DE2415412A1 - METHOD AND DEVICE FOR TREATMENT OF HIGH MOLECULAR HYDROCARBONATES OR ALTOELE - Google Patents

Description

Notifier; SUMITOMO SHIPBUILDING & MACHINERY CO. LTD. No. 2-1, Ohte-maehi 2-chome »Chiyoda-ku, Tokyo, Japan

Method and device for the treatment of wt hochmolekularey HydrocarbonateyT or Altölej f

The invention relates to a method and an apparatus for treating high molecular weight hydrogen carbonates, typically Plastic waste or used oils with a high water content.

With the recent increase in the use of plastics for packaging or containers, the question of the disposal of plastic waste has become a matter of public concern .

Processes based on thermal cracking are generally known for treating waste materials of this type. For this purpose, three methods are applicable, namely, a method of thermal cracking by direct melting of waste plastics, a process for thermal cracking after dissolving the waste plastic in a suitable Heating Solvent and a Process for Immediate Thermal Cracking of Waste Plastics in a fluid bed. The first two methods mentioned

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are, however, connected with the still technically unsolved problem that the efficiency of the heat transfer is very low, that coal or coke is deposited on the heating surfaces and that intensive circulation is necessary. Therefore, the current focus is particularly on a process by burning or charring the plastics themselves using a pleated bed. A fluidized bed thermal cracking apparatus has the advantage that it is easy to operate and is cost-saving compared to an externally heated thermal cracking apparatus. On the other hand, such a device has the disadvantage that the residence time of the plastics in the fluidized bed is comparatively short, so that they cannot always be cracked satisfactorily. In the case of recovery of oil by direct introduction of a received from a fluidized bed thermal cracking product into a known condenser, the recovered oil thus contains a relatively large proportion with it mixed heavy components, thereby making it impossible ₉ a recovered oil higher to achieve quality This phenomenon occurs particularly in the treatment of polyethylene. In the case of polyvinyl chloride waste, the thermal cracking product contains hydrogen chloride (HCl) with carbon and heavy metals; there is a danger that these materials check _s üokgewonnsnönöl r-mix with the Bisher- * "was a large

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Part of those used in gas stations, automobile repair shops, ironworks, iron rolling mills, petrochemical factories etc. accumulating waste oils destroyed by incineration. Since the disposal of waste oils by incineration with Soot and smoke formation and other environmental nuisances is, various methods for recovering fuel oil or the like are recently from such waste oils by chemical treatment of the same has been proposed. All previously proposed procedures however, require complicated pretreatment; they are still not suitable, high quality oils in one to provide the degree of complexity of the process, so that it is economical from the standpoint processing of waste oil are not satisfactory. Currently, the amount of waste oils produced is annually estimated at more than 5 million tons in Japan; this amount will increase in the future. With regard to this issue is currently looked forward with interest to the development of a process suitable for the recovery of heating oils from oils of poor quality, such as waste oils, by chemically refining them, is suitable without disturbing the environment to cause.

The invention is therefore based on the object of a method and to provide an apparatus for treating high molecular weight hydrocarbonates such as those caused by plastic waste

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or waste oils are formed. According to the invention, these substances, which may contain water or sludge, are one Fluidized bed cracking furnace fed to be thermally cracked therein to become. The resulting thermal cracking product is then introduced into a fractionation tower (distillation column), in which it is divided into a light component that rises towards the top of the tower and one that sinks to the bottom heavy component is fractionated. The light component is then cooled so that it is in a vapor phase and a liquid phase is divided, the latter of which is recovered as the oil treated according to the present invention.

In a modified embodiment of the invention, the separated, the heavy components sinking to the bottom of the tower are thermally cracked again. This is the heat of combustion the vapor phase separated from the light component is used as a heat source. With renewed thermal Cracking the heavy component is desirable to remove the carbonaceous substances contained therein beforehand. The heavy component, however, is always so viscous that it is difficult to get carbons and other solids through Separate filtration therefrom. As a result, in a further modification of the invention, the heavy component to a separating zone kept at an elevated temperature and packed with refractory, inorganic particles.

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leads in which the vaporizable substances of the heavy component evaporated and the non-evaporable substances in the The vaginal zone can be left behind. In this embodiment, the separation zone by supplying an oxygen-containing Gas to the separating zone containing the non-evaporable substances are regenerated by these substances be oxidized.

In a further embodiment of the invention, the Plüssigphase, which was obtained by separating the vapor phase from the light top fraction in the tower, with stirring mixed with water. The mixture is then allowed to settle. This embodiment is particularly applicable if the liquid phase contains water-soluble substances; relocate the water-soluble substances contained in the liquid phase into the water phase formed on settling.

In the following, preferred exemplary embodiments of the invention are explained with reference to the accompanying drawings. It demonstrate:

Pig. 1 shows a schematic representation of an embodiment a device for carrying out the method according to the invention for the treatment of plastic waste or waste oils;

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Pig. 2 a schematic representation of a process sequence, in which the heavy component separated in a praction tower and sinking to the tower floor again is thermally cracked, with the heavy component after the liberation of carbonaceous materials by filtration for further thermal cracking by burning gas from the vapor phase of the light Head fraction is heated; .

Fig. 3 is a schematic representation of a process sequence in which the separation of carbonaceous materials is conducted from the heavy component by using refractory inorganic particles _s, and

Fig. 4 mixed a schematic representation of another process sequence, wherein the liquid phase of the light overhead fraction under stirring with water and then protrudes _s to thereby off the remaining liquid phase in the water-soluble substances, zutrennen.

According to Figure 1 the plastic chunks in a mill or a crusher 1 and are inputted into pieces having an edge length of about 20 mm crushed _s which then su with a conveyor 2 to a feeder 3 are transferred. At the dar-

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The embodiment provided is a screw feeder as the feeder 3 used. The plastic fed into a plied bed cracking furnace 4 through the feeder 3 is supported Air supplied via a fan 5 self-ignites and at a temperature in the range of 45o-55o C. thermally cracked. The gas produced in the cracking furnace 4 is freed from carbon and the like in a cyclone separator 6, the pesticides collected by the cyclone separator 6 can be received by a carbon storage container 7. The gas produced during cracking is then Introduced into the middle part of a parliamentary group tower 8, in which the heavy component consisting of high-boiling fractions is separated, whereby it sinks to the bottom. That Cracked product completely freed from the high-boiling fractions ■ becomes a condenser from the top of the tower transferred and cooled in this to a temperature lying only slightly above the dew point of water, with the kerosene and / or fractions corresponding to heavy oils are condensed. The condensed fractions are in a gas / Liquid separator Io separated from the vapor phase component. A part of the separated oil is returned as reflux to the top of the tower 8 by means of a pump 11, while the remainder as thermally cracked oil in an oil container 12 is recovered.

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The aforementioned vapor phase component, the low-boiling one Fractions containing water, HCl or sulfuric acid gas or the like is made by combustion in a gas burner 13 destroyed. The exhaust gas flowing out of the gas burner 13 is directed to a stripper 14, wherein the hydrogen chloride and the sulfuric acid gas contained in the exhaust gas are absorbed by water are introduced into the extraction device by means of a pump 16 and discharged to an acid storage container 15 will. The resulting, HCl-free exhaust gas is released into the air via a chimney 17.

In a similar way, waste oils can be treated or processed with the aid of the device according to FIG. 1 as follows: The oil initially stored in a waste oil container (not shown) is fed to the fluidized bed cracking furnace by a pump 4 fed in. In this case, a stirrer and a heating device are preferably arranged in the waste oil container to the to uniformly disperse water and / or sludge parts contained in the oil in advance. While an essentially made of quartz sand with a mean grain size of about 200 u existing fluid medium at a temperature of 400 - 500 ° C within the fluidized bed cracking furnace 4 with the help of through the Fan 5 supplied air or hot blast is kept constantly in a flowing state, it is fed to the furnace

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Thermally cracked waste oil. The resulting cracked product is removed as a vaporous distillate from the top of the furnace deducted. The distillate coming from the cracking furnace is passed through the cyclone separator 6 into the lower part of the fractionation tower 8 introduced and here in a heavy component and a light component containing bitumen, carbon, sand and the like separated. The heavy component is on the tower. collected at the bottom, while the light components are discharged overhead, sent through the condenser 9 and then transferred to the gas / liquid separator 10. In the latter will a refined oil separated from the vapor phase component. A portion of this oil is refluxed to the top of the fractionation tower recycled, while the rest in the refining oil tank 12 is recovered.

The separated heavy component sinking to the bottom of the tower 8 can be returned to the cracking furnace 4 if required. The vapor phase component obtained by the gas / liquid separator is burned in the gas burner 13 and then via the stripper 14 and the forge 17, in the same way as before, discharged from the system.

In this treatment method, a heating oil can do better Quality corresponding to the intermediate fraction between kerosene and heavy oil Α with a yield of 50-80% by weight by thermal cracking from water and / or sludge

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- ίο -

Low quality oil can be obtained without pretreating the oil must become. According to the invention, it is possible to use a used oil with a black-brown color that has a viscosity of 57 cP (at 10 ° C), a specific gravity of 0.88 and a 90 # distillation point of 385 ° C '' a brown, transparent oil with a viscosity of 7 cP, a specific gravity of 0.86 and a 90 # Refine distillation point at 357 C. In addition, a certain amount of desulfurization can also be achieved in the process according to the invention to be expected. For example, treating a waste oil with $ 0.6 sulfur makes a refined oil with Get a sulfur content of $ 0.48.

The heavy component contained in the thermal cracking product of waste plastic is usually cracked again (about 2 hours at a temperature of more than 400 ° C). The yield of recovered oil can also be increased by thermally cracking the heavy component again will. Figure 2 shows an example of this method. Here, the separated and collected at the bottom of the tower 8 Heavy component to remove the carbonaceous substances sent through a filter 21 and then fed into a heat exchanger 23 via a pump. In this heat exchanger 23 the Scliwex 'component is thermally cracked.

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The heat exchanger is powered by exhaust gas from the gas burner 13 heated. The cracked products of the component are returned to the compression tower. The light component of Craek's product goes as part of the heads fraction in the tower into the condenser 9.

Figure 3 illustrates a method for performing the removal of carbonaceous materials and the thermal cracking in a single device without the need for special equipment to remove the carbonized matter in the heavy component during renewed thermal cracking the heavy component is used in the manner previously explained will. FIG. 3 shows an operating mode in which two fluidized beds packed with refractory, inorganic particles can be used so that one bed regenerates

while the other is driven for deposition and thermal cracking. However, it is in accordance with the invention also possible to use more than two fluid beds.

According to FIG. 3, the heavy component exiting at the bottom of the fractionating tower is conveyed to the with via a line 31 refractory, inorganic particles packed fluidized bed (fluidized bed) 33 transferred. Here, a valve 32 opened and a valve 32 * closed. The fluidized bed 33 is in one with a further fluidized bed 33 ' Chamber 34, into which the gas delivered by the gas burner 13

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combustion gas, usually at a temperature of 800-1000 ° C, is introduced by which the fluidized beds 33 and 33 'are heated to a temperature of about 400 ° C or higher. As a result, the vaporizable and crackable substances contained in the heavy component flowing into the fluidized bed 33 are vaporized and cracked in the fluidized bed; the light component obtained is recycled through the line 36 via a valve 35 at the same time the valve is closed for 35 ^s fractionation. 8

The non-evaporable substances contained in the heavy component remain, namely carbon-containing materials and other contaminants, on or between the particles in the fluidized bed 33, so that they can be evaporated from the and / or crackable substances are separated. When the fluidized bed 33 is completely with non-evaporable Substances has been enriched and it is no longer able to absorb any further substances of this type, the valves become 32, 35 closed and the valves 32 'and 35 * opened, so that the flow of the heavy component now to the fluidized bed 33 * is directed, in which the same working method is carried out. During the operation of the fluidized bed 33 ', the fluidized bed 33 is regenerated. More precisely, it by supplying air from the fan 37 to the fluidized bed 33 after the valves 38 'and 39' have been closed, they are not vaporizable substances burned. By keeping the air

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sam is fed in, the formation of dust can be reduced to a minimum. That when burning the The gas produced by non-evaporable substances is introduced into a line 40 via a valve 39 and a gas extraction and cleaning device 41 supplied. Because this combustion gas by contacting with by a pump

43 cleaned in the pulling device 4l circulated water , even if this gas contains vaporous cadmium and / or lead, these metals will settle in a waste water tank 42 from, so that they in no way to the air will be released. Since the gas produced during combustion after the cleaning described above still contains carbon monoxide, it can be removed via a pipe

44 are fed to the gas burner 13. In this way, the regeneration of the plied bed 33 is achieved. The fluid bed 33 'can be regenerated in the same way by switching the valves accordingly. As in that at least illustrates the flow diagram according to FIG. 3 using two plied beds, the treatment of the heavy component and the regeneration of the fluidized bed take place simultaneously and one after the other.

When using the procedure according to Figure 3, it is possible not only carbon and others in the heavy component to separate contained impurities without the aid of a special filtration device, but also to remove the heavy

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component to crack again in this separation. Because here "the carbon and others separated from the heavy component Impurities can be burned in the fluidized bed, there is no risk of significant coking is caused in the fluidized bed. As a result of the refractory, inorganic particles packed in the fluidized bed the fluidized bed has a high heat capacity. This thus offers the advantage that the combustion of the carbon can easily be carried out at the time of the regeneration of the fluidized bed and the resulting heat can be stored until the next separation operation. Even if the heavy component contains heavy metals, such as cadmium and lead, these will go along with the carbon and others Impurities in the fluidized bed are separated out on this Heavy metals that have been separated off are evaporated during the regeneration of the fluidized bed and can be passed through a downstream Strippers are caught so they are not in danger represent for an environmental pollution.

Figure 4 is a schematic representation of a plant which is used for cleaning by washing a liquid phase supplied by the gas / liquid separator 10 according to FIG. In the embodiment shown, the cleaning device has a washing container 51 and a settling container on. A part of the outflow from the separator 10 according to FIG.

4ft flft ί 1 ί ft BO 1

the liquid phase is returned as reflux to the top of the fractionation tower 8 in the manner previously described, while the remainder is transferred to the washing container 51 and is mixed with water therein with stirring. Afterward the resulting oil / water mixture is introduced into the settling tank 52, in which it is in oil (above) and water (below) separates. While the liquid phase coming from the separator 10 follows the above-described mixing and the settling process is subjected, the substances contained in the liquid phase, such as water-soluble substances, are displaced HCl, organic acids, organic oxides, etc. into the water phase. In general, the appropriate volume ratio of oil to water is that in the washing treatment according to the invention should be applied at 1: 1 or higher, preferably at 1: 2 (or higher). By having such a volume The washing treatment carried out in the ratio of oil to water can change the color tone, smell, etc. of the recovered oil is considerable be improved. When comparing the properties of a recovered oil that has undergone a washing treatment Preparation of the volume ratio of oil to water to 1: 2 was subjected with the same oil before the washing treatment, the results listed in the table below were achieved:

Color Odor pH

"Vo τ * Α pt *

black pungent odor 2-3

treatment

Visible odor after brownish-penetrating treatment

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The separated oil, which forms the upper layer in the settling tank 52, is transferred to the oil tank 12 according to FIG. during the water phase, the water-soluble ones xirelche Contains substances from the bottom of the sedimentation tank 52 as waste water is discharged. This waste water can be used to flush or sprinkle the combustion gas emerging from the gas burner 13 to be used.

As can be seen from the foregoing description, the invention compares the recovery of oils high quality from waste plastics or used oils. Especially when treating those containing chlorine The recovered oils obtained from plastics are free of hydrogen chloride and / or heavy metals.

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Claims (1)

1. Process for the treatment of high molecular weight hydrocarbonates or waste oils, characterized in that the hydrocarbonates or waste oils are stored in a fluidized bed cracking furnace be thermally cracked, that the resulting thermal cracking product into a light component and a heavy component is separated so that the light component is cooled for splitting into a vapor phase and a liquid phase is that the vapor phase is subjected to combustion and the resulting combustion gas after washing with Water is discharged, and that oils are comparatively from the liquid phase high quality can be recovered. 2. The method according to claim 1, characterized in that plastic waste is used as the high molecular weight hydrocarbonate will. 3. The method according to claim 1, characterized in that the heavy component utilizing the heat of combustion of the Vapor phase stream is thermally cracked again. k. Process according to Claim 3, characterized in that the heavy component is thermally cracked by being brought into contact with at least one fluidized bed (33, 33 ') which 409841/0827 is equipped with refractory, inorganic particles heated by the combustion of the vapor phase, while the Product from the thermal cracking in vapor phase is discharged from the fluidized bed and that remaining in the fluidized bed Is oxidized residue with regeneration of the fluidized bed. 5. The method according to claim 3, characterized in that the heavy component for the renewed thermal cracking Removal of the carbonaceous substances it contains is filtered. 6. The method according to claim 1, characterized in that the liquid phase is intimately mixed with water and then left to stand so that the contained in the liquid phase water-soluble substances can migrate into the water. 7 Device for the treatment of high molecular weight hydrocarbonates or waste oils, characterized by a fluidized bed cracking furnace (4) for thermal cracking of the hydrocarbonates or waste oils, a fractionation tower (8) for separating the cracked product emerging from the cracking furnace into a light and a heavy component , a separator (10) for separating the light component emerging from the fractionation tower (8) into a vapor phase and a liquid phase, a device (11) for returning part of the liquid phase to the top 409841/0827 of the fractionation tower and for the recovery of the remainder thereof, a combustion device (13) for the combustion of the steam ' phase and a stripping column (14) for cleaning the exhaust gas emerging from the combustion device (13). 8. The device according to claim 7> characterized by a piltration device (21) for separating the carbonaceous material from the heavy component emerging from the fractionation tower and a heat exchanger (23) which is heated by the exhaust gas emerging from the combustion device. 9. Apparatus according to claim 7, characterized by one or several fluid beds (33 »33 *), which are equipped with a refractory, inorganic material are packed, and in which the heavy component is thermally cracked, the cracking product is removed by evaporation, while the carbonaceous substances contained in the heavy component are retained and a device for heating the fluidized beds by utilizing the exhaust gas supplied by the combustion device. 10. The device according to claim 7, characterized by a washing container (Io) for mixing the liquid phase (reduced by the reflux to the top of the distillation column) while stirring Water, and through a sedimentation tank to separate the from Wash tank supplied oil / water mixture in water and oil by letting the mixture stand. 409841/0827