JPS59123593A - Treatment of reaction mixture or waste liquor - Google Patents

Abstract

PURPOSE:To remove substantially incorporated irritating substances by adding hexamethylenetetramine to a reaction mixture or waste liquor obtained by liquid-phase oxidation of hydrocarbons with an O2-contg. gas using a heavy metal compd. and a bromine compd. as a catalyst. CONSTITUTION:The materials to be treated consisting of a reaction mixture obtained by oxidation of hydrocarbons or substituted hydrocarbons with an O2- contg. gas, its waste liquor or the residue after removing a solvent from the waste liquor or the like, are treated as follows. Namely, 1/3-5 times by wt. as much hexamethylenetetramine as the irritating substances expected to be included is added to the materials to be treated at 50-200 deg.C. The time required for the treatment is 1-10hr, preferably 2-6hr. Consequently, the irritating substances always present only in an extremely dilute concn. are treated with an extremely small amt. of hexamethylenetetramine, and the irritating substances are reduced to the extent that the irritation is insensible to eye and skin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating reaction mixtures or waste liquids. More specifically, it is a reaction characterized by adding hexamethylenetetramine to a reaction mixture obtained by liquid-phase oxidation of a hydrocarbon or substituted hydrocarbon with a molecular oxygen-containing gas using a heavy metal compound and a bromine compound as catalysts, or a waste liquid thereof. This invention relates to a method for treating a mixture or waste liquid.

Many of the carboxylic acids, ketones, aldehydes, etc. used as raw materials for pharmaceuticals and agricultural chemicals, such as terephthalic acid, trimellitic acid, and pyromellitic acid, which are produced in large quantities as raw materials for fibers and resins, contain heavy metal compounds and bromine compounds. The catalyst is produced from the corresponding hydrocarbon or substituted hydrocarbon by liquid phase oxidation using a molecular oxygen-containing gas. Such liquid phase oxidation methods often produce by-products that sting the eyes and irritate the skin. These by-products pose a major health hazard to those involved in the process of distributing reactants, drying products, treating waste liquids after distributing products, and recovering solvents from waste liquids.

In order to solve this problem, the present inventors conducted extensive research and arrived at the present invention.

Compounds that cause the above-mentioned problems include halogen compounds such as penzyl halide, penzyl halokenide, halogenated ketones, and halogenated fatty acids, but these are bromine compounds and oxidized compounds. , it is thought that it is produced by side reactions with catalyst ligands, solvents, etc.

Furthermore, there are cases where chlorine atoms or bromine atoms in the oxidized substance are separated during the liquid phase oxidation reaction and converted to the above-mentioned halogen compounds.

One method for removing these compounds is to add a base such as sodium acetate, but this requires a large amount of reagent and is difficult to completely remove the irritating substances. Further, when the reaction mixture contains a strongly acidic substance, the effect of a basic substance such as sodium acetate can hardly be expected.

The present inventors tested various compounds and found that -\xamethylenetetramine was very effective. Although the mechanism is not clear, it has been observed that almost no active halogen compounds of the penzyl halide type are detected in gas chromatographic analysis of the reaction mixture after treatment with hexamethylenetetramine.

It is surprising that an irritating substance that exists only in very dilute concentrations can be reduced to the point where it is no longer noticeable to the eyes or skin by treating it with a very small amount of hexamethylenetetramine.

Next, the present invention will be explained in detail.

The present invention uses a heavy metal compound and a bromine compound as catalysts to oxidize hydrocarbons or substituted hydrocarbons with a molecular oxygen-containing gas at normal pressure or under pressure, and removes the solvent from the reaction mixture, its waste liquid, or waste liquid. Applies to residual assets, etc.

The treatment method is to avoid the presence of irritating substances.
/ About 3 to 5 times the weight, preferably 172 to 3 times the weight of hexamethylenetetramine is added to the material to be treated, and 50 to 2 times the weight is added.
00°C1 is preferably 80 to 150°C, preferably 2 to 6 hours.

The present invention is particularly advantageous when applied to the production of carboxylic acids, ketones, aldehydes, and the like having a norogen atom as a substituent.

Specific examples of hydrocarbons or substituted hydrocarbons and treatment formats include (a) liquid phase oxidation of toluene, xylene, trimethylbenzene, etc. with molecular oxygen using heavy metal compounds and bromine compounds as catalysts; or removal of irritating substances in the solvent (e.g. acetic acid) after separation of the target product (b) o-, m-, p-, chlorotoluenes, 2.
3-,' 2.4-, 2.5-+ 2.6-, dichlorotoluenes 1, trichlorotoluenes, chloro, bromotoluenes, fluorotoluenes, dichlorotoluenes, chloro, fluoro, toluenes, bromo , fluorotoluenes, dichlorofluoro-1-luenes, sifukumofluorotoluenes, chlorodichlorotoluenes, fromodichlorotoluenes, etc. are treated with molecular oxygen using a heavy metal compound and a bromine compound as catalysts, using a liquid phase oxidation method. , Removal of irritating substances in the reaction solution when obtaining the corresponding aldehydes, benzyl alcohol derivatives, carboxylic acid derivatives, etc., or in the solvent after separating the target product (c) Ethylbenzene, o, m, p- Irritation in the reaction solution or waste solution when obtaining the corresponding acetophenones and carboxylic acids from chloroethylbenzenes, dichloroethylbenzenes, trichloroethylbenzenes, etc. by liquid phase oxidation with molecular oxygen using heavy metal compounds and bromine compounds as catalysts. (For removal of substances) Removal of irritating substances in the reaction solution or waste solution after performing a liquid phase oxidation reaction with molecular oxygen on aliphatic hydrocarbons using heavy metal compounds and bromine compounds as catalysts.

(e) Carboxylic acids, aldehydes, benzyl alcohol obtained by liquid phase oxidation with molecular oxygen using heavy metal compounds and bromine compounds as catalysts from toluene, xylene, ethylbenzene, etc. substituted with nitro, cyano, alkoxy, phenoxy, etc. and acetophenones.

Hereinafter, this will be explained in detail with reference to examples.

Example 1゜Acetic acid 4 swamp, Co (OA C)2 ・4 H2037,
4g-1Mn(OAC)2-4T(20o, 37P, N
a Br 30.9 &-Zirconium octenoate 58
．． 4 Pl, 2-10 rho 4-fluorotoluene 2 k
A liquid phase air oxidation was carried out by blowing air under normal pressure at a rate of i/min while stirring strongly. The reaction was completed after 12 hours at 90°C. It was found that about 1% of the compound determined by gas chromatography was produced. 881 portions of hexamethylenetetramine was added thereto, and the mixture was refluxed at 115° C. for 3 hours. This one wasn't there. After cooling the reaction mixture, it was poured into water, and the precipitated crystals were filtered. No eye or skin irritation was observed during filtration or from the waste liquid. When the obtained crystals were dried at 80° C. in an electric dryer, no irritating substances were released that could be felt by the eyes or skin.

Comparative Example 1 After liquid phase oxidation in the same manner as in Example 1, hexamethylenetetramine treatment was not performed. Although the same post-treatment as in Example 1 was carried out in a fume hood, it was very painful to the eyes and the work was difficult.

Example 2゜Co (OAC)2 4 H2050f in acetic acid 1-e
F, BrCH2C0OH28fi-12-chloro-4-
After charging 347 g of fluorotoluene and raising the temperature to 85°C, oxygen was introduced while stirring vigorously. The reaction was carried out for 6 hours while gradually increasing the temperature to 1.15°C.

After the reaction was completed, the reaction solution was divided into two parts. Hexamethylenetetramine 151 was added to one side and refluxed for 3 hours.

Subsequently, post-treatment was carried out in the same manner as in Example 1, but no irritating substances were observed to be released during the soaking, filtration, and drying steps or from the waste liquid.

Comparative Example 2 Acetic acid Sorb 251 was added to half the amount of the reaction solution obtained in Example 2, and the mixture was refluxed for 3 hours. I tried to cool it, drain it, and filter it in the same way as in Example 1, but my eyes hurt and I couldn't work. When the crystals that had been filtered in a fume hood were dried in a dryer, a strong substance with lachrymatory properties was released.

Example 3 In a flask, 4.507 g of 0-chlorotoluene, 160 g of -chlorobenzoic acid, 1.4 ml of water, Co (O
AC)...4H203,04? , Mn (OAC)2
・4H200,03! i'Nata. While vigorously stirring, air was blown in at 500 ml/min to cause a reaction. Subsequently, 0-chlorotoluene was added at 32.5 q-/hr, catalyst, Co (OAC)2 ・4 I-I,, O was added at 0.0
365p/hrMn(OAC)24H20wo0.000
36 Plhr, while continuously charging a portion of the reaction solution into a withdrawal flask while keeping the height of the reaction solution level constant. From this sometimes dropper,
It was sampled and crystallized. glass of this
・I filtered it with a filter, but it hurt my eyes very much, so I kept the flask for extraction at 120°C, made hexamethylenetetramine present at 1.5% of the total, and then performed the same filtration as above. However, I felt almost no stimulation.

This was used to prepare a mixed solution (X below) whose composition was assumed to be the mixture after the liquid phase oxidation reaction, and as is clear from the table, it is thought that tetrahexamethylene was present in this mixture.

In the above, 0.39% of sodium acetate was used in place of hexamethylenetetramine and the resultant product was refluxed for 3 hours. Also, almost no reducing effect of hexamethylenetetramine was observed.

× Mixed liquid acetic acid 10 c
c'( Co (OAC)2 ・4 H200,08!i' Zirconium acetylacetonate 0.078 P Sodium bromide 0.066 P Water
0.66 cc Patent applicant Nippon Kayaku Co., Ltd.

Claims (1)

[Claims] (1) A reaction characterized by adding hexamethylenetetramine to a reaction mixture obtained by liquid-phase oxidation of hydrocarbons or substituted hydrocarbons with a molecular oxygen-containing gas using a heavy metal compound and a bromine compound as catalysts, or to the waste liquid thereof. Method for treating mixtures or waste liquids.