JPS6054096B2 - Adsorbent for lower aldehydes - Google Patents

Description

[Detailed Description of the Invention] The main components of odor in the wet oxidation treatment method for human waste are hydrocarbons and lower aldehydes, and from the perspective of odor threshold, it is important to remove lower aldehydes such as aldehydes and acrolein. On the other hand, the odor generated from garbage collection pits also contains many lower aldehydes, and an effective adsorbent for aldehydes was required to remove the garbage odor.

However, conventional adsorbents such as activated carbon, activated clay, silica gel, alumina, and ion exchange resins are insufficient *R-CH0+NH2
OH, HCl → RCH = N10H + I translation - CHO + (N
H2OH)2H2SO4→2RCH=N・(R4H0+
No. So. +H2O-RCH/\ Since the reaction represented by equation (3) when a water-soluble sulfite that is highly reactive with lower aldehydes is reacted with lower aldehydes is an equilibrium reaction, it is impregnated with the adsorbent * Deodorizing effect is Not obtained.

As a result of intensive research, the present inventors have invented an effective adsorbent for lower aldehydes.

That is, the present invention relates to an adsorbent for lower aldehydes made of activated carbon impregnated with hydrochloric acid or hydroxylamine sulfate, and an adsorbent for lower aldehydes made of activated carbon impregnated with water-soluble sulfite and hydrochloric acid or hydroxylamine sulfate. and they can be prepared by soaking activated carbon with hydrochloric acid or hydroxylamine sulfate, or by soaking activated carbon with a water-soluble sulfite and hydrochloric acid or hydroxylamine sulfate. The water-soluble sulfite salts include sodium, potassium, and ammonium salts of sulfite.

The reaction of lower aldehydes with hydrochloric acid, hydroxylamine sulfate, and water-soluble sulfite in the present invention is considered as follows.

-1+H2O...(1) I+ H2SO4+2H20...(2)+Na
OH・・・・・(3) The fact that not all of the supported sodium sulfite participates in the reaction, and that it is oxidized by oxygen in the air while supported on the adsorbent, producing sulfur dioxide gas. As a drug, it has a fatal flaw.

According to the present invention, by mixing a small amount of sulfuric acid or hydroxylamine hydrochloride with water-soluble sulfite, (1) or
The acid produced by equation 2) and the caustic soda produced by equation (3) are removed from the system by a neutralization reaction, which moves the reaction to the right and accelerates it, and at the same time prevents the generation of sulfur dioxide gas. It has a remarkable effect of preventing.

The odor threshold for SO2 is 0.47p. p. m, but 1%
-SO at the outlet of the adsorbent immersed in Na2sO3 solution
2 concentration is 0.5p. p. m, making it unsuitable as a deodorizing adsorbent.

In contrast, 1%-Na2sO3 and 0.1% (NH2OH
) The SO2 concentration at the outlet of the adsorbent of the present invention immersed in a mixed solution of 2H2S04 is 0p. p. It was m. The mixing ratio of the mixed solution in the invention set forth in claim 2 is higher when there is more sulfuric acid (hydrochloric acid) hydroxylamine than sulfite in terms of aldehyde adsorption performance, but 0
．． If it exceeds 6, SO2 will be generated, and as the amount of hydroxylamine sulfate is increased from 0.7 to 0.9, the SO2 concentration will increase and become inappropriate. In terms of chemical costs, the cost for removing 1 m0I of aldehyde is lowest and most economical when the mixing ratio of sulfite and sulfuric acid or hydroxylamine hydrochloride is 1:0.1.

However, in actual plants, there are cases where 1:0.6, which has a higher adsorption capacity, is more effective. Below is a graph showing the relationship between the amount of acetaldehyde adsorbed and the price required to remove 1 mole of acetaldehyde with respect to the mixing ratio of the mixed solution.Firstly, the relationship between the pH of the solution and the amount of SO2 generated from the solution with respect to the mixing ratio of the mixed solution. This is shown in the second graph. As described above, according to the present invention, an economical adsorbent with excellent adsorption performance for lower aldehydes can be obtained. Examples are shown below. Example 1 After immersing 50 ml of granulated activated carbon (2-4 mesh) in an aqueous solution of 1 gr sodium sulfite and 0.1 gr hydroxylamine sulfate dissolved in 100 ml deionized water for 1 hour, the excess adhering to the activated carbon surface was removed. With the exception of drugs,
The impregnated adsorbent was obtained by heating and drying at 80° C. for 2 hours.

The equilibrium adsorption amount for acetaldehyde is 4640 p. p. 0.139gT″/Gr in m
It was hot.

The concentration of acetaldehyde was measured using the gas chromatography method based on the Environment Agency Notification No. 47, and the equilibrium adsorption amount was measured using r1/n in the JIsl474r granular activated carbon test method.
The procedure was carried out in accordance with the section on equilibrium adsorption performance of solvent vapor.

Example 2 Hydroxylamine sulfate in Example 1 was changed to 0.3 gr.

The equilibrium adsorption amount for acetaldehyde is 4640 p. p. It was 0.16gr/Gr in m. ”Example 3 Hydroxylamine sulfate in Example 1 was changed to 0.6 gr.

The equilibrium adsorption amount for acetaldehyde is 4640 p. p. It was 0.193gr/Gr' in m. Example 4 As a result of using the same amount of hydroxylamine hydrochloride in place of hydroxylamine sulfate in Example 1, the equilibrium adsorption amount for acetaldehyde was found to be at a concentration of 4640p. p.
It was 0.144gr/Gr in m.

Example 5 50ml of granulated activated carbon (2 to 4 mesh) was
After immersing it in an aqueous solution in which hydroxylamine hydrochloride (f) was dissolved in 100 ml of deionized water for 1 hour, excess chemicals adhering to the surface of the activated carbon were removed, and the mixture was heated and dried for 2 hours in step 8 to obtain an impregnated adsorbent. .

The equilibrium adsorption amount for acrolein is at a concentration of 56
0p. p. It was 0.098gr'/Gr at m.

Example 6 As a result of using the same amount of hydroxylamine sulfate in place of hydroxylamine hydrochloride in Example 5, the equilibrium adsorption amount for acrolein was found to be 560p. p
．． It was 0.077gr/Gr in m.

Claims (1)

[Scope of Claims] 1. An adsorbent for lower aldehydes comprising activated carbon impregnated with hydroxylamine hydrochloride or hydroxylamine sulfate. 2. An adsorbent for lower aldehydes consisting of activated carbon impregnated with a water-soluble sulfite and hydroxylamine hydrochloride or hydroxylamine sulfate.