KR960013605B1 - Hydrocarbon oil production method from waste plastics by pyrolysis - Google Patents

Abstract

supplying the volatile material which is obtained from the waste plastic by thermal decomposition, into the receptacle; condensing at least some of the volatile material into the liquid, and the chemical reaction and separation are processed in the phase of vapor-liquid; reheating the condensed liquid having high boiling point, which is obtained from the receptacle, with the waste plastic, and circulating it into the receptacle; and separating and collecting the hydrocarbon having low boiling point from the upper or center of the receptacle.

Description

Recovery method of low boiling hydrocarbon oil by pyrolysis treatment of waste synthetic resin

1 is a schematic process diagram of a packed bed built-in pyrolysis treatment apparatus suitable for carrying out the method of the present invention.

Figure 2 is a schematic process diagram of a packed bed separation pyrolysis treatment apparatus suitable for carrying out the method of the present invention.

* Explanation of symbols for main parts of the drawings

1 melting tank 2,13 pyrolysis tank

3,21: heating furnace 4,14: packed bed

5,20 gas outlet 6,16 condenser

7: supply pump 8: circulation pump

9,23: reflux pipe 10: gas injection pipe

11: Hopper 12: Screw Feeder

15 heater 17 residue outlet

18: motor 19: burner

22 impeller 24 reaction promoter injection tube

The present invention relates to a method for recovering a useful low boiling point hydrocarbon oil having a low flow point such as gasoline, kerosene, and diesel oil by pyrolysis treatment of waste synthetic resin.

In recent years, due to the rapid development of petrochemicals, the production of synthetic resins represented by plastics has been rapidly increased, and the disposal of such wastes has become a social problem.

Recycling, incineration, landfill, etc. have been mainly used for the treatment of waste synthetic resins. However, it is urgent to develop effective new treatment technologies due to various problems such as the limitation of reclaimable materials, generation of toxic substances during incineration, and non-rotating properties.

Pyrolysis treatment of waste synthetic resin generally refers to a technique of thermally decomposing waste synthetic resin in a reducing atmosphere into a gas and cooling the gas in a condenser to make it into an oil. The term pyrolysis used in the present invention includes not only pyrolysis in this general sense but also a method of adding a separate additive to the waste synthetic resin to chemically react with it to promote decomposition.

By the way, generally, the gasification component obtained by thermal decomposition of waste synthetic resin contains the high boiling point heavy component which is not fully decomposed. Heavy components, when cooled in a condenser, harden into wax and become a very dangerous condition. This is because the outlet side of the pyrolysis reaction means is blocked by the wax component and the internal pressure rises, which may cause an explosion. In addition, this heavy component has high viscosity at room temperature and low fluidity, making transportation and processing difficult.

Therefore, in the pyrolysis treatment process of waste synthetic resin, it is necessary to be able to remove the intermediate components contained therein before introducing the pyrolysis gas into the condenser. Various apparatuses have been developed for removing heavy components and circulating them to the pyrolysis reaction means. For example, special apparatuses disclosed in Japanese Patent Application Laid-Open Nos. 50-146,680, JP-A 3-86,791, and JP-A-4-50,292. There is.

The devices are all installed as separate devices between the pyrolysis tank and the condenser and have a special structure for effectively removing only wax components. The removed wax component is reheated and decomposed by circulating through a pyrolysis tank, and in this process, a large amount of energy is lost since it is once cooled to room temperature and then heated to a pyrolysis temperature again.

Conventional pyrolysis products are oils having a high pour point even when removing heavy components that become waxes at room temperature, and thus have low utilization value, and are subsequently introduced into separate reaction means to be decomposed and reformed.

For example, Japanese Patent Laid-Open No. 4-50,292 uses a metal catalyst for this reaction means, and US Patent 4,851,601 uses a zeolite catalyst to produce a high quality oil having a gasoline component of about 50%. All of these methods involve catalytic conversion of pyrolysis products through a catalyst bed installed inside the reactor in the vapor phase, and the quality of the final product oil is determined by the type of catalyst and reaction conditions. In addition, in order to obtain an oil of a uniform component, such as gasoline, a distillation step for separating the component is further required.

The object of the present invention is to provide a method for recovering low boiling point hydrocarbons by pyrolysis treatment of waste synthetic resin with high energy efficiency and low processing cost by performing heavy component removal and chemical reaction in one apparatus, unlike conventional pyrolysis treatment technology. It is.

It is another object of the present invention to provide a method for pyrolysis of waste synthetic resins capable of producing low boiling point hydrocarbon oils having high utilization and uniformity without going through a separate subsequent separation process.

The present invention introduces a multicomponent vapor product generated by melting and thermally decomposing waste synthetic resin into a packed bed, and maintains an appropriate temperature distribution according to the height of the packed bed, thereby allowing at least a portion of the vapor product directed upward in the packed bed to be liquid phase. Condensation is directed downwards, thereby allowing chemical reactions and component separations to occur continuously or alternately, with gas-liquid contact between the condensate and the vapor product at the column contents surface of the packed bed. The high boiling point condensate refluxed from the bed to the bottom together with the melt of the waste synthetic resin to generate a steam product, and then circulated back to the packed bed, characterized in that the low boiling hydrocarbon is separated and recovered from the top or middle of the packed bed. By pyrolysis treatment of waste synthetic resin Boiling point hydrocarbon is significant recovery method.

In the present invention, the waste synthetic resin may be any thermoplastic resin. For example, polyethylene, polypropylene, polystyrene, nylon, ABS resin, polycarbonate, polyvinyl chloride, vinyl acetate, unsaturated polyester, PBT, PET, polyacetal and the like. In addition, synthetic resins and thermosetting resins other than plastics such as synthetic rubbers and tires that can be thermally decomposed to obtain oils or monomers can also be used.

Waste synthetic resin is usually discharged as industrial waste, municipal waste, rejects in factories, etc., and may be any type of film, sheet or molded article. The waste synthetic resin may contain a small amount of foreign substances such as water, dirt, paper, iron, and glass as long as it does not interfere with the pyrolysis reaction. In addition, the waste synthetic resin may be mixed with oil such as vegetable oil, mineral oil, waste oil and the like.

1 is a schematic process diagram of a packed bed built-in pyrolysis treatment apparatus suitable for carrying out the method of the present invention. Figure 2 is a schematic process diagram of a packed bed separation pyrolysis treatment apparatus suitable for carrying out the method of the present invention. Hereinafter, the method of the present invention will be described according to FIG. 1.

The waste synthetic resin is crushed by appropriate means and then melted in the melting tank 1. The melting tank may be of any type as long as it has a function of heating raw materials to form a uniform melt, and an agitating tank provided with a total heating means may be used, but an extruder or the like other than the stirring tank may be used.

It is also well known to add oil obtained through pyrolysis to increase the melt rate. The melt is then introduced into the pyrolysis tank 2 and cracked by heat at the bottom thereof.

The waste synthetic resin may be fed into the pyrolysis tank in a solid state without melting, thereby performing melting and pyrolysis together in the pyrolysis tank. The melt is preferably supplied to the bottom of the pyrolysis tank so that the melt level is kept constant. The heating temperature depends on the pyrolysis temperature of the workpiece, but is about 250 to 600 ^o C near normal pressure.

The heating is carried out by introducing the melt in the pyrolysis tank into the heating furnace 3, heating it to a desired temperature, and then circulating it in the pyrolysis tank 2. In addition, the bottom of the pyrolysis tank may be directly heated or a heating coil may be installed inside the melt to heat the same. The pressure condition is not particularly limited but may be near normal pressure. The steam product generated by the pyrolysis in the pyrolysis tank is introduced into the packed bed 4 provided on the melt surface in the pyrolysis tank. Although it is installed in the pyrolysis tank of the packed bed here, it may be installed separately from the pyrolysis tank.

The vapor product introduced into the packed bed 4 is partially condensed into a liquid phase by keeping the temperature distribution of the packed bed 4 within an appropriate range, thereby causing gas-liquid contact in the packed bed, and in this state, Component separation by distillation occurs simultaneously, so that the low boiling point useful components are directed upwards of the packed bed and the high boiling heavy components are directed downwards.

One of the important features of the present invention is to allow the chemical reaction and component separation to occur simultaneously in a single device, in which a packed bed is installed to facilitate this and sufficient activity at the temperature of the packed bed to facilitate the reaction as necessary. This catalyst component is included in the packed bed.

In the present invention, in order to more efficiently convert pyrolysis products into useful low-boiling hydrocarbons, decomposition and reforming catalyst components may be included and used in the packed bed. The decomposition and reforming catalyst component that can be used in the present invention may be any material that promotes the decomposition reaction or the reforming reaction of the pyrolysis product. For example, nickel, copper, aluminum, iron, titanium, stainless steel, transition metal Metal catalysts such as alumina, inorganic catalysts such as alumina, silica-alumina, synthetic or natural zeolites are used.

In addition, in a broad sense, the concept of the catalyst of the present invention includes a conversion catalyst or adsorbent for removing harmful substances such as chloride, sulfide, and nitride contained in a pyrolysis product, a low temperature oxidation catalyst for regeneration of the adsorbent, and heating of PVC. Alkali neutralizing agents for the treatment of generated hydrogen chloride gas are also included.

For example, precious metals such as platinum, palladium, and silver may be used as the conversion catalyst, and transition metal oxides such as Co ₃ O ₄ , MoO ₃ , CrO ₃ , V ₂ O ₅ , and NiO may be used as the low temperature oxidation catalyst. Can be. Moreover, activated carbon, molecular sieve, etc. can be used as an adsorbent, soda ash, caustic soda, etc. can be used as an alkali neutralizer.

In the packed bed of the present invention, in addition to the catalyst component as described above, a separate chemical substance may be injected in order to lower the decomposition temperature or to speed up the decomposition rate. That is, a gas such as hydrogen, oxygen, water vapor or the like is injected into the bottom or middle of the packed bed, or liquid and solid phase reaction accelerators such as carbonic acid, metal oxides, organometallic salts, enzymatic substances, radical initiators, and peroxides By injecting a small amount, not only pyrolysis but also a separate chemical reaction can be promoted to decompose the polymer waste plastics.

Examples of the added substance include acetic acid, propionic acid and lactic acid as carbonic acid, iron oxide and chromium oxide as metal oxide, copper stearic acid and aluminum stearate as organic metal salt, and t-butyl as radical initiator. Hydrogen peroxide etc. can be used for a pert-butyl hydroperoxide, etc., and a peroxide.

As in the present invention, the process in which the chemical reaction and the component separation occur simultaneously is partly similar to the phenomenon in the distillation process called reaction distillation. Reaction distillation, a term widely known in the chemical manufacturing industry, was first proposed in the early 1920s in esterification processes using homogeneous catalysts.

Recently, it has been mainly applied to solid catalysis, and a typical example is the manufacturing process of MTBE, an octane number improver for gasoline. Reaction distillation employing a solid catalyst is suitable for systems in which the optimum temperature range of the catalyst coincides with or substantially overlaps the appropriate temperature range. Reaction distillation can reduce costs by performing two processes, reaction and distillation at the same time, and cost reduction, and high conversion rate can be obtained by simultaneously separating products into the top and bottom of the distillation column for certain chemical reactions. There is an advantage (see Chemical Engineering Process, March 1992, pp. 43-50).

The present invention has the advantage that the high boiling point components and low boiling point components in the packed bed can be separated and at the same time a chemical reaction can take place to take advantage of the reaction distillation process. However, the present invention differs considerably in terms of operating method from reaction distillation in the original meaning.

That is, in the present invention, unlike the reaction distillation in which the separated substances are respectively discharged from the upper and lower portions of the distillation column, low boiling point components to be recovered only at the upper portion of the packed bed are discharged. In addition, unlike the reaction distillation for high-purity single component separation, the present invention separates and recovers components below a certain boiling point in the form of a mixture.

Hereinafter, the present invention will be described with reference to the embodiment of the pyrolysis treatment of a typical general-purpose plastic polyethylene (PE).

When the polyethylene is melted and heated to about 400 ^o C or more, full-scale pyrolysis begins to occur in the liquid phase, and pyrolysis products having a vapor pressure higher than the decomposition pressure are discharged to the gas phase. If the decomposition pressure is atmospheric pressure, the gaseous pyrolysis product discharged from the melt consists of heavy components, most of which are waxes at room temperature. If these heavy components are immediately discharged out of the pyrolysis tank, it is possible to clog condenser, pipe, etc., so it is better to re-decompose them into lower boiling components in the pyrolysis tank as much as possible.

According to the experiments of the present inventors, when the volume of the upper portion of the molten liquid in the pyrolysis tank was increased and the heating rate, that is, the pyrolysis rate was lowered, the wax outside the pyrolysis tank was maintained at a temperature of about 280 ^° C. No ingredients were discharged. This is believed to be due to the fact that the heavy gaseous constituents, which become waxes at room temperature, are thermally decomposed or modified secondaryly while remaining sufficiently in a high temperature pyrolysis tank of about 300 ^° C. or higher, resulting in lower boiling point components.

In this case, the heat of reaction required for pyrolysis or reforming is shown to be supplied by condensation of the surrounding heavy components under adiabatic conditions. That is, the gas phase pyrolysis reaction of the heavy component and the liquid reflux occur at the same time in the space above the molten liquid surface of the pyrolysis tank. Thus, an arbitrary temperature distribution is formed between the molten weak surface and the gas outlet, for example, 280 to 400 ^° C.

When the pyrolysis rate was increased above a certain limit, a large amount of wax was discharged out of the pyrolysis tank to block the condenser and further operation was impossible, and the temperature of the gas outlet rose to 280 ^° C. or more. On the contrary, the smaller the thermal decomposition rate, the lower the temperature of the gas outlet, so that lower boiling point components can be recovered, while the production rate is lowered.

As described above, in the pyrolysis treatment of polyethylene waste, by controlling the pyrolysis rate and maintaining the temperature of the gas outlet at the top of the pyrolysis tank below about 280 ^° C., low boiling oil may be recovered without a separate wax removal device.

However, in this method, since the pyrolysis rate is limited by the volume of the upper surface of the molten liquid in the pyrolysis tank, the recovery rate of the oil is very low, and there is a problem in the stable control of the process according to the change in the operating conditions.

The present inventors have invented a method of installing a packed bed composed of effective gas-liquid contacting means on top of the melt surface in the pyrolysis tank to solve the above problems.

As described above, it is substantially difficult to control the gas outlet temperature when the decomposition and condensation of heavy components occur in the empty space without the packed bed. This is because the refluxed condensate and the vapor product are not in effective contact, resulting in poor heat transfer. On the other hand, when the packed bed is used, the temperature of the gas outlet can be easily controlled, and the temperature distribution of the packed bed can be controlled by heating or cooling the packed bed, thereby increasing or decreasing the oil recovery rate arbitrarily. have.

In addition, the use of such a packed bed effectively separates the components by distillation, and thus has the advantage of separating and recovering a low boiling point component of a more uniform composition from the top of the packed bed.

Therefore, this method can perform pyrolysis, wax removal, and component separation at the same time, and can achieve the effect of cutting the equipment cost and energy cost. In addition, in the present invention, the packed bed contains a catalyst component that promotes secondary reaction of pyrolysis products such as decomposition and reforming reactions, so that the oil having a low boiling point component can be produced more efficiently. In terms of catalytic contacting method, the present invention is characterized in that a catalytic reaction occurs in a gas-liquid contact state unlike the conventional method of decomposing and reforming a pyrolysis product through a catalyst bed in a vapor phase.

Therefore, when the catalyst component is included in the packed bed, in addition to the above-described effects of the thermal decomposition, the removal of the wax component, and the separation of the components, the secondary reaction by the action of the catalyst can be achieved. This is improved and the energy efficiency is much higher.

The temperature distribution of the packed bed is kept high like the temperature distribution of a general distillation column, and depends on the type of catalyst and the desired increase in the amount of the final oil produced, but the range is preferably 200 to 500 ^° C.

This temperature distribution is determined by various variables such as the height of the packed bed, the composition and temperature of the introduced pyrolysis product, the pressure of the packed bed, and the reflux conditions of the packed bed steel. In order to obtain a temperature range in a desired range, the above parameters must be properly adjusted, and a method of heating or cooling the packed bed may be used independently to control the temperature distribution.

Any form may be used as the packed bed of the present invention as long as it has a component separation function by efficient gas-liquid contact.

For example, the column internals of a plate column or a caked column, which are gas-liquid contacting means generally used in a chemical process, can be used as the packed layer of the present invention. If necessary, a catalyst component is included in the column contents.

For example, the sieve tray, bubble-cap tray, valve tray, and the like in the case of a plate column may be spherical or pelletized particles in the case of a packet column. Raching ring, Fall ring, Intalox saddle, Structural packing. In addition, those developed for other purposes, such as tube bundles, demisters, and the like, are also included in the scope of the tower contents of the present invention when used as gas-liquid contacting means.

Currently, various types of special tower contents for reaction distillation have been developed and may be used in the present invention. In the case of using a combination of different types of gas-liquid contact means, such as, for example, a metal demister for removing heavy components at the bottom of the packed bed and a catalyst ring shaped as a lashing at the top, Included in the category.

The relatively uniform low boiling point components, which are inverted and separated in the packed bed, come out from the packed bed, enter the condenser 6, cool, and separate into gaseous and liquid products.

In the present invention, a part of the liquid product is not generally refluxed to the top of the packed bed, but in order to recover low boiling point components having a more uniform distribution, a small amount of the liquid product may be refluxed to control the temperature distribution of the packed bed.

Further, in the present invention, the low boiling point components are separated and recovered from the top of the packed bed, but it is also possible to selectively separate and recover certain ingredients from the middle of the packed bed.

The liquid heavy component refluxed from the bottom of the packed bed is reheated together with the melt of the waste synthetic resin and the resulting steam product is circulated back to the packed bed. Residues generated during the pyrolysis process are periodically discharged from the bottom of the pyrolysis tank by the appropriate discharge means.

The liquid product separated in the condenser is a highly utilizable oil made up of a mixture of low boiling hydrocarbons. The gaseous product can be used for applications such as gas fuel, and can be effectively used in the present invention, for example, as a fuel for heating of the furnace 3.

As described above, when the method of the present invention is used in the thermal decomposition treatment of waste synthetic resin, the following effects can be obtained.

First, there is no need for a separate device to remove the heavy components that become wax at room temperature, and second, cost reduction of equipment cost, operation cost, etc. by performing chemical reaction and component separation in one device, and third, inside the packed bed The decomposition reaction, the reforming reaction, and the separation of components to occur in combination to reduce the energy consumption, and fourth, there is an excellent effect, such as easy to recover the hydrocarbon oil made of low boiling point components of high utilization.

For example, it will be described in detail as follows.

Example 1

Experiments were carried out using the apparatus as shown in FIG. The recovered polyethylene bottle was coarsely pulverized to a size of about 2 cm or less by a pulverizer, and the polyethylene pulverized particles were put in advance and continuously injected into the molten bath 1 that had been heated and melted for a long time to melt.

The melting tank was heated with fruit oil of a jacket (not shown) installed outside the tank, and the temperature of the melt in the melting tank was maintained at about 300 ^° C. at all. Subsequently, the molten liquid in a melting tank was supplied to the lower part of the thermal decomposition tank 2 of diameter 10cm and height 90cm with the feed pump 7. At the same time, the melt supplied to the bottom of the pyrolysis tank was introduced into the furnace 3 with a circulation pump 8, heated to about 430 ^° C., pyrolyzed and returned to the bottom of the pyrolysis tank 2 again.

Subsequently, the steam product generated by pyrolysis is introduced into a packed bed 4 having a height of about 45 cm made of silica-alumina pellets of about 5 mm in size, and the temperature distribution of the packed bed is maintained as follows to decompose in a state where gas-liquid contact takes place. Modification reaction and component separation were allowed to occur. The temperature distribution of the packed bed 4 was adjusted to the flow rate (pyrolysis throughput) of the circulating pump 8 without using a separate heating or cooling device, and this temperature was about 280 ^o C based on the temperature of the top of the packed bed. It was kept.

The low boiling hydrocarbon discharged from the top of the packed bed 4 was cooled and condensed in the condenser 6 to be separated into an oil component and a gas component. The oil components were stored in a low oil tank (not shown) and the gas components were burned with a burner. In addition, the residue component was periodically discharged from the bottom of the pyrolysis tank.

As a result of continuous operation for about 10 hours, the average throughput per hour was about 2.9 kg, the liquid yield 82%, the gas yield 11%, and the residue 7%. There was almost no wax in the product oil, and the distillate fraction below 260 ^° C was 96.3 vol% by ASTM distillation analysis. The physical property test results of the resultant oil are shown in Table 1.

Comparative Example 1

The same pyrolysis experiment as in Example 1 was conducted except that no packed bed was provided. The temperature of the gas outlet (5) is about 280 for stable operation Continuous operation experiments were carried out while keeping them at or below C.

If the circulation amount by the circulation pump, that is, the heating amount is gradually increased, the temperature of the gas outlet and the throughput increase proportionally, but the temperature of the gas outlet is about 280 When it was above C, a lot of wax was discharged, so stable operation was impossible.

As a result of continuous operation for about 10 hours, the average throughput per hour was about 1.4 kg, oil yield 90%, gas yield 6%, and residue 4%. The product oil contained a small amount of wax, which was obtained by ASTM distillation analysis. The distillate fraction below C was 83.2 vol%. The experimental results of the physical properties of the resulting oil are shown in Table 1.

Compared to Example 1 and Comparative Example 1, when using the packed bed according to the present invention is a low density and viscosity can be recovered high-quality light oil having a good fluidity and much aromatic components and the processing speed is also increased about twice It can be seen that there is an effect.

Example 2

Experiments were carried out using the apparatus as shown in FIG. Pulverized mixed waste plastic mixed with polyethylene, polypropylene, and polystyrene waste plastics in a ratio of 50:50:25 by weight ratio of about 1 cm or less and pyrolyzed from the hopper 11 using a screw feeder 12 The tank 13 was quantitatively supplied and pyrolyzed.

The pyrolysis tank was heated by the burner 19 of the heating furnace 21 installed outside the tank, and the pyrolysis temperature was about 420. Kept at C. Subsequently, a steam product generated by pyrolysis is introduced into the packed bed 14, and the temperature distribution of the packed bed is heated by a heater 15 installed outside thereof, thereby providing 290-400. It was kept in the C range so that decomposition reforming reaction and component separation occurred in the state where gas-liquid contact took place.

The packed layer was filled with synthetic zeolite particles having a diameter of 10 cm and a height of 45 cm, a metal demister in the lower 20 cm, and a diameter of about 5 mm in the upper 25 cm. Subsequently, the hydrocarbon gas discharged from the gas outlet 20 in the upper portion of the packed bed was cooled and condensed in the water-cooled condenser 16 to be separated into an oil component and a gas component.

The oil component was stored in a low oil tank (not shown) and the gas component was used as fuel of the burner 19. In addition, the residue component was periodically discharged from the residue outlet 17 of the lower portion of the pyrolysis tank.

After about 10 hours of continuous operation, the average throughput per hour was 3.8 kg and the oil yield was 85%, the gas yield 8% and the residue 7%. The density and viscosity of the recovered oil were 0.812 g / cc and 1.634 cP, respectively.

Comparative Example 2

The same experiment as in Example 2 was conducted except that no packed bed was provided. The temperature of the gas outlet 20 is about 290 for stable operation. Continuous operation experiments were carried out while keeping them at or below C.

If the heating amount of the burner 19 is gradually increased, the temperature and throughput of the gas outlet 20 increase in proportion to this, but the temperature of the gas outlet is about 290. When it was above C, a lot of wax was discharged, so stable operation was impossible.

After about 10 hours of continuous operation, the average throughput per hour was 2.1 kg, oil yield 88%, gas yield 4% and residue 8%. The density and viscosity of the recovered oil were 0.785 g / cc and 1.540 cP, respectively.

Compared to Example 2 and Comparative Example 2, it can be seen that when using the packed bed according to the present invention, light oil having low density and viscosity and good fluidity can be recovered, and the processing speed is also increased about twice. have.

Example 3

The same pyrolysis experiment as in Example 1 was performed. However, the flow rate of the circulating pump 8 is increased to increase the temperature at the top of the packed bed to 280. After raising to higher than C, the flow rate of the circulating pump 8 is fixed, and a small amount of condensate separated from the condenser 16 is refluxed through the reflux tube 9 to the upper part of the packed bed to increase the temperature at the top of the packed bed. The pressure was kept constant at C. As a result, oil of similar quality as in Example 1 could be recovered and the processing speed was about the same.

Example 4

The same experiment as in Example 1 was conducted except that a small amount of heated steam was injected through the gas injection pipe 10. As a result, oil of similar quality as in Example 1 could be recovered and the average throughput per hour increased to about 3.4 kg. From this test result, the reaction promoting effect of water vapor was confirmed.

Example 5

The radical initiator t-butylhydroperoxide was injected through the reaction promoter inlet tube 24, and the pyrolysis temperature was about 380. The same experiment as in Example 2 was carried out except that it was maintained at C. As a result, the average throughput per hour was 3.9 kg and the quality of recovered oil was similar to that of Example 2. From the experimental results, it can be seen that using the reaction accelerator, the same treatment rate can be obtained at lower pyrolysis temperature.

Claims (13)

The multicomponent vapor product generated by melting and pyrolyzing the waste synthetic resin is introduced into the packed bed, and maintains an appropriate temperature distribution according to the height of the packed bed to condense at least a portion of the vapor product directed upward in the packed bed into the liquid phase. To the bottom, thereby allowing chemical reactions and component separations to occur continuously or alternately in the state of gas-liquid contact between the condensate and the vapor product in the charge, and refluxing from the top packed bed to the bottom. The point condensate is reheated together with the melt of the waste synthetic resin to generate a steam product, and then circulated back to the packed bed, and the low boiling point hydrocarbon is separated and recovered from the upper or middle portion of the packed bed. To recover low-boiling hydrocarbons . The method of claim 1, wherein a portion of the packed bed is heated or cooled by a separate heating or cooling means to maintain an appropriate temperature distribution according to the height in the packed bed. Recovery method. The method according to claim 1, wherein the hydrocarbon separated and recovered from the upper or middle portion of the packed bed is cooled to separate into a liquid product and a gas product, and at least a portion of the liquid acid product is returned to the packed bed to provide a suitable height according to the packed bed. A method for recovering low boiling hydrocarbon oil by pyrolysis treatment of waste synthetic resin, characterized by maintaining a temperature distribution. The method of claim 1, wherein the pyrolysis temperature of the waste synthetic resin is in the range of 250 to 600 ^° C. The method of claim 1, wherein the temperature distribution of the packed bed is in the range of 200 ~ 500 ^° C. The low boiling point hydrocarbon oil recovery method by thermal decomposition treatment of the waste synthetic resin. The method for recovering low boiling point hydrocarbon oil by pyrolysis of waste synthetic resin according to claim 1, wherein the packed bed comprises a plate column, a packed column, or a combination thereof. The top content of claim 6 wherein the top content is a sieve tray, bubble-cap tray, valve tray spherical or pelletized particles, Raching ring, Pall. by pyrolysis treatment of waste synthetic resin, characterized in that it is a gas-liquid contact means such as rings, intalox saddles, structured packing demisters, and tube bundles. Low boiling hydrocarbon oil recovery method. 7. The waste synthetic resin according to claim 6, wherein the column contents contain at least one or more of components such as decomposition reforming catalyst, conversion catalyst for harmful substances, adsorbent for harmful substances, alkali neutralizer, low temperature oxidation catalyst, and the like. A low boiling point hydrocarbon oil recovery method by pyrolysis treatment. 9. The cracking reforming catalyst according to claim 8, wherein the decomposition reforming catalyst includes a metal catalyst such as nickel, copper, aluminum, iron, titanium, stainless steel, transition metal, and an inorganic catalyst such as alumina, silica alumina, synthetic or natural zeolite. A low boiling point hydrocarbon oil recovery method by pyrolysis treatment of waste synthetic resin. The method for recovering low boiling hydrocarbon oil by pyrolysis of waste synthetic resin according to claim 1, wherein a gas capable of promoting the reaction is supplied to the lower part or the middle of the packed bed. The method for recovering low-boiling hydrocarbon oil by pyrolysis of waste synthetic resin according to claim 1, wherein a reaction accelerator for liquid or solid phase is supplied to the upper or middle portion of the packed bed. The method for recovering low-boiling hydrocarbon oil by pyrolysis of waste synthetic resin according to claim 10, wherein the gas is a mixture of at least one or more of gases such as hydrogen, oxygen, water vapor or the like with an inert gas. The recovery of the low-boiling hydrocarbon oil by thermal decomposition treatment of the waste synthetic resin according to claim 11, wherein the reaction accelerator is at least one component of carboxylic acids, metal oxides, organometallic salts, enzymatic substances, radical initiators, and peroxides. Way.