[go: up one dir, main page]

EP0188718B1 - Process for the chemical-thermal decomposition of higher halogenated hydrocarbons - Google Patents

Process for the chemical-thermal decomposition of higher halogenated hydrocarbons Download PDF

Info

Publication number
EP0188718B1
EP0188718B1 EP85115514A EP85115514A EP0188718B1 EP 0188718 B1 EP0188718 B1 EP 0188718B1 EP 85115514 A EP85115514 A EP 85115514A EP 85115514 A EP85115514 A EP 85115514A EP 0188718 B1 EP0188718 B1 EP 0188718B1
Authority
EP
European Patent Office
Prior art keywords
calcium
halogenated hydrocarbons
oxide
iron oxide
chemical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85115514A
Other languages
German (de)
French (fr)
Other versions
EP0188718A1 (en
Inventor
Paul-Gerhard Dr. Dipl.-Chem. Maurer
Daniel Dr. Dipl.-Chem. Neupert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nukem GmbH
Original Assignee
Nukem GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nukem GmbH filed Critical Nukem GmbH
Priority to AT85115514T priority Critical patent/ATE30120T1/en
Publication of EP0188718A1 publication Critical patent/EP0188718A1/en
Application granted granted Critical
Publication of EP0188718B1 publication Critical patent/EP0188718B1/en
Expired legal-status Critical Current

Links

Classifications

    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D3/00Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
    • A62D3/40Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by heating to effect chemical change, e.g. pyrolysis
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D3/00Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances
    • A62D3/30Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances by reacting with chemical agents
    • A62D3/36Detoxification by using acid or alkaline reagents
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/04Pesticides, e.g. insecticides, herbicides, fungicides or nematocides
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/06Explosives, propellants or pyrotechnics, e.g. rocket fuel or napalm
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2101/00Harmful chemical substances made harmless, or less harmful, by effecting chemical change
    • A62D2101/20Organic substances
    • A62D2101/22Organic substances containing halogen
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62DCHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
    • A62D2203/00Aspects of processes for making harmful chemical substances harmless, or less harmful, by effecting chemical change in the substances
    • A62D2203/04Combined processes involving two or more non-distinct steps covered by groups A62D3/10 - A62D3/40

Definitions

  • the invention relates to a process for the chemical-thermal decomposition of higher halogenated hydrocarbons by reaction with calcium oxide and / or calcium hydroxide in a superstoichiometric ratio at temperatures of 600 to 800 ° C in a reactor.
  • halogenated hydrocarbons are used very frequently in industry and research.
  • fluorocarbons serve as dough gas and refrigerants and are the starting materials for the production of chemically very resistant plastics.
  • Chlorinated hydrocarbons are used in large quantities as degreasing agents in metal processing plants. Other areas of application are chemical cleaning of all kinds.
  • chlorinated hydrocarbons are the starting materials for the production of polymers, pesticides and herbicides.
  • the polychlorinated hydrocarbons were used as heat transfer oils or hydraulic fluids due to their high chemical and thermal resistance.
  • the polychlorinated biphenyls (PCB) are typical representatives of this class of substances.
  • PCBs which in the past were mainly used as transformer oils and as dielectrics in capacitors. Simply by replacing these liquids with substitutes, the Federal Republic of Germany expects to dispose of around 6000 t of polychlorinated biphenyls annually over the next ten years.
  • DE-OS 3028193 describes a process for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances, these being reacted with calcium oxide / calcium hydroxide in a superstoichiometric ratio at temperatures of 300 to 800 ° C. in a reactor.
  • the disadvantage of this process is that not all halogenated hydrocarbons can be decomposed without problems.
  • the temperatures required for the quantitative decomposition of the chemically and thermally very stable higher halogenated hydrocarbons, to which the polychlorinated biphenyls in particular must be counted, are above 600 ° C. Above this temperature, mixtures of CaO and Ca (OH) 2 form with the corresponding calcium chlorides, Melt. This fact presents considerable difficulties since the necessary continuous throughput of solids through the reactor is thereby hindered and may even become impossible.
  • the formation of melts also leads to a considerable reduction in the decomposition rate of the halogenated hydrocarbons. This is due to the large reduction in the surface area of the solid reactants, which have a significant influence on the reaction in gas-solid reactions. Even a strong excess of the basic compounds mentioned cannot prevent melt formation with subsequent incrustation in the cooling phase at temperatures above 600 ° C.
  • This object was achieved according to the invention in that the calcium oxide and / or calcium hydroxide, based on the halogen to be set, is present in at least a two-fold stoichiometric excess and contains 2 to 30% by weight of iron oxide.
  • a two to five-fold stoichiometric excess of calcium oxide and / or calcium hydroxide is preferably used, it being possible for some of the calcium compounds to be replaced by the corresponding magnesium compounds.
  • Iron oxide additives in the size of 3 to 25% by weight have proven successful, it being possible for the iron oxide to be present as such or in the form of substances containing iron oxide.
  • the red mud obtained in the production of aluminum can be used fly ash from combustion plants is advantageously used.
  • the added iron oxide also has a catalytic effect on the chemical-thermal decomposition of halogenated hydrocarbons.
  • the amount of calcium oxide and / or calcium hydroxide used, based on the halogen to be set is used in twice the stoichiometric amount. Equally good results cannot be achieved without the addition of iron oxide.
  • the iron oxide can be replaced by cheaper iron oxide-containing substitutes.
  • fly ash has proven to be particularly advantageous. Fly ash is produced in large quantities during the combustion of hard coal and lignite in power plants and must also be disposed of so that no further costs arise when using the fly ash. Typical levels of iron oxide in fly ash are 5 to 18% by weight. In addition, fly ash also sometimes contains considerable amounts of calcium oxide, so that calcium oxide can also be saved.
  • the resulting gaseous reaction products are halogen-free.
  • the exhaust gas contains corresponding amounts of hydrogen, methane and possibly other partly saturated and partly unsaturated low hydrocarbons as well as small amounts of carbon monoxide.
  • the exhaust gas still has a considerable calorific value and can be used accordingly or simply post-burned to carbon dioxide and water in a post-combustion chamber.
  • the chemical-thermal decomposition according to the invention of higher halogenated hydrocarbons by reaction with calcium oxide and / or calcium hydroxide and iron oxide or substances containing iron oxide is a very environmentally friendly and inexpensive method of disposing of these substances. No formation of metabolites, such as polychlorinated dibenzodioxins or furans, takes place in the process mentioned, so that there are no safety-related concerns from this point of view either.
  • the waste gases escaping from the reactor during the test are free of halogenated hydrocarbons and are re-burned in a post-combustion chamber with a slight excess of air.

Landscapes

  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Fire-Extinguishing Compositions (AREA)
  • Processing Of Solid Wastes (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

A halohydrocarbon is destroyed chemical-thermally by reacting at 600 DEG to 800 DEG C. with calcium oxide and/or calcium hydroxide. The process can be carried out problem-free by having the calcium oxide of hydroxide present in at least twice the stoichiometric excess based on the halogen to be bound and by having the composition contain 2-30 wt. % iron oxide.

Description

Die Erfindung betrifft ein Verfahren zur chemisch-thermischen Zersetzung von höher halogenierten Kohlenwasserstoffen durch Umsetzung mit Calciumoxid und/oder Calciumhydroxid in einem überstöchiometrischen Verhältnis bei Temperaturen von 600 bis 800°C in einem Reaktor.The invention relates to a process for the chemical-thermal decomposition of higher halogenated hydrocarbons by reaction with calcium oxide and / or calcium hydroxide in a superstoichiometric ratio at temperatures of 600 to 800 ° C in a reactor.

Höher halogenierte Kohlenwasserstoffe werden in Industrie und Forschung sehr häufig eingesetzt. So dienen Fluorkohlenwasserstoffe als Teibgas und Kältemittel und sind Ausgangsstoffe zur Herstellung von chemisch sehr beständigen Kunststoffen. Chlorkohlenwasserstoffe werden in grossen Mengen als Entfettungsmittel in metallverarbeitenden Betrieben eingesetzt. Weitere Anwendungsgebiete sind chemisch Reinigungen aller Art. Darüber hinaus sind die Chlorkohlenwasserstoffe, Ausgangsstoffe zur Herstellung von Polymeren, Pestiziden und Herbiziden. Insbesondere die polychlorierten Kohlenwasserstoffe wurden aufgrund ihrer hohen chemischen und thermischen Beständigkeit als Wärmeträgeröle oder Hydraulikflüssigkeiten eingesetzt. Die polychlorierten Biphenyle (PCB) sind typische Vertreter dieser Stoffklasse.Highly halogenated hydrocarbons are used very frequently in industry and research. For example, fluorocarbons serve as dough gas and refrigerants and are the starting materials for the production of chemically very resistant plastics. Chlorinated hydrocarbons are used in large quantities as degreasing agents in metal processing plants. Other areas of application are chemical cleaning of all kinds. In addition, chlorinated hydrocarbons are the starting materials for the production of polymers, pesticides and herbicides. In particular, the polychlorinated hydrocarbons were used as heat transfer oils or hydraulic fluids due to their high chemical and thermal resistance. The polychlorinated biphenyls (PCB) are typical representatives of this class of substances.

Obwohl von der Möglichkeit der Rezyklierung gebrauchter Halogenkohlenwasserstoffe, soweit dies technisch möglich und wirtschaftlich vertretbar ist, Gebrauch gemacht wird, fallen in der Bundesrepublik Deutschland jährlich ca. 30000 bis 40 000t t Chlorkohlenwasserstoffe mit Chlorgehalten > 20% an, die entsorgt werden müssen.Although use is made of the possibility of recycling used halogenated hydrocarbons, insofar as this is technically possible and economically justifiable, approx. 30,000 to 40,000 tonnes of chlorinated hydrocarbons with> 20% chlorine content accrue in the Federal Republic of Germany, which have to be disposed of.

Bei diesen sogenannten Sonderabfällen handelt es sich neben Rückständen aus Rezyklierungsanlagen und Produktionsrückständen auch um Stoffe, deren Verwendung aus sicherheits- und umwelttechnischen Gesichtspunkten immer mehr eingeschränkt wird und die letztendlich einer Entsorgung zugeführt werden müssen. Das bekannteste Beispiel hierfür sind PCB, die in der Vergangenheit hauptsächlich als Trafoöle und als Dielektrika in Kondensatoren eingesetzt wurden. Allein durch Austausch dieser Flüssigkeiten gegen Ersatzstoffe rechnet man in der Bundesrepublik in den nächsten zehn Jahren mit jährlich ca. 6000 t zu entsorgenden polychlorierten Biphenylen.In addition to residues from recycling plants and production residues, these so-called special wastes are also substances whose use is being increasingly restricted from a safety and environmental point of view and which ultimately have to be disposed of. The best-known example of this are PCBs, which in the past were mainly used as transformer oils and as dielectrics in capacitors. Simply by replacing these liquids with substitutes, the Federal Republic of Germany expects to dispose of around 6000 t of polychlorinated biphenyls annually over the next ten years.

Als Möglichkeit zur Entsorgung von Halogenkohlenwasserstoffen wird derzeit nur die Verbrennung auf See angesehen. Internationale Abkommen (Osloer und Londoner Konvention) zielen jedoch darauf hin, die Verbrennung auf See bis Ende dieses Jahrzehnts gänzlich einzuschränken. Als Alternative dazu bleibt dann nur noch die Verbrennung an Land. Die Verbrennung von Halogenkohlenwasserstoffen, insbesondere fluorierten und höher chlorierten, in bestehenden Sonderabfallverbrennungsanlagen ist problematisch. Die wesentlichen Gründe für die Schwierigkeiten sind die Korrosionsgefahr für die Ausmauerung und die Abgasstrecke durch eine hohe Rohgasbeladung an Halogenwasserstoffen (HF und HCI), die Emissionssituation, insbesondere bei Verbrennung von fluorierten Kohlenwasserstoffen, und der hohe Einsatz an Energie.At present, only incineration at sea is considered to be an option for the disposal of halogenated hydrocarbons. However, international agreements (the Oslo and London Conventions) aim to limit combustion at sea entirely by the end of this decade. The only alternative then is incineration on land. The combustion of halogenated hydrocarbons, especially fluorinated and more chlorinated ones, in existing hazardous waste incineration plants is problematic. The main reasons for the difficulties are the risk of corrosion for the brick lining and the exhaust gas section due to a high raw gas load of hydrogen halide (HF and HCI), the emission situation, especially when burning fluorinated hydrocarbons, and the high use of energy.

Besonders durch den Umstand, dass bei unzureichenden Verbrennungsbedingungen bei der Chlorkohlenwasserstoff-Verbrennung hochgiftige polychlorierte Dibenzodioxien und Dibenzofurane gebildet werden können, ist diese Entsorgungspraxis zunehmender Kritik ausgesetzt.This disposal practice is subject to increasing criticism, in particular due to the fact that highly toxic polychlorinated dibenzodioxien and dibenzofurans can be formed in the case of insufficient combustion conditions during chlorinated hydrocarbon combustion.

In der DE-OS 3028193 ist ein Verfahren zur pyrolytischen Zersetzung von Halogene und/oder Phosphor enthaltenden organischen Substanzen beschrieben, wobei diese mit Calciumoxid/Calciumhydroxid in einem überstöchiometrischen Verhältnis gemischt bei Temperaturen von 300 bis 800°C in einem Reaktor umgesetzt werden.DE-OS 3028193 describes a process for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances, these being reacted with calcium oxide / calcium hydroxide in a superstoichiometric ratio at temperatures of 300 to 800 ° C. in a reactor.

Nachteilig bei diesem Verfahren ist es, dass nicht alle Halogenkohlenwasserstoffe problemlos zersetzt werden können. Die notwendigen Temperaturen zur quantitativen Zersetzung der chemisch und thermisch sehr stabilen höher halogenierten Kohlenwasserstoffe, zu denen insbesondere die polychlorierten Biphenyle gezählt werden müssen, liegen über 600° C. Oberhalb dieser Temperatur bilden Mischungen aus CaO und Ca (OH)2 mit den entsprechenden Calciumchloriden, Schmelzen. Diese Tatsache bereitet erhebliche Schwierigkeiten, da der notwendige kontinuierliche Feststoffdurchsatz durch den Reaktor dadurch behindert und unter Umständen sogar unmöglich wird. Neben den verfahrenstechnischen Schwierigkeiten führt die Bildung von Schmelzen gleichzeitig zu einer erheblichen Herabsetzung der Zersetzungsrate der halogenierten Kohlenwasserstoffe. Dies ist auf die starke Verringerung der Oberfläche der festen Reaktionspartner zurückzuführen, die bei Gas-Feststoffreaktionen einen wesentlichen Einfluss auf die Reaktion ausüben. Selbst ein starker Überschuss der genannten basischen Verbindungen vermag bei Temperaturen über 600° C eine Schmelzenbildung mit anschliessender Verkrustung in der Abkühlphase nicht zu verhindern.The disadvantage of this process is that not all halogenated hydrocarbons can be decomposed without problems. The temperatures required for the quantitative decomposition of the chemically and thermally very stable higher halogenated hydrocarbons, to which the polychlorinated biphenyls in particular must be counted, are above 600 ° C. Above this temperature, mixtures of CaO and Ca (OH) 2 form with the corresponding calcium chlorides, Melt. This fact presents considerable difficulties since the necessary continuous throughput of solids through the reactor is thereby hindered and may even become impossible. In addition to the process engineering difficulties, the formation of melts also leads to a considerable reduction in the decomposition rate of the halogenated hydrocarbons. This is due to the large reduction in the surface area of the solid reactants, which have a significant influence on the reaction in gas-solid reactions. Even a strong excess of the basic compounds mentioned cannot prevent melt formation with subsequent incrustation in the cooling phase at temperatures above 600 ° C.

Es war daher Aufgabe der vorliegenden Erfindung, ein Verfahren zur chemisch-thermischen Zersetzung von höher halogenierten Kohlenwasserstoffen zu entwickeln, durch Umsetzung mit Calciumoxid und/oder Calciumhydroxid in einem überstöchiometrischen Verhältnis bei Temperaturen von 600 bis 800°C in einem Reaktor, bei dem sich keine Schmelzen bilden und bei dem die Abgase halogen- und insbesondere dioxinfrei sind.It was therefore an object of the present invention to develop a process for the chemical-thermal decomposition of higher halogenated hydrocarbons by reaction with calcium oxide and / or calcium hydroxide in a superstoichiometric ratio at temperatures of 600 to 800 ° C in a reactor in which there is none Form melts and in which the exhaust gases are halogen and especially dioxin free.

Diese Aufgabe wurde erfindungsgemäss dadurch gelöst, dass das Calciumoxid und/oder Calciumhydroxid bezogen auf das abzubindende Halogen in mindestens zweifachen stöchiometrischen Überschuss vorliegt und 2 bis 30 Gew.-% Eisenoxid enthält.This object was achieved according to the invention in that the calcium oxide and / or calcium hydroxide, based on the halogen to be set, is present in at least a two-fold stoichiometric excess and contains 2 to 30% by weight of iron oxide.

Vorzugsweise verwendet man einen zwei- bis fünffachen stöchiometrischen Überschuss an Calciumoxid und/oder Calciumhydroxid, wobei ein Teil der Calciumverbindungen auch durch die entsprechenden Magnesiumverbindungen ersetzt sein kann. Bewährt haben sich Eisenoxidzusätze in der Grösse von 3 bis 25 Gew.-%, wobei das Eisenoxid als solches oder in Form von eisenoxidhaltigen Substanzen vorliegen kann. Als eisenoxidhaltige Substanz kann beispielsweise der bei der Aluminiumherstellung anfallende Rotschlamm eingesetzt werden, vorteilhafterweise verwendet man jedoch Flugasche aus Feuerungsanlagen.A two to five-fold stoichiometric excess of calcium oxide and / or calcium hydroxide is preferably used, it being possible for some of the calcium compounds to be replaced by the corresponding magnesium compounds. Iron oxide additives in the size of 3 to 25% by weight have proven successful, it being possible for the iron oxide to be present as such or in the form of substances containing iron oxide. As a substance containing iron oxide, for example, the red mud obtained in the production of aluminum can be used fly ash from combustion plants is advantageously used.

Es hat überraschenderweise gezeigt, dass schon bei einem Anteil von 2 Gew.-% Eisenoxid im Calciumoxid oder Calciumhydroxid eine Schmelzenbildung durch entstehendes Calciumchlorid zuverlässig verhindert wird und die nach der Halogenkohlenwasserstoffzersetzung vorliegende Feststoffmischung selbst bei Temperaturen von 800°C rieselfähig bleibt und beim Abkühlen auch nicht verkrustet.Surprisingly, it has been shown that even with a proportion of 2% by weight of iron oxide in calcium oxide or calcium hydroxide, melt formation due to calcium chloride formed is reliably prevented and that the solid mixture present after the halogenated hydrocarbon decomposition remains free-flowing even at temperatures of 800 ° C. and also not during cooling encrusted.

Das zugesetzte Eisenoxid zeigt neben seiner Eigenschaft im vorliegenden Fall Verkrustungen zu verhindern auch katalytische Wirkung auf die chemisch-thermische Zersetzung von Halogenkohlenwasserstoffen. Für die vollständige Zersetzung von höher halogenierten Kohlenwasserstoffen reicht es aus, wenn die eingesetzte Menge an Calciumoxid und/oder Calciumhydroxid, bezogen auf das abzubindende Halogen, in zweifacher überstöchiometrischer Menge eingesetzt wird. Gleich gute Ergebnisse lassen sich ohne Zusatz von Eisenoxid nicht erzielen.In addition to its property of preventing incrustations, the added iron oxide also has a catalytic effect on the chemical-thermal decomposition of halogenated hydrocarbons. For the complete decomposition of higher halogenated hydrocarbons, it is sufficient if the amount of calcium oxide and / or calcium hydroxide used, based on the halogen to be set, is used in twice the stoichiometric amount. Equally good results cannot be achieved without the addition of iron oxide.

Da die Reaktion von höher halogenierten Kohlenwasserstoffen mit Calciumoxid zu Calciumchlorid exotherm ist, kann bei entsprechend hoher Dosierrate der Reaktionspartner eine Wärmeabfuhr notwendig werden. Auf eine über die üblichen Wärmeverluste durch Abstrahlung und Wärmeleitung hinausgehende Wärmeabfuhr durch Kühlung des Reaktormantels kann aber dann verzichtet werden, wenn das Calciumoxid de Reaktionsmischung teilweise durch Calciumhydroxid ersetzt wird.Since the reaction of higher halogenated hydrocarbons with calcium oxide to calcium chloride is exothermic, heat removal may be necessary if the reactants are dosed accordingly high. In addition to the usual heat losses due to radiation and heat conduction, heat dissipation by cooling the reactor jacket can be dispensed with if the calcium oxide de reaction mixture is partially replaced by calcium hydroxide.

Bei geeignetem Mischungsverhältnis, das bei kontinuierlicher Umsetzung experimentell einfach ermittelt und über geeignete Dosiereinrichtungen eingestellt werden kann, ist auf diese Weise sogar eine autotherme Reaktionsführung möglich. Mit diesem Verfahren ist damit eine kontinuierliche chemisch-thermische Zersetzung von höher halogenierten Kohlenwasserstoffen ohne zusätzlichen Energieeinsatz durchzuführen.With a suitable mixing ratio, which can be easily determined experimentally in the case of continuous implementation and adjusted using suitable metering devices, an autothermal reaction procedure is even possible in this way. With this process, a continuous chemical-thermal decomposition of higher halogenated hydrocarbons can be carried out without additional energy consumption.

Als zusätzliche Möglichkeit zur kostengünstigen Gestaltung des erfindungsgemässen Verfahrens kann das Eisenoxid durch billigere eisenoxidhaltige Ersatzstoffe ersetzt werden. Als besonders vorteilhaft hat sich die Verwendung von Flugasche herausgestellt. Flugasche fällt in grossen Mengen bei der Verbrennung von Steinkohle und Braunkohle in Kraftwerken an und muss ebenfalls einer Entsorgung zugeführt werden, so dass beim Einsatz der Flugasche keine weiteren Kosten entstehen. Typische Gehalte an Eisenoxid in Flugasche betragen 5 bis 18 Gew.-%. Flugasche enthält darüber hinaus zum Teil auch noch erhebliche Mengen an Calciumoxid, so dass auch Calciumoxid eingespart werden kann.As an additional option for the cost-effective design of the method according to the invention, the iron oxide can be replaced by cheaper iron oxide-containing substitutes. The use of fly ash has proven to be particularly advantageous. Fly ash is produced in large quantities during the combustion of hard coal and lignite in power plants and must also be disposed of so that no further costs arise when using the fly ash. Typical levels of iron oxide in fly ash are 5 to 18% by weight. In addition, fly ash also sometimes contains considerable amounts of calcium oxide, so that calcium oxide can also be saved.

Die entstehenden gasförmigen Reaktionsprodukte sind halogenfrei. Im Falle der Zersetzung von nicht perhalogenierten Kohlenwasserstoffen enthält das Abgas entsprechende Mengen an Wasserstoff, Methan und evtl. andere teils gesättigteteils ungesättigte niedrige Kohlenwasserstoffe sowie geringe Anteile Kohlenmonoxid. Das Abgas besitzt in diesem Falle noch einen erheblichen Heizwert und kann entsprechend genutzt werden oder auch einfach in einer Nachbrennkammer zu Kohlendioxid und Wasser nachverbrannt werden.The resulting gaseous reaction products are halogen-free. In the case of the decomposition of non-perhalogenated hydrocarbons, the exhaust gas contains corresponding amounts of hydrogen, methane and possibly other partly saturated and partly unsaturated low hydrocarbons as well as small amounts of carbon monoxide. In this case, the exhaust gas still has a considerable calorific value and can be used accordingly or simply post-burned to carbon dioxide and water in a post-combustion chamber.

Die erfindungsgemässe chemisch-thermische Zersetzung von höher halogenierten Kohlenwasserstoffen durch Reaktion mit Calciumoxid und/ oder Calciumhydroxid und Eisenoxid oder eisenoxidhaltigen Stoffen ist ein sehr umweltverträgliches und kostengünstiges Verfahren zur Entsorgung dieser Substanzen. Eine Bildung von Metaboliten, wie polychlorierten Dibenzodioxinen oder Furanen, erfolgt bei dem genannten Verfahren nicht, so dass auch aus dieser Sicht keine sicherheitstechnischen Bedenken bestehen.The chemical-thermal decomposition according to the invention of higher halogenated hydrocarbons by reaction with calcium oxide and / or calcium hydroxide and iron oxide or substances containing iron oxide is a very environmentally friendly and inexpensive method of disposing of these substances. No formation of metabolites, such as polychlorinated dibenzodioxins or furans, takes place in the process mentioned, so that there are no safety-related concerns from this point of view either.

Das erfindungsgemässe Verfahren soll am folgenden Beispiel näher erläutert werden:

  • Der Reaktor, in dem die chemisch-thermische Zersetzung der Halogenkohlenwasserstoffe durchgeführt wird, ist als Rührbettreaktor gemäss DE-OS 3028193 ausgeführt. In diesem Reaktor befinden sich ca. 10 kg einer Kugelschüttung, die auf einem für feinkörnige oder pulvrige Feststoffe durchlässigen Tragrost ruht. Die Kugelschüttung besteht aus Keramikkugeln mit Durchmessern von ca. 16 mm und wird mit einem Wendelrührer umgewälzt. Die Rührerdrehzahl beträgt ca. 2 Umdrehungen pro Minute. Vor Beginn der Halogenkohlenwasserstoff-Einspeisung wird das Rührbett elektrisch aufgeheizt. Nach Erreichen der Betriebstemperaturen von 700°C wird eine Mischung aus 40% CaO, 10% Ca (OH)2 und 50% Flugasche mit 8% Eisenoxidgehalt in den Rührbettreaktor von oben mit einer Dosierrate von ca. 500 g/Stunde eindosiert. Nach einer Vorlaufzeit von etwa 10 Minuten wird eine Dosierpumpe eingeschaltet, die die zu zersetzenden Halogenkohlenwasserstoffe über eine getrennte Zuführung in den Reaktor einspeist. Die Abfallösung besteht aus etwa 40% Dichlormethan und 60% polychlorierten Biphenylen (PCB). Durch die Rührbewegung der Kugelschüttung werden die Reaktanden sowie die Reaktionsprodukte von oben nach unten durch das heisse Kugelbett hindurchtransportiert.
The process according to the invention will be explained in more detail using the following example:
  • The reactor in which the chemical-thermal decomposition of the halogenated hydrocarbons is carried out is designed as a stirred bed reactor in accordance with DE-OS 3028193. This reactor contains approx. 10 kg of a ball bed, which rests on a supporting grate that is permeable to fine-grained or powdery solids. The ball bed consists of ceramic balls with a diameter of approx. 16 mm and is circulated with a spiral stirrer. The stirrer speed is approx. 2 revolutions per minute. The stirred bed is heated electrically before starting the hydrocarbon feed. After the operating temperatures of 700 ° C. have been reached, a mixture of 40% CaO, 10% Ca (OH) 2 and 50% fly ash with 8% iron oxide content is metered into the stirred bed reactor from above at a metering rate of approximately 500 g / hour. After a lead time of about 10 minutes, a metering pump is switched on, which feeds the halogenated hydrocarbons to be decomposed into the reactor via a separate feed. The waste solution consists of approximately 40% dichloromethane and 60% polychlorinated biphenylene (PCB). The reactants and the reaction products are transported from top to bottom through the hot ball bed by the stirring movement of the ball bed.

Nach Beendigung des 2stündigen Versuchs haben sich unterhalb des Tragrosts, über eine Schleuse abgezogen, ca. 1500 g eines pulvrigen Feststoffs in einem Behälter angesammelt. Diese Feststoffmischung enthält vornehmlich überschüssigen gebrannten Kalk und Flugasche sowie Calciumchlorid und Eisenverbindungen. Sie ist frei von organischen Stoffen.After the end of the 2-hour test, about 1500 g of a powdery solid had collected in a container below the supporting grate, drawn off via a lock. This mixture of solids mainly contains excess burnt lime and fly ash as well as calcium chloride and iron compounds. It is free of organic substances.

Die während des Versuches aus dem Reaktor entweichenden Abgase sind frei von Halogenkohlenwasserstoffen und werden in einer Nachbrennkammer mit leichtem Luftüberschuss nachverbrannt.The waste gases escaping from the reactor during the test are free of halogenated hydrocarbons and are re-burned in a post-combustion chamber with a slight excess of air.

Claims (4)

1. A process for the chemico-thermal decomposition of relatively highly halogenated hydrocarbons by reaction with calcium oxide and/or calcium hydroxide in an overstoichiometric ratio at temperatures of from 600 to 800°C in a reactor, characterised in that the calcium oxide and/or calcium hydroxide is present, based on the halogen to be removed, in an at least double stoichiometric excess and contains from 2 to 30% by weight of iron oxide.
2. A process according to claim 1, characterised in that a double to five-fold stoichiometric excess of calcium oxide and/or calcium hydroxide is used.
3. A process according to claims 1 and 2, characterised in that the calcium oxide and/or calcium hydroxide contains from 3 to 25% by weight of iron oxide.
4. A process according to claims 1 to 3, characterised in that the iron oxide is present in the form of flue dust from furnaces.
EP85115514A 1984-12-24 1985-12-06 Process for the chemical-thermal decomposition of higher halogenated hydrocarbons Expired EP0188718B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85115514T ATE30120T1 (en) 1984-12-24 1985-12-06 PROCESS FOR THE CHEMICAL-THERMAL DECOMPOSITION OF HIGHER HALOGENATED HYDROCARBONS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3447337 1984-12-24
DE3447337A DE3447337C2 (en) 1984-12-24 1984-12-24 Process for the chemical-thermal decomposition of higher halogenated hydrocarbons

Publications (2)

Publication Number Publication Date
EP0188718A1 EP0188718A1 (en) 1986-07-30
EP0188718B1 true EP0188718B1 (en) 1987-10-07

Family

ID=6253854

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85115514A Expired EP0188718B1 (en) 1984-12-24 1985-12-06 Process for the chemical-thermal decomposition of higher halogenated hydrocarbons

Country Status (4)

Country Link
US (1) US4654203A (en)
EP (1) EP0188718B1 (en)
AT (1) ATE30120T1 (en)
DE (2) DE3447337C2 (en)

Families Citing this family (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3517019C2 (en) * 1985-05-11 1987-03-26 Nukem Gmbh, 6450 Hanau Process for the chemical-thermal decomposition of halogenated hydrocarbons
DE3640573A1 (en) * 1985-11-28 1987-06-04 Suppan Friedrich Process and plant for energy recovery from toxic waste materials with simultaneous disposal thereof
US5276250A (en) * 1986-07-11 1994-01-04 Hagenmaier Hans Paul Process for decomposing polyhalogenated compounds
DE3623492A1 (en) * 1986-07-11 1988-01-21 Hagenmaier Hans Paul METHOD FOR DEGRADING HALOGENATED AROMATES
DE3632363A1 (en) * 1986-09-24 1988-03-31 Boelsing Friedrich METHOD FOR DEHALOGENATING HALOGENED CARBON HYDROGEN
DE3716444A1 (en) * 1987-05-16 1988-12-01 Hartmann Helmut METHOD AND PLANT FOR CLEANING CONTAMINATED Bulk Goods
DE3731688A1 (en) * 1987-09-21 1989-03-30 Degussa METHOD FOR THE CATALYTIC IMPROVEMENT OF HYDROCARBON, HALOGEN CARBON HYDROGEN AND CARBON MONOXIDE CONTAINING EXHAUST GASES
US4844875A (en) * 1987-10-13 1989-07-04 Westinghouse Electric Corp. Fly ash recycling to reduce toxic gaseous emissions
US5124805A (en) * 1988-12-08 1992-06-23 Daewoo Electronics, Co., Ltd. Remote control operated moving television receiver
US5185134A (en) * 1988-12-21 1993-02-09 The United States Of America As Represented By The U.S. Environmental Protection Agency Reduction of chlorinated organics in the incineration of wastes
US5021229A (en) * 1988-12-21 1991-06-04 The United States Of America As Represented By The Environmental Protection Agency Reduction of chlorinated organics in the incineration of wastes
DE3902843A1 (en) * 1989-01-27 1990-08-02 Herbst Umwelttech Gmbh Process for purifying gases
DE3918716C1 (en) * 1989-06-08 1990-06-28 Nukem Gmbh, 6450 Hanau, De
DE4119390C2 (en) * 1991-06-12 1995-09-14 Johne Patricia Vertreten Durch Process for the treatment and leaching-resistant solidification of filter dusts and reaction products from the flue gas cleaning of waste and sewage sludge incineration plants
FI88364C (en) * 1991-08-09 1993-05-10 Ahlstroem Oy FOER FARING BEHANDLING AV HALOGENFOERENINGAR INNEHAOLLANDE PROCESS- ELLER ROEKGASER
DE4404329C2 (en) * 1994-02-11 1996-07-11 Cs Halbleiter Solartech Disposal of chlorofluorocarbons and halons
DE4420400A1 (en) * 1994-06-08 1995-12-14 Lemmerbrock Karl Heinrich Process for decontamination of substances containing polychlorinated biphenyls
DE69524326T2 (en) * 1994-09-14 2002-08-08 Toda Kogyo Corp., Hiroshima Process for the incineration of combustible waste and chlorine scavengers
NO308831B1 (en) * 1995-03-22 2000-11-06 Nkt Res Ct As Process for the treatment of halogen-containing waste material
US5817284A (en) * 1995-10-30 1998-10-06 Central Glass Company, Limited Method for decomposing halide-containing gas
US5744689A (en) * 1996-10-28 1998-04-28 Hiromi Taguchi Treating material for polychlorobiphenyl-containing oils
EP0937483B1 (en) * 1998-02-10 2003-09-24 Miyoshi Yushi Kabushiki Kaisha Treatment method of solid waste
RU2178116C2 (en) * 1999-12-28 2002-01-10 Барунин Анатолий Анатольевич Method and device for thermal destruction of toxic and highly toxic agents
RU2178117C2 (en) * 1999-12-28 2002-01-10 Красник Валериан Вигдорович Method and device for thermal decontamination of chlorine-containing agents
JP2001219031A (en) * 2000-02-08 2001-08-14 Air Liquide Japan Ltd Method and device for decomposing perfluorinated compound
US20040247508A1 (en) * 2003-06-09 2004-12-09 Kiyoharu Sakurai Decomposing dialkyl phthalates using coal fly ash
HU229808B1 (en) * 2009-09-24 2014-08-28 Mta Kemiai Kutatokoezpont Process and apparatus for annihilation of harmful waste containing polychlorinated hydrocarbons
US8128902B2 (en) * 2011-04-12 2012-03-06 Midwest Refrigerants, Llc Method for the synthesis of anhydrous hydrogen halide and anhydrous carbon dioxide
US8043574B1 (en) 2011-04-12 2011-10-25 Midwest Refrigerants, Llc Apparatus for the synthesis of anhydrous hydrogen halide and anhydrous carbon dioxide
US8834830B2 (en) 2012-09-07 2014-09-16 Midwest Inorganics LLC Method for the preparation of anhydrous hydrogen halides, inorganic substances and/or inorganic hydrides by using as reactants inorganic halides and reducing agents
CN104307193A (en) * 2014-11-10 2015-01-28 华玉叶 Immersed evaporation method

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3845191A (en) * 1972-06-02 1974-10-29 Du Pont Method of removing halocarbons from gases
US4201751A (en) * 1975-05-06 1980-05-06 Heinz Gresch Gas purification
DE2855650C2 (en) * 1978-12-22 1984-10-25 Nukem Gmbh, 6450 Hanau Process for the pyrohydrolytic decomposition of phosphorus-containing liquids contaminated with highly enriched uranium
US4230053A (en) * 1979-02-05 1980-10-28 Deardorff Paul A Method of disposing of toxic substances
DE3028193C2 (en) * 1980-07-25 1984-11-22 Nukem Gmbh, 6450 Hanau Method and device for the pyrolytic decomposition of halogens and / or phosphorus-containing organic substances
DE3313889A1 (en) * 1983-04-16 1984-10-18 Martina Von Ahn Method and apparatus for the elimination of toxic and special refuse

Also Published As

Publication number Publication date
ATE30120T1 (en) 1987-10-15
DE3447337A1 (en) 1986-07-03
DE3560739D1 (en) 1987-11-12
EP0188718A1 (en) 1986-07-30
US4654203A (en) 1987-03-31
DE3447337C2 (en) 1986-11-06

Similar Documents

Publication Publication Date Title
EP0188718B1 (en) Process for the chemical-thermal decomposition of higher halogenated hydrocarbons
EP0204910B1 (en) Process for the chemical-thermal decomposition of halogenated hydrocarbons
DE69102702T2 (en) CARBON DIOXIDE FORMATION IN A MULTI-PHASE MELTING BATH.
DE69219347T2 (en) Process and plant for controlling reactions in a molten bath
DE3513731C2 (en)
DE69623034T2 (en) WASTE TREATMENT METHOD AND DEVICE
EP0249131B1 (en) Process of pyrorecombination of mixtures containing waste material
DE2330592A1 (en) PROCESS FOR THE RECOVERY OF VALUABLE METALS
DD296847A5 (en) PROCESS FOR REMOVING POLYCHLORATED BIPHENYLE
EP0604826A1 (en) Installation and process for the valorization of combustible materials especially industrial wastes and domestic waste
DE3517864A1 (en) METHOD FOR CONVERTING HALOGENIC TOXIC SUBSTANCES
DE2261795B2 (en) Process for the production of hydrogen chloride by thermal cleavage of organic substances containing chlorine
DE4208821A1 (en) METHOD FOR PRODUCING A SOLID COMBUSTION MATERIAL BASED ON SOLID, URBAN WASTE AND / OR INDUSTRIAL WASTE ASSIMILABLE IN URBAN AND / OR AGRICULTURAL WASTE
DE3918716C1 (en)
DE1467071B2 (en) Process and device for burning gaseous, liquid or flowable solid halogen-containing organic compounds to form carbon dioxide and hydrogen halide
WO1994017332A2 (en) Process for burning substantially plastic waste, in particular pvc waste
DD273274A5 (en) FUEL LABEL BASED ON WASTE MATERIALS
DD203565A5 (en) PROCESS FOR PROTECTING METAL MATERIALS OF AN ADDITIONAL EQUIPMENT TO A HAZARDOUS LUBRICANTS INCORPORATION BEFORE CORROSION
DE3600644A1 (en) METHOD FOR PREPARATORY TREATMENT OF CONTAMINATED AND CONTAMINATING SUBSTANCES
DE3940903A1 (en) Toxic waste esp. halogenated organic and heavy metal disposal - by fixing with synthetic calcium hydro-silicate and opt. calcium aluminosilicate
EP0666299A1 (en) Recovery of raw materials and energy form polymers and chlorinated hydrocarbons
DE3810418C1 (en)
EP0043470B1 (en) Process for sanitizing carbonatation sludge
DE19613376C2 (en) Process for recycling activated carbon loaded with organic compounds
EP0298472B1 (en) Process for workin-up chlorination residues

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19851206

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT CH DE FR GB IT LI

17Q First examination report despatched

Effective date: 19870211

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE FR GB IT LI

REF Corresponds to:

Ref document number: 30120

Country of ref document: AT

Date of ref document: 19871015

Kind code of ref document: T

ITF It: translation for a ep patent filed
REF Corresponds to:

Ref document number: 3560739

Country of ref document: DE

Date of ref document: 19871112

ET Fr: translation filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19871206

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19871231

Ref country code: CH

Effective date: 19871231

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19880831

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19880901

26N No opposition filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19891206

GBPC Gb: european patent ceased through non-payment of renewal fee