DE2810142A1 - Removing impurities of chlorinated phenol derivs. - by treatment with acetylene or its derivs. - Google Patents

Abstract

Method for removing impurities of chlorinated phenols (I) comprises treatment with acetylene and/or acetylene derivs. Suitably the material to be treated is mixed with finely-divided Ca carbide, then treated with water or steam. Alternatively an organic alkyne cpd. is used in an inert solvent, esp. acetylene dicarboxylic acid or propiolic acid esters, or ethereal oils derived from Boleko, Matricaria or Artemisia. During or after treatment the mixt. may be exposed to visible or UV light (to accelerate the reaction). (I) esp. the tetra- and penta-chloro derivs., are fungi-statics and bactericides, esp. useful for treating wood, controlling slime in paper making and as harvesting aids for e.g. cotton. The (roxic) halogenated polycyclic impurities formed during mfr. are quickly and easily removed from (I) themselves or from equipment used in the process. A single treatment removes 90-98% of the impurities.

Description

Process for removing contaminants from chlorinated phenols

The invention relates to a method for removal that can be carried out in a simple manner unwanted halogenated multi-cycle compounds, which are used in technical. Manufacture of halogenated phenols, e.g.

of tetra- and pentachlorophenol, can be formed by treatment with compounds containing carbon triple bonds.

From the large-scale by various processes, e.g. by chlorination phenol or hydrolysis of hexachlorobenzene produced more highly chlorinated phenols Tetra- and pentachlorophenol and their derivatives have become particularly important. They are primarily fungistatic, and also have a bactericidal effect and become to a considerable extent in construction, various industrial processes and used in agriculture, for example as a wood preservative and preservative, as a treatment agent for woods that are attacked by microorganisms that cause blue stain can be used to combat slime, e.g. in the paper industry, as an aid when harvesting e.g. cotton.

From technical polychlorinated phenols can take unfavorable Conditions impurities are formed, some of which are toxic.

These impurities can be divided into four groups: 1. Chlorinated dibenzo-p-dioxins 2. Chlorinated dibenzofurans 3. 3. Chlorinated hydroxydiphenyl ethers (Predioxins and isoprädioxins) 4. Chlorinated diphenyl ethers Other accompanying substances are only detectable in very small amounts by gas chromatography the The toxicity of the first-mentioned group of compounds is known; those of the other liaison groups is significantly lower, but little has been clarified in detail so far.

The chlorinated dibenzo-p-dioxins, but also the substances of the third and fourth group are polychlorinated, multicyclic aromatic or heteroaromatic Substances extremely stable and chemically difficult to attack.

Attempts were made to break down the substances through the effects of ultraviolet light, if necessary with an additional curtain of olive oil, to accelerate, but the effect and imaging speed is low.

A technically applicable method for the rapid destruction of the named Impurities have not been known to date.

The invention relates to a method for removing contaminants chlorinated phenols, which is characterized in that the impurities or substances containing them come into contact with acetylene and / or acetylene derivation to be brought.

It has been recognized that substances which contain the ethynylene group are suitable for the treatment -C-C- contain or can form substances with this group, thus substances with Reactive EohlenStoff trebles.

So much for a release of acetylene or other ethynylene derivatives vaten has to be done, this can be done with water or steam, if necessary by means of the humidity or e.g. with acids.

As inorganic acetylene derivatives, which in the presence of water with the release of acetylene, salt-like carbides, in particular, can react the A] rali and / or alkaline earth salts of acetylene are used. An inexpensive and the salt available in large quantities is calcium carbide. It is therefore preferred uses examples of organic acetylene derivatives or those containing the ethynylene group Substances are acetylenedicarboxylic acid esters, propiolic acid esters and containing alkyne groups Oils of natural origin, such as boleko oil, chamomile oil from Mat.ricaria inodorate, or the essential oil from Artemisia vulgaris.

Numerous other carbon triple bond derivatives are also available effective and only less preferred because of the sometimes difficult accessibility.

The residues to be treated according to the process or the substances with These residues are in particular the distillation residues from production of penta- and tetrachlorophenol.

If necessary, residues of the chlorination can also be used for this purpose Phenols and the bromination of phenols come into consideration.

The commercially available pentachlorophenol itself requires generally no treatment as it is free from the residues mentioned.

Furthermore, laboratory equipment used in experiments or investigations, Boiler. Parts of apparatus etc. are treated in accordance with the procedure.

The substances to be treated according to the method can in the broadest sense be any objects that start with in particular substances of the first two have come into contact intentionally or unintentionally. Here it has to be taken into account that the impurities are almost without exception very small Concentration in or on a material that is in itself a treatment not required. It should also be taken into account that the concentration is small in itself the impurities can fluctuate within very wide limits; while concentrating Very little in crude chlorination products of phenols, higher concentrations occur e.g. in cleaning residues.

The treatment can optionally lead to an accumulation of the residues by, for example, extraction, absorption with solvents such as benzene or methylene chloride or distillation precede.

The treatment measures carried out according to the present procedure therefore different proportions of other substances have to be taken into account, i.e. Can be inert to the treatment agents or with the treatment agents can react.

In general, therefore, there is always an excess of the treatment agent to use. In samples with proportions of substances of unknown chemical nature is a high excess of the treatment means up to, to 2 to 5 parts by weight appropriate for each part by weight of the materials to be treated. The excess of the treatment agent can be used for known substances and substances with high proportions that are inert during treatment considerably to about 0.1 to 2.0 parts by weight of treatment agent or less per part by weight of the materials to be treated are reduced. An analytical review e.g. by gas chromatography is appropriate.

In general, a single treatment is sufficient, but can two treatments, especially when removing small residues, are advisable be. A three-time treatment only needs to be carried out in exceptional cases.

The treatment agent and the substances to be treated should be mixed well As far as the treatment agents, such as the carbides, are solids these should be used finely powdered or ground. The effect more fluid Treatment agents, e.g. by spraying on or dipping, can be replaced by surface-active Substances are supported.

The effect of the treatment agent is already at room temperature high, but can be increased by temperatures in the range of 20 to 500C, if necessary up to 90 ° C.

In the case of the use of carbides, water, in liquid form, is as steam or, if necessary, in the form of air humidity, in order to convert acetylene to release.

An excess of water is often expedient.

The action of acetylene itself or of compounds with ethynylene groups can be supported by water, but water is not a requirement here.

The treatment can be carried out in such a way that if there is an excess of the treatment agent and if necessary with water, the treatment is finished in a few minutes. One such treatment is expediently carried out in a closed vessel, e.g. in a reactor, given before with a stirrer and optionally with a drain for excess Acetylene is equipped.

Treatment can also be carried out by simply sprinkling solid treatment agents on top or pouring on e.g. spraying liquid treatment agents, if necessary in situ, are executed. In this treatment there is a deficit of the treatment agent and a multiple Repetition of the treatment possible. water or steam can also be used, but the release of the Acetylene are also left to the effect of the air humidity. Long treatment times of several hours or days are possible here and without any unfavorable effects.

Simultaneous exposure to visible light or des W is often useful and can accelerate the reaction considerably. at Treatments in closed vessels, if necessary also for treatments in In situ, the additional action of light is appropriate; in sftu the action can the daylight or any light source expediently take place.

One-time treatments can be 90 - 98% of the originally existing Remove impurities, practically complete removal is by two times Treatment achievable.

The success of the treatment can be achieved by extracting the neutral components with solvents after conversion of the phenolic components into the salts and analytical Examination of the extracts of the treated samples in comparison to the extracts of the untreated samples are checked.

Treated samples became highly viscous in a number of cases Substances extracted, which have a multiple of the molecular weight of the impurities. In these apparently by reaction of acetylene or acetylene derivatives with the impurities The residues are no longer or are only the result of highly condensed substances Detectable in very small amounts compared to the original amounts. From further treated samples, especially after two treatments, are only even small amounts of very highly viscous substances can be extracted, in which fractions the original backlogs no longer occur; apparently the one that dominates Proportions of the substances formed during the treatment with such a high degree of condensation, that extraction with solvents is no longer possible.

Example a) 100 g of an elevated temperature produced technical Pentachlorophenols are completely dissolved in 600 ml of benzene.

This solution is in a 2 l separating funnel with 600 ml of 5 wt .-% shaken out aqueous sodium hydroxide solution. The benzene phase is separated and dehydrated with Dried sodium sulfate. After removing the remaining proportions of chlorophenols through Column chromatography, the solution is evaporated on a water bath. The received small evaporation residue is soluble in numerous organic solvents, which are typical for solving niadermolecular organic neutral substances, for example in aromatic and aliphatic hydrocarbons such as benzene, chlorinated hydrocarbons such as methylene chloride or ethers such as diethyl ether.

The evaporation residue contains the impurities mentioned at the beginning. The aqueous phase contains the chlorinated phenols and is according to gas chromatography Investigations free from the named impurities.

b) A sample of 0.2 g collected from these evaporation residues dissolved in 10 ml of methylene chloride and transferred to a flask with a stirrer. 0.5 g Calcium carbide are finely powdered in three servings within 2 Added minutes at room temperature with constant stirring. Wake up every addition of CaC2 is added to 50 ml of water. After an after-reaction of 5 minutes and at Room temperature extracted exhaustively with methylene chloride and the extract gas chromatographed.

Compared to the gas chromatogram of the comparison sample of the untreated Evaporation residue are only in the extract when the sensitivity of the detector is increased some of the original components can still be seen in the treated sample.

From the comparison of the intensities it is concluded that at least 95% fo the impurities no longer contained in the extract of the treatment sample is.

Example 2 A sample of evaporation residue according to Example 1b of 0.2 g is treated as in Example 1b, but during the treatment at 350C warmed up. From the gas chromatogram it is concluded that 95 to 97% of the impurities destroyed during treatment.

Example 3 A sample of evaporation residue according to Example 1a of 0.2 g is treated with CaC2 as in Example 1b, but was during. 10 mins as much water vapor is introduced into the flask until a weight increase of 2.5 g had occurred.

The gas chromatogram after the treatment corresponds to that of the example 1 b.

Example 4 Samples of 50 g of material containing chlorinated impurities Phenols were examined. An extrusion test showed that about 2 % extractable substance and 98% present in the extraction of inert substances was.

The gas chromatogram showed chlorinated phenols in addition to only very small ones Proportions according to the impurities of the evaporation residue according to the example 1 a.

Part of the sample was treated as in Example 1b.

After the treatment, no impurities could be found in the gas chromatogram more to be noted.

Part of the sample was extracted according to Example 1a and the evaporation residue Treated according to Example 2.

In the gas chromatogram, the impurities were no longer residues 1 adjustable.

Samples of the above material were distributed on areas of each and evenly sprinkled with a) 30 g of finely powdered CaC2 and b) with 50 g of dimethyl acetylenedicarboxylate sprayed evenly. After that, the surfaces were sprayed: 100 ml of water each time.

After 2 days, samples of 50 g were taken and examined as above. No indications of any remaining impurities were found.

Example 5 From a reactor used to chlorinate phenols the porous sieve plate used to distribute the chlorine was removed.

The sieve plate was placed in a container in 3 l of methanol with a water content of 5% by weight and dipped in four portions within 20 minutes of 20 g of CaC2 added with stirring.

During the treatment, the surface of the container was exposed to 7UV light irradiated.

After the treatment, the sieve plate was boiled in benzene, and the benzene evaporated. A very small residue was removed from the residue in 2 ml of renzene recorded.

The residue from the treatment became exhaustive with methylene chloride extracted. The evaporation residue of the extract was taken up with 2 ml of benzene.

In both benzene samples, none of the identified impurities.

Example 6 A sample of evaporation residue according to Example 1 a of 0, g was mixed with 0.5 g of CaC2 in three portions with the addition of 10 ml of water at the same time Irradiation with light for 10 minutes. After the treatment, the treatment residue was treated extracted completely with diethyl ether and evaporated. The residue was 0.16 g and consisted mainly of sparingly soluble, highly viscous components, which apparently by reacting the acetylene with the impurities. The gas chromatogram of the highly viscous evaporation residue showed that for the original evaporation residue typical bands with only very low intensity.

It was concluded that at least 95 I / O of the contaminants in the original evaporation residue were implemented.

Treatment in the presence of UV light was carried out on the residue first treatment and repeated with the extract of the first treatment.

After extraction and evaporation as above, only 0.008 g or 0.006 g evaporation residue found. No contaminants were found in the gas chromatogram found at the extraction of the re-treated extract of the In the first treatment, a large part was no longer extractable, very highly condensed Substances detected; the extractable portion was also almost exclusively present highly condensed substances.

Example 7 0.5 g of oleic acid 2,4,7,9-tetramethyl-5-decyne-4,7-diol diester were dissolved in methylene chloride with 0.2 g of pentachlorophenol extract.

The solution was irradiated with UV light for two hours by the irradiation A highly viscous mass 1 formed from addition products of the acetylene ester with the by-products of pentachlorophenol existed.

The impurities were no longer detectable in the gas chromatogram.

Claims (6)

Claims: 1. Method for removing impurities chlorinated phenols, characterized in that the impurities or the 7 substances containing se brought into contact with acetylene and / or acetylene derivation will. 2. The method according to claim 1, characterized in that the impurity or a substance containing these with acetylene, which is composed of one of its salts and water is generated, is converted. 3. The method according to claim 1, characterized in that the impurities or a substance containing them with a salt-like carbide, preferably calcium carbide mixed in fine division and the mixture with water in liquid or vapor form Condition is treated. 4. The method according to claim 1, characterized in that the impurities or a substance containing these with an organic alkyne compound, if appropriate in an inert solvent, is brought into close contact. 5 The method according to claim 1, characterized in that the organic Alkyne compound is an acetylenedicarboxylic acid ester, propiolic acid ester and / or an ethereal one Oil from Boleko, Matricaria and Artemisia is. 6. The method according to any one of claims 1 to 5, characterized in that that visible light or UV light acts during or after the treatment.