JP3608583B2 - Oily treatment method for polymer waste - Google Patents

Description

【００４７】
次に、前記熱分解油、軽質油及び改質油の蒸留性状（℃）を表２に示す。
【００４８】
【表２】

【００４９】
【発明の効果】
本発明の方法によれば、高分子廃棄物、特に従来処理の困難であった混合高分子廃棄物を原料とし、これから燃料油等として有用な油を経済的にかつ効率良く製造することができる。
【図面の簡単な説明】
【図１】本発明の基本プロセスについてのフローシートを示す。
【図２】比重差分離機能を有する気液分離装置の１例についての説明構造図を示す。
【図３】２つの気液分離装置を用いて気液分離を行うフローシートを示す。
【図４】高分子廃棄物の油化処理する場合のフローシートの１例を示す。
【符号の説明】
１、２０１ 熱分解槽
２、２５、１２５、２０２、２０３ 気液分離装置
３、２０４ 加熱炉
４、２０５ 接触改質装置
２０６ 脱塩素処理槽[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for oily treatment of polymer waste.
[0002]
[Prior art]
In order to liquefy the polymer waste, a method of melting the polymer waste and thermally decomposing the melt is known. This thermal decomposition treatment is performed using a thermal decomposition tank provided with a heating jacket on the wall surface and a heating coil inside, and in a thermal supply tank using such a heating jacket and heating coil, a heat transfer surface is used. There is a drawback that the thermal efficiency is likely to deteriorate due to dirt or the like.
[0003]
On the other hand, in order to perform thermal decomposition of polymer waste melt, it is known that superheated steam as a heat source or an inert gas heated to a high temperature is blown into the melt. Causes a problem that the corrosion of the apparatus becomes severe because chlorine present in the melt is converted into highly corrosive hydrochloric acid. Since inert gas is expensive, its use is not economical.
[0004]
In order to improve the problem of heat supply necessary for the thermal decomposition of the polymer waste melt, a part of the melt in the thermal decomposition tank is led to a heating furnace outside the tank, and then heated in the thermal decomposition tank. Has been proposed (Japanese Patent Laid-Open No. 3-86790). However, in this method, since the pyrolysis residual oil is contained in the circulating fluid, the heat transfer surface of the heating coil is heavily soiled when heated in the heating furnace, which is not a practical method.
[0005]
Gaseous material obtained by thermal decomposition of polymer waste melt is still high in molecular weight and high in boiling point and poor in handleability. Have been proposed (Japanese Patent Publication No. 60-15684, Japanese Patent Laid-Open No. 63-17819, etc.). However, such a catalytic cracking method can be effectively applied when the polymer waste is made of only a polyolefin resin, but the polymer waste is not only polyolefin resin but also ABS resin, AS resin, nylon. In the case of containing a nitrogen-containing resin such as a resin or a chlorine-containing resin such as a vinyl chloride resin, gaseous substances obtained by thermal decomposition of the polymer waste melt include HCN and NH which are catalyst poisons. ₃ Since reactive gas such as HCl is contained, it cannot be effectively applied.
[0006]
[Problems to be solved by the invention]
It is an object of the present invention to provide a method for treating polymer waste that can be effectively applied to various polymer wastes and that can be carried out continuously and stably over a long period of time. To do.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, according to the present invention, in the method of oil-treating polymer waste,
(I) a thermal decomposition step of heating and decomposing the polymer waste melt,
(Ii) a condensation step of cooling the gaseous product obtained in the pyrolysis step and condensing at least a part of the pyrolysis oil vapor contained in the gaseous product;
(Iii) a gas-liquid separation step of separating the condensate obtained in the condensation step into a gaseous product and a liquid product;
(Iv) A vaporization step in which a part of the liquid material obtained in the gas-liquid separation step is heated and converted into high-temperature steam,
(V) a high-temperature steam circulation step for circulating the high-temperature steam obtained in the vaporization step to the thermal decomposition step;
(Vi) a high-temperature vapor dispersion step of dispersing the high-temperature vapor circulated to the thermal decomposition step in the polymer waste melt;
A part of the liquid material obtained in the gas-liquid separation step is added to the gaseous product in the condensation step or the gaseous product sent to the condensation step. An oil conversion method is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The type of polymer waste used as a raw material to be treated in the present invention is not particularly limited, and examples thereof include polyolefin resins such as polyethylene, polypropylene, polybutylene, and ethylene / propylene copolymers, and polystyrene resins such as polystyrene. In addition to hydrocarbon polymers such as resins, chlorine-containing polymers such as polyvinyl chloride resin and polyvinylidene chloride resin, nitrogen-containing polymers such as nylon, polyacrylonitrile, ABS resin, AS resin, polyethylene terephthalate, polymethyl methacrylate And other oxygen-containing polymers. The present invention is particularly advantageously applied to polymer waste composed of hydrocarbon polymers and non-hydrocarbon polymers. In this case, the non-hydrocarbon polymer includes a chlorine-containing polymer, a nitrogen-containing polymer, an oxygen-containing polymer, and the like. The upper limit of the content of these non-hydrocarbon polymers should be set to 30% by weight or less, preferably 10% by weight or less in the total polymer waste.
[0009]
Next, the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a flow sheet for the basic process of the present invention. In FIG. 1, 1 is a pyrolysis tank, 2 is a gas-liquid separator, 3 is a heating furnace, 4 is a catalytic reformer, 5 is a cooling condenser, 6 is a cooler, 8 is a heating coil, and 20 is a catalyst packed bed. Indicates.
[0010]
The pyrolysis tank 1 has a gas dispersion means 7 in the lower part thereof, a polymer waste melt (hereinafter also simply referred to as a melt) inlet and a gaseous substance discharge outlet in the upper part, and a heat in the bottom part. It has a decomposition residue discharge port. Examples of the gas dispersion means 7 include a branch pipe type dispersion plate and a tube body having a large number of gas ejection holes. The pyrolysis tank 1 can be provided with a scraper (not shown) for removing deposits on the inner wall.
The gas-liquid separator 2 has a function of separating a mixture of gas and liquid into gas and liquid, and includes a hollow sealed tank. The gas-liquid separation device 2 has a gas discharge port at the upper portion thereof, and has a gas-liquid mixture inlet and a liquid discharge port at the lower portion thereof. Moreover, this gas-liquid separator may be a device having a spray nozzle or a packed bed in the upper part thereof. In the case of a gas-liquid separator having a spray nozzle at the top, fine droplets of cooling cracked oil are sprayed through the spray nozzle onto the gaseous matter rising in the tank, and the pyrolysis oil vapor contained in the gaseous matter At least a part of can be cooled and condensed. On the other hand, in the case of a gas-liquid separator having a packed bed (a packed bed made of a filler such as a Raschig ring, a metal piece, or a ceramic ball) on the top, cooling cracked oil flows down from the upper surface of the packed bed, By raising the inside of the packed bed, at least a part of the pyrolysis oil vapor in the gaseous matter can be condensed.
Furthermore, this gas-liquid separation can be performed using a plurality of gas-liquid separation devices. In this case, to the gaseous substance obtained by the preceding gas-liquid separator, the liquid substance obtained by the latter gas-liquid separator is cooled and added, and the resulting condensate (gas-liquid mixture) is gas-liquid separated. Separated into gaseous and liquid materials.
The heating furnace 3 includes a combustion furnace having a heating coil 8 therein, and heats and vaporizes the liquid flowing through the heating coil.
[0011]
The catalytic reformer 4 includes a packed tower having a catalyst packed bed 20 inside. Examples of the catalyst include conventionally known solid acid catalysts such as silica alumina, alumina, zeolite (pentacyl type zeolite, faujasite type zeolite, etc.), dealuminated mordenite, and the like. These solid acid catalysts can also contain metal components such as rare earth metals as necessary. The average particle diameter of the solid acid catalyst is 1 to 10 mm, preferably 1 to 5 mm.
In the present invention, this catalytic reformer is not essential, and can be omitted when the liquid material obtained from the gas-liquid separator 2 is used as it is as heavy fuel oil.
[0012]
In FIG. 1, a polymer waste melt is introduced into a pyrolysis tank 1 through a line 11, and a liquid material (pyrolysis oil) separated in a gas-liquid separator 2 is heated in a heating furnace 3. Vaporized and introduced through line 19 in the form of hot steam.
The high-temperature steam of the pyrolysis oil introduced into the pyrolysis tank 1 is ejected into the melt through the gas dispersion means 7 and rises while being dispersed in the form of bubbles in the melt. Due to the dispersion of the high-temperature steam of the pyrolysis oil in the melt, the melt is stirred and heat supply to the melt is achieved.
[0013]
The reaction temperature in the pyrolysis tank 1 is 350 to 550 ° C., preferably 400 to 450 ° C., and the reaction pressure is usually normal pressure, but may be increased or reduced depending on circumstances. The reaction time is usually 60 to 350 minutes, preferably 100 to 250 minutes. The temperature of the high-temperature steam of the pyrolysis oil to be dispersed in the melt is at least 50 ° C. higher than the melt temperature, preferably about 50 to 100 ° C. The amount of high-temperature steam introduced into the pyrolysis tank 1 is an amount necessary to keep the melt at the reaction temperature, and is usually based on 1 part by weight of the melt introduced into the pyrolysis tank 1. It is about 4 to 10 parts by weight, preferably about 6 to 8 parts by weight.
[0014]
In the pyrolysis tank 1, a thermal decomposition reaction of the molten liquid is performed, and the molten liquid is subjected to the thermal decomposition reaction so that the non-condensable gas, the lower boiling point pyrolytic oil than the molten liquid, and the higher boiling point heat than the molten liquid. Converted into decomposition residue. The pyrolysis oil is discharged as a vapor from the pyrolysis tank through the line 13 together with the non-condensable gas, and the gaseous product discharged from the pyrolysis tank is led to the cooling condenser 5, where The gaseous product is added with the liquid pyrolysis oil separated in the gas-liquid separator 2 through the line 16 and the cooler 6, thereby at least one of pyrolysis oil vapor in the gaseous product. The part is cooled and condensed to form a gas-liquid mixture. This gas-liquid mixture is introduced into the gas-liquid separator 2 through the line 14.
As the cooling condenser 5, one having a structure in which the gaseous product and the cooling liquid are brought into direct contact is preferably used. Such a cooling condenser can be a tube (pipe) having a liquid inlet on the pipe wall, and has a liquid spray nozzle and a gaseous product inlet at the top, and a gas-liquid mixture at the bottom. It can be a liquid spray tower or the like having a discharge port.
The temperature of the pyrolysis oil added to the gaseous product from line 13 is at least 50 ° C., preferably about 100-250 ° C., more preferably about 100-150 ° C. lower than the temperature of the gaseous product. Temperature. The amount of pyrolysis oil added is 4 to 10 parts by weight, preferably 6 to 8 parts by weight, based on 1 part by weight of the gaseous product.
As shown in FIG. 1, the cooling condensation of the gaseous product is circulated from the gas-liquid separation device 2, and the pyrolysis oil added to the gaseous product is cooled in advance and added to the gaseous product. In addition to this, the mixture obtained by adding the circulating pyrolysis oil to the gaseous organism can be sent to an indirect heat exchange type cooling condenser, where it can be cooled and condensed.
In the present invention, the circulating pyrolysis oil from the gas-liquid separation device is directly added to and mixed with the gaseous product in the cooling condenser or the gaseous product sent to the cooling condenser. An effect is obtained, and solid matter such as crystals generated during cooling and condensation of the gaseous product is prevented from adhering to the tube wall or the like.
[0015]
In the gas-liquid separator 2, gas-liquid separation of the gas-liquid mixture is performed, and the gas-liquid mixture is separated into a gaseous product and a liquid material. The separated gaseous product consists of a non-condensable gas or a mixture of non-condensable gas and pyrolysis oil vapor, and the liquid product consists of pyrolysis oil. When pyrolyzed oil vapor is contained in the separated gaseous product, in order to condense the pyrolyzed oil vapor, the gaseous product is further cooled, and then the second gas-liquid separation device. It can be introduced and gas-liquid separated.
[0016]
The liquid pyrolysis oil separated in the gas-liquid separation device 2 is discharged through the line 15, a part thereof is sent to the cooling condenser 5 through the line 16 and the cooler 6, and the other part is supplied to the line 18. Then, it is introduced into the heating furnace 3, where it is vaporized into high-temperature steam and then introduced into the pyrolysis tank 1, and the remainder is introduced into the catalytic reformer 4 through the line 17.
[0017]
In the catalytic reformer 4, catalytic cracking of the pyrolysis oil is performed, and the pyrolysis oil is converted into a hydrocarbon oil having a lower boiling point, and reactions such as isomerization and aromatization of the hydrocarbon oil also occur. An easily handled hydrocarbon oil (reformed oil) that is liquid at room temperature can be obtained.
As shown in FIG. 1, the pyrolysis oil separated in the gas-liquid separation device 2 can be supplied to the catalytic reforming device 4 as it is, but if necessary, this is once disposed in the heating furnace 3. In addition, it can be heated by circulating in a heating coil different from the heating coil 8, and can be supplied to the catalytic reforming device 4 after being brought into a gas-liquid mixed phase state or a gas phase state at an elevated temperature.
[0018]
The reaction temperature and pressure conditions in the catalytic reformer 4 are preferably temperatures and pressures at which the pyrolysis oil exhibits a liquid phase or gas-liquid mixed phase, and use of such a high temperature that the pyrolysis oil exhibits a gas phase is excessive. It is not preferable. In order to maintain the pyrolysis oil in the gas phase, a large amount of heat energy is required, which is extremely disadvantageous in terms of economy. The reaction temperature in the catalytic reformer 4 is generally 250 to 400 ° C, preferably 250 to 350 ° C. The pressure is a pressure for keeping the pyrolysis oil in a liquid phase or a gas-liquid mixed phase, and is usually 1 to 20 atm.
[0019]
In the present invention, it is preferable that a part of the high-temperature steam passing through the line 19 is dispersed in the liquid obtained by the gas-liquid separator 2. As a result, non-condensable gas such as reactive gas that is dissolved in the liquid material and becomes a catalyst poison is evaporated (stripped) and removed from the liquid material. Such pyrolysis oil from which the reactive gas has been removed is suitable as a raw material oil for catalytic reforming and does not easily cause catalyst poisoning.
In the present invention, the gaseous matter obtained by the gas-liquid separation device 2 is cooled by bringing the liquid matter obtained by the gas-liquid separation device 2 into contact with the gaseous matter, and the pyrolysis oil contained in the gaseous matter. It is preferred to condense at least a portion of the vapor.
[0020]
When treating polymer waste according to the present invention, when the polymer waste contains a chlorine-containing polymer such as polyvinyl chloride resin, the melt obtained by heating and melting the polymer waste is: It is preferable to dechlorinate in advance without introducing it into the pyrolysis tank as it is, and introduce the dechlorination solution into the pyrolysis tank. When the chlorine-containing polymer is pyrolyzed in the pyrolysis tank, hydrogen chloride gas is generated. This hydrogen chloride is highly corrosive and corrodes not only the pyrolysis tank but also the gas-liquid separator at the subsequent stage. Therefore, it is preferable to remove chlorine contained in the polymer waste before introducing it into the thermal decomposition tank. This dechlorination treatment is also important in terms of minimizing the amount of chlorine mixed in the pyrolysis oil.
In order to remove chlorine contained in the polymer waste, the polymer waste melt is sent to a dechlorination tank (not shown), where the chlorine-containing polymer is subjected to a dehydrochlorination reaction. The reaction temperature in this case is 300 to 350 ° C., preferably 320 to 330 ° C., and the reaction pressure is usually atmospheric pressure, but may be increased or reduced depending on the case. The reaction time is 5 to 60 minutes, preferably 10 to 30 minutes. Hydrogen chloride gas generated by pyrolysis of the chlorine-containing polymer is discharged out of the system. The removal rate of chlorine in the dechlorination treatment is at least 80% by weight, preferably 90 to 95% by weight of the total chlorine contained in the polymer waste.
[0021]
In the method according to the present invention, the polymer waste can be efficiently converted into oil.
In the case of the present invention, the pyrolysis oil from the gas-liquid separation device is heated and vaporized with respect to the melt in the pyrolysis tank and directly dispersed as high-temperature steam, so that heat is supplied to the melt with high heat transfer efficiency. be able to. In addition, in the case of the present invention, the heating furnace heats the pyrolysis oil that does not contain the cracked residual oil, so that the heating coil is prevented from being contaminated with the pyrolysis residue, and the thermal efficiency of the heating coil is improved even for a long time operation. The great advantage that no reduction occurs can be obtained.
In the case of the present invention, the high-temperature steam of the pyrolysis oil to be dispersed in the melt in the pyrolysis tank is a hydrocarbon fraction distilled as steam from the pyrolysis tank. The gas phase is maintained without causing condensing, and the melt is dispersed in the form of bubbles. Therefore, since the melt in the pyrolysis tank is efficiently stirred and mixed by the high-temperature steam of the pyrolysis oil, the temperature distribution and viscosity distribution of the melt are made uniform, and no special stirrer is provided. However, it is possible to achieve uniform stirring of the melt, thereby realizing improvement in thermal efficiency and reduction in stirring power.
[0022]
In the case of the present invention, the liquid cooled pyrolysis oil from the gas-liquid separator is directly added to the gaseous product discharged from the pyrolysis tank, thereby obtaining a cleaning effect on the pipe wall and the like. . Gaseous products from the pyrolysis tank include hydrocarbon oils and oxygen-containing compounds that are not compatible with hydrocarbon oils (for example, terephthalic acid and phthalic acid produced by thermal decomposition of polyester). In many cases, however, when the gaseous product is cooled, crystals of the oxygen-containing compound are precipitated, causing troubles such as blocking the piping. In the present invention, since the liquid pyrolysis oil is added directly to the gaseous matter, the inner wall surface of the pipe is washed with the liquid pyrolysis oil, and the occurrence of trouble of the pipe clogging due to crystal adhesion to the inner wall surface is effectively prevented. The
[0023]
Furthermore, in the case of the present invention, the raw material to be supplied to the catalytic reformer is not a gaseous product from the thermal decomposition tank, but NH obtained from a gas-liquid separator. ₃ In addition, since it is a pyrolysis oil from which reactive gases serving as catalyst poisons such as HCN and HCl have been removed, it is possible to effectively prevent the catalyst from being deteriorated in catalytic reforming. In addition, the catalytic reforming in the present invention is advantageously performed under conditions where the pyrolysis oil exhibits a liquid phase or a gas-liquid mixed phase. Therefore, since the outer surface of the catalyst is always washed with the liquid cracked oil, troubles of clogging of the catalyst packed bed can be prevented even during long-time operation. Moreover, in the case of the present invention, as described above, the pyrolysis oil is supplied to the catalytic reformer in a liquid phase or gas-liquid mixed phase state without being substantially converted into high-temperature steam, so that energy saving is achieved. This is also very advantageous.
[0024]
In the present invention, the liquid material separated by the gas-liquid separator is preferably separated into a light component and a heavy component having a higher specific gravity by specific gravity difference separation. The liquid material separated by the gas-liquid separator contains not only hydrocarbon oil but also oxygen-containing compounds and nitrogen-containing compounds derived from polymers other than hydrocarbon polymers. Such compounds are carbonized. Since hydrogen oil has poor compatibility, when it is left standing and separated by specific gravity difference, it is separated into a lower layer as a heavy component, while hydrocarbon oil is separated into an upper layer as a light component. In this case, the heavy component in the lower layer is composed of an oxygen-containing compound or a nitrogen-containing compound, or a mixture (slurry liquid) of these oxygen-containing compound or nitrogen-containing compound crystals and a hydrocarbon oil. Such heavy components are separated from the hydrocarbon oil, which is a light component, and discharged out of the system.
[0025]
In order to separate the liquid material separated by the gas-liquid separator into the light component and the heavy component, the liquid material can be taken out of the tank and used in a stationary tank. Perform in the device. FIG. 2 shows a structural explanatory diagram of an example of a gas-liquid separator having a function of separating a specific gravity difference of a liquid material.
In FIG. 2, 25 is a gas-liquid separator, 26 is a partition plate, 27 is a guide plate, 28 is a liquid dispersion means, 29 is a pump, 30 is a cooler, and 37 is a gas dispersion means.
[0026]
The gas-liquid separation device 25 as a whole consists of a sealed tank (container), and a partition plate 26 extending upward from the bottom plate is erected at the lower part, and the lower part of the tank is partitioned into a first chamber a and a second chamber b. Yes. A guide plate 27 is disposed above the partition plate 26 at a distance from the upper end thereof. The guide plate 27 is inclined downward in the direction of the first chamber a, the tip thereof is located above the first chamber a, and a liquid material (from the liquid dispersion means 28) that flows down from the upper part in the gas-liquid separator. The dispersed liquid and the condensate of pyrolysis oil vapor from the gaseous matter rising in the apparatus) are guided to the first chamber a. This guide plate 27 is not necessarily required, and its installation can be omitted. A liquid dispersion means 28 is disposed above the gas-liquid separator 25. This liquid dispersion means can be a liquid spray nozzle or the like. Although this liquid dispersion | distribution means is for condensing the pyrolysis oil vapor | steam contained in the gaseous substance which raises the inside of an apparatus, it is not necessarily required and the installation can be abbreviate | omitted.
Gas dispersion means 37 is disposed in the second chamber b. The gas dispersion means 37 can be a gas spray nozzle or the like, and is connected to the line 19 shown in FIG.
[0027]
In order to gas-liquid separate the cooling condensate passing through the line 14 in FIG. 1 using the gas-liquid separation device 25 shown in FIG. 2, this cooling condensate is separated from the line 31 (corresponding to the line 14). 25 is introduced into the first chamber a and accommodated therein. The cooling condensate accommodated in the first chamber a is gas-liquid separated here, and the gaseous matter rises in the apparatus. In the liquid material stored in the first chamber a, the light component forms an upper layer due to the specific gravity difference separation, and the upper layer light component overflows from the upper end of the partition plate 26 to the second chamber b, and the second chamber b. Is housed in. 1 is introduced into the gas dispersion means 37 in the second chamber b through the line 36, and is jetted into the liquid from the line 36. The non-condensable gas dissolved in the gas is evaporated (stripping). The heavy components forming the lower layer of the first chamber a are discharged out of the system through the line 32, and the light components accommodated in the second chamber b are discharged through the line 33.
[0028]
A part of the light component (hydrocarbon oil) discharged through the line 33 is circulated to the liquid dispersion means 28 via the pump 29 and the cooler 30, and from there, is dispersed in the gaseous matter rising in the apparatus. Thereby, the vapor | steam of the pyrolysis oil contained in a gaseous substance is condensed, This condensate is guided by the guide plate 27, and flows down in the 1st chamber a. The gaseous matter containing non-condensable gas is discharged to the outside through the line 34.
A portion of the cooled hydrocarbon oil passing through line 38 is sent through line 39 to cooling condenser 5 shown in FIG.
A part of the hydrocarbon oil discharged through the lines 33 and 35 is sent to the heating furnace 3 shown in FIG. 1, and the remaining part is sent to the catalytic reformer 4 shown in FIG.
[0029]
The gas-liquid separation in the present invention can be advantageously performed using a plurality of gas-liquid separation devices. FIG. 3 shows an example of a flow sheet when gas-liquid separation is performed using two gas-liquid separators.
In FIG. 3, 25 and 125 indicate gas-liquid separators, 26 and 126 are partition plates, 27 and 127 are guide plates, 28 and 128 are liquid dispersion means, 29 and 129 are pumps, 30 and 130 are coolers, Reference numerals 37 and 137 denote gas dispersion means.
In order to gas-liquid-separate a gas-liquid mixture using the gas-liquid separator system shown in FIG. 3, first, the gas-liquid mixture is introduced into the first gas-liquid separator 25 through a line 31, and FIG. Gas-liquid separation is performed in the same manner as described above. From the upper part of the first gas-liquid separator 25, a gaseous substance composed of non-condensable gas and pyrolysis oil vapor is discharged through a line 113. The cooled hydrocarbon oil introduced therethrough is added and mixed, whereby at least a part, preferably all, of the pyrolysis oil contained in the gaseous substance is cooled and condensed.
From the lower part of the first gas-liquid separator, the liquid material (hydrocarbon oil) in the second chamber b is discharged via lines 33 and 35, and part of the liquid is discharged to the heating furnace 3 shown in FIG. The remainder is sent to the catalytic reforming apparatus 4 shown in FIG. 1 through the line 38 and the line 117.
[0030]
The gas-liquid mixture from the cooling condenser 105 is introduced into the second gas-liquid separator 125 through the line 131 and is separated from the gas-liquid as in the case of the first gas-liquid separator 25.
[0031]
The non-condensable gas is discharged from the upper part of the second gas-liquid separator 125 through the line 134, and the heavy components in the first chamber a are discharged from the lower part through the line 132. The light components in the second chamber b are discharged through 133. A part of the light components discharged through the line 133 passes through the pump 129, is cooled through the cooler 130, and a part thereof is sent to the liquid dispersing means 128, from which it rises in the apparatus. It is ejected in the form of a mist toward the gaseous substance, while the remainder is sent to the cooling condenser 105 through the line 116.
The temperature of the liquid (liquid hydrocarbon oil) sent to the cooling condenser 105 through the line 116 is at least 50 ° C. lower than the temperature of the gaseous product introduced into the cooling condenser 105 through the line 113; The temperature is preferably about 100 to 250 ° C., more preferably about 100 to 150 ° C.
[0032]
The hydrocarbon oil discharged through the lines 133 and 135 is sent to the catalytic reformer 4 shown in FIG. 1 through the line 117 together with the hydrocarbon oil from the line 38. Used as
[0033]
FIG. 4 shows an example of a flow sheet when the polymer waste is oiled.
In FIG. 4, 201 is a thermal decomposition tank, 202 is a first gas-liquid separator, 203 is a second gas-liquid separator, 204 heating furnace, 205 is a catalytic reformer, 206 is a dechlorination tank, and 207 is hydrogen chloride. The removal device is shown.
In FIG. 4, the polymer waste is made into a melt according to a conventionally known method, and then introduced into the dechlorination tank 206 through a line 225, where the chlorine-containing polymer is pyrolyzed at 300 to 350 ° C. to form The hydrogen chloride gas thus passed through 226 is introduced into the hydrogen chloride removing device 207.
The hydrogen chloride removing device 207 is filled with a filler (Raschig ring, metal piece, ceramic ball, etc.) to form a filling tank 219. Alkaline water is introduced into the upper portion of the apparatus through a line 256, and the alkaline water flows down in the packed bed 219. On the other hand, a gas containing hydrogen chloride passing through the line 226 is introduced into the lower part of the apparatus, and then rises in the apparatus and comes into contact with the alkaline water. The hydrogen chloride is captured by the alkaline water and separated from the gas. Alkaline water that has captured hydrogen chloride is discharged through line 257. As alkaline water, NaOH, NaCO ₃ , Ca (OH) ₂ , CaCO ₃ An aqueous solution containing a hydroxide or carbonate of an alkali metal such as alkaline earth metal or the like is used.
[0034]
The melt after the dechlorination treatment is introduced into the thermal decomposition tank 201 through a line 227, where it is thermally decomposed at a temperature of 350 to 550 ° C. The pyrolysis oil and non-condensable gas generated by this pyrolysis are discharged as gaseous substances from the top of the pyrolysis tank through line 228, while the pyrolysis residue is discharged through line 229. The amount of heat required for the thermal decomposition of the molten liquid is obtained by heating and vaporizing the pyrolysis oil discharged from the second chamber b of the gas-liquid separator 202 at the subsequent stage through the line 236 through the heating coil 220 in the heating furnace 204. The high temperature steam obtained is supplied by blowing it into the melt.
[0035]
Gaseous product discharged from the pyrolysis tank through the line 228 is mixed with pyrolysis oil discharged from the second chamber b of the gas-liquid separator 202 through the line 230 and cooled by the cooler 213. Let Thereby, a part of pyrolysis oil vapor | steam contained in a gaseous product is cooled and condensed, and a gas-liquid liquid mixture is formed.
The cooling condensation temperature in the first cooling condensation is 200 to 350 ° C., preferably 250 to 300 ° C. By setting the condensation temperature in this manner, a compound that is easily crystallized (for example, terephthalic acid) contained in the gaseous product can be precipitated as crystals. The gas-liquid mixture containing the crystal is introduced into the first chamber a of the gas-liquid separator 202 through the line 233.
[0036]
The gas-liquid mixture containing the crystals introduced into the first chamber a is gas-liquid separated in the first chamber a, and the gaseous matter separated from the liquid rises in the apparatus. On the other hand, in the liquid after separation of the gaseous matter, the slurry liquid composed of pyrolysis oil containing crystals forms a lower layer as a heavy component, and the pyrolysis oil not containing crystals forms an upper layer as a light component. The pyrolysis oil forming the upper layer overflows from the upper end of the partition plate 211 into the second chamber b and is accommodated in the second chamber b.
[0037]
The slurry liquid containing crystals forming the lower layer in the first chamber a is discharged out of the system through the line 234. On the other hand, a part of the pyrolyzed oil not containing crystals in the second chamber b is extracted through the line 230 and cooled by the cooler 213, and then a part of the pyrolyzed oil passes through the line 232 in the line 228. The remainder is supplied to the upper surface of the packed bed 212 formed on the upper part of the gas-liquid separator 202 through the line 231. The pyrolysis oil supplied to the upper surface of the packed bed 212 flows down in the packed bed 212 and comes into contact with the gaseous matter rising in the apparatus, and a part of the pyrolyzed oil vapor contained in the gaseous matter is Cooled and condensed. Uncondensed gaseous matter is discharged through line 240.
[0038]
Part of the light oil separated by the second gas-liquid separator 203 is mixed into the gaseous matter discharged through the line 240 through the line 244, and this mixture is cooled by the cooler 214. The cooling temperature in this case is 20 to 60 ° C., preferably 30 to 40 ° C. By this cooling, the pyrolysis oil vapor contained in the gaseous substance is condensed, and a gas-liquid mixture composed of the pyrolysis oil and the non-condensable gas is generated. This mixture is introduced into the second gas-liquid separator 203 where it is gas-liquid separated, and the separated non-condensable gas is discharged through a line 242.
The gaseous matter discharged from the line 242 is introduced into an incinerator (not shown) where it is incinerated at a high temperature of 1000 ° C. or higher. The incineration gas is washed with alkaline water and then released into the atmosphere.
The pyrolysis oil discharged from the second gas-liquid separator 203 through the line 243 and the line 245 is stored in the tank as a light product oil.
[0039]
A part of the heat separation oil in the second chamber b of the gas-liquid separator 202 is discharged through the line 236, and a part thereof enters the heating furnace through the line 237, where it is heated to 250 to 400 ° C. After that, it is introduced into the catalytic reformer 205 through the line 238, while part of it flows through the heating coil 220, where it is at least 50 ° C. higher than the melt temperature in the pyrolysis tank 201, usually It is heated to 450 to 550 ° C. and blown into the melt in the pyrolysis tank through line 239 in the state of high-temperature steam.
[0040]
The pyrolysis oil introduced into the catalytic reformer 205 is catalytically reformed at a temperature of 250 to 400 ° C. under pressure conditions in which the pyrolysis oil exhibits a liquid phase or a gas-liquid mixed phase. The oil is discharged through a line 249, cooled to 60 ° C. or lower, usually 30 to 40 ° C. by a cooler 216, and stored in a tank as a product reforming oil.
[0041]
The boiling point range of the product-modified oil obtained as described above is usually 40 to 400 ° C., preferably 40 to 350 ° C., and the boiling point range of the product light oil is usually 10 to 350 ° C.
[0042]
【Example】
Next, the present invention will be described in more detail with reference to examples.
[0043]
Example 1
The polymer waste was oiled according to the flow sheet shown in FIG. In this case, the polymer waste includes 29% by weight of polyethylene, 16% by weight of polypropylene, 25% by weight of polystyrene, 15% by weight of polyvinyl chloride resin, 5% by weight of polyethylene terephthalate, acrylonitrile / butadiene / styrene copolymer (ABS resin). ) A mixture of 10% by weight was used.
[0044]
The main operating conditions in this embodiment are shown below in relation to the apparatus and line shown in FIG.
(1) Line 225
Melt
Temperature: 320 ° C
Flow rate: 7kg / hr
(2) Dechlorination tank 206
Melt
Temperature: 310 ° C
Residence time: 30 minutes
Dechlorination rate: 90% by weight
(3) Pyrolysis tank 201
Melt
Temperature: 410 ° C
Residence time: 4 hours
(4) Line 239
Circulating pyrolysis oil
Temperature: 450 ° C
Flow rate: 65kg / hr
(5) Line 229
Thermal decomposition residue
Flow rate: 1.4kg / hr
(6) Line 233
Gas-liquid mixture
Temperature: 220 ° C
Flow rate: 70kg / hr
(7) Line 234
Solid content (slurry liquid containing terephthalic acid)
Temperature: 220 ° C
(8) Line 230
Circulating pyrolysis oil
Temperature: 200-220 ° C
Flow rate: 65kg / hr
(9) Line 231
Circulating pyrolysis oil
Temperature: 150 ° C
(10) Line 236
Circulating pyrolysis oil
Temperature: 200-220 ° C
(11) Contact reformer 205
(1) Pyrolysis oil
Temperature: 250 ° C
Pressure: 0.05kg / cm ² G
Flow rate: 1.8kg / hr
(2) Catalyst: Synthetic zeolite
(12) Line 240
Gaseous matter
Temperature: 160 ° C
Flow rate: 3kg / hr
(13) Line 241
Gas-liquid mixture
Temperature: 40 ° C
Flow rate: 13kg / hr
(14) Line 245
Light oil
Temperature: 40 ° C
Flow rate: 2.7 kg / hr
(15) Line 242
Non-condensable gas
Temperature: 40 ° C
Flow rate: 0.6kg / hr
(16) Line 250
Reformed oil
Temperature: 40 ° C
Flow rate: 1.8kg / hr
[0045]
Next, Table 1 shows the properties of pyrolysis oil, light oil and reformed oil.
[0046]
[Table 1]

[0047]
Next, Table 2 shows the distillation properties (° C.) of the pyrolysis oil, light oil and reformed oil.
[0048]
[Table 2]

[0049]
【The invention's effect】
According to the method of the present invention, it is possible to economically and efficiently produce a polymer waste, in particular, a mixed polymer waste that has been difficult to treat conventionally, as a raw material, and an oil useful as a fuel oil or the like. .
[Brief description of the drawings]
FIG. 1 shows a flow sheet for the basic process of the present invention.
FIG. 2 is an explanatory structural diagram of an example of a gas-liquid separator having a specific gravity difference separation function.
FIG. 3 shows a flow sheet for performing gas-liquid separation using two gas-liquid separators.
FIG. 4 shows an example of a flow sheet when oily treatment of polymer waste is performed.
[Explanation of symbols]
1,201 Pyrolysis tank
2, 25, 125, 202, 203 Gas-liquid separator
3,204 Heating furnace
4,205 catalytic reformer
206 Dechlorination tank

Claims (10)

In a method for oil-treating polymer waste,
(I) a thermal decomposition step of heating and decomposing the polymer waste melt,
(Ii) a condensation step of cooling the gaseous product obtained in the pyrolysis step and condensing at least a part of the pyrolysis oil vapor contained in the gaseous product;
(Iii) a gas-liquid separation step of separating the condensate obtained in the condensation step into a gaseous product and a liquid product;
(Iv) A vaporization step in which a part of the liquid material obtained in the gas-liquid separation step is heated and converted into high-temperature steam,
(V) a high-temperature steam circulation step for circulating the high-temperature steam obtained in the vaporization step to the thermal decomposition step;
(Vi) a high-temperature vapor dispersion step of dispersing the high-temperature vapor circulated to the thermal decomposition step in the polymer waste melt;
A part of the liquid material obtained in the gas-liquid separation step is added to the gaseous product in the condensation step or the gaseous product sent to the condensation step. Oiling method. The polymer waste melt is sent to the dechlorination treatment process, where it is held at 300 to 350 ° C. for 5 to 60 minutes to remove chlorine in the chlorinated polymer as hydrogen chloride, and then supplied to the thermal decomposition process. The method of claim 1. The method according to claim 1 or 2, wherein a part of the liquid material obtained in the gas-liquid separation step is sent to the catalytic reforming step and contacted with the solid acid catalyst in a liquid phase or gas-liquid mixed phase. The gas-liquid separation step comprises a plurality of gas-liquid separation steps, and after cooling a part of the liquid material obtained in the subsequent gas-liquid separation step to the gaseous material obtained in the preceding gas-liquid separation step Addition and condensation of at least part of the pyrolysis oil vapor contained in the gaseous matter, and the resulting condensate is sent to a subsequent gas-liquid separation step for gas-liquid separation. Method. The method according to any one of claims 1 to 4, wherein the liquid material obtained in the gas-liquid separation step is separated into a light component having a low specific gravity and a heavy component having a higher specific gravity in the specific gravity difference separation step. In order to perform the gas-liquid separation of the condensate in the gas-liquid separation step and the specific gravity difference separation of the liquid material in the specific gravity difference separation step with the same device, the lower part of the device is separated from the first chamber a by a partition plate extending upward from the bottom surface. Using a gas-liquid separator having a structure partitioned from the second chamber b, the condensate is introduced into the first chamber a of the gas-liquid separator, and the upper liquid in the first chamber a The method in any one of Claims 1-5 made to overflow in the 2nd chamber b from. The method according to claim 3 or 6, wherein a part of the liquid in the second chamber b is sent to the vaporization step and the catalytic reforming step. The method in any one of Claims 1-7 which cools the gaseous product in this condensation process in piping. A part of the high-temperature steam obtained in the vaporization step is dispersed in the liquid material obtained in the gas-liquid separation step, and the non-condensable gas contained in the liquid material is removed by transpiration. Either way. A part of the liquid material obtained in the gas-liquid separation step is cooled and brought into contact with the gaseous material obtained in the gas-liquid separation step, so that at least one of the pyrolysis oil contained in the gaseous material. The method in any one of Claims 1-9 which condense a part.

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