in the same manner as in Example 1,
8.8mg/g at 10ppm concentration, 13.9mg/g at 100ppm concentration
It had the performance of g. Example 4 The formaldehyde removal performance of the removal agent prepared in Example 1 was measured in the same manner as the acetaldehyde removal performance measurement method of Example 1, and the results shown in Table 3 were obtained.

【table】

[Table] Example 5 500 g of 30 to 60 mesh of montmorillonite (sulfuric acid treatment - heat treated product) produced in Niigata Prefecture and 25 g of aniline hydrochloride were mixed, 400 g of water was added to the mixture, kneaded, and then extruded using an extrusion molding machine. It was molded into a cylindrical shape with a diameter of 3 mm and a length of 5 to 10 mm, and dried in an air bath dryer at 110° C. to obtain a removing agent. As a result of measuring the acetaldehyde removal performance of this removal agent in the same manner as in Example 1, it was found that 10ppm
The performance was 8.0 mg/g at a concentration and 13.0 mg/g at a concentration of 100 ppm. Example 6 500 g of sepiolite used in Example 1 was weighed out and 25 g of benzylamine was sprayed with stirring using a small sprayer to obtain a remover containing 5 weight percent of benzylamine. The acetaldehyde removal performance of this removal agent was measured in the same manner as in Example 1, and the performance was 12.8 mg/g at a concentration of 10 ppm and 28.5 mg/g at a concentration of 100 ppm. Example 7 500 g of attapulgite used in Example 3 was weighed out, and 25 g of sulfanilic acid (aniline/p-sulfonic acid) was dissolved in 400 ml of water.
A removing agent containing 5% by weight of sulfanilic acid was obtained by supporting in the same manner as described above. The acetaldehyde removal performance of this removal agent was measured in the same manner as in Example 1, and the performance was 8.0 mg/g at a concentration of 10 ppm and 11.5 mg/g at a concentration of 100 ppm. Example 8 500 g of sepiolite used in Example 1 was weighed, and 25 g of methanic acid (aniline/m-sulfonic acid) was added.
g dissolved in 400 ml of water was supported in the same manner as in Example 1 to obtain a removal agent containing 5% by weight of methanic acid. Regarding this remover, the formaldehyde removal performance was measured in the same manner as in Example 1, and the results were as follows:
7.1mg/g at 10ppm concentration, 11.6mg/g at 100ppm concentration
It had the performance of g. Example 9 500 g of irregularly shaped particles of 6 to 8 meshes of allofen from Kyushu were weighed out, placed in a 5-capacity tabletop mixer, and 25 g of benzylamine was sprayed with stirring using a small sprayer.
A removal agent containing % by weight was obtained. The formaldehyde removal performance of this remover was measured in the same manner as in Example 1, and the performance was 7.6 mg/g at a concentration of 10 ppm and 12.3 mg/g at a concentration of 100 ppm.

[Brief explanation of drawings]

FIG. 1 shows a gas circulation type adsorption test apparatus used in the Examples to measure lower aldehyde removal performance. In the figure, A...Gas holder, B...Diaphragm pump, C...Flowmeter, D...Sample column, E
...Gas sampling hole, F...Bypass, G...
... Shows the gas flow path switching knob.

Claims (1)

[Claims] 1. A lower aldehyde remover comprising a clay mineral having a one-dimensional or two-dimensional structure supporting an aromatic or araliphatic primary amine or a salt thereof.