JPH10237461A - Waste plastic oil treatment - Google Patents

Abstract

(57) [Problem] To provide a waste plastic oil treatment method in which waste plastic oil treatment equipment can be significantly simplified, the operation is simple, and the equipment has high stability. SOLUTION: A single treatment tank 13 is formed by combining waste plastic with a heavy oil component produced by oil-treating waste plastic.
After that, the waste plastic and the heavy oil produced are heated and mixed in the treatment tank 13 while sequentially changing the heating temperature and the heating time, and a dehydration / drying step 40, a dechlorination step 41, Pyrolysis / oiling step 42 and residue discharging step 43
And try to do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for converting waste plastics to oil, which can produce low-boiling hydrocarbon oils from waste plastics.

[0002]

2. Description of the Related Art Conventionally, as one form of waste plastic oil treatment equipment for obtaining low-boiling hydrocarbon oil (hereinafter referred to as "generated oil") by thermally decomposing waste plastic, Japanese Patent Application No. Hei.
There is a waste plastic oil treatment facility B described in No. 18114, the configuration of which is shown in FIG. As shown in the figure, the waste plastic (fluff) finely crushed in the pretreatment section is supplied to the extruder 68 of the oiling section 52 by the bucket conveyor 67 and melted and kneaded at about 300 ° C. Vessel 6
9

[0003] In the raw material mixing tank 69, the pyrolysis oil produced in the subsequent pyrolysis tank 70 is refluxed and mixed to be completely dissolved. The waste plastic dissolved in the pyrolysis oil is sent to the pyrolysis tank 70, and the pyrolysis oil heating furnace 7
1 and circulates between them to be heated and pyrolyzed. Hydrogen chloride generated in the extruder 68 and the raw material mixing tank 69 is neutralized in the wash stack 72 by an alkali solution. In the pyrolysis step, a pyrolysis oil vapor of plastic is generated from the pyrolysis tank 70, and hydrogen chloride is removed from the pyrolysis oil vapor by the hydrogen chloride remover 73 and sent to the catalytic cracking tank 74.

Further, since pyrolysis is performed at a high temperature in the pyrolysis tank 70, carbon residues are generated at the bottom of the pyrolysis tank 70, and such carbon residues are removed from the solid-liquid mixture formed by a gravity settler or a centrifugal separator. It is separated from the pyrolysis oil by the separation tank 75 and discharged out of the system as secondary waste. In the catalytic cracking tank 74, the pyrolysis oil vapor is decomposed into a low-boiling hydrocarbon oil vapor and reformed by a catalytic cracking reaction with a catalyst. Next, the pyrolyzed oil vapor is cooled by a condenser 76 to obtain a low-boiling hydrocarbon oil, and then sent to a generated oil storage tank 78 via a receiving tank 77. The gas in the condenser 76 is discharged from the flare stack 80 via the gas holder 79.

[0005]

However, the method for liquefying waste plastic using the waste plastic liquefaction facility B has the following problems to be solved. That is, to perform complicated operations on high-temperature fluids,
Many equipments are required including an extruder 68, a raw material mixing tank 69, a thermal decomposition tank 70, a hydrogen chloride remover 73, and a catalytic cracking tank 74, and these apparatuses are likely to have special specifications. Therefore, the equipment cost of the waste plastic oil treatment equipment B is high. The operation of these devices is also complicated. Furthermore, accumulation of operation inhibiting substances tends to occur due to continuous operation, and equipment stability is poor. In addition, it is necessary to add a facility for separating and removing the accumulated substances, and the facility cost is likely to increase.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a waste plastic oil treatment method which can significantly simplify waste plastic oil treatment equipment.

[0007]

According to the present invention, there is provided a semiconductor device comprising:
The waste plastic oil-treating method according to the method is to put waste plastic into a single treatment tank together with a heavy oil component obtained by oil-treating the waste plastic, and then in the treatment tank, While changing the heating temperature and the heating time, heating and mixing the waste plastic and the produced oil heavy component, a dehydration / drying step, a dechlorination step, a thermal decomposition / oiling step,
The residue discharging step is performed independently.

According to a second aspect of the present invention, there is provided a method of treating waste plastic according to the first aspect of the present invention, wherein the waste plastic and the produced oil heavy component are separated in the dehydration / drying step. 100 hours with a stirrer for 1-3 hours
The water is removed from the material to be stirred by stirring at a temperature of from 200 ° C. to 200 ° C., and in the dechlorination step, the waste plastic and the heavy product oil are separated by the stirrer for 1 to 3 hours at 200 ° C. to 3 ° C.
Stirring at a temperature of 50 ° C. decomposes polyvinyl chloride in the waste plastic and removes hydrogen chloride from the material to be agitated. In the thermal decomposition / oiling step, the agitated material from which the chlorine has been removed is removed. Stir the product for 1 to 4 hours at 380 ° C
By stirring at a temperature of 450 ° C., the waste plastic from which the chlorine has been removed is thermally decomposed and turned into oil.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. With reference to FIG. 1, a method for liquefying waste plastic according to one embodiment of the present invention will be described.

First, a waste plastic oil treatment facility A to which the waste plastic oil treatment method according to the present embodiment can be applied will be described with reference to FIG. As shown in the figure, in the present embodiment, the waste plastic oil treatment equipment A includes a pretreatment equipment 10 and a pyrolysis oil treatment equipment 11. The pretreatment facility 10 includes a primary crusher, a secondary crusher, a waste plastic receiving tank, and the like (not shown), and a supply device (a final stage device) for supplying waste plastic to a processing tank 13 described below. For example, a bucket conveyor 12 is provided. On the other hand, the pyrolysis oil conversion equipment 11
Is substantially the same as the conventional extruder 6 described with reference to FIG.
8, a processing tank 13 composed of a single tank corresponding to the raw material mixing tank 69, the thermal decomposition tank 70, and the hydrogen chloride remover 73, a solid-liquid separation tank 14, a distillation tower 15, and a generated oil storage tank 16 are provided. .

The structure of the processing tank 13 will be further described. As shown in FIG.
Are provided concentrically and rotatably, and the stirrer 1
Reference numeral 7 denotes a rotary motor 1 mounted on the top of the processing tank 13.
8 is driven to rotate. A raw material inlet 19 is provided at the top of the processing tank 13. Through the raw material supply pipe 19 a and the raw material inlet 19, waste plastic from the supply device 12 and generated oil from a generated oil partial reflux pipe 25 described later are formed. The heavy oil can be put into the treatment tank 13 in a mixed state.

At the top of the processing tank 13, a pyrolysis oil vapor outlet 20, a hydrogen chloride gas outlet 21, and a steam outlet 22 are further provided. The pyrolysis oil vapor outlet 20 is connected to the inlet of the distillation tower 15 by a vapor transfer pipe 23, and the distillation tower 15 is connected to the heavy oil storage tank 16A by a heavy oil transfer pipe 24A and a light oil transfer pipe 24B. The light oil storage tank 16B is communicatively connected to an inlet of the light oil storage tank 16B. The other end of the generated oil partial reflux pipe 25, which has one end connected to the middle part of the heavy oil transfer pipe 24A, is connected to the middle part of the raw material supply pipe 19a. The hydrogen chloride gas outlet 21 is connected to an inlet of a neutralization tank 27 by a hydrogen chloride gas transfer pipe 26, and the outlet of the neutralization tank 27 is open to the atmosphere. Steam outlet 2
Numeral 2 is communicated with the atmosphere via a water vapor extraction pipe 28.

On / off valves 29, 30, and 31 are attached to the vapor transfer pipe 23, the hydrogen chloride gas transfer pipe 26, and the steam extraction pipe 28, respectively. A solid-liquid separation tank 14 composed of a centrifugal separator or the like is attached to a solid substance taking-out pipe 32 led out from the bottom of the processing tank 13, and a separation oil outlet 33 of the solid-liquid separation tank 14 passes through a reflux pipe 34 through a processing tank. 1
3 is connected in communication. Further, an opening / closing valve 35 is attached to a base of the solid matter taking-out pipe 32.

Next, a method for liquefying waste plastic by the waste plastic liquefaction facility A having the above configuration will be described with reference to FIGS. 1 and 2. FIG. As shown in the figure, the waste plastics supplied from the pretreatment equipment 10 to the pyrolysis oil conversion equipment 11 by the supply device 12 removes the same weight of the generated oil heavy fraction that has been refluxed from the generated oil partial reflux pipe 25. After being mixed, it is put into the processing tank 13. Then, in the treatment tank 13, the waste plastic and the heavy oil generated are heated by the external heating device H as shown in FIG. That is, the waste plastic and the generated oil heavy component are, in order, a dehydration / drying step 40 in which the heating temperature and the heating time are different from each other, a dechlorination step 41,
After the oiling step 42 and the residue discharging step 43, the heat treatment is performed as described below.

First, in the dewatering / drying step 40, the waste plastic and the heavy product oil are stirred by the stirrer 17 at a temperature of 100 ° C. to 200 ° C. for 1 to 3 hours. Therefore,
Water is removed as water vapor from the object to be stirred, and the on-off valve 31 is opened.
By opening, the water vapor is released into the atmosphere through the water vapor extraction pipe 28. The lower limit of the heating temperature was set to 100 ° C. because the boiling point of water was 100 ° C., and the upper limit of the heating temperature was set to 200 ° C. because a small amount of chlorine began to be generated by decomposition of polyvinyl chloride. This is because the chlorine treatment is performed in the dechlorination treatment 41 which is the next step.

Next, in the dechlorination step 41, the waste plastic and the heavy oil produced are mixed at 200 ° C. for 1 to 3 hours with a stirrer.
The mixture is stirred at a temperature of 350 ° C. to decompose polyvinyl chloride in the waste plastic and to remove hydrogen chloride gas from the material to be stirred. Thereafter, by opening the on-off valve 30, the hydrogen chloride gas is sent to the neutralization tank 27 through the hydrogen chloride gas transfer pipe 26, is rendered harmless by neutralization, and is released into the atmosphere. The lower limit of the heating temperature was set to 200 ° C. in order to increase the dechlorination efficiency by generating a predetermined amount or more of hydrogen chloride, and the upper limit of the heating temperature was set to 350 ° C. in the next step. This is because the temperature is close to the starting temperature of the thermal decomposition / oiling process.

Next, in the thermal decomposition / oiling step, the agitated object from which the chlorine has been removed is treated with a stirrer for 1 to 4 hours at 380 hours.
The waste plastic from which the chlorine has been removed is thermally decomposed by stirring at a temperature of about 450C to about 450C to generate a pyrolyzed oil vapor. Note that the lower limit of the heating temperature was set to 380 ° C.
The upper limit of the heating temperature was set to 450 ° C because the heating temperature was too high at a higher temperature because the heating temperature was too high to secure carbon deposition. This is because the amount increases, which is a problem in operation, and lowers thermal efficiency.

The pyrolysis oil vapor is supplied to a vapor transfer pipe 2
3 and sent to the distillation column 15 for distillation. The heavy oil and light oil separated by distillation are separated from the heavy oil transfer pipe 24A,
The oil is transferred to and stored in the heavy oil storage tank 16A and the light oil storage tank 16B through the light oil transfer pipe 24B. Among them, the heavy oil component is returned to the middle of the raw material supply pipe 19a through the generated oil partial return pipe 25, and is supplied to the treatment tank 13 while being mixed with the waste plastic as described above.

Also, in the above-mentioned waste plastic oil treatment method, since solid matter such as carbon residue is generated at the bottom of the treatment tank 13, in the residue discharge step 43, the on-off valve 35 is periodically opened to open the solid matter. (Metal, earth and sand in waste plastic, carbon accompanying pyrolysis) is taken out, the pyrolysis oil contained in the solid-liquid separation tank (for example, centrifugal separator) 14 is separated, and is returned to the processing tank 13 through the reflux pipe 34. I do. On the other hand, the solid matter from which the pyrolysis oil has been completely removed is taken out and discarded. The residue discharging step 43 is completed in about one hour including the cooling time.

As described above, in the present embodiment, as the heavy oil to be mixed into the waste plastic, a part of the heavy oil produced by subjecting the waste plastic to oil conversion is used by refluxing, And the waste plastics can be efficiently liquefied. By simultaneously charging the waste plastic and the heavy product oil into the treatment tank 13, the gap between the waste plastics is filled with the heavy product oil and the heat conduction to the waste plastic is improved. The period of each step 40 to 42 can be shortened. Specifically, by appropriately setting the heating temperature and the heating time, the above-described raw material supply step,
The drying step 40, the dechlorination step 41, the thermal decomposition / oiling step 42, and the residue discharging step 43 can be performed in about 5 to 12 hours.

Since a single treatment tank 13 is used for the series of steps 40 to 42 described above, the waste plastic oil treatment equipment A can be made compact. Since the carbon produced by the thermal decomposition in the treatment tank 13 is dispersed in the heavy oil produced, the operation of the waste plastic oil treatment facility A is not hindered. The waste plastic oil liquoring method according to the present embodiment is a batch operation, so that the content of foreign matter such as metal pieces and earth and sand mixed in the waste plastic is acceptable even if it is relatively large, and the pretreatment is performed. A degree of crushing is sufficient. Accordingly, the number of the pretreatment facilities 10 in the waste plastic oil treatment facility A can be reduced, and the facility cost can be further reduced.

As described above, the present invention has been described with reference to an embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and is described in the claims. It also includes other embodiments and modifications that can be considered within the scope of the matters described. For example, in the above-described embodiment, the waste plastic in the treatment tank is indirectly heated by using an external heating device, but the waste plastic can also be heated by heating and circulating heavy oil.

[0023]

According to the first and second aspects of the present invention, the waste plastic is put into a single treatment tank together with the heavy component oil produced by oil-treating the waste plastic. Then, in the treatment tank, the waste plastic and the heavy oil produced are heated and mixed while sequentially changing the heating temperature and the heating time, and the dewatering / drying step, the dechlorination step, and the thermal decomposition are performed.・ The oiling process and the residue discharging process are performed.

As described above, by simultaneously feeding the waste plastic and the heavy product oil into the treatment tank, the gap between the waste plastics is filled with the heavy product oil, and the heat conduction to the waste plastic is improved. As a result, the time for each of the above-described steps can be reduced. In addition, since the above-described series of steps are performed using a single processing tank, a special-purpose fluid transfer device such as a high-temperature fluid pump is not required, and the waste plastic oil processing equipment has a compact and inexpensive structure. Can be

Furthermore, because of the treatment by batch operation, the content of foreign substances such as metal chips and earth and sand mixed into the waste plastic is allowed to be relatively large, and the pretreatment is only required to be crushed. Therefore, the number of pretreatment facilities in the waste plastic oil treatment facility can be reduced, and the facility cost can be further reduced.

In the method for converting waste plastic into oil according to the second aspect of the present invention, in the dewatering / drying step, the waste plastic and the heavy oil produced are treated with a stirrer for 1 to 3 hours.
Stirring is performed at a temperature of 100 ° C to 200 ° C to remove water from the object to be stirred, and in the dechlorination step, the waste plastic and the heavy oil produced are stirred at a temperature of 100 ° C to 200 ° C for 1 to 3 hours with a stirrer. Then, while decomposing polyvinyl chloride in the waste plastic and removing hydrogen chloride from the agitated object, in the thermal decomposition / oiling step, the agitated object from which chlorine has been removed is subjected to 1 to 1 with a stirrer.
The waste plastic from which chlorine has been removed is thermally decomposed and turned into oil by stirring at a temperature of 380 ° C. to 450 ° C. for 4 hours. Thus, by appropriately setting the heating temperature and the heating time, the dehydration / drying step, the dechlorination step,
The pyrolysis / oiling step and the residue discharging step can be performed in about 5 to 12 hours.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration explanatory view of a main part of waste plastic oil treatment equipment to which a waste plastic oil treatment method according to an embodiment of the present invention is applied.

FIG. 2 is an explanatory view of a process in a processing tank.

FIG. 3 is a conceptual configuration explanatory view of an oil treatment section of a conventional waste plastic oil treatment apparatus.

[Explanation of symbols]

Reference Signs List A Waste plastic oil treatment equipment H External heating device 10 Pretreatment equipment 11 Pyrolysis oil treatment equipment 12 Supply device 13 Processing tank 14 Solid-liquid separation tank 15 Distillation tower 16A Heavy oil storage tank 16B Light oil storage tank 17 Stirrer 18 Rotary motor 19 Feed port 19a Feed pipe 20 Pyrolysis oil vapor outlet 21 Hydrogen chloride gas outlet 22 Steam outlet 23 Vapor transfer pipe 24A Heavy oil transfer pipe 24B Light oil transfer pipe 25 Partial oil return pipe 26 Hydrogen chloride gas Transfer pipe 27 Neutralization tank 28 Steam extraction pipe 29 On-off valve 30 On-off valve 31 On-off valve 32 Solids extraction pipe 33 Separated oil outlet 34 Reflux pipe 35 On-off valve 40 Dehydration / drying step 41 Dechlorination step 42 Thermal decomposition /
Oiling process 43 Residue discharging process

Claims (2)

[Claims] After a waste plastic is put into a single treatment tank together with a heavy oil component obtained by oil-treating the waste plastic, a heating temperature and a heating time are sequentially set in the treatment tank. While changing, the waste plastic and the produced oil heavy component are heated and mixed, and the dehydration / drying step, the dechlorination step, the thermal decomposition / oiling step, and the residue discharge step are performed independently. A method for liquefying waste plastics, characterized in that: 2. In the dehydration / drying step, the waste plastic and the produced oil heavy component are separated by a stirrer for 1 to 3 hours.
Stirring is performed at a temperature of 00 ° C. to 200 ° C. to remove water from the object to be stirred, and in the dechlorination step, the waste plastic and the generated oil heavy component are stirred at 200 ° C. for 1 to 3 hours using the stirrer.
Stirring at a temperature of about 350 ° C. to decompose polyvinyl chloride in the waste plastic and remove hydrogen chloride from the material to be agitated, and in the thermal decomposition / oiling step, remove the chlorine from the waste plastic. The agitated material is stirred for 380 hours for 1 to 4 hours.
The waste plastics liquefaction method according to claim 1, wherein the waste plastic from which the chlorine has been removed is thermally decomposed and oiled by stirring at a temperature of from 450C to 450C.