KR100265273B1 - Emulsification Method and Apparatus of Waste Plastic - Google Patents

Abstract

PURPOSE: A method for emulsifying waste plastics is provided to recover oil at low cost and high yield, and to release sludge during continuous process, thereby minimizing environmental pollutants. CONSTITUTION: The method for emulsifying waste plastics comprises: the first process for crushing waste plastics; the second process for thermally decomposing parts of the crushed waste plastics and heating the other parts of the crushed waste at 300-500 deg.C to carry out a relaxing mixing process of the two reactants; the third process for separating gas and oil compounds from the mixture; the fourth process for injecting an extractant several times at a ratio of 100:0.8-2.4 to extract sludge, deodorizing and stabilizing the color; the fifth process for performing fractional distillation of the products of the above process to gasoline and diesel etc. After the process, the fused residues from the second process and the sludge from the fourth process are recovered and turned into coke used as a boiler fuel for heating the devices.

Description

Emulsification Method and Apparatus of Waste Plastic

The present invention relates to a method and apparatus for emulsifying waste plastics. More specifically, it is possible to recover oils such as gasoline and diesel oil at low cost and high yield by using a low temperature pyrolysis reaction without using a catalyst from waste plastics, and remove residues (residue or waste) during the continuous process. The present invention relates to an emulsification method and apparatus for waste plastics capable of discharging, and maximally suppressing the generation of environmental pollutants.

When plastics are heated, they each thermally decompose at a specific temperature, which reduces their weight and produces various low molecular weight compounds. It also has the property of igniting when heated to a higher temperature in an oxygen atmosphere.

Pyrolysis temperatures of plastics are unique to each plastic, but may be of the same kind depending on the type, form, etc., and on the effects of plasticizers or other fillers. Films and foams generally have low pyrolysis temperatures. In the thermal decomposition of thermoplastics, hardening and melting are involved.

Pyrolysis of plastics differs depending on the presence of air, the presence of water vapor or inert gas, or the addition of catalysts or other chemicals.In general, many types of gases, oily substances, residues, etc. Is generated. Pyrolysis temperatures of plastics are usually around 400 to 500 ° C, usually around 450 ° C. However, there are significant differences in the difficulty of pyrolysis depending on the type of polymer material.

Pyrolysis of thermoplastics involves the cleavage reaction of the main chain (polyethylene, polypropylene), the decomposition of monomers (polymethyl methacrylate), the decomposition of monomers and various low molecules (polystyrene, polyisobutylene), the separation or crosslinking of side chains ( Polyvinyl chloride, vinyl polyvinyrate) and the like, and decomposes at a relatively short time at high temperature. The pyrolysis rate may be 90 to 99%, but this also depends on the type of plastic and the decomposition conditions.

As described above, when the polyethylene is pyrolyzed, a mixture of a gas containing some ethylene monomer and a hydrocarbon phase in an oil phase or a wax phase is generated at room temperature. Thermal decomposition of polymethylmethacrylate produces monomers at a high rate. In addition, the pyrolysis of polystyrene produces a liquid hydrocarbon mixture at room temperature, and also produces styrene monomer, toluene, ethylbenzene, and α-methylstyrene.

Some monomers are obtained in high yield by pyrolysis depending on the kind of polymer. A typical example is polymethyl methacrylate, and industrial recovery of monomers from such waste plastics has been practiced for a long time. Polystyrene also has a high rate of monomer production. However, both polymethacrylate and polystyrene have a limited amount of collection, so the industrialization is limited.

Polyethylene, polypropylene, and the like produce little monomer when thermally decomposed under normal conditions, and usually produce a gaseous, oily, and waxy hydrocarbon mixture at room temperature. In addition, since the control of pyrolysis conditions allows the preferential obtaining of liquids, the development of this technology is currently being actively conducted in view of the treatment and effective use of waste plastics.

For example, oils such as heavy oil are recovered by pyrolyzing atactic polypropylene by-produced in the production of polypropylene and low molecular weight polymer by-produced in the production process of polyethylene by the low pressure method, which are commonly used as fuels. In addition, some waste plastic pyrolysis including expanded polystyrene and vinyl chloride resin is also performed.

When various plastics are pyrolyzed by two-stage pyrolysis, the materials shown in Table 1 are obtained.

TABLE 1

With the development of modern civilization, the plastics industry develops, and thus the amount of plastic discarded is growing almost exponentially. However, plastics can take hundreds of years to decompose when landfilled, and incineration releases large amounts of pollutants. Therefore, recently used plastic products have been introduced, which is too early to be widely used due to the high cost of the product.

As more plastics are discarded as mentioned above, their recycling methods are continuously studied, and the most prominent among them is the method of recycling waste plastics into various gases or oily hydrocarbons.

Conventional emulsification processes for waste plastics include thermal (catalytic) decomposition and invented methods developed in Japan. However, these methods are mainly for emulsifying thermoplastic resins, but also for kinds of resins that cannot be treated (for example, polyethylene terephthalate, polyvinyl chloride, etc. in the case of thermal catalytic decomposition), and especially because they use a catalyst for pyrolysis of waste plastics. Due to the high risk of secondary pollution by the work process has not yet been made continuously, as well as other various problems.

It is an object of the present invention to provide an emulsification method of waste plastics capable of recovering oils such as gasoline and diesel oil at low cost and high yield by using a low temperature pyrolysis reaction that does not use a catalyst from waste plastics.

Another object of the present invention is to provide an emulsification method of waste plastics which can discharge wastes (residues) during the continuous process of pyrolysis of waste plastics and can suppress the generation of environmental pollutants to the maximum. .

In addition, another object of the present invention is to provide an apparatus for proceeding the emulsification process of the waste plastic as described above.

1 is a block diagram showing an emulsification process of waste plastics according to the present invention.

Figure 2 is a schematic layout of the waste plastic emulsifying apparatus according to the present invention.

* Explanation of symbols for main parts of the drawings

M-1: Crusher R-1, R-2: Melting Furnace

R-3: Decomposition reaction tank PL-1, PL-2: Cooling water tank

PL-3: Oil Separator PL-4: Compressor

T-1: Oil-Gas Separation Tower T-1A: Diesel Absorption Tower

C-3: Gas Tank T-2, T-3: Extraction Tower

T-4A: Refinery Tank R-4: Distillation Furnace

T-5: Rectification tower T-6, T-7, T-8: Top stripper

C-4: Recovery Dehydration Tank C-6: Liquid-Gas Separator

C-6A: Tank Tank C-7: Stabilization Tank

C-9: LPG Storage Tank C-10: Gasoline Storage Tank

C-12: light diesel oil tank C-15: heavy diesel oil tank

C-16: Heavy oil tank T-4: Washing tower

In order to achieve the object of the present invention, the waste plastic emulsification method is a non-catalytic liquid phase pyrolysis method, which proceeds a pyrolysis reaction at 300 to 500 ° C. at a normal pressure and a relatively low temperature without using a catalyst. First step of crushing; A second step of heating the waste plastic crushed product in the above process to thermally decompose and thermally melting a portion of the crushed product to a temperature of 300 to 500 ° C. to relax and mix the pyrolyzed reactant; A third step of separating the gas and oil mixture from the treated product of the step; A fourth step of adding the extractant to the oil mixture in the above process at a weight ratio of 100: 0.8 to 2.4, and extracting the sludge by performing the addition in a plurality of steps, and stabilizing, deodorizing and stabilizing the color; And a fifth step of fractionally distilling the treated product of the above step into gasoline, diesel oil, or the like.

In addition, the waste plastic emulsifying apparatus includes a crusher for crushing the waste plastic raw material to a predetermined size or less; A decomposition reaction tank configured to heat-melt and crack the waste plastic crushed material supplied from the crusher and decompose it into a gas and oil mixture; An oil-gas separation tank for separating the processed product of the decomposition reaction tank into an oil mixture mule and a gas; An extraction tower for removing and refining various sludges from the oil mixture separated by the oil-gas separation tank; A washing tank for stabilizing by washing the oil mixture purified in the extraction tower; In the emulsification apparatus of the waste plastic comprising a fractionation distillation tank for separating the oil mixture stabilized in the washing tank with gasoline, diesel oil, etc., the waste plastic crushed product which is crushed by the crusher is supplied and melted, The apparatus further includes a molten heating furnace for relaxing mixing the cracking reactant, and an automatic opening / closing supply device for supplying the waste plastics pulverized in the crusher to the decomposition reaction tank and the heating melting furnace by a predetermined amount. It is characterized in that the odor removal, color stabilization and purification of the oil mixture is made by the assembly reaction process that is configured to vary the extractant is added to each extraction tower.

Hereinafter, the present invention will be described in more detail. The emulsification method of waste plastics according to the present invention is largely divided into six processes, which will be described with the apparatus used in each process with reference to the block diagram of FIG. 1.

[Pretreatment and Medical Input Process of Waste Plastic]

After removing miscellaneous materials such as sand, stone, and metal mixed in the waste plastic, the crusher is crushed to a predetermined size or less in the crusher (M-1) (S10). The shredded plastic is then conveyed to the automatic switchgear (M-2, M-3, M-4), the so-called "sealed feeder" by a belt-type conveyor, where a certain amount of waste plastic shreds The melting furnaces (R-1, R-2) and the decomposition reaction tank (R-3) are respectively supplied (S20).

Melt decomposition and decomposition reaction process

When waste plastic crushed material is supplied from the automatic switchgear (M-2, M-3, M-4) to the melting furnace (R-1, R-2) and the decomposition reaction tank (R-3), The plastic is heated and melted to a temperature (300 ~ 500 ℃) optionally set (S30), the waste plastic melted in the melting furnace (R-1, R-2) is transferred to the decomposition reaction tank (R-3) Relaxing is mixed and decomposed into an oil mixture and gas (S40).

In this process, residues (precipitates or debris) that remain in the melting furnaces (R-1, R-2) and decomposition reactors (R-3) without proceeding to the next process are removed during the process operation and made into coke. Then used as a fuel for boiler for heating the various devices of the present invention (S32).

Specifically, a large amount of miscellaneous mixed matter contained in waste plastics, varnishes contained in plastic polymers, various kinds of additives such as titanium powder, hard carbon carbide, and coke deposits generated during the pyrolysis reaction are generated at about 8-15% of the feedstock. This can be discharged at any time during the process, so that the emulsification process of the waste plastic can be continued.

Therefore, residues can be discharged during the process, and waste plastic raw materials can be mixed and added without being sorted or cleaned, and secondary environmental pollution caused by the discharge of contaminated washing water generated during the cleaning of waste plastics can be avoided. You can prevent it.

In addition, since the catalyst is not used in the pyrolysis reaction, poisoning from the catalytic reaction can be eliminated. For example, there is no problem of catalyst poisoning such as polyethylene chloride. Therefore, various solid plastic raw materials can be mixed and added without screening.

It will be described for the waste plastic that can be used in the present invention.

Waste plastic raw materials can be mainly classified into five kinds such as polyethylene (PE), polyethylene terephthalate, polypropylene (PP), polystyrene and polyvinyl chloride.

In addition, there are phenol resins (electrical and electronic parts), acrylonitrile butadiene styrene resins (ABC resins, TVs, home appliance parts, etc.), alcohol-carboxyl type polymer resins (various buttons), and the like. Since most of these waste plastics are non-hydrocarbon polymers, alcohols, aldehydes, acid compounds and the like are emitted during the thermal decomposition reaction. Therefore, the odor is emitted by them, so it is difficult to apply to fuel production. However, if a small amount is incorporated into the raw material, it does not affect the overall pyrolysis reaction.

Products such as nylon and teflon can use pyrolysis to produce fuel oil. However, the production rate is relatively low and should only be used as part of the raw material.

Specifically, the types of waste plastic resins that can be used in the present invention are shown in Tables 2 and 3 below. Tables 2 and 3 below show the waste plastic airflow that can be applied to each process as compared with the conventional thermal contact decomposition method and the Japanese method of generating.

In Tables 2 and 3, X means not available, ● means combination treatment, ■ means mixing treatment, and 혼합 means that it is assumed that it can be used.

TABLE 2

TABLE 3

[Oil-Gas Separation Process]

The gas and oil mixture decomposed in the decomposition reaction tank (R-3) is cooled through the first cooling water tank (PL-1), which is one of a kind of cooling means, and then oil-gas that maintains a temperature of 450 to 500 ° C. at low pressure. It is transferred to the separation tower (T-1). Both the conveyed gas and the oil mixture inside the tower, the liquid effluent oil sinks to the bottom and the gas is collected at the top. The liquid effluent oil of the bottom of the tower T-1 is transferred to the first extraction tower T-2 by pumping (S42).

On the other hand, the decomposed gas flows out of the upper part of the tower T-1, passes through the low pressure gas tank C-3, and enters the diesel oil absorption tower T-1A. The remaining C 1 -C 4 gaseous hydrocarbons are transferred to the cracked gas compression separation process.

In this process, a predetermined additive may be added to the tower T-1 for easy separation of oil and gas.

Extraction-Refining Process

The liquid effluent oil transferred to the first extraction tower T-2 by pumping is subjected to three stages of extraction and purification while passing through the second continuous extraction tower T-3 and the washing tower T-4. . When this process proceeds, as well as the removal of the sludge contained in the outflow oil is removed odor and is classified as stable color refined oil (S50) (S60).

In this process, a so-called extractant is added to remove the odor of the oil and stabilized color (S52), and as the extractant, the inorganic extractive grease second extraction tower (T-3) is used in the first extraction tower (T-2). Inject inorganic alkali. The charged amount is 3 parts by weight or less based on 100 parts by weight of the spilled oil, and the preferred amount is 0.8 to 2.4 parts by weight.

In addition, the sludge removed here may also be made of coke and used as fuel for the boiler for operating the apparatus of the invention, and the water used for washing can be continuously used three times (S62).

The oil mixture extracted after pyrolysis of the waste plastic resin contains abnormal components regardless of non-catalytic or catalytic process, resulting in bad smell, dark color, and unstable components.

Therefore, in the extraction process of the present invention, by eliminating the existing processes such as medium to high pressure catalytic hydrogenation refining process, each reaction unit process is designed as a collective reaction process to increase the reaction rate to reduce the equipment investment and simplify the operation method To reduce costs.

Fractional distillation of the oil mixture that has undergone this extraction-purification process of the present invention stabilizes both odor and gasoline or diesel oil products. The color of gasoline is hundreds of white or light yellow, and it is transparent and the color does not change even if it is stored for more than one year.

[Separation-distillation process]

After passing through the extraction and purification process, the refined oil is transferred to the refinery tank (T-4A) and stored, transferred to the distillation furnace (R-4) by pumping, and heated and vaporized to the top of the rectification tower (T-5). And fractionated distillation as follows. Gasoline vapors are leaked from the upper part of the tower (T-5) and light diesel and thick diesel oils are extracted from the side of the tower as the gas is discharged. Only a small amount of heavy oil remains at the bottom of the tower (T-5) (S70).

The gasoline vapor is cooled in the cooling water tank (PL-1), and then enters the recovery dehydration tank (C-4), which is a gasoline agglomeration tank, and a product (passed product) satisfying a predetermined condition is a gasoline storage tank (C-10). And the rejected product is recycled back to the top of the tower T-5.

Petroleum, light diesel oil, heavy diesel oil, etc. are first introduced into the top stripper (T-6) (T-7) and then cooled through a second cooling tank (PL-2), which is a separate cooling means. Respectively stored in the oil storage tank (C-14), light diesel oil storage tank (C-12), heavy diesel oil storage tank (C-16) and heavy oil storage tank (C-15).

[Decomposition Gas Compression-Separation Process]

The cracked gas discharged to the upper portion of the diesel oil absorption tower (T-1A) is sucked and compressed by the gas compressor (M-6), and is passed through a second cooling water tank (PL-2) to a liquid-gas separation tank under high pressure ( C-6). The cracked gas sent to the liquid-gas separation tank C-6 is sinked to the bottom of the tank by high pressure, which is liquefied petroleum gas (LPG). LPG is transported, injected and stored in LPG storage tanks (C-9) with PIM.

On the other hand, the dry gas is left in the upper portion of the liquid-gas separation tank (C-6), which is stabilized in the gas-dry stabilization tank (C-7) via a water tank (C-6A) sealed by water, the present invention It is used as a boiler fuel for heating the apparatus, and some of them are burned by blowing.

The emulsification process of the waste plastic according to the present invention constituted as described above is a continuous operation process system combining advanced reaction unit processes in a collective reaction process, and waste oil or the like may be mixed with the waste plastic as a raw material.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The chemical composition of gasoline and diesel oil produced by purifying waste plastics (PE and PP mixtures) and typical hydrocarbon compositions and structures were measured using gas chromatography using the process technology of the present invention. It is as showing in Table 5 and Table 6.

TABLE 4

TABLE 5

TABLE 6

Table 4 shows the results of hydrocarbon chemical composition of gasoline and diesel oil measured from gas chromatography. From the analysis results, it can be seen that more than 98% (mol%) belongs to the C ₆ to C ₁₁ various hydrocarbons. Among them, the C ₈ hydrocarbon content is 45.43% and the C ₉ hydrocarbon content is 27.86%, accounting for the largest portion. The paraffin content is 41.15% and the aromatic hydrocarbon content is 11.35%. Since the content of aromatic hydrocarbons and naphthenes is high, the refined gasoline from waste plastic or octane number during extraction is excellent.

Table 5 shows the chemical structural composition of typical various hydrocarbons of gasoline. Looking at the hydrocarbons contained, it can be seen that all of them have the property of being susceptible to abnormal explosion by the addition of ethyl benzene. This means that the gasoline is stable.

Table 6 shows the chemical structural composition of typical hydrocarbon hydrocarbons of diesel oil. As a result of analysis, paraffin-based and olefin-based hydrocarbons and alkenes-based hydrocarbons may be found to contain more alkene-based compounds at 46.95 mol% and 80.50 mol%. This means that diesel oil's Cetane Number is not small and its solidification point is low, so the quality is excellent.

The principle of the pyrolysis reaction of the present invention is briefly described. As already mentioned above, the structure of the chemical reaction can be outlined from the results from the hydrocarbon chemical composition and the structural composition of gasoline and diesel oil. That is, when the waste plastics (PE, PP) are heated and melted and then subjected to the relaxation reaction in the liquid phase, the gas and oil mixtures are separated, and the oil mixtures are separated into gasoline and diesel oil by fractional distillation.

In the present invention, the raw material input amount was 16,800 kg based on PE and PP in the net waste plastic (50: 50 parts by weight), and the emulsification process was performed. The results are shown in Table 7. In addition, the mixture of PE and PP (50:50 parts by weight) and the waste oil was mixed in half and the amount of raw material was set at 16,80Okg and the emulsification process was performed. The results are shown in Table 8.

Referring to Table 7 and Table 8, the product production rate is related to the waste plastic raw materials and pyrolysis reaction conditions, it can be seen that there is a difference of about 15% of the production amount according to the change of raw materials and reaction conditions.

TABLE 7

TABLE 8

The quality of the emulsified product prepared in the present invention was submitted to the Petroleum Acid Quality Supervision Laboratory under the Xinxiang Province of China, and the results are shown in Table 9 and Table 10.

TABLE 9

TABLE 10

In the emulsification process of the present invention, gasoline and diesel oil were produced according to China Petrochemical Corporation's standard standard SHO112 and Chinese national standard GB255, and the evaluation values were suitable for the quality index standard requirements. Of these, gasoline-free octane number was only up to 78. Since M0N-78 is roughly equivalent to RON-90, the octane number of the gasoline actually measured reaches RON-90.

In the present invention, secondary environmental pollution by wastewater, residues, and waste generated during the production process is hardly generated.

In the apparatus of the present invention, the refined wash water is the main wastewater. The oil refining process is a secondary extraction process that removes non-ideal components, removes odors, and stabilizes decolorization, and uses washing water. In this process, the first refinery wash water is recycled three or more times. The discharged wash water is generally mixed with a small amount of oil residues, the content of which is about 0.1%, but it can be reduced to about 0.01% (about 100PPM) or less by using a conventional oil separation tank.

In addition, when a large amount of PVC is included in the waste plastic to be input, thermal decomposition may generate substances such as C1 ₂ , HCl, and chlorine substituted alkanes. However, in the process of the present invention, organic odor containing sulfur, nitrogen, oxygen, chlorine, etc., and special odorous carbonaceous matter separately contained in inorganic matter (high-performance dehydrogenated aromatic cyclic compound composed of C and H elements, about CHO.6 hydrate) ) Is completely processed and decomposed into non-toxic substances such as salts. Chlorinated alkanes are acidic or polar and are easily decomposed and removed to form substances such as salts.

Plastics have a very high degree of single purity in the production of polymerization. In general, the purity of the group is 99.98% or more. It also does not contain any other elements (except PVC containing chlorine atoms), so that no hydrocarbon tubes or compounds containing toxic elements are formed during pyrolysis of waste plastics. Special odor before extraction (dark coke odor) is due to C and H in charcoal. No toxicity is present. Special odors can be completely removed in the extraction process, as described above.

In addition, in the process of the present invention, the residual water is discharged from the reactor. Residues are sludge and gravel introduced into waste plastics and various additives contained in plastics, such as hard calcium carbide, titanium powder and heavy oil reactants. Residue is a sewage substance consisting of Onisa and coke powder containing 30 to 50% oil. It is agglomerate at room temperature and it is a non-toxic organic material that can be used as fuel for boilers. When used as fuel, it does not form toxic gases and burns similarly to heavy oil combustion products.

Chemical fertilizers, pesticides, cement, clothing, etc. may be attached and mixed in the waste plastics, but the amount is very small. It can decompose into traces of inorganic oxides and hydrides at high temperatures. Ammonia, nitric acid, phosphoric acid, carboxylic acid and the like are easily decomposed through the extraction process of the present invention and eventually used as fuel for boilers along with other residues to be converted into non-toxic sludge.

In the present invention, the waste is mainly a gas discharged from the communication after the combustion of coal and dry season (methane, ethane, ethylene). In this device, the amount of coal used is only 100 ~ 200kg per ton of raw materials, and since it uses self-generated dry gas, the amount of flue gas is smaller than that of the existing Boryeong boiler. The other disposal is dry season combustion blowers. Blowing lamps emit a small amount of air into the air for the purpose of dry periods for the purpose of operating the entire system. After combustion, the product is not much different from domestic liquefied gas, steam produced after gas combustion and carbon dioxide, and it is almost harmless to human body and environment.

The waste generated from the unit is generated when the boilers and fires are burned by coal, heavy oil and dry season (methane, ethane, ethylene). Because of this, the basic composition is toxic to carbon dioxide, water vapor and nitrogen gas.

As described in detail above, according to the emulsification process of the waste plastic according to the present invention, the recovery rate of the emulsified product is 75% or more, and the dissolved residue and dry gas are used as the fuel of the boiler during the process to discharge the environmental pollutants. This is very small. In addition, the residue can be removed during the process, the waste plastic raw materials can be added in a mixed state without sorting or washing, as well as to proceed with the continuous process. In addition, since the pyrolysis reaction is performed at low temperature without a catalyst, cost reduction can be achieved, and a good quality product can be improved by a deodorization and stabilization process, which is a physicochemical deodorization system.

Claims (1)

A first step of crushing the waste plastic raw material; A second step of heating the waste plastic crushed product in the above process to pyrolyze the reaction, and heating and melting a portion of the crushed product separately at a temperature of 300 to 500 ° C. to relax and mix the pyrolysis reactant; A third step of separating the gas and oil mixture from the treated product of the step; A fourth step of adding an extractant to the oil mixture in the process, extracting the sludge by proceeding the input in a plurality of steps, and deodorizing and stabilizing color stabilization; And a fifth step of fractionally distilling the treated material of the above step into gasoline, diesel oil, and the like, wherein the waste residue of the second step or the sludge of the fourth step is recovered and coked to be used as fuel for heating the device. The emulsification method for waste plastics according to claim 4, wherein the extractant input ratio of the fourth step is limited to a ratio of 100: 0.8 to 2.4 by weight of the extractant.

Images