CN109438751B - Low-temperature degradation method of halogen-containing plastic - Google Patents

Low-temperature degradation method of halogen-containing plastic Download PDF

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CN109438751B
CN109438751B CN201811292207.5A CN201811292207A CN109438751B CN 109438751 B CN109438751 B CN 109438751B CN 201811292207 A CN201811292207 A CN 201811292207A CN 109438751 B CN109438751 B CN 109438751B
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halogen
bottle
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aluminum trichloride
pvc
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CN109438751A (en
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高建峰
段政
刘艳
郝敏
徐春燕
徐明英
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North University of China
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C08J11/16—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with inorganic material
    • C—CHEMISTRY; METALLURGY
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    • C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
    • C07C1/26—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only halogen atoms as hetero-atoms
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    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C2521/00—Catalysts comprising the elements, oxides or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium or hafnium
    • C07C2521/02—Boron or aluminium; Oxides or hydroxides thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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    • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
    • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
    • C08J2327/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
    • C08J2327/06—Homopolymers or copolymers of vinyl chloride
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
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    • Y02W30/62—Plastics recycling; Rubber recycling

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Abstract

The invention discloses a low-temperature degradation method of halogen-containing plastics, which comprises the steps of taking PVC as a raw material, taking aluminum powder as a catalyst, taking aluminum trichloride and iodine as initiators, and reacting in an activated solvent system at 43-100 ℃ to generate aluminum trichloride and halogen-free carbon-containing compounds. The invention avoids the problems that most of the prior halogen-containing plastics can be carried out under the high-temperature cracking condition of 800 ℃, nitrogen protection is needed more, and the product hydrochloric acid is greatly corroded; the energy consumption can be effectively reduced, and the equipment corrosion is avoided; and the aluminum powder is converted into anhydrous aluminum trichloride after the reaction is finished, so that the problem of difficult degradation of halogen-containing plastics is solved, and the great economic value is generated by degrading the plastics.

Description

Low-temperature degradation method of halogen-containing plastic
Technical Field
The invention belongs to the technical field of plastic degradation, and relates to a degradation method of halogen-containing plastic, in particular to a low-temperature degradation method of halogen-containing plastic.
Background
With the rapid development of the plastic industry, plastic products are also widely applied to the industries of automobiles, electronics, electrics, buildings, packaging and the like, and most of the products at present make requirements on flame retardant grade, so that the halogen flame retardant is widely applied to plastics. However, the halogen in the plastic increases the difficulty of recovering the halogen-containing waste plastic. In the treatment process, the halogen in the halogen-containing plastics is easy to form toxic and harmful halogen-containing compounds such as hydrogen halides, halogenated phenols, dioxin, furan and the like, so that the environment is polluted, treatment equipment is corroded, and the treatment cost is increased; and also cause difficulty in recycling these products once halogen-containing organics enter the liquid and gaseous products. Therefore, most of the plastic wastes cannot be degraded or recycled, and people can pack the plastic wastes together with other wastes into the deep position of a garbage field or burn the plastic wastes on the spot, so that not only is the resource waste caused, but also the great and irreversible environmental pollution is generated. In recent years, with the recovery of large amounts of halogen-containing plastics from electronic and electric wastes, the demand for environmental protection has been further increased. The dehalogenation of the halogen-containing waste plastics becomes a necessary link in the recovery and regeneration.
The halogen in the halogen-containing plastic is mainly derived from polyvinyl chloride (PVC) and halogen-containing flame retardant, and the dehalogenation mainly comprises destructive dehalogenation and non-destructive dehalogenation. Destructive dehalogenation is mainly to realize dehalogenation by decomposing the plastic itself under certain conditions, such as two-stage thermal decomposition dehalogenation, thermal decomposition adsorption dehalogenation and thermal decomposition catalytic dehalogenation; non-destructive dehalogenation is the removal of halogen elements without changing the main chain structure of the plastic macromolecule, such as hydrolytic dehalogenation, solvent extraction, chemical reduction and the like. At present, the non-destructive dehalogenation technology mostly adopts a supercritical technology, the cost is extremely high, and the application value is not available at present; although the destructive dehalogenation technology is put into industrial application, the dehalogenation effect is not satisfactory enough, and two major problems exist, the first condition is high temperature (generally more than 280 ℃), and the energy consumption is large; the cost for the second experiment is high, and the second experiment is difficult to be widely applied.
Because the waste halogen-containing plastics have two characteristics of resource and pollution, how to reduce the pollution to the environment when recycling the waste halogen-containing plastics is a big problem and challenge at the present stage. Therefore, the realization of harmless dehalogenation at the present stage is a very worthy research project.
Disclosure of Invention
In order to solve the problems of high reaction temperature, more waste liquid, high energy consumption and harsh reaction equipment and conditions commonly existing in the treatment process of halogen-containing plastics in the prior art, the invention discloses a low-temperature degradation method of halogen-containing plastics, which comprises the steps of initiating the reaction of active metal powder and a halohydrocarbon solvent by using an initiator, enabling the metal to be changed into the active metal, then reacting with the halogen-containing plastics at the temperature of 43-100 ℃, and capturing halogen in the halogen-containing plastics to degrade the plastics.
The technical scheme of the invention is realized as follows:
the invention discloses a low-temperature degradation method of halogen-containing plastics, which comprises the steps of reacting PVC (polyvinyl chloride) serving as a raw material, aluminum powder serving as a catalyst and aluminum trichloride and iodine serving as initiators in an activated solvent system at 43-100 ℃ to generate aluminum trichloride and halogen-free carbon-containing compounds; the reaction time is determined by the reaction temperature and is generally 20-80 min; further, after the reaction of the reaction raw materials, the catalyst and the initiator is completed at the temperature of 43-100 ℃, the mixture is distilled to recover liquid, and the liquid is mainly characterized by unreacted carbon tetrachloride through infrared characterization.
Dissolving anhydrous aluminum trichloride in anhydrous ethanol, performing suction filtration to obtain yellow filtrate and black filter residue, washing the filter residue with anhydrous ethanol for multiple times, distilling all the filtrate, separating out distillate at 70-78 deg.C, mainly ethanol, stopping distillation when a large amount of yellow crystals are separated out in the solution, indicating that the anhydrous ethanol is basically recovered, and cooling to obtain yellow solid of anhydrous aluminum trichloride; and drying the filter residue at 80 +/-5 ℃ for 6-10 h to obtain the halogen-free carbon-containing compound containing-C = C-and amorphous carbon.
The second method for processing the residual solid is direct distillation, low-temperature organic matters (less than 100 ℃) are recovered at different temperatures, and anhydrous aluminum trichloride is recovered by a sublimation method at a higher temperature (100-150 ℃) to obtain the anhydrous aluminum trichloride and black filter residues.
As a preferred embodiment, the mass fraction of the initiator in the activating solvent is 0.5-2%, and the mass ratio of aluminum trichloride to iodine in the initiator is 1: 1.
Of course, other halogen-containing plastics such as polytetrafluoroethylene can also be degraded at low temperature in an activated solvent system by taking aluminum powder as a catalyst and taking aluminum trichloride and iodine as initiators.
The method is carried out under the low-temperature condition, and as a preferred embodiment, the reaction condition is 45-75 ℃; more preferably, the reaction conditions are 58 ℃.
As a preferred embodiment, the activating solvent is a halogen-containing small molecule solvent; preferably, the activating solvent is ethyl bromide and/or carbon tetrachloride; preferably, the activating solvent is carbon tetrachloride; further, the mass ratio of the PVC to the activating solvent is 1.5-15: 1.
Further, the halogen-free carbon-containing compound contains polyacetylene and amorphous carbon containing a graphite structure.
As a preferred embodiment, the mass ratio of the PVC to the aluminum powder is 1-3: 1; preferably, the mass ratio of the PVC to the aluminum powder is 3: 2.
According to the method, hydrochloric acid is generated by hydrolysis of anhydrous aluminum trichloride to destroy a compact oxide film on the surface of aluminum powder, so that simple substance aluminum powder is exposed; the exposed aluminum powder has high activity and reacts with the activating solvent to remove halogen atoms on the activating solvent, so that aluminum simple substances are more and more exposed along with the reaction, and then the aluminum simple substances react with polyvinyl chloride to remove chlorine atoms in the polyvinyl chloride in the form of HCl. HCl reacts with aluminum to produce aluminum trichloride and H2. The small molecules on the carbon chain end groups are also gradually pyrolyzed as the reaction exotherms.
Note: the aluminum trichloride in the present invention refers to anhydrous aluminum trichloride.
Compared with the prior art, the invention has the following beneficial effects:
(1) the aluminum powder is used as a catalyst, the aluminum trichloride and the iodine are used as initiators, and the aluminum trichloride and the iodine can be efficiently degraded at the temperature lower than 100 ℃ to generate the aluminum trichloride, olefin micromolecule gas, polyacetylene and amorphous carbon, so that the problems that most of the existing halogen-containing plastics can be cracked at the high temperature of 800 ℃, nitrogen protection is needed, and the product hydrochloric acid is greatly corroded are solved; the energy consumption can be effectively reduced, and the equipment corrosion is avoided;
(2) the method takes the aluminum powder as the catalyst, the aluminum powder is converted into the anhydrous aluminum trichloride after the reaction is finished, and the price of the aluminum powder (the molar mass is 27) is about 1-1.3 ten thousand per ton, the anhydrous aluminum trichloride (the molar mass is 133.3) is 5 thousand per ton, and one ton of the aluminum powder is converted into 5 tons of anhydrous aluminum trichloride.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIGS. 1a and 1b are thermogravimetric maps of PVC, PVC and aluminum powder, respectively, in example 1 of the present invention.
FIG. 2 is an infrared spectrum of a violet liquid in example 1 of the present invention.
FIG. 3 is an infrared spectrum of the halogen-free carbon-containing compound obtained after drying the filter residue in example 1 of the present invention.
FIG. 4 is a scanning electron microscope image of the halogen-free carbon-containing compound obtained after drying the filter residue in example 1 of the present invention.
Fig. 5 is a raman spectrum of the halogen-free carbon-containing compound obtained after drying the filter residue in example 1 of the present invention.
Fig. 6 is a thermogravimetric diagram of the halogen-free carbon-containing compound and PVC obtained after drying the filter residue in embodiment 1 of the present invention.
FIG. 7 is an XRD spectrum of the halogen-free carbon-containing compound in example 1 of the present invention.
FIG. 8 is an infrared spectrum of a yellow crystal (solid) in example 1 of the present invention.
FIG. 9 is an infrared spectrum of the halogen-free carbon-containing compound obtained after drying the filter residue in example 2 of the present invention.
FIG. 10 is an infrared spectrum of the halogen-free carbon-containing compound obtained after drying the filter residue in examples 1 and 3 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 58 ℃, wherein a solution is purple red (iodine is dissolved in carbon tetrachloride) at the beginning of the reaction, and the solution is changed into purple black with a small amount of white smoke after 10 min; after 12min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) at 14min and the solution becomes pure black; finishing the reaction after 31min to obtain a viscous reaction solution; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
As can be seen from the thermogravimetric maps of fig. 1a and 1 b: the maximum peak value becomes large after the PVC and the aluminum powder are mixed in the weight loss of the first stage. The factors causing the change mainly have two aspects, namely, the aluminum powder absorbs heat, the temperature rises upwards, and the pyrolysis can be seen only by needing higher temperature; secondly, the aluminum powder takes part in the reaction to release heat, and the temperature rises. Meanwhile, the area of the weight loss peak is enlarged, and the thermal effect range is enlarged, which further indicates that the aluminum powder participates in the reaction. Dechlorination is realized due to the existence of aluminum in the first stage, and only carbon-carbon bonds with poor stability are left in the weight loss in the second stage, so that the maximum peak value of the weight loss is reduced.
When bubbles begin to emerge in the bottle, the emerging gas is poured into a test tube containing acidic potassium permanganate by a small glass tube, the color in the test tube is purple red, the purple red gradually fades when the bubbles emerge gradually and finally becomes colorless, and the potassium permanganate is continuously dropped into the test tube during the period until no bubbles emerge. The reason is that the acid potassium permanganate has strong oxidizing property, so that the fading of the potassium permanganate has certain reducibility, the acid potassium permanganate is a gaseous substance generated by the reaction as can be seen from the experimental process, and the boiling point of the gas discharged from the reaction system can be judged to be low due to the low temperature of the condenser pipe; it is calculated according to the reaction raw materials that the fading of potassium permanganate can only be organic matter, so the gas emitting the fading of potassium permanganate is olefin, namely ethylene (boiling point: -103.7 ℃) or propylene (boiling point: -47.6 ℃). The reaction equation is as follows:
5CH2=CH2+12KMnO4+18H2SO4==10CO2↑+12MnSO4+28H2O+6K2SO4
CH3CH=CH2+2KMnO4+3H2SO4==CH3COOH+CO2↑+2MnSO4+4H2O+K2SO4
when bubbles begin to bubble in the bottle, the gas which bubbles out is poured into a test tube filled with silver nitrate by a small glass tube, the test tube is colorless and transparent, the bubbles gradually bubble out and do not change at the beginning, white solid is generated in the test tube after the hydrogen is introduced, and the color in the test tube becomes turbid milky after a few seconds. This is because after the gas is poured into the test tube, a white precipitate is formed in the solution, and the presence of HCl small molecules in the product can be judged. The reaction equation is as follows:
AgNO3+HCI→AgCl↓+HNO3
as can be seen from the infrared spectrum of the purple liquid of FIG. 2: the wave number is 4500-500 cm-1Looking up the infrared spectrum of carbon tetrachloride can see that the infrared spectrum is only 800-750 cm-1The wave number has characteristic absorption peak of infrared spectrum, which is only 791.33cm in the lower graph-1Has characteristic absorption peak, and can analyze purple liquid mainly comprising carbon tetrachloride by contrasting with infrared spectrogramUnreacted carbon tetrachloride and a small amount of iodine.
As can be seen from fig. 3: the wave number is 4500-500 cm-1From polyvinyl chloride infrared spectra[16-18]The thickness of the coating is 800-750 cm-1The wave number has characteristic absorption peak of infrared spectrum, and the infrared spectrum is analyzed mainly by the absorption peak in the region, the wave number is 794.60cm-1The absorption peak is mainly C-Cl stretching vibration absorption peak, and the comparison of the black solid product after the reaction shows that no absorption peak can be seen, and chlorine atoms are successfully removed from the polyvinyl chloride after the reaction; meanwhile, the bond is 1620-1680 cm at-C = C--1There is a characteristic absorption peak, from which it can be seen that the product is 1646.48cm-1The presence of a characteristic absorption peak indicates the presence of a double bond in the product.
As can be seen from fig. 4: the black solid product has large particles with an average particle size of 100 μm, and has a rough surface without agglomerated particles and irregular shape.
Using Raman spectroscopy[19]And (4) characterizing the degraded black solid product to obtain the information of the change of the surface molecular structure of the product. The Raman spectrum of FIG. 5 was found to be 1549cm-1There is a shoulder, and the Raman spectrum of polyacetylene[21]At 1530cm-1There is a sharp peak around it, from which the presence of polyacetylene in the black solid product can be inferred.
The solid without carbon tetrachloride is subjected to thermogravimetry, and the solid can be seen as a mixture in fig. 6, because the temperature rise speed is high, the weight loss starts from 25 ℃, a first weight loss platform appears at the temperature of below 200 ℃, and the weight loss is close to 30 wt.%. The part of the aluminum trichloride is lost by small molecular substances such as ethylene or propylene and part of the anhydrous aluminum trichloride, and then the weight loss is continuously reduced along with the rise of the temperature, wherein the weight loss is more than 60 wt%, and the anhydrous aluminum trichloride is mainly used. The final residue remaining was 44.3 wt.%.
Comparing two lines in thermogravimetric maps of halogen-free carbon-containing compounds generated by degradation of PVC in carbon tetrachloride solvent and PVC in FIG. 6, it is obvious that pyrolysis has changed greatly, and it is obvious that the pyrolysis temperature of PVC is reduced greatly after adding solvent, so that the method is very effective and feasible, and many small molecular substances are generated by judging from the graph, so that the initial temperature and peak value of pyrolysis in the first stage are reduced greatly; meanwhile, in the second stage after the pyrolysis in the first stage, because halogen is removed in the first stage, only carbon-carbon bond stability is not good, and the weight loss peak value is reduced; and the residue after pyrolysis of the PVC is 9.2wt.%, compared with the product generated after degradation, the pyrolysis performance reduction of the degraded partial substance is more stable, and the product after PVC degradation contains partial amorphous carbon by combining with XRD spectrogram analysis of figure 7.
From the XRD pattern of the halogen-free carbon-containing compound generated by the degradation of PVC in carbon tetrachloride solvent in fig. 7, it can be seen that: a first strong diffraction peak appears at 10.38 degrees, a second strong diffraction peak appears at 26.86 degrees, and by comparing XRD patterns of graphite and graphene, the peak near 10 degrees completely disappears due to reduction of the graphene through hydrazine hydrate, while the characteristic peak of the graphite is near 10 degrees, and the second strong diffraction peak is the characteristic peak of the graphite. Therefore, the product has the characteristics of graphite, but the structure of amorphous carbon in the product can be judged by graphene.
As shown in the infrared spectrum of the yellow crystal (solid) in FIG. 8: the wave number range is 4500-500 cm-1At 637.56cm-1Has strong absorption peak, and is found in 601cm by consulting literature-1An Al-Cl stretching vibration absorption peak is formed, and aluminum trichloride has a plurality of Al-Cl stretching vibration absorption peaks, so that the wave number moves to a long wave number position, and the aluminum trichloride in the yellow solid can be judged.
Example 2
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.025g of aluminum trichloride, 0.025g of iodine and 10g of bromoethane into a three-neck flask containing magnetons, reacting at 58 ℃, wherein the solution is orange at the beginning of the reaction and bubbles emerge, and the solution disappears after 30 s; after 19min, the PVC in the bottle has swelling phenomenon, the surface is solidified into solid, and the color is brown; after 25min, the reaction in the bottle turned into pure black; finishing the reaction in 41min, and discharging gas to enable the acid potassium permanganate to fade when hydrogen is not introduced; the gas discharged after the hydrogen is introduced can not lead the silver nitrate to generate white precipitate; yellow solid is arranged on the bottle wall of the three-neck flask along with the distillation, a large amount of white smoke is arranged in the bottle, and the distillate flows out at 37 ℃ and is purple red; the filter residue is black, ethanol is poured to wash the solid, and when the solid is filtered by a sand core funnel, black purple liquid can be seen to flow downwards; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, and the solution is in a black-purple viscous state when little solution is left; and drying to obtain black purple solid.
After the reaction in the active solvent (i.e. replacing carbon tetrachloride in example 1 with bromoethane, and keeping the other reaction parameters unchanged), the reaction phenomenon mainly changes in the first reaction stage, and the swelling phenomenon and the color change of PVC occur under the bromoethane activator, but the product is not changed through the characterization of gas and solid products.
As can be seen from the ir spectrum of fig. 9: the wave number is 4500-500 cm-1The infrared spectrum of the polyvinyl chloride can be seen to be 800-750 cm-1The wave number has a characteristic absorption peak of an infrared spectrum, and the absorption peak of the region is mainly analyzed when the infrared spectrum is analyzed; wave number 794cm-1The absorption peak is mainly C-Cl stretching vibration absorption peak, and the comparison of black products after reaction shows that no absorption peak can be seen here, so that chlorine atoms are successfully removed from the polyvinyl chloride after the reaction.
Example 3
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.035g of aluminum trichloride, 0.035g of iodine, 7g of bromoethane and 3g of carbon tetrachloride into a three-mouth flask containing magnetons, reacting at the temperature of 58 ℃, and enabling a solution to be pink purple when the reaction starts; after 7min, the bottle begins to bubble and the color becomes dark; after 16min the colour turned to pure black with a small amount of white smoke. The reaction was complete in 48 min. And only gas with a relatively low boiling point can be discharged due to the condensing device. The gas evolved in the absence of hydrogen gas discolors acidic potassium permanganate. The gas discharged after the hydrogen gas is introduced can lead the silver nitrate to generate white precipitate. Yellow solid is arranged on the bottle wall of the three-neck flask along with the distillation, a large amount of white smoke is arranged in the bottle, and the distillate flows out at 70 ℃ and is purple red in color. The filter residue is pure black. The solid was washed by pouring ethanol and when filtered through a sand-core funnel, a yellow liquid was seen to flow down. When the filtrate is distilled, boiling occurs in the bottle, and the distillate flows out at 78 ℃. When crystals are separated out from the solution, the liquid is poured out and dried to form yellow solid.
As can be seen from fig. 10 with the activating agent of carbon tetrachloride and ethyl bromide mixed, and the infrared spectrum of carbon tetrachloride: the wave number is 4500-500 cm-1Both PVC degradation solid products are at 794cm-1No C-Cl stretching vibration absorption peak exists, and it can be seen that chlorine is successfully removed from PVC.
Example 4
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 0.5g of aluminum powder, 0.06g of aluminum trichloride, 0.06g of iodine and 6g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 45 ℃, wherein a solution is purple red (the color of iodine dissolved in carbon tetrachloride) at the beginning of the reaction, and the solution is changed into purple black after 11min and simultaneously emits a small amount of white smoke; after 23min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) and the solution becomes pure black after 30 min; finishing the reaction after 40min to obtain a viscous reaction solution; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 5
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.5g of aluminum powder, 0.08g of aluminum trichloride, 0.08g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 50 ℃, wherein a solution is purple red at the beginning of the reaction, and after 12min, the solution turns purple black and simultaneously emits a small amount of white smoke; after 20min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) and the solution becomes pure black after 30 min; finishing the reaction after 45min to obtain a viscous reaction solution; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 6
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 65 ℃, wherein a solution is purple red at the beginning of the reaction, and after 8min, the solution turns purple black and simultaneously emits a small amount of white smoke; after 12min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) and the solution becomes pure black after 15 min; after 50min, finishing the reaction, wherein the reaction solution is viscous; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 7
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 70 ℃, wherein a solution is purple red at the beginning of the reaction, and after 8min, the solution turns purple black and simultaneously emits a small amount of white smoke; after 10min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) and the solution becomes pure black after 22 min; after 50min, finishing the reaction, wherein the reaction solution is viscous; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 8
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 75 ℃, wherein a solution is purple red at the beginning of the reaction, and after 6min, the solution turns purple black and simultaneously emits a small amount of white smoke; after 12min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) at 23min and the solution becomes pure black; after 30min, finishing the reaction, wherein the reaction solution is viscous; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 9
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, reacting at 100 ℃, wherein a solution is purple red at the beginning of the reaction, and after 6min, the solution turns purple black and simultaneously emits a small amount of white smoke; after 10min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) at 25min and the solution becomes pure black; finishing the reaction after 32min to obtain a viscous reaction solution; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
Example 10
A low-temperature degradation method of halogen-containing plastics comprises the steps of putting 1.5g of PVC, 1.0g of aluminum powder, 0.05g of aluminum trichloride, 0.05g of iodine and 10g of carbon tetrachloride into a three-neck flask containing magnetons, and reacting at the temperature of 43 ℃, wherein a solution is purple red when the reaction starts. After 14min, the solution turns purple black with a little white smoke; after 20min, small bubbles begin to emerge in the bottle, and the bubbles become larger and larger (the reaction is violent) at 31min and the solution becomes pure black; finishing the reaction after 40min to obtain a viscous reaction solution; and only gas with lower boiling point can be discharged due to the condensing device; the gas exhausted when the hydrogen is not introduced can fade the acid potassium permanganate, the gas exhausted after the hydrogen is introduced can enable the silver nitrate to generate white precipitate, ethanol is poured into the bottle to instantly release a large amount of heat, the bottom of the bottle is boiled, a large amount of white smoke is emitted from the bottle, and meanwhile, yellow solid on the wall of the bottle is dissolved to form yellow viscous liquid and flows into the bottom of the bottle; when the filtration is carried out by using a sand core funnel, the yellow liquid is obviously viscous at the beginning, the filter residue after the filtration is pure black, the filter residue is placed into a glass culture dish and is placed into an oven for drying for 8 hours at the temperature of 80 ℃, and the obtained black solid is a halogen-free carbon-containing compound; when the filtrate is distilled, the bottle is boiled, the distillate flows out at 78 ℃, the distillation is stopped when yellow crystals are separated out from the solution, the residual liquid is poured into a glass culture dish and dried in a drying box for 8 hours at 80 ℃, and the yellow crystals (solids) are anhydrous aluminum trichloride.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (6)

1. A low-temperature degradation method of halogen-containing plastics is characterized by comprising the following steps: taking PVC as a raw material, taking aluminum powder as a catalyst, taking aluminum trichloride and iodine as initiators, and reacting in an activated solvent system at 43-100 ℃ to generate aluminum trichloride and a halogen-free carbon-containing compound; the activating solvent is bromoethane and/or carbon tetrachloride, and the mass ratio of the PVC to the activating solvent is 1.5-15: 1; the mass ratio of the PVC to the aluminum powder is 1-3: 1, the initiator accounts for 0.5-2% of the mass of the activating solvent, and the mass ratio of aluminum trichloride to iodine in the initiator is 1: 1.
2. A method for the low temperature degradation of halogen-containing plastics according to claim 1, wherein: the reaction condition is 45-75 ℃.
3. A method for the low temperature degradation of halogen-containing plastics according to claim 2, wherein: the reaction conditions were 58 ℃.
4. A method for the low temperature degradation of halogen-containing plastics according to claim 1, wherein: the activating solvent is carbon tetrachloride.
5. A method for the low temperature degradation of halogen-containing plastics according to claim 1, wherein: the halogen-free carbon-containing compound contains polyacetylene and amorphous carbon.
6. A method for the low temperature degradation of halogen-containing plastics according to claim 5, wherein: the mass ratio of the PVC to the aluminum powder is 3: 2.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5608136A (en) * 1991-12-20 1997-03-04 Kabushiki Kaisha Toshiba Method and apparatus for pyrolytically decomposing waste plastic
JP2002020534A (en) * 2000-07-07 2002-01-23 Tsukishima Kikai Co Ltd Method for thermally decomposing chlorine-containing plastic waste material
JP2006110531A (en) * 2004-10-13 2006-04-27 Aasu Recycle Kk Process for separating valuable materials from mixed plastics containing pvc(polyvinylidene chloride as well) and pet, and plastics/aluminum composite films
CN106349500A (en) * 2016-09-23 2017-01-25 苏州大学 Dechlorination method for chlorine-containing plastic
WO2018011642A1 (en) * 2016-07-13 2018-01-18 Sabic Global Technologies, B.V. A process which does simultaneous dehydrochlorination and hydrocracking of pyrolysis oils from mixed plastic pyrolysis while achieving selective hydrodealkylation of c9+ aromatics

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5608136A (en) * 1991-12-20 1997-03-04 Kabushiki Kaisha Toshiba Method and apparatus for pyrolytically decomposing waste plastic
JP2002020534A (en) * 2000-07-07 2002-01-23 Tsukishima Kikai Co Ltd Method for thermally decomposing chlorine-containing plastic waste material
JP2006110531A (en) * 2004-10-13 2006-04-27 Aasu Recycle Kk Process for separating valuable materials from mixed plastics containing pvc(polyvinylidene chloride as well) and pet, and plastics/aluminum composite films
WO2018011642A1 (en) * 2016-07-13 2018-01-18 Sabic Global Technologies, B.V. A process which does simultaneous dehydrochlorination and hydrocracking of pyrolysis oils from mixed plastic pyrolysis while achieving selective hydrodealkylation of c9+ aromatics
CN106349500A (en) * 2016-09-23 2017-01-25 苏州大学 Dechlorination method for chlorine-containing plastic

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