CN85106220A

CN85106220A - The conversion of poisonous halogenide

Info

Publication number: CN85106220A
Application number: CN85106220.2A
Authority: CN
Inventors: 西德尼·W·本森; 梅亚·A·维斯曼
Original assignee: University of Southern California USC
Current assignee: University of Southern California USC
Priority date: 1984-05-21
Filing date: 1985-08-19
Publication date: 1987-03-18
Also published as: DE3517864A1; GB8512160D0; DK214085D0; FR2564324A1; GB2159137A; CA1260959A; KR850008452A; JPH0638862B2; CN1003372B; DE3517864C2; JPS6182767A; AU4247385A; FR2564324B1; GB2159137B; DK214085A

Abstract

In reducing atmosphere, transform a kind of method of chloro organic cpd, under the situation that does not have hydrochloric ether basically, produce hydrogenchloride by vapour-phase pyrolysis.

Description

The conversion of poisonous halogenide

The present invention is relevant with organic chemistry filed, especially relevant with the detoxification of Hazardous wastes usually.

Chemistry, agricultural and other industrial waste treatment are serious problems in the present age.Especially, many chemical wastes are arranged, for example various halohydrocarbon is non-biodegradable, so must be stored in safety, specified zone, perhaps incinerates in custom-designed reactor.

For example, designed incineration system and be used to destroy halohydrocarbon, can make Polychlorinated diphenyl (PCB) compound detoxification especially.Because the persistence and the ecological damage effect of these compounds, the U.S. has stopped producing since 1976, but is still storing in a large number, and this is a kind of serious harm.

In the particular processing process, organic waste are vaporized under about 1000 ℃ of temperature and completely or partially oxidation.Aphlogistic ash content is by directly discharge in the reaction chamber, and waste gas makes the complete thermolysis of compound by the second about 1200 ℃ combustion chamber.But, this incineration system not only needs two sizable combustion chambers of intake, and often can not eliminate fully and have halohydrocarbon to exist in flowing out refuse.It seems, be used for this of burning halohydrocarbon under the situation that air exists and before other incineration system, in the combustion chamber, produce chlorine freely, in exporting effluent, form halohydrocarbon again then.Although initial hazardous compound is by these reactions cracking, but any halohydrocarbon all is dangerous, and be product such as hydrochloric ether, these products are that the existence owing to free chlorine produces in the combustion chamber, still are an impediment to safe handling and incinerate product.Therefore,, just must handle again and check again, and " dirty " ash content must good seal and store if the ash content that produces is unclean, until safe treatment process become feasible till.

Present invention is a technology of handling halogen-containing organic compound, for example handle tetracol phenixin, chloroform, trichloroethane, zellon, carrene, freonll-11, polychlorinated biphenyls, dioxins and other, these compounds are changed into the material of environmental sound.

Especially, provide a kind of method of handling halogen-containing organic compound, this method is in about 825 ° of-1,125 ℃ of scopes, at reducing atmosphere pyrolysis compound.Particularly above-mentioned temperature of reaction can produce by combustion of methane and oxygen, and the consumption of methane surpasses by stoichiometric calculation and the required quantity of oxygen reaction, and therefore reducing atmosphere is provided.

The compound to be transformed of vaporizing in accordance with known methods mixes methane and this compound formation reducing atmosphere then in the container made from suitable heat-stable material.Required temperature can be provided by the external heater around the reaction vessel, perhaps provides at reaction vessel internal combustion methane and limited amount oxygen.But should be noted that the methane consumption must surpass with oxygen presses the consumption that the following formula reaction is calculated.

Under these conditions, the key between halogen and the carbon will disconnect, and promptly all chlorine will react and generate hydrogenchloride, and all organic compound will be transformed into the compound of hydrogen, ethene, acetylene and benzene, and have less carbon and more aromatics.Owing to there is not remaining oxygen in reaction vessel, dioxins and other hydrochloric ether just can not form or form.Hydrogenchloride carries out with scale, lime can removing from air-flow after suitable heat exchange or the general alkali cleaning, and hydro carbons and carbon can be used as fuel or chemical purposes.

Certainly, reducing atmosphere can produce with other reactants, hydrogen for example, and without methane.But the methane source is wide, and uses easily, is elaborated with regard to methane below.

Accompanying drawing mainly illustrates

Accompanying drawing schematically illustrates the present invention and gives an example, and comprises a device that is fit to carry out this process according to the present invention.

As required, disclose a kind of detailed, illustrative concrete device of the present invention here.Certainly, this device only is an explanation example of the present invention, and the present invention can adopt different therewith devices.Therefore, specific 26S Proteasome Structure and Function details can not be interpreted as necessary restriction, and just constitutes the basis that limits claim of the present invention.

Technological process operation is, in reducing atmosphere, cracked compound about 1 second is treated in heating under 1000 ℃ of temperature at least.Reactor can externally heat to keep this temperature, for example uses methane well heater or similar heating installation, and perhaps oxygen combustion of methane or other fuel carry out inner heating so that required temperature of reaction to be provided.Remaining fuel produces the pyrolysis of reductibility when heating in inside to added chlorinated compound.Another kind method is that reductibility mixture (residual fuel and Organohalogen compounds) can carry out the oxidation heating intermittently, makes the interrupted effluent of handling keep separately.

Explanation more accurately please refer to accompanying drawing.The reactor 10 that provides comprises an air-locked sleeve pipe 12, and this sleeve pipe defines inner elongate reaction chamber or reaction zone 14.Because the hydrogenchloride that produces at reaction zone 14 is corrosive, sleeve pipe 12 should be coated with pottery in inside, for example aluminum oxide, silica or analogous material, perhaps metallic carbide, moride or nitride.Reactor 10 at one end 15 has a gas inlet duct 16, and in order to methane is imported first inlet tube 18, reactor 10 also has second gas inlet duct 20, in order to oxygen input tube 18.

Gas inlet duct

16 and 20 all is equipped with under meter metered

valve

22 and 24 respectively, controls the flow that methane and oxygen enter pipe 18 and reaction zone 14 inner burner tips 26 in proportion, with the oxidation heating of needing carrying out.In general, will provide enough heats from about 1625 ° to 2100 ℃ flame temperature.Lining 28 passes reactor wall and 15 inserts in the end, passes end 15 and stretches out

electric wire

30 and 32 and link on the resistance wire 34 in the

reaction zone

14, and 34 are placed in oxidation adds near the heated tip 26.Otherwise spark coil or other portfires also can adopt.

Reactor 10 also comprises inlet 36 and inlet conduits 40 and 42.Inlet 36 is used for halogen-containing compound or waste material are imported second inlet tube 38;

Inlet conduits

40 and 42 is respectively applied for input methane and water vapor.Inlet 36,40 and 42 is equipped with

metering valve

44,46 and 48 respectively, is used to control by the flow of inlet tube 38 to reaction zone 14 interior most advanced and sophisticated 50 corresponding gases.The corresponding end 52 of reactor 10 has outlet unit 54, is used to discharge the gaseous product of reaction zone 14, and outlet metering valve 56 is housed.Preferably this reaction is intended to discharge product so that keep transforming the required residence time, and general about two to five seconds.Therefore,

regulate transfer valve

22,24,46,48 and 68 and metering outlet valve 56,, be approximately barometric point to keep the pressure in the reaction zone 14.But, suitably regulate above-mentioned valve and in reactor 10, produce superatmospheric pressure and can increase throughput.

Heat exchanger 58 is used to control the temperature of reaction zone 14, and it comprises the seal that keeps reaction zone 14 temperature required in this case.Other method, heat exchanger 58 can comprise methane well heater (not shown), from indirect heating sleeve pipe 12 and reaction zone 14.Perhaps, install 58 in case of necessity and can comprise various types of electrically-heated coils or cooling coil.In order further to control the temperature of reaction zone 14, can measure from 42 the water yields that enter the mouth inhibited oxidation heating partly in reactor 14 to pipe 38.

Fractionated washing of reactor product and separating station 60, the

conduit

62 and 64 of carrying dehalogenation hydrocarbon and carbon waste material and hydrogenchloride to store or dispose respectively on figure, have also been represented.Separating station 60 also comprises conduit 66, in order to the recirculation compound of dehalogenation not as yet, it is sent to inlet tube 38 by metering valve 68 handles.

During operation, the methane of the number of computations of having measured and oxygen carry out mixed flow to tip 26 there by

inlet conduits

16 and 20 input inlet tubes 18, then enter reaction zone 14.The dehalogenation compound for the treatment of that has measured directly enters pipe 38 by inlet conduits 36, has the methane gas of sufficient amount to surpass the fuel that calculates by conduit 40 to provide simultaneously, thereby forms reducing atmosphere at reaction zone 14.Can add water by conduit 42 when needing, so that the temperature in the control reaction zone.After the methane gas and oxygen or air admission reaction zone 14 of input incendivity quantity, guiding

line

30 and 32 galvanizations make the resistance wire 34 scorching hot gaseous mixture of lighting from most advanced and sophisticated 26 and 50 that conflux.Also can adopt electrical spark or other portfires.

Much less, can adopt various method and apparatus with described gas input reaction zone 14.For example, the fuel of calculating and oxygen mixture can be imported by first inlet, and remaining fuel and compound directly enter reaction zone 14 by the second and the 3rd inlet respectively.And fuel, oxygen and compound can be imported respectively, perhaps by an inlet.If necessary, waste material mixture or compound were preferably suitably analyzed and homogenizing before input reactor 10.Unlikely excessive in order to guarantee mineral compound, need handle.For example resemble some nontoxic water-soluble materials such as salt and lime and should not add in a large number, reduce the thermo-efficiency of sleeve pipe 12 because these materials can react the formation vitreous coating with heat-resistant lining.Preferably with liquid or solid-state refuse heating or flash to gaseous state, input pipe 36 just then.

Except hydrogen halide, comprise dehalogenation compound and a spot of addition compound and the element that enters wherein from main component in the effluent of reaction zone 14.For example, the product water steam and the carbon oxides of combustion processes if the sulphur existence is arranged in this compound or sulphur input reaction zone 14 is arranged, then will generate sulfur oxide and appear in the effluent.If air is as source of oxygen, then non-flammable composition for example produces nitrogen oxide with oxidized.All these oxide compounds, all water solubles, and the aqueous solution are acid, can remove from conflux together in company with hydrogenchloride at washing separating station 60.

After above-mentioned reaction product, can generate carbonaceous compound by the cracking of dehalogenation hydrocarbon or by incidental impurities, for example ethene, acetylene and high-molecular weight hydrocarbon comprise the carbon of some soot forms.Any carbon that accumulates in the reactor, under regularly being higher than 675 ℃ of temperature with air during by reactor, all can be oxidized and remove.

Adopt above program, the reaction times is very short, generally in seconds finishes.Be preferably in the hot-zone of reactor and keep two to ten seconds of the residence time.

As above-mentioned, the product of reaction separates and recovery at washing separating station 60.The method and apparatus of separating hydrogen chloride and other water-soluble gas is known from hydro carbons.For example, can be with reference to 2,488, No. 083 United States Patent (USP) of people such as Gorlin.Light gas in the reaction product can be removed with fractionator.

This being reflected in the reducing atmosphere by key between division carbon and halogen undertaken, and produces hydrogen halide and dehalogenation hydrocarbon thereupon.In the above-mentioned special reaction, hydrogenchloride is because special hydrochloric ether tetracol phenixin and the chlorobenzene of cracking produces, and these compounds are elected the typical case of said process as.Carbon-the halogen bond of other halohydrocarbon a little less than, perhaps use the mechanical effect dehalogenation, intensity of activation is lower.These compounds are discussed hereinafter specially.

" chemical kinetics basis " (McGraw-Xi Er based on the Benson work, 1960) speed data (NSRD in " gas phase single molecule reaction dynamics data " book of people's works such as the method for the Analysis of Complex chain reaction of Chan Shuing and Benson, NBS, 21,1970), tetracol phenixin is the easiest pyrolytic chloro hydrogen, and chlorobenzene is the most difficult pyrolytic hydrochloric ether.Other chloro thing, for example chloroform, trichloroethane, zellon, carrene, many chlorinations diphenyl and dioxins, carbon-halogen bond energy are between tetracol phenixin and chlorobenzene, therefore in the scope of stating example.In addition, iodo and hydro carbons bromo pyrolysis at a lower temperature, and respectively under about 200 ° and 100 ℃ of temperature (being lower than the temperature of the chlorinatedorganic of having stated) be converted into halocarbon and hydrogen iodide and hydrogen bromide.

Following example will further be set forth the present invention.

Example one

Adopt the device that schematically illustrates in the accompanying drawings, combustion of methane and oxygen, the reacting by heating district is with the pyrolysis tetracol phenixin.The quantity that the methane consumption surpass to calculate is so that produce reducing atmosphere, and the ratio of tetracol phenixin and methane is about three to one, and tetracol phenixin weight accounts for 25%.Reactor is maintained at about 1025 ℃, and keeps throughput to make the residence time be about for 3 seconds.The carbon that contains ethene, acetylene, benzene, hydrogen and some high-molecular weight hydro carbons and soot form in the outlet effluent.Comprise all former chlorine that is used as the tetracol phenixin input in the outlet effluent, with the form appearance of hydrogenchloride, promptly the quantity of hydrogenchloride accounts for 65% mol of exit gas.

Example two

In this example, chlorobenzene is elected the exemplary of chloride aromatic substance as.And, known it be the most difficult pyrolytic compound in all chlorinated organics.Each molar chlorobenzene is with two molar methane (about 21% weight), and these gases under 1125 ℃ of temperature by reaction zone, the residence time in about three seconds.The outlet effluent mainly is benzene and ethene, has all chlorine that occur with hydrogenchloride.Adduct comprises acetylene, hydrogen, unsaturated heavy hydrocarbon and carbon.

Recall simply and can see, the method for the cracking halogen contained compound that is proposed is simple, economy and efficient height, and wherein all chlorine all is converted into and is easy to separate and neutral hydrogenchloride.

Claims

1, transform a kind of method of halogen-containing organic compound, this method is in reducing atmosphere, and pyrolysis compound under 825 ℃ of temperature produces the hydrogen halide effluent under the situation that does not have halohydrocarbon basically at least.

2, be to mix methane and oxygen formation in a reaction chamber at the reducing atmosphere described in article one method, the consumption of methane surpasses by the required quantity of following reaction formula calculating:

3, according to article one or second, compound is selected from following: tetracol phenixin, chloroform, trichloroethane, zellon, carrene, many chlorinations diphenyl and dioxins, the effluent of generation comprises the hydrogenchloride that produces under the situation that does not have hydrochloric ether basically.

4, first or the second method described in temperature be from about 1025 ° to about 1125 ℃.

5, in the second method compound from following tetracol phenixin and the chlorobenzene selected.

6, temperature is from about 1025 ° to 1125 ℃ in the 3rd method.

7, the method for the halogen-containing organic compound of conversion comprises:

The compound of gas phase is imported first end of single reaction chamber, and reaction chamber temperature is from about 825 ° to about 1125 ℃.

In above-mentioned reaction chamber, keep reducing atmosphere, the halogen in this compound is converted into hydrogen halide; And

Discharge the gas that has transformed from second end of reaction chamber, these gases comprise hydrogen halide, do not have halohydrocarbon basically.

8, also be included in input and burning oxygen and a kind of inflammable gas in the reaction chamber in the 7th method, consumption enough produces above-mentioned temperature, and amount of oxygen will be less than the required quantity of oxidation inflammable gas calculating in the reaction chamber, so that produce above-mentioned reducing atmosphere.

9, in the 7th or the 8th method, compound is a chloro organic cpd, discharges gas and comprises hydrogenchloride, does not have hydrochloric ether basically.

10, in the 9th method, compound is to select from following: tetracol phenixin, chloroform, trichloroethane, zellon, carrene, and chlorination diphenyl and dioxin, the effluent of generation comprises hydrogenchloride, does not have hydrochloric ether basically.

11, in the 9th method, compound is tetracol phenixin or chlorobenzene.