EP0647459A1 - Method of dechlorination of chlorinated aromatic compounds - Google Patents
Method of dechlorination of chlorinated aromatic compounds Download PDFInfo
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- EP0647459A1 EP0647459A1 EP94115054A EP94115054A EP0647459A1 EP 0647459 A1 EP0647459 A1 EP 0647459A1 EP 94115054 A EP94115054 A EP 94115054A EP 94115054 A EP94115054 A EP 94115054A EP 0647459 A1 EP0647459 A1 EP 0647459A1
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D3/00—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
- A62D3/30—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
- A62D3/32—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents by treatment in molten chemical reagent, e.g. salts or metals
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- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62D2101/00—Harmful chemical substances made harmless, or less harmful, by effecting chemical change
- A62D2101/20—Organic substances
- A62D2101/22—Organic substances containing halogen
Definitions
- the present invention relates to a process for the dechlorination of chlorinated aromatic compounds with the formation of low-chlorine and / or chlorine-free aromatic compounds.
- Highly chlorinated aromatic compounds such as those obtained as by-products in the production of low-chlorinated aromatic compounds, as used functional liquids (e.g. transformer oils) or as by-products in the combustion of various chlorinated organic compounds, are often environmentally harmful. According to known methods, they can only be converted into recyclable materials or burned in a complex manner.
- Transchlorination processes are also known in which chloroaromatics with medium degrees of chlorination are obtained in a kind of comproportionation reaction from higher chlorinated and lower chlorinated or chlorine-free aromatics (see e.g. Chem. Lett. 1987, 2051-2052).
- the disadvantage is the use of additional (lower chlorinated or chlorine-free) aromatics to remove chlorine from higher chlorinated aromatics.
- chlorinated aromatic compounds for use in the process according to the invention are those which are derived from benzene, pyridine, naphthalene, quinoline, isoquinoline, diphenyl ether or dioxin as the base body. They contain at least one chlorine atom bound to the base body per molecule.
- They preferably contain from two to the maximum possible number of chlorine atoms, for example 2 to 6 chlorine atoms for a benzene base, 2 to 5 chlorine atoms for a pyridine base, 2 to 8 chlorine atoms for a naphthalene base, for a quinoline or isoquinoline -Base 2 to 7 chlorine atoms, in a diphenyl ether base 2 to 10 chlorine atoms and in a dioxin base 2 to 8 chlorine atoms.
- chlorine atoms for example 2 to 6 chlorine atoms for a benzene base, 2 to 5 chlorine atoms for a pyridine base, 2 to 8 chlorine atoms for a naphthalene base, for a quinoline or isoquinoline -Base 2 to 7 chlorine atoms, in a diphenyl ether base 2 to 10 chlorine atoms and in a dioxin base 2 to 8 chlorine atoms.
- Chlorinated aromatic compounds which can be used in the process according to the invention may optionally contain further substituents in addition to chlorine atoms.
- Such further substituents can be, for example, C1-C4-alkyl, C6-C10-aryl, C1-C4-alkyl-C6-C10-aryl, mono- to trichloro-C1-C4-alkyl or mono- to pentachloro-C6 Act -C10 aryl.
- chlorobenzene 1,2-, 1,3- or 1,4-dichlorobenzene, 1,2,3-, 1,2,4- or 1,3,5-trichlorobenzene, tetra- , Penta- or hexachlorobenzene, mono- or polychlorotoluenes, mono- or polychlorxylenes or chlorinated biphenyls.
- the salts used to form the molten salt are e.g. inorganic, ionic salts and mixtures containing them come into question insofar as they have a melting point below 450 ° C.
- the melting point of the salt or salt mixture used is preferably below 360 ° C., particularly preferably below 300 ° C.
- the molten salt can e.g. Chlorides contain, such as lithium chloride, sodium chloride, potassium chloride, zinc chloride, copper (I) chloride, copper (II) chloride, silver chloride, thallium chloride, tin (II) chloride, aluminum chloride and / or iron (III) chloride. Mixtures containing zinc chloride, copper (I) chloride, copper (II) chloride and / or potassium chloride are preferred. Mixtures of copper (I) chloride and potassium chloride are particularly preferred, in particular those which contain 50 to 90% by weight of copper (I) chloride and in addition to 100% by weight of potassium chloride.
- Preferred temperatures for carrying out the process according to the invention are those in the range from 350 to 400 ° C., particularly preferably those in the range from 360 to 385 ° C.
- the pressure in the process according to the invention can be varied within wide limits.
- the method according to the invention is carried out in a closed vessel under the pressure which sets itself or under the pressure specified by a pressure-maintaining valve.
- Suitable prints are e.g. in the range 1 to 50 bar.
- Preferred pressures are in the range 5 to 20 bar.
- Water and coal can be added to the process according to the invention as such or in the form of a so-called coal slurry, i.e. in the form of a pumpable mixture containing ground coal and water.
- the coal and / or water can also be generated in situ under reaction conditions, e.g. from added substances which tend to charring and / or water elimination at elevated temperature.
- Such substances are e.g. Sugars like sucrose, molasses and modified sugars like propoxylated sucrose.
- Such substances can also be used in the form of an aqueous solution.
- the process according to the invention can be carried out batchwise or continuously.
- 0.1 to 1 mole of chlorinated aromatic compounds can be reacted, for example, in a reactor of 1 liter with 0.5 liter of molten salt per hour. It is advantageous to stir when carrying out the process according to the invention.
- reaction vessels which are anticorrosive, for example by lining them with tantalum. In the absence of water or water vapor or coal, the dechlorination reaction stops.
- the process according to the invention provides aromatic compounds which contain less chlorine than the starting compound (s) and / or no more chlorine.
- hydrogen chloride, carbon dioxide and carbon monoxide are formed.
- Undefined by-products such as tar or soot are practically not formed from the chlorinated aromatic compounds used.
- the gaseous reaction products can be separated from the reaction mixture by expansion or via a pressure-maintaining valve. Fractional distillation allows the chlorine-free and chlorine-free aromatic compounds obtained to be separated off and isolated and used in a variety of ways, for example as intermediates for the preparation of active compounds. Unreacted starting compounds and still relatively highly chlorinated reaction products can optionally be fed back into the process according to the invention. The molten salt can be reused, if necessary after adding water and / or coal again.
- the process according to the invention makes it possible to convert higher-chlorinated aromatic compounds into recyclable lower-chlorinated or chlorine-free aromatic compounds in a simple and inexpensive manner.
- Example 2 The procedure was as in Example 1, but 1 g of water and 6 g of activated carbon were used instead of sucrose. After 1 hour, more than 95% by weight of the 1,2,4-trichlorobenzene used had reacted to form a mixture which contained 6.8% by weight of 1,2-dichlorobenzene and 35.7% by weight of 1,3- Dichlorobenzene, 44.1% by weight 1,4-dichlorobenzene, 11.7% by weight monochlorobenzene and 1.3% by weight benzene.
- This example shows the presence of water or water vapor, which is essential to the invention.
- This example shows the presence of coal essential to the invention.
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Abstract
Description
Die vorliegende Erfindung betrifft ein Verfahren zur Dechlorierung von chlorierten aromatischen Verbindungen unter Bildung von chlorärmeren und/oder chlorfreien aromatischen Verbindungen.The present invention relates to a process for the dechlorination of chlorinated aromatic compounds with the formation of low-chlorine and / or chlorine-free aromatic compounds.
Höherchlorierte aromatische Verbindungen, wie sie beispielsweise als Nebenprodukte bei der Herstellung niederchlorierter aromatischer Verbindungen, als gebrauchte funktionelle Flüssigkeiten (z.B. Transformatorenöle) oder als Nebenprodukte bei der Verbrennung der verschiedensten chlorierten organischen Verbindungen anfallen, sind häufig umweltbelastend. Sie können nach bekannten Verfahren nur in aufwendiger Weise in wiederverwertbare Materialien überführt oder verbrannt werden.Highly chlorinated aromatic compounds, such as those obtained as by-products in the production of low-chlorinated aromatic compounds, as used functional liquids (e.g. transformer oils) or as by-products in the combustion of various chlorinated organic compounds, are often environmentally harmful. According to known methods, they can only be converted into recyclable materials or burned in a complex manner.
So sind Verfahren bekannt, bei denen die Dechlorierung mit Wasserstoff oder sonstigen Reduktionsmitteln in Gegenwart von Katalysatoren erfolgt (siehe Helv. Chim. Acta 51, 8290-8297 (1968); Tetrahedron Letters 1969, 1223-1226; Environ. Sci. Technol. 21, 1085-1088; J. Chem. Soc. Chem. Comm. 1992, 806-807; JP-OS 12 694/65; JP-OS 24 776/65), bei denen Umsetzungen mit elementarem Natrium nötig sind (siehe z.B. US-PS 4 601 817), bei denen elektrochemisch reduziert wird (Z. Naturforsch., B: Chem. Sci. 45, 1105-1107 (1990)) und bei denen eine Photolyse durchgeführt wird (siehe Tetrahedron Letters 22, 2059-2062 (1979)). Nachteilig hierbei sind die Bereithaltung und Handhabung von Wasserstoff und anderen Reduktionsmitteln, Katalysatoren, elementarem Natrium und Spezialgeräten.Methods are known in which the dechlorination with hydrogen or other reducing agents takes place in the presence of catalysts (see Helv. Chim. Acta 51 , 8290-8297 (1968); Tetrahedron Letters 1969, 1223-1226; Environ. Sci. Technol. 21 , 1085-1088; J. Chem. Soc. Chem. Comm. 1992, 806-807; JP-OS 12 694/65; JP-OS 24 776/65), in which reactions with elemental sodium are necessary (see, for example, US -PS 4 601 817), in which electrochemically reduced (Z. Naturforsch., B: Chem. Sci. 45 , 1105-1107 (1990)) and in which photolysis is carried out (see Tetrahedron Letters 22 , 2059-2062 ( 1979)). The disadvantage here is the availability and handling of hydrogen and other reducing agents, catalysts, elemental sodium and special devices.
Weiterhin sind Transchlorierungsverfahren bekannt, bei denen in einer Art Komproportionierungsreaktion aus höherchlorierten und niedriger chlorierten oder chlorfreien Aromaten Chloraromaten mit mittleren Chlorierungsgraden erhalten werden (siehe z.B. Chem. Lett. 1987, 2051-2052). Nachteilig ist der Einsatz von zusätzlichen (niedriger chlorierten oder chlorfreien) Aromaten, um aus höherchlorierten Aromaten Chlor zu entfernen.Transchlorination processes are also known in which chloroaromatics with medium degrees of chlorination are obtained in a kind of comproportionation reaction from higher chlorinated and lower chlorinated or chlorine-free aromatics (see e.g. Chem. Lett. 1987, 2051-2052). The disadvantage is the use of additional (lower chlorinated or chlorine-free) aromatics to remove chlorine from higher chlorinated aromatics.
Bei den bekannten Verbrennungen von chlorierten Aromaten entstehen entweder brauchbare, leicht siedende Verbindungen und undefinierte Massen, z.B. chlorhaltige Teere, oder, bei höheren Temperaturen, praktisch nur Chlorwasserstoff und Ruß. Chlorhaltige Teere sind ebenfalls umweltbelastend und bei der Bildung von Ruß geht der aromatische Grundkörper verloren.The known burns of chlorinated aromatics produce either usable, low-boiling compounds and undefined masses, e.g. tars containing chlorine, or, at higher temperatures, practically only hydrogen chloride and soot. Chlorine-containing tars are also harmful to the environment and the aromatic base is lost when soot is formed.
Es besteht daher immer noch das Bedürfnis nach einem einfachen und kostengünstigen Verfahren zur Dechlorierung von chlorierten aromatischen Verbindungen, bei dem deren Chlorgehalt erniedrigt oder ganz beseitigt wird und der aromatische Grundkörper für weitere chemische Weiterverwendungen erhalten bleibt.There is therefore still a need for a simple and inexpensive process for the dechlorination of chlorinated aromatic compounds in which their chlorine content is reduced or completely eliminated and the aromatic base body is retained for further chemical use.
Es wurde nun ein Verfahren zur Dechlorierung von chlorierten aromatischen Verbindungen gefunden, das dadurch gekennzeichnet ist, daß man chlorierte aromatische Verbindungen in einer Salzschmelze in Gegenwart von Wasser und/oder Wasserdampf und Kohle auf 300 bis 450°C erhitzt.A process has now been found for the dechlorination of chlorinated aromatic compounds, which is characterized in that chlorinated aromatic compounds are heated to 300 to 450 ° C. in a molten salt in the presence of water and / or steam and coal.
Als chlorierte aromatische Verbindungen zum Einsatz in das erfindungsgemäße Verfahren kommen beispielsweise solche in Betracht, die sich von Benzol, Pyridin, Naphthalin, Chinolin, Isochinolin, Diphenylether oder Dioxin als Grundkörper ableiten. Sie enthalten pro Molekül mindestens ein an den Grundkörper gebundenes Chloratom. Vorzugsweise enthalten sie von zwei bis zur maximal möglichen Anzahl Chloratome, also beispielsweise bei einem Benzol-Grundkörper 2 bis 6 Chloratome, bei einem Pyridin-Grundkörper 2 bis 5 Chloratome, bei einem Naphthalin-Grundkörper 2 bis 8 Chloratome, bei einem Chinolin- oder Isochinolin-Grundkörper 2 bis 7 Chloratome, bei einem Diphenylether-Grundkörper 2 bis 10 Chloratome und bei einem Dioxin-Grundkörper 2 bis 8 Chloratome.Examples of suitable chlorinated aromatic compounds for use in the process according to the invention are those which are derived from benzene, pyridine, naphthalene, quinoline, isoquinoline, diphenyl ether or dioxin as the base body. They contain at least one chlorine atom bound to the base body per molecule. They preferably contain from two to the maximum possible number of chlorine atoms, for example 2 to 6 chlorine atoms for a benzene base, 2 to 5 chlorine atoms for a pyridine base, 2 to 8 chlorine atoms for a naphthalene base, for a quinoline or isoquinoline -Base 2 to 7 chlorine atoms, in a diphenyl ether base 2 to 10 chlorine atoms and in a dioxin base 2 to 8 chlorine atoms.
In das erfindungsgemäße Verfahren einsetzbare chlorierte aromatische Verbindungen können außer Chloratomen gegebenenfalls weitere Substituenten enthalten. Bei solchen weiteren Substituenten kann es sich beispielsweise um C₁-C₄-Alkyl, C₆-C₁₀-Aryl, C₁-C₄-Alkyl-C₆-C₁₀-aryl, Mono- bis Trichlor-C₁-C₄-alkyl oder Mono- bis Pentachlor-C₆-C₁₀-aryl handeln.Chlorinated aromatic compounds which can be used in the process according to the invention may optionally contain further substituents in addition to chlorine atoms. Such further substituents can be, for example, C₁-C₄-alkyl, C₆-C₁₀-aryl, C₁-C₄-alkyl-C₆-C₁₀-aryl, mono- to trichloro-C₁-C₄-alkyl or mono- to pentachloro-C₆ Act -C₁₀ aryl.
Bevorzugt werden in das erfindungsgemäße Verfahren eingesetzt: Chlorbenzol, 1,2-, 1,3- oder 1,4-Dichlorbenzol, 1,2,3-, 1,2,4- oder 1,3,5-Trichlorbenzol, Tetra-, Penta- oder Hexachlorbenzol, Mono- oder Polychlortoluole, Mono- oder Polychlorxylole oder chlorierte Biphenyle.The following are preferably used in the process according to the invention: chlorobenzene, 1,2-, 1,3- or 1,4-dichlorobenzene, 1,2,3-, 1,2,4- or 1,3,5-trichlorobenzene, tetra- , Penta- or hexachlorobenzene, mono- or polychlorotoluenes, mono- or polychlorxylenes or chlorinated biphenyls.
Selbstverständlich kann man in das erfindungsgemäße Verfahren auch beliebige Gemische verschiedener chlorierter aromatischer Verbindungen einsetzen.Of course, any mixtures of different chlorinated aromatic compounds can also be used in the process according to the invention.
Als Salze zur Bildung der Salzschmelze kommen z.B. anorganische, ionische Salze und diese enthaltende Gemische in Frage, soweit sie einen Schmelzpunkt unter 450°C aufweisen. Vorzugsweise liegt der Schmelzpunkt des eingesetzten Salzes oder Salzgemisches unter 360°C, besonders bevorzugt unter 300°C.The salts used to form the molten salt are e.g. inorganic, ionic salts and mixtures containing them come into question insofar as they have a melting point below 450 ° C. The melting point of the salt or salt mixture used is preferably below 360 ° C., particularly preferably below 300 ° C.
Die Salzschmelze kann z.B. Chloride enthalten, wie Lithiumchlorid, Natriumchlorid, Kaliumchlorid, Zinkchlorid, Kupfer(I)-chlorid, Kupfer(II)-chlorid, Silberchlorid, Thalliumchlorid, Zinn(II)-chlorid, Aluminiumchlorid und/oder Eisen(III)-chlorid. Bevorzugt sind Gemische, die Zinkchlorid, Kupfer(I)-chlorid, Kupfer(II)-chlorid und/oder Kaliumchlorid enthalten. Besonders bevorzugt sind Gemische aus Kupfer(I)-chlorid und Kaliumchlorid, insbesondere solche, die 50 bis 90 Gew.-% Kupfer(I)-chlorid und ergänzend zu 100 Gew.-% Kaliumchlorid enthalten.The molten salt can e.g. Chlorides contain, such as lithium chloride, sodium chloride, potassium chloride, zinc chloride, copper (I) chloride, copper (II) chloride, silver chloride, thallium chloride, tin (II) chloride, aluminum chloride and / or iron (III) chloride. Mixtures containing zinc chloride, copper (I) chloride, copper (II) chloride and / or potassium chloride are preferred. Mixtures of copper (I) chloride and potassium chloride are particularly preferred, in particular those which contain 50 to 90% by weight of copper (I) chloride and in addition to 100% by weight of potassium chloride.
Bezogen auf 100 g in das erfindungsgemäße Verfahren eingesetzte chlorierte aromatische Verbindungen kann man beispielsweise 1 bis 20 kg der jeweiligen Salzschmelze einsetzen.Based on 100 g of chlorinated aromatic compounds used in the process according to the invention, for example 1 to 20 kg of the respective molten salt can be used.
Bevorzugte Temperaturen für die Durchführung des erfindungsgemäßen Verfahrens sind solche im Bereich 350 bis 400°C, besonders bevorzugt solche im Bereich 360 bis 385°C.Preferred temperatures for carrying out the process according to the invention are those in the range from 350 to 400 ° C., particularly preferably those in the range from 360 to 385 ° C.
Der Druck beim erfindungsgemäßen Verfahren kann in weiten Grenzen variiert werden. Im einfachsten Fall führt man das erfindungsgemäße Verfahren in einem geschlossenen Gefäß unter dem sich von selbst einstellenden oder unter dem durch ein Druckhalteventil vorgegebenen Druck durch. Geeignete Drucke liegen z.B. im Bereich 1 bis 50 bar. Bevorzugte Drucke liegen im Bereich 5 bis 20 bar.The pressure in the process according to the invention can be varied within wide limits. In the simplest case, the method according to the invention is carried out in a closed vessel under the pressure which sets itself or under the pressure specified by a pressure-maintaining valve. Suitable prints are e.g. in the range 1 to 50 bar. Preferred pressures are in the range 5 to 20 bar.
Wasser und Kohle, letztere vorzugsweise in pulvriger Form, können dem erfindungsgemäßen Verfahren als solche zugeführt werden oder in Form eines sogenannten Kohleslurries, d.h. in Form eines pumpfähigen Gemisches, das gemahlene Kohle und Wasser enthält. Man kann die Kohle und/oder das Wasser unter Reaktionsbedingungen auch in situ entstehen lassen, z.B. aus zugegebenen, bei erhöhter Temperatur zur Verkohlung und/oder Wasserabspaltung neigenden Substanzen. Solche Substanzen sind z.B. Zucker wie Saccharose, Melasse und abgewandelte Zucker wie propoxylierte Saccharose. Solche Substanzen kann man auch in Form einer wäßrigen Lösung einsetzen. Vorzugsweise kommt gemahlene, schwefelfreie Kohle und z.B. aus Zucker oder Melasse zugängliche Aktivkohle zum Einsatz.Water and coal, the latter preferably in powder form, can be added to the process according to the invention as such or in the form of a so-called coal slurry, i.e. in the form of a pumpable mixture containing ground coal and water. The coal and / or water can also be generated in situ under reaction conditions, e.g. from added substances which tend to charring and / or water elimination at elevated temperature. Such substances are e.g. Sugars like sucrose, molasses and modified sugars like propoxylated sucrose. Such substances can also be used in the form of an aqueous solution. Preferably comes sulfur-free coal and e.g. Activated carbon available from sugar or molasses.
Bezogen auf 1 g-Atom aus den chlorierten aromatischen Verbindungen abzuspaltendem Chlor setzt man im allgemeinen mindestens 1/2 Mol Wasser und 1/4 g-Atom Kohle zu, wobei jedoch auch größere Überschüsse in Frage kommen, beispielsweise bis zu 1 Mol Wasser und bis zu 0,5 g-Atome Kohle pro g Atom aus den chlorierten aromatischen Verbindungen abzuspaltendem Chlor.Based on 1 g-atom of chlorine to be split off from the chlorinated aromatic compounds, at least 1/2 mole of water and 1/4 g-atom of coal are generally added, although larger excesses are also possible, for example up to 1 mole of water and bis to 0.5 g atoms of coal per g atom of chlorine to be split off from the chlorinated aromatic compounds.
Das erfindungsgemäße Verfahren kann diskontinuierlich oder kontinuierlich durchgeführt werden. Bei kontinuierlicher Fahrweise kann man beispielsweise in einem Reaktor von 1 l Inhalt mit 0,5 l Salzschmelze pro Stunde 0,1 bis 1 Mol chlorierte aromatische Verbindungen umsetzen. Es ist vorteilhaft, bei der Durchführung des erfindungsgemäßen Verfahrens zu rühren.The process according to the invention can be carried out batchwise or continuously. In the case of continuous operation, 0.1 to 1 mole of chlorinated aromatic compounds can be reacted, for example, in a reactor of 1 liter with 0.5 liter of molten salt per hour. It is advantageous to stir when carrying out the process according to the invention.
Da sowohl die Salzschmelze, als auch der entstehende Chlorwasserstoff korrosiv sind, ist es vorteilhaft Reaktionsgefäße zu verwenden, die antikorrosiv ausgerüstet sind, beispielsweise durch Auskleidung mit Tantal. Bei Abwesenheit von Wasser bzw. Wasserdampf oder Kohle kommt die Dechlorierungsreaktion zum Erliegen.Since both the molten salt and the hydrogen chloride formed are corrosive, it is advantageous to use reaction vessels which are anticorrosive, for example by lining them with tantalum. In the absence of water or water vapor or coal, the dechlorination reaction stops.
Das erfindungsgemäße Verfahren liefert aromatische Verbindungen, die weniger Chlor als die Ausgangsverbindung(en) und/oder kein Chlor mehr enthalten. Daneben entstehen Chlorwasserstoff, Kohlendioxid und Kohlenmonoxid. Undefinierte Nebenprodukte wie Teer oder Ruß werden aus den eingesetzten chlorierten aromtischen Verbindungen praktisch nicht gebildet.The process according to the invention provides aromatic compounds which contain less chlorine than the starting compound (s) and / or no more chlorine. In addition, hydrogen chloride, carbon dioxide and carbon monoxide are formed. Undefined by-products such as tar or soot are practically not formed from the chlorinated aromatic compounds used.
Aus dem Reaktionsgemisch kann man die gasförmigen Reaktionsprodukte durch Entspannung oder über ein Druckhalteventil abtrennen. Durch fraktionierte Destillation kann man die erhaltenen chlorarmen und chlorfreien aromatischen Verbindungen abtrennen und isolieren und auf vielfältige Weise weiterverwenden, beispielsweise als Zwischenprodukte zur Herstellung von Wirkstoffen. Unumgesetzte Ausgangsverbindungen und noch immer relativ hochchlorierte Reaktionsprodukte kann man gegebenenfalls erneut dem erfindungsgemäßen Verfahren zuführen. Die Salzschmelze kann, gegebenenfalls nach erneuter Zudosierung von Wasser und/oder Kohle, wiederverwendet werden.The gaseous reaction products can be separated from the reaction mixture by expansion or via a pressure-maintaining valve. Fractional distillation allows the chlorine-free and chlorine-free aromatic compounds obtained to be separated off and isolated and used in a variety of ways, for example as intermediates for the preparation of active compounds. Unreacted starting compounds and still relatively highly chlorinated reaction products can optionally be fed back into the process according to the invention. The molten salt can be reused, if necessary after adding water and / or coal again.
Das erfindungsgemäße Verfahren gestattet es auf einfache und kostengünstige Weise höherchlorierte aromatische Verbindungen zu wiederverwertbaren niederchlorierten oder chlorfreien aromatischen Verbindungen umzusetzen.The process according to the invention makes it possible to convert higher-chlorinated aromatic compounds into recyclable lower-chlorinated or chlorine-free aromatic compounds in a simple and inexpensive manner.
In einem mit Tantal ausgekleideten Druckreaktor von 1 l Inhalt wurden 720 g Kupfer(I)-chlorid, 280 g Kaliumchlorid, 6 g Saccharose und 18,15 g 1,2,4-Trichlorbenzol vorgelegt. Dann wurde der Druckreaktor verschlossen und unter kräftigem Rühren auf 375°C erhitzt. Nach 1 Stunde wurde der Reaktor abgekühlt, entspannt und die organischen Bestandteile des Reaktionsgemisches quantitativ analysiert. Es hatten sich über 95 Gew.-% des eingesetzten 1,2,4-Trichlorbenzols umgesetzt zu einem Gemisch, das 8 Gew.-% 1,2-Dichlorbenzol, 35 Gew.-% 1,3-Dichlorbenzol, 44,6 Gew.-% 1,4-Dichlorbenzol, 10,8 Gew.-% Monochlorbenzol und 1,4 Gew.-% Benzol enthielt.720 g of copper (I) chloride, 280 g of potassium chloride, 6 g of sucrose and 18.15 g of 1,2,4-trichlorobenzene were placed in a pressure reactor lined with tantalum and containing 1 liter. The pressure reactor was then closed and heated to 375 ° C. with vigorous stirring. After 1 hour the reactor was cooled, let down and the organic constituents of the reaction mixture were analyzed quantitatively. Over 95% by weight of the 1,2,4-trichlorobenzene used had reacted to form a mixture which comprised 8% by weight of 1,2-dichlorobenzene, 35% by weight of 1,3-dichlorobenzene and 44.6% by weight .-% 1,4-dichlorobenzene, 10.8 wt .-% monochlorobenzene and 1.4 wt .-% benzene contained.
Es wurde verfahren wie in Beispiel 1, jedoch wurde statt Saccharose 1 g Wasser und 6 g Aktivkohle eingesetzt. Nach 1 Stunde hatten sich über 95 Gew.-% des eingesetzten 1,2,4-Trichlorbenzols umgesetzt zu einem Gemisch, das 6,8 Gew.-% 1,2-Dichlorbenzol, 35,7 Gew.-% 1,3-Dichlorbenzol, 44,1 Gew.-% 1,4-Dichlorbenzol, 11,7 Gew.-% Monochlorbenzol und 1,3 Gew.-% Benzol enthielt.The procedure was as in Example 1, but 1 g of water and 6 g of activated carbon were used instead of sucrose. After 1 hour, more than 95% by weight of the 1,2,4-trichlorobenzene used had reacted to form a mixture which contained 6.8% by weight of 1,2-dichlorobenzene and 35.7% by weight of 1,3- Dichlorobenzene, 44.1% by weight 1,4-dichlorobenzene, 11.7% by weight monochlorobenzene and 1.3% by weight benzene.
Es wurde verfahren wie in Beispiel 1, jedoch wurde statt Saccharose 3 g Aktivkohle eingesetzt. Nach 1 Stunde waren lediglich 2 Gew.-% des eingesetzten 1,2,4-Trichlorbenzols umgesetzt worden.The procedure was as in Example 1, but 3 g of activated carbon were used instead of sucrose. After 1 hour, only 2% by weight of the 1,2,4-trichlorobenzene used had been reacted.
Dieses Beispiel zeigt die erfindungswesentliche Gegenwart von Wasser bzw. Wasserdampf.This example shows the presence of water or water vapor, which is essential to the invention.
Es wurde verfahren wie in Beispiel 1, jedoch wurde statt Saccharose 1 g Wasser zugesetzt. Nach 1 Stunde waren lediglich 1,5 Gew.-% des eingesetzten 1,2,4-Trichlorbenzols umgesetzt worden.The procedure was as in Example 1, but 1 g of water was added instead of sucrose. After 1 hour, only 1.5% by weight of the 1,2,4-trichlorobenzene used had been reacted.
Dieses Beispiel zeigt die erfindungswesentliche Gegenwart von Kohle.This example shows the presence of coal essential to the invention.
Claims (10)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4334056 | 1993-10-06 | ||
| DE4334056A DE4334056A1 (en) | 1993-10-06 | 1993-10-06 | Process for the dechlorination of chlorinated aromatic compounds |
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| Publication Number | Publication Date |
|---|---|
| EP0647459A1 true EP0647459A1 (en) | 1995-04-12 |
Family
ID=6499538
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP94115054A Withdrawn EP0647459A1 (en) | 1993-10-06 | 1994-09-23 | Method of dechlorination of chlorinated aromatic compounds |
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| Country | Link |
|---|---|
| US (1) | US5552549A (en) |
| EP (1) | EP0647459A1 (en) |
| JP (1) | JPH07206721A (en) |
| DE (1) | DE4334056A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1098880A4 (en) * | 1998-07-15 | 2002-10-23 | Reilly Ind Inc | Dechlorination of pyridines in acidic, zinc-containing mediums |
| DE10242223A1 (en) * | 2002-09-12 | 2004-03-25 | Clariant Gmbh | Process for the hydrodechlorination of nuclear chlorinated ortho-xylenes |
| DE10242224A1 (en) * | 2002-09-12 | 2004-03-25 | Clariant Gmbh | Process for the core chlorination of ortho-xylene |
| JP2006020909A (en) * | 2004-07-09 | 2006-01-26 | Mitsui Eng & Shipbuild Co Ltd | Method for heating/decomposing contaminant and halogenated aromatic compound decomposition agent |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4422872A (en) * | 1980-10-14 | 1983-12-27 | Geskin Ernest S | Method of heating, melting, and coal coversion and apparatus for the same |
| WO1993010862A1 (en) * | 1991-12-06 | 1993-06-10 | Technological Resources Pty. Limited | Treatment of waste |
| WO1993020898A1 (en) * | 1992-04-21 | 1993-10-28 | Elaia S.R.L. | High temperature process and plant for treatment and resources recovery of hazardous waste |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4188346A (en) * | 1978-05-18 | 1980-02-12 | The Dow Chemical Company | Dehydrohalogenation of (polyhaloalkyl)benzenes |
| US4337368A (en) * | 1980-04-21 | 1982-06-29 | The Franklin Institute | Reagent and method for decomposing halogenated organic compounds |
| US4601817A (en) * | 1984-09-21 | 1986-07-22 | Globus Alfred R | Treatment of hazardous materials |
| US4602574A (en) * | 1984-11-08 | 1986-07-29 | United States Steel Corporation | Destruction of toxic organic chemicals |
| US4574714A (en) * | 1984-11-08 | 1986-03-11 | United States Steel Corporation | Destruction of toxic chemicals |
| DE3632363A1 (en) * | 1986-09-24 | 1988-03-31 | Boelsing Friedrich | METHOD FOR DEHALOGENATING HALOGENED CARBON HYDROGEN |
| US4816609A (en) * | 1987-05-26 | 1989-03-28 | The Dow Chemical Company | Process and catalyst for the dehydrohalogenation of halogenated hydrocarbons |
| FR2677980B1 (en) * | 1991-06-19 | 1993-09-03 | Atochem | PROCESS FOR DEHYDROCHLORINATING 1,1-BIS (PHENYL) 2,2,2-TRICHLOROETHANES. |
| US5369214A (en) * | 1993-03-18 | 1994-11-29 | The United States Of America As Represented By The United States Department Of Energy | Method for selective dehalogenation of halogenated polyaromatic compounds |
-
1993
- 1993-10-06 DE DE4334056A patent/DE4334056A1/en not_active Withdrawn
-
1994
- 1994-09-23 EP EP94115054A patent/EP0647459A1/en not_active Withdrawn
- 1994-09-29 US US08/315,001 patent/US5552549A/en not_active Expired - Fee Related
- 1994-10-05 JP JP6264386A patent/JPH07206721A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4422872A (en) * | 1980-10-14 | 1983-12-27 | Geskin Ernest S | Method of heating, melting, and coal coversion and apparatus for the same |
| WO1993010862A1 (en) * | 1991-12-06 | 1993-06-10 | Technological Resources Pty. Limited | Treatment of waste |
| WO1993020898A1 (en) * | 1992-04-21 | 1993-10-28 | Elaia S.R.L. | High temperature process and plant for treatment and resources recovery of hazardous waste |
Also Published As
| Publication number | Publication date |
|---|---|
| US5552549A (en) | 1996-09-03 |
| DE4334056A1 (en) | 1995-04-13 |
| JPH07206721A (en) | 1995-08-08 |
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