JP2005103110A - Deodorant and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a deodorant having high deodorizing effect for all acidic, alkaline and neutral odor components, provided with sufficient strength. <P>SOLUTION: At the time of mixing an inorganic raw material and an organic material for carbonization and firing, they are mixed such that the dry weight of the organic material becomes less than 30 wt.% to the dry weight of the whole. The mixture is kneaded and the deodorant is composed by carbonizing and firing the kneaded material in an unglazed shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a deodorizer having a high deodorizing effect with respect to any of acidic, alkaline and neutral odor components.

  2. Description of the Related Art Conventionally, as a deodorant for removing odor components in the air, one that adsorbs and removes odor components using an adsorbent having a porous structure such as activated carbon is known. The activated carbon is widely used as a deodorant because it has excellent adsorption performance, but it has low strength and is difficult to be molded into an arbitrary shape. And there were limitations in terms of design.

As a solution to the above problem, Patent Document 1 discloses an adsorption formed by baking paper sludge of 30-60% by weight, aluminas of 5-30% by weight, and clays of 10-60% by weight. The materials are listed. This adsorbent can be molded into an arbitrary shape by using clays.
JP 63-256132 A

  However, since the adsorbent contains 30 to 60% by weight of a large amount of paper sludge in order to increase the deodorizing ability, there has been a problem that the strength of the adsorbent is reduced. Adsorbents are effective for either acidic odor components or alkaline odor components depending on their surface properties, but generally are not effective for the other. Has a problem that the adsorption ability of odorous components such as ammonia is relatively weak.

  Therefore, the present invention aims to provide a deodorizing agent that has a high deodorizing effect on any of acidic, alkaline and neutral odor components, can be molded into an arbitrary shape, and has sufficient strength after molding. To do.

  As a result of various studies by the present inventors to solve the above-mentioned problems, conventionally, inorganic materials such as clay, which have been used for the purpose of forming an adsorbent into an arbitrary shape, and an organic material for carbonization firing are mixed. If carbonized and baked into a baked form, acidic odor components such as hydrogen sulfide and methyl mercaptan can be deodorized at the same level as activated carbon even if the amount of organic material to be blended is small. The inventors have found that it is possible to deodorize and have completed the present invention.

  That is, in the present invention, when the inorganic raw material and the organic material for carbonization firing are mixed, the organic material is blended so that the dry weight of the organic material is less than 30% by weight with respect to the total dry weight, and this mixture is mixed. After kneading and forming, the kneaded product is carbonized and fired into an unglazed form.

  According to the above configuration, a deodorizing agent that exerts a deodorizing effect on any of acidic, alkaline, and neutral odor components can be obtained, and since the blending amount of the organic raw material relative to the inorganic raw material is not large, both are mixed. The obtained mixture can be easily formed into an arbitrary shape, and a fired body having sufficient strength can be obtained even in a state of firing in an unglazed form.

  Here, the dry weight means the weight in a state where the inorganic raw material and the organic material are each dried at 105 ° C. for 24 hours. In addition, firing in an unglazed form means firing so as to form an inorganic porous structure having air permeability by firing at a temperature lower than the sintering temperature of the inorganic raw material. Furthermore, the carbonization firing is generated when the organic raw material is carbonized and the organic raw material is carbonized by firing the organic material together with the inorganic raw material in a sealed space or a nitrogen atmosphere. It means fixing the soot to the fired body.

  In the present invention, since the organic material is mixed with the inorganic raw material, the state of the fired body after the carbonization firing is maintained in a state where the carbide generated by carbonizing the organic material is dispersed in the inorganic porous structure. In addition, a product in a state where soot is attached and held on the surface of the porous structure is obtained. Therefore, as the deodorizing agent, a product whose surface and cross section of the fired body are colored black is obtained.

  It should be noted that the deodorizer obtained in the present invention has a high ability to deodorize acidic odor components even when the amount of the organic material used as the raw material of the carbide is less than 30% by weight. is there. Usually, an unglazed inorganic structure has little ability to deodorize acidic odor components such as hydrogen sulfide and methyl mercaptan, and therefore the ability to deodorize acidic odor components depends exclusively on the deodorizing ability of activated carbon. Therefore, conventionally, in order to deodorize the acidic odor component, it has been considered that the amount of activated carbon (carbide) needs to be increased, and as a result, there is a problem that the strength of the fired body is lowered.

  However, with the deodorizer according to the present invention, it is possible to sufficiently deodorize acidic odor components even if the amount of the organic material is small, so that the deodorization can be achieved by finally suppressing the amount of carbide remaining in the fired body. The strength of the agent can be increased.

  In the embodiment described later, the amount of the paper sludge (hereinafter referred to as PS) (dry weight) is changed from 74 to 6% by weight with respect to the dry weight of the entire mixture to prepare six kinds of fired body samples, Each of the samples was evaluated for deodorization performance, and it was confirmed that both samples deodorized both acidic and alkaline odor components in a balanced manner at the same level.

  Thus, it has not been known so far that a deodorant having a PS of less than 30% by weight has the same deodorizing performance as a deodorizer containing 30% by weight or more of PS. Thus, a deodorizing agent having sufficient strength can be obtained.

  Specifically, when the strength of a fired body obtained by firing 100% inorganic raw material containing no organic material under the same conditions as the above sample (hereinafter referred to as unglazed product) is 100, PS in the mixture When the content is less than 30% by weight, it has a strength exceeding 60% of the unglazed product. When the PS content is 23% by weight, the strength is 69% of the unglazed product, and the PS content is 12% by weight. In this case, the strength is 74% of the unglazed product, and when the PS content is 6% by weight, the strength is 81% of the unglazed product.

  As the strength of the fired body, it has been confirmed that it can be used practically as long as it has a strength of 50% of the unglazed product, and the PS content in the deodorant mixture according to the present invention is 30% by weight. The lower the PS content, the lower the content of 23%, 12%, and 6% by weight, which is preferable because the strength of the fired body increases.

  Although it is not clear why the acidic odor component can be deodorized even with a small amount of carbide, the deodorization performance as a deodorant is the same even if the amount of organic material is changed. Considering the fact that non-fired unglazed products do not have the ability to deodorize acidic odor components such as hydrogen sulfide and methyl mercaptan, there are inorganic porous structures and soot adhering to the surface of inorganic porous structures by carbonization firing. Presumably acting synergistically.

  In this embodiment, although the PS content is evaluated only in the range of 6% by weight or more, the evaluation result shows that sufficient deodorization performance is exhibited even if the amount of the organic material is less than 6% by weight. It is estimated to be. As the minimum amount of organic material required to exhibit sufficient deodorizing performance, it is sufficient to use an amount of organic material that can generate soot that covers the entire surface of the porous structure. Presumed.

  In the present invention, the inorganic raw material is a raw material for firing, and generally clay which is a raw material for ceramics or the like can be used. The firing temperature for firing the inorganic raw material into a raw baking shape varies depending on the sintering temperature of the inorganic raw material, but is about 770 ° C. to 930 ° C. in the case of clay for general ceramics. When the temperature is lower than 770 ° C., the strength of the fired body may be reduced. When the temperature is higher than 930 ° C., the porous structure may be densified and the surface area of the fired body may be reduced.

  Any organic material may be used as long as it is carbonized while generating cocoons by carbonization and firing. For example, rice husk, paper, wood pieces, rice straw, paper sludge and the like can be used. However, in order to reduce the variation in the strength of the fired body after the carbonization firing, it is necessary to make the structure of the fired body homogeneous, and for this purpose, it is desirable to use the organic material by pulverizing it as finely as possible. From this point of view, paper sludge is discharged in large quantities from paper mills, and is easily available, and is made of paper short fibers and filler-derived inorganic substances (kaolin, talc, calcium carbonate, etc.). It is preferable in that it is made of a mixture and can be easily kneaded with an inorganic raw material to obtain a fired body having a uniform structure.

  The deodorant obtained as described above has a high deodorizing effect on any of acidic, alkaline and neutral odor components, can be molded into an arbitrary shape, and has sufficient strength even after firing. Very high added value.

  Since the deodorizer according to the present invention is a mixture of an inorganic raw material and an organic material at a predetermined weight ratio, it can be molded into an arbitrary shape and is carbonized and fired into an unglazed form. In spite of the small amount of carbon in the medium, it is possible to efficiently deodorize the acidic odor component, and to suppress a decrease in strength of the fired body.

[Production of deodorant]
Next, the manufacturing method of the deodorizer which concerns on this invention is demonstrated. In this embodiment, unless otherwise specified, “%” indicates “% by weight”.

As an inorganic raw material, clay (water content: 20%, SiO ₂ : 54.3%, Al ₂ O ₃ : 16.4%, Fe ₂ O ₃ : 0.4%, TiO ₂ : 0.00%, which is a ceramic raw material. 2%, CaO: 0.2%, MgO: 0.2%, K ₂ O: 2.4%, Na ₂ O: 1.2%, others: 4.7%) Sun-dried PS (water content: 3.5%, loss on ignition: 59.8%, amount of residue: 36.7%) was used. The moisture content of the clay and PS was sampled in advance, measured the initial weight, then measured the dry weight after drying at 105 ° C. for 24 hours, and calculated by the following formula (1).

Water content (% by weight) = (initial weight−weight after drying) × 100 / initial weight (1)
Next, as shown in Table 1, seven types of mixtures in which the actual use weight ratio of clay and PS was changed were prepared and kneaded uniformly. Table 1 shows the dry weight ratio of clay and PS and the content of the dry weight of PS with respect to the dry weight of the entire mixture. The dry weight of clay and PS was calculated as follows based on the water content calculated by the above formula (1).

Clay dry weight = Clay actual use weight × (1−0.20)
PS dry weight = PS actual use weight × (1-0.035)
Subsequently, the said mixture was shape | molded, the obtained molded object was accommodated in the airtight container (sheath), and carbonization baking (800 degreeC x 7.5 to 8.5 hours) was carried out with the kiln. The shape of the fired body thus obtained was a bowl shape with a bottom area of 9.4 cm ² , a height of 6.0 cm, an opening circumferential length of 21.6 cm, and a wall thickness of 4.7 mm.

  Moreover, the fired body had an inorganic porous structure, and the carbide was dispersed and held in the inorganic porous structure, and the soot was attached to the porous surface and exhibited a black color as a whole. Table 1 also shows the weight of the fired body obtained for each sample.

[Performance evaluation of deodorizer]
The deodorizing performance was evaluated using the seven types of deodorizing agents produced as described above. As an evaluation method, first, four samples were made into a set, and each sample was housed in a 10-liter capacity tedra bag. Using four types of odor components, ammonia, trimethylamine, hydrogen sulfide, and methyl mercaptan, 8 liters of a reference gas prepared to a concentration of 100 ppm each was enclosed in the four tedra bags, and the gas concentration was set every predetermined time. Was measured (detector tube method), and the deodorization rate was calculated by the following equation (2) based on the measured gas concentration.

Deodorization rate (%) = (initial gas concentration−measured gas concentration) × 100 / initial gas concentration (2)
For comparison, the same evaluation was performed using a fired body (unglazed product) fired using clay alone without mixing PS and a 44 g commercial deodorizer (hereinafter referred to as activated carbon). The result of a deodorizing rate is shown to FIGS. 1-4 and Tables 2-5.

[Measurement of carbon content and carbon content of deodorizer]
In the deodorizer according to the present invention, it is considered that the carbon derived from the carbide and soot present in the sample contributes to the deodorizing performance of the acidic odor component. Therefore, the carbon content (% by weight) in the deodorizer was measured using the above seven types of deodorizer. The measurement conditions are described below.

  As an analysis method, a CHN automatic analyzer (varioEL) manufactured by Elemental Co., Ltd., equipped with a thermal conductivity detector, helium gas (gas flow rate: 200 ± 5 ml / min) as a carrier gas, and combustion tube temperature It was carried out by setting 950 ° C. and reducing tube temperature 500 ° C. Acetanilide was used as a reagent, and analysis was performed with a sample amount of 3 mg. The obtained carbon content was multiplied by the weight of each sample, and the carbon content (g) present in the sample (fired body) was calculated. These analysis results are also shown in Table 1.

[Strength evaluation of deodorizer]
A strength test was conducted using the above seven types of deodorants. The contents of the test are as follows. The strength was evaluated using a rheometer (manufactured by Sun Science Co., Ltd.) under the following conditions.

  A sample was placed on a test bench, a probe having a tip diameter of 0.45 mm was pressed against it, and the maximum strength was measured at an approach speed of 60 mm / min. The test results are also shown in Table 1.

[Evaluation results]
1-4 and Tables 2-5, the unglazed product has poor deodorizing performance of hydrogen sulfide and methyl mercaptan, which are acidic odor components, and activated carbon has an ammonia deodorization test (FIGS. 1 and 2), even after 1 hour has passed. It can be seen that the deodorization rate is lower than those of other fired samples (samples 1 to 6 and unglazed products).

  On the other hand, it was confirmed that Samples 1 to 6 produced in this embodiment efficiently deodorized any odor components of ammonia, trimethylamine, hydrogen sulfide, and methyl mercaptan. In particular, in the deodorization test (FIG. 4, Table 5) of methyl mercaptan, which is an acidic odor component, it can be seen that a higher deodorization rate is reached earlier than activated carbon.

  This is because the samples 1 to 6 are shaped like a bowl and have a large contact area directly in contact with odor components, whereas activated carbon is contained in a container as an aggregate of granular materials, It was assumed that it was difficult to come in contact with odor components. Thus, the performance of the deodorizer is considered to be greatly influenced by its shape as well as the adsorption performance of the material itself.

  When comparing the samples 1 to 6 and the activated carbon, the carbon content contained in the samples 1 to 6 is 3.1 to 0.8 g, which is significantly smaller than the activated carbon 44 g. In particular, it was confirmed that the sample 6 showed the same level of deodorization performance as the other samples, although the carbon content was as small as 0.8 g.

However, although samples 1 and 2 have excellent deodorizing performance, the strength is only about 23 to 29% of the strength of the unglazed product and is brittle (Table 1). When the strength is Y and the PS dry weight% is X, there is a correlation of Y = −9600.7X + 8695 (R ² = 0.9531).

  Therefore, when the dry weight% of PS is less than 30% with respect to the dry weight of the entire mixture, the strength of the deodorizer will exceed 5815, and the strength of greater than about 60% of the unglazed product strength will be maintained. Become. It has been confirmed that if it has 50% strength of the unglazed product, it can be used without any problem in practical use. Can be obtained.

  Furthermore, when the PS content is 23% by weight, the strength of the unglazed product is 69%, when the PS content is 12% by weight, the strength of the unglazed product is 74%, and when the PS content is 6% by weight. It can be seen that the unglazed product has 81% strength, and the strength of the fired body increases as the PS content decreases. Therefore, the lower the PS content, the better the strength of the fired body.

  As mentioned above, although the relationship seen in PS content and the sintered body strength with respect to the whole mixture was demonstrated, the same relationship is seen also about a carbon content rate and a sintered body strength. That is, the smaller the carbon content in the fired body, the greater the strength of the fired body. Specifically, when the carbon content is less than 2.1%, the strength higher than 56% of the strength of the unglazed product is retained. When the carbon content is 1.8%, the strength of the unglazed product is 69%. When the carbon content is 1.2%, the strength of the unglazed product is 74%, and when the carbon content is 1.0%. Has a strength of 81% of the unglazed product, and the strength of the fired body increases as the carbon content decreases.

  In this embodiment, the PS content with respect to the entire mixture was evaluated as 6%, and the carbon content was 1.0% as the lowest level (Sample 6), but the deodorizing performance was different from that of other samples (Samples 1 to 5). The result was unchanged.

  On the other hand, in an unglazed product that has not been carbonized and fired, there is almost no deodorizing ability with respect to acidic odor components such as hydrogen sulfide and methyl mercaptan. Considering these factors, it was speculated that the deodorizing ability of the acidic odor component is exhibited mainly by the synergistic action of the inorganic porous structure and the soot adhering to the surface of the inorganic porous structure. .

  From the above evaluation results, it is estimated that even if the amount of the organic material is less than 6% by weight or the carbon content is less than 1.0%, sufficient deodorizing performance is still exhibited. As the minimum amount of organic material required to exhibit sufficient deodorizing performance, it is sufficient to use an amount of organic material that can generate soot that covers the entire surface of the porous structure. Presumed.

Graph showing the deodorization performance of ammonia in each deodorizer Graph showing the deodorization performance of trimethylamine in each deodorant Graph showing the deodorization performance of hydrogen sulfide in each deodorizer Graph showing the deodorization performance of methyl mercaptan in each deodorant

Claims (5)

When mixing the inorganic raw material and the organic material for carbonization firing, the organic material is blended so that the dry weight of the organic material is less than 30% by weight with respect to the total dry weight, and the mixture is kneaded and the kneaded A method for producing a deodorant, characterized in that a product is carbonized and fired into an unglazed form. The method for producing a deodorant according to claim 1, wherein the organic material is paper sludge. A deodorant formed by molding a mixture of an inorganic raw material and an organic material and carbonizing and firing it into an unglazed form, wherein the blending ratio of the organic material in the mixture is less than 30% by dry weight Deodorant. A deodorizer, which is a porous structure obtained by carbonizing and firing a mixture of an inorganic raw material and an organic material in an unglazed form, wherein the carbon content in the structure is less than 2.1% by weight. The deodorizer according to claim 3 or 4, wherein the organic material is paper sludge.