JPS629374B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a deodorizing adsorbent that can selectively adsorb and remove basic gases such as ammonia and amines from odor gases generated from human waste treatment plants, sewage treatment plants, or garbage treatment plants. Conventionally,
Methods for removing these basic gases include: Cleaning method using gas-liquid contact with water or acid aqueous solution Catalytic oxidation method using a catalyst Adsorption method using granulated activated clay, zeolite, etc. as an adsorbent Non-volatile activated carbon Adsorption methods using impregnated charcoal or sulfonated charcoal as adsorbents are known. However, these methods have advantages and disadvantages; for example, the cleaning method has a high removal rate and is effective when the basic gas concentration in the gas to be treated is high, but it is effective when the basic gas concentration is low. It often happens that the deodorization rate is reduced and complete deodorization cannot be achieved without the aid of adsorbents for finishing. Moreover, in the case of this cleaning method, a secondary problem of waste liquid treatment occurs because a large amount of waste liquid is discharged. In the case of the following catalytic oxidation method, the temperature is usually 300℃.
Because the catalyst and gas are brought into contact at such high temperatures, fuel costs are too high unless the concentration is extremely high, and NO _x is produced as a by-product in the exhaust gas, which may cause secondary pollution. In addition, the catalyst is easily poisoned by sulfur compounds such as hydrogen sulfide and methyl mercaptan that coexist with basic gas in the gas to be treated.
As a result, it has the disadvantage of causing catalyst deterioration. In the case of an adsorption method using an adsorbent, since the adsorption capacity of activated clay, zeolite, etc. for basic gases is not so large, it is difficult to say that the adsorption amount of the adsorbent of the granules is sufficiently large. As a result, when filled in a deodorizing device, the adsorption life is short and the adsorbent has to be replaced frequently. In the case of an adsorption method using an adsorbent such as impregnated carbon or sulfonated carbon, the base activated carbon simultaneously adsorbs various hydrocarbons coexisting in the gas to be treated, resulting in a significant decrease in basic gas removal ability. Furthermore, activated carbon also adsorbs moisture when the gas to be treated has a relative humidity of 60% or more (for example, in deodorizing a sewage treatment plant, the relative slope is 80% or more on average). The pressure drop in the agent layer increases,
The amount of gas to be treated (m ³ /min) decreases, the attached non-volatile acid dissolves into the activated carbon coagulation water, and an acid aqueous solution with a low PH value flows out, causing corrosion and other effects on the deodorizing device itself. It also has the disadvantage of As a result of intensive research, the present inventors have overcome the above-mentioned drawbacks of conventional methods and have invented an adsorbent that has a very large adsorption amount and is economically very inexpensive. That is, the present invention relates to an adsorbent for basic gas deodorization characterized by using titanium oxysulfate (TiOSO ₄ ), which cannot be predicted to be used as an adsorbent based on the prior art. Titanium oxysulfate is used alone or mixed with a natural clay mineral such as activated clay in a certain ratio and granulated. The titanium oxysulfate used in the present invention is produced by using an intermediate product obtained by removing iron impurities from ilmenite as iron sulfate when producing titanium oxide using a sulfuric acid method from ilmenite, which is a raw ore containing titanium. is more economical. Binders used for granulation include single or mixed emulsions such as vinyl acetate, acrylic resin, and styrene, water-soluble binders such as polyvinyl alcohol, sodium carboxymethylcellulose, and sodium alginate, and methylolated binders such as melamine resin and urea resin. Use thermosetting resin. In addition, basic gas refers to ammonia and amines, such as monoalkylamines such as methylamine and ethylamine, dialkylamines such as dimethylamine and diethylamine, trialkylamines such as trimethylamine and triethylamine, methylene diamine, 1 such as alkylene diamines such as ethylenediamine, hydroxyalkylamines such as methanolamine and ethanolamine, etc.
Refers to amines having one or more nitrogen atoms in the molecule. Since the adsorbent of the present invention has a very large adsorption amount,
The amount used is extremely small compared to conventional ones, and since it is inexpensive, the basic gas adsorption unit cost is low, and it brings about an economical breakthrough effect in this field. The present invention will be explained in detail below using Examples and Comparative Examples. Example 1 Titanium sulfate powder (300 mesh or less) 100
g and 20 g of commercially available vinyl acetate emulsion were uniformly mixed to form a paste, which was granulated into pellets using a granulator and dried at 80° C. for 2 hours to obtain an adsorbent. Fill 8 ml of this material into a column with an inner diameter of 10 mmφ, and feed the gas to be treated containing 100 ppm of ammonia and 50 ppm of trimethylamine at a linear velocity of 30 mm.
cm/sec and adsorbed until ammonia was 1 ppm and trimethylamine was 0.5 ppm at the outlet of the adsorption column, and the amount of adsorption was measured, and the result was 5.2 mol/cm/sec for ammonia and 1.3 mol/cm/sec for trimethylamine. Ta. In addition, the adsorption unit price per 1 mol of ammonia calculated from the raw material unit price was 62.6 yen. The basis for calculating the adsorption unit price is as follows.

[Table] Therefore, the unit price per kg of the adsorbent of the present application is 427.27
Yen/Kg. The bulk specific gravity of the obtained adsorbent is 0.761
Since 1 kg is 1.314, the unit price per unit is 325.17 yen/. Also, the NH ₃ adsorbent per 1 adsorbent is
Since it is 5.2 mol/, the adsorption unit price per 1 mol of NH ₃ is 325.17 ÷ 5.2 = 62.53 yen → 62.6 yen. Example 2 Titanium sulfate powder (300 mesh or less) 20
g and commercially available activated clay powder (300 mesh or less) 80
Then, 20 g of a commercially available acrylic emulsion was uniformly mixed to obtain an adsorbent in the same manner as in Example 1. In the same manner as in Example 1, 8 ml was packed into a 10 mmφ column and the ammonia adsorption amount was measured at 100 ppm of ammonia. The result was 0.96 mol/, and the adsorption unit price per 1 mol of ammonia calculated from the raw material unit price was 96.9 yen. . The basis for calculating the adsorption unit price is as follows.

[Table] Therefore, the unit price per kg of the adsorbent of this application is 184.44
It becomes a yen. The bulk specific gravity of the obtained adsorbent is 0.504, and 1 kg is 1.983. Therefore, the unit price per adsorbent is 93.01 yen/
becomes. The amount of NH ₃ adsorbed by this adsorbent is 0.96mol/
Therefore, the adsorption unit price per 1 mol of NH ₃ is 93.01÷
0.96 = 96.88 yen → 96.9 yen. Comparative Example 1 Using 100 g of activated clay powder (300 mesh or less) and 20 g of the same vinyl acetate emulsion as in Example 1, an adsorbent was made in the same manner as in Example 1, and the amount of ammonia adsorbed was measured, and the result was 0.23 mol/unit price of raw materials. The adsorption unit price per 1 mol of ammonia calculated from this is 237.3 yen. The basis for calculating the adsorption unit price is

[Table] Therefore, the unit price per kg is 130.91 yen/Kg.
The bulk specific gravity of this adsorbent is 0.417, and 1 kg is 2.398
becomes. Therefore, the unit price per adsorbent is 54.58 yen/
becomes. The amount of NH ₃ adsorbed by this adsorbent is 0.23mol/
Therefore, the adsorption unit price per mole of NH ₃ is 54.58÷
0.23=237.30 yen. Comparative Example 2 Adding phosphoric acid to commercially available granulated activated carbon at a weight ratio of 20%
After drying, impregnated carbon was obtained. The amount of ammonia adsorbed on this impregnated carbon was measured in the same manner as in the example, and the result was 0.86 mol/. The adsorption unit price per 1 mol of ammonia calculated from the raw material unit price is 412.3 yen. The basis for calculating the adsorption unit price is

[Table] Therefore, the unit price per kg of impregnated coal is 449.92 yen/kg. The bulk specific gravity of the obtained adsorbent was 0.788,
1Kg is 1.269, and the unit price per adsorbent is
It becomes 354.55 yen/. Since the adsorption amount of NH ₃ in this impregnated carbon is 0.86 mol/, the adsorption unit price per 1 mol of NH ₃ is 354.55÷0.86=
412.27 yen → 412.3 yen.

Claims (1)

[Claims] 1. An adsorbent for basic gas deodorization characterized by using titanium oxysulfate.