JPH0995678A - Removal of aluminum chloride from oil product of waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject removing method capable of efficiently and easily removing harmful aluminum chloride contaminating inevitably in producing an oil product of waste plastics. SOLUTION: An oil product from waste plastics is first obtained by passing the thermal decomposition product of waste plastic materials through a dehydrochlorination tank packed with alumina particles to conduct a dehydrochlorination treatment followed by catalytic decomposition of the resultant thermal decomposition product by a zeolite-based catalyst. Next, the oil product is mixedly agitated with water or an alkaline solution such as an aqueous calcium hydroxide solution followed by, in the succeeding process, separation of the oil product from an aqueous aluminum chloride solution or separation of the oil product from a solution containing chloride(s) and aluminum compound(s).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing aluminum chloride from waste plastic oil products obtained by oil treatment of discarded plastic materials.

[0002]

2. Description of the Related Art In recent years, from the standpoint of environmental protection and resource protection, waste plastic oil products of low molecular weight such as gasoline, light oil, and kerosene are used rather than high molecular weight plastic materials to be discarded (hereinafter referred to as waste plastic materials). Is being extracted and used as an effective resource. However, in such an oil treatment, since the waste plastic material contains chlorine derived from an organic chlorine compound such as polyvinyl chloride, a large amount of the waste plastic material is melted by heating or reacted. Hydrogen chloride gas is generated. Therefore, the vaporized thermal decomposition product (hereinafter referred to as thermal decomposition oil) obtained by melting the waste plastic material is catalytically decomposed by using a zeolite catalyst or the like, and the low boiling point gasoline, kerosene, gas oil, etc. are discarded. When producing a plastic oil product, this hydrogen chloride becomes a factor that reduces the catalytic activity of the catalyst mainly composed of zeolite used for catalytic cracking (hereinafter referred to as zeolite catalyst). In addition, gasoline, which is the final product of such chlorine compounds,
When chlorine compounds remain in waste plastic oil products such as kerosene and light oil, the corrosiveness of the combustion gas at the time of combustion increases, and the combustion characteristics and other qualities deteriorate significantly.

In order to remove the hydrogen chloride in the pyrolysis oil generated in the pyrolysis tank during the oil treatment of the waste plastic material, for example, as described in Japanese Patent Application No. 5-196544, A method is known in which a dehydrochlorination tank for removing hydrogen chloride in oil is provided and hydrogen chloride is removed by adsorption or the like.

FIG. 3 shows an example of a waste plastic oiling treatment facility equipped with such a dehydrochlorination tank. A method for oiling a waste plastic material will be described below with reference to FIG. The waste plastic material crushed into small pieces and temporarily stored in the waste plastic receiving tank 30 has about 300 inside due to the heat medium supplied from the heat medium oil circulation heating furnace 32 on the conveyor 31.
The mixture is conveyed into the extruder 33 heated to ℃, where it is heated and kneaded into a liquid state and heated to about 350 ° C.
Be delivered to. Then, the raw material mixing tank 34 and the extruder 3
Pyrolysis oil vapor containing hydrogen chloride gas generated in 3 is introduced into the hydrochloric acid neutralization tower 35 from the upper part of the raw material mixing tank 34, where sodium hydroxide (NaOH) aqueous solution or the like is sprayed for neutralization, and then treated. The exhaust gas after that is discarded to the outside of the system via the fan 47.

The melted waste plastic material is transferred from the lower part of the raw material mixing tank 34 to the upper part of the thermal decomposition tank 36, and the melted waste plastic material is thermally decomposed in the thermal decomposition tank 36 to have a low molecular weight thermal decomposition. A process for producing oil vapor is performed. The thermal decomposition tank 36 is heated by the sensible heat of the thermal decomposition oil circulating between the thermal decomposition tank 36 and the thermal decomposition oil circulation heating furnace 37. Then, in the thermal decomposition tank 36, the molten waste plastic material and the high-temperature thermal decomposition oil are brought into contact with each other, so that the molten waste plastic material is thermally decomposed to generate a waste plastic oil product, and Steam (vapor) is transferred to the dehydrochlorination tank 40 through the upper portion of the thermal decomposition tank 36.

Particles of quick lime (CaO) or the like are stacked and packed in the dehydrochlorination tank 40 as a reaction adsorbent with hydrogen chloride (HCl), and hydrogen chloride in the pyrolysis oil vapor reacts with quick lime. , Calcium chloride (CaC
l ₂ ) to be fixed in the packed bed,
A layer of inorganic particles having a particle size of 20 to 40 mm is arranged as a rectifying material for equalizing the flow of the pyrolysis oil vapor introduced. In the catalytic cracking tank 39, the thermally cracked oil vapor is brought into contact with a catalyst such as zeolite at a predetermined pressure and temperature, and a waste plastic oil product (hydrocarbon oil) such as gasoline, light oil, kerosene or the like having a desired average molecular weight is obtained. Reform to.

The pyrolysis gas further decomposed into a low molecular weight by the catalytic cracking tank 39 becomes a waste plastic oil product, which is cooled by a total compressor 41 having the same structure as the heat exchanger, and is used as gasoline, kerosene or light oil. And the like (total condensed oil which is a waste plastic oil conversion product) and is temporarily stored in the total condensed oil receiving tank 42 and finally stored in the total condensed oil storage tank 43. On the other hand, the gas that has not been liquefied by the total compressor 41 is sent to the catalytic cracking gas holder 45 by the fan 44, and a part of the gas is used as fuel for the thermal cracking oil circulation heating furnace 37 and the heating medium oil circulation heating furnace 32. , Others are burned and released from the chimney 46 into the atmosphere. The liquefied portion of the gas component stored in the catalytic cracking gas holder 45 is returned to the catalytic cracking tank 39 and circulated between the catalytic cracking tank 39 and the catalytic cracking gas holder 45 to maintain an efficient catalytic cracking reaction. You can do it.

[0008]

However, in the waste plastic oil products such as gasoline, kerosene, and light oil obtained by the method of using alumina as the filling material of the dehydrochlorination tank, hydrogen chloride and dechlorination are contained. Aluminum chloride (AlCl2) formed by the reaction with the alumina component of the filler in the hydrogen tank
₃ , Al ₂ Cl ₆ ) is contained, and if it is used as it is, it will be a factor that greatly deteriorates the quality characteristics of the waste plastic oil product. The present invention has been made in view of such circumstances, and in producing a waste plastic oil product by treating a waste plastic material containing an organic chlorine compound such as polyvinyl chloride by thermal decomposition and catalytic decomposition. An object of the present invention is to provide a method for removing aluminum chloride from a waste plastic oil product, which can efficiently and easily remove aluminum chloride which is inevitably mixed.

[0009]

A method according to the above-mentioned object.
The method for removing aluminum chloride from the waste plastic oiled product is described in which the thermal decomposition product of the waste plastic material is passed through a dehydrochlorination tank in which alumina particles are placed to perform dehydrochlorination treatment, and then this is treated with zeolite. A method for removing aluminum chloride from a waste plastic oil product obtained by catalytic decomposition with a system catalyst, wherein the waste plastic oil product is mixed and stirred with water or an alkaline solution such as an aqueous solution of calcium hydroxide, In the next step, waste plastic oil product and aluminum chloride aqueous solution, or waste plastic oil product and solution containing chloride and aluminum compound are separated.

The dehydrochlorination tank removes hydrogen chloride from the pyrolysis products of the waste plastic material to be charged. As a result, in the catalytic cracking using the zeolite-based catalyst in the latter stage, the catalytic activity is maintained without being impaired. The mixing and stirring is performed by washing water or a mixture of an alkaline solution such as an aqueous solution of calcium hydroxide and a waste plastic oil product with a stirring blade to mix and wash the waste plastic oil product. Is done. The operation of separating the waste plastic oil product and the aluminum chloride aqueous solution, or the solution containing chloride and aluminum compound from the mixture is performed by allowing the treated product washed in the washing tank to stand up and down in an oil / water separation tank. Separated into
Obtaining the desired waste plastic oil product.

[0011]

In the method for removing aluminum chloride from a waste plastic oil product according to claim 1, the thermal decomposition product of the waste plastic material containing hydrogen chloride reacts with the alumina component during dehydrochlorination to form a chloride. This produces aluminum.
Then, the waste plastic oil product containing aluminum chloride is mixed and stirred with water or an alkaline solution such as an aqueous solution of calcium hydroxide in a washing tank, so that aluminum chloride having a high solubility in water is dissolved in water to form waste plastic. The oiled product is washed. Further, when an alkaline solution such as an aqueous solution of calcium hydroxide is used, a neutralization reaction with aluminum chloride or the like occurs in the mixed solution, so that better separation efficiency can be obtained. Further, a mixture of the waste plastic oil composition and water after the washing treatment is separated into a waste plastic oil product and an aqueous solution of aluminum chloride or a solution containing a chloride, and a solution containing an aluminum compound. Aluminum chloride can be easily removed from the chemical composition. In addition, as water in the present invention, tap water, industrial water, and the like are good and have the same action and effect.

[0012]

Therefore, in the method for removing aluminum chloride from the waste plastic oil product according to the first aspect, the following effects (1) to (4) are exhibited. By removing aluminum chloride from waste plastic oil products, it is possible to maintain qualities such as combustion characteristics required for gasoline, kerosene, and light oil, and corrosiveness of combustion gas. Alumina particles and the like are filled in a dehydrochlorination tank, etc., a reaction of converting hydrogen chloride generated when oiling a waste plastic material into aluminum chloride, or a catalytic cracking reaction using a zeolite-based catalyst containing alumina, Since it can be positively performed without considering the decrease in the catalytic activity of the zeolite-based catalyst, the production efficiency of the waste plastic oil product can be maintained at a high level, and the waste plastic oil process can be easily performed. No expensive chemicals are required to remove aluminum chloride, and water or an alkaline solution such as calcium hydroxide aqueous solution is used as a cleaning liquid, so cleaning processing can be performed at low cost, and work safety is high. At the same time, the water after washing can be collected and circulated for use, so that the environment is unlikely to be polluted. It is possible to simultaneously remove other solid components other than aluminum chloride, impurities and the like existing in the waste plastic oil product. The structure of the cleaning processing device for waste plastic oil products can be easily configured, the facility cost is low, and the maintenance is easy.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a block diagram of an aluminum chloride removing apparatus applied to a method for removing aluminum chloride from waste plastic oil products according to an embodiment of the present invention, and FIG. 2 is a block diagram of the same waste plastic oil processing equipment. Is.

A waste plastic material oilification treatment facility 10 and an aluminum chloride removal apparatus 21 to which the method for removing aluminum chloride from a waste plastic oil product according to one embodiment of the present invention is applied are configured as shown in FIG. Has been done. The aluminum chloride removing device 21 stores a produced oil storage tank 22 for storing a waste plastic oil production product (hereinafter also referred to as produced oil) supplied from the waste plastic oil treatment plant 10, and a produced oil supplied from the produced oil storage tank 22. And a washing tank 25 for washing a mixture of water or an alkaline solution such as an aqueous solution of calcium hydroxide by rotating a stirring blade 24 using a motor 23, and a treatment liquid from the washing tank 25 is separated into a produced oil and a washing liquid. Oil-water separation tank 26 and oil-water separation tank 2
The cleaning liquid storage tank 27 temporarily stores the cleaning liquid separated in 6 and supplies the cleaning liquid to the cleaning tank 25.

Further, the waste plastic oil treatment equipment 10
As shown in FIG. 2, the extruder 11 that kneads and melts the shredded or crushed waste plastic material while heating it, and the waste plastic material that is discharged from the extruder 11 and is in a substantially molten state is decomposed from the pyrolysis tank 13. A raw material mixing tank 12 that mixes with the refluxed high-temperature pyrolyzed oil and is further melted, and a melt of the waste plastic material melted in the raw material mixing tank 12 is extracted from the lower part of the raw material mixing tank 12 to heat it. Pyrolysis tank 13 that lowers the molecular weight by decomposition, heating furnace 14 that circulates the pyrolysis oil heated to pyrolysis tank 13, and hydrogen chloride content in the pyrolysis oil vapor produced from pyrolysis tank 13 Remove 2
Dehydrochlorination tanks 18 arranged in parallel with each other, and a pyrolysis oil vapor treated in the dehydrochlorination tank 18 are brought into contact with a zeolite-based catalyst to further reform into a waste plastic oil product having a low molecular weight. Catalytic decomposition tank 15 and raw material mixing tank 12
Of hydrogen chloride generated from the upper part of the extruder and the extruder 11
By cooling the washing tower 17 neutralized with a sodium hydroxide solution or the like supplied from the H supply line 19 and the pyrolysis oil vapor produced in the catalytic cracking tank 15, liquefied hydrocarbon oil (waste plastic oil production) And a pyrolyzed oil vapor cooler 16 for separating the cracked gas and the cracked gas.

In the thermal decomposition tank 13, the molten waste plastic material supplied from the raw material mixing tank 12 has a temperature of 400 ° C.
Are retained in the solution, and the low-boiling components are increased by lowering the molecular weight by thermal decomposition. The dehydrochlorination tank 18 is a substantially cylindrical steel container, inside of which alumina particles having an average particle diameter of 2 mm, a pore volume of about 0.5 ml / g, and an alumina purity of 99 wt% are 80 mm thick. The layers are arranged in layers. Then, the pyrolysis oil vapor supplied from the pyrolysis tank 13 and the alumina particles are brought into contact with each other under the condition that the temperature in the dehydrochlorination tank 18 is 250 to 350 ° C. and the pressure is slightly higher than the atmospheric pressure. Is set to. As a result, hydrogen chloride in the thermal decomposition product of the waste plastic material reacts with the alumina particles and is converted into aluminum chloride. Zeolite-based catalysts are arranged in layers in the catalytic cracking tank 15.
It is set so that the catalytic cracking reaction of the thermally cracked oil vapor occurs at a temperature of 0 ° C. and normal pressure. Zeolite is a mineral composed of tectoaluminosilicate that contains a cation having a high ion exchange property and has a three-dimensional network structure that is bonded to weakly retained water. General formula of the chemical composition _{W m Z n O 2 n ·} sH 2 O ( where, W is Na, Ca,
Represents any element of K, Ba and Sr elements or a combination thereof, Z is an element of Si and Al having a Si / Al ratio of 1 or more, and m, n and s are each an invariant) Be done.

Next, a method for producing a waste plastic oil product using the waste plastic material oiling facility 10 described above will be described in detail. First, the general waste plastic discharged from a general household is pulverized into particles of about 5 to 20 mm by a cutter, a crusher, or the like not shown. Next, the crushed plastic is put into the extruder 11 at 30 kg / h.
And the outlet temperature of the extruder 11 is 250-
The mixture was kneaded and melted while being heated to 300 ° C. Then, the plastic melted by the extruder 11 is supplied to the raw material mixing tank 12 connected to the outlet side of the extruder 11, and the pyrolysis oil refluxed from the latter thermal decomposition tank 13 in the raw material mixing tank 12 is used. And heated to 280-320 ° C. In the melting process, about 90 wt% of chlorine compounds already contained in the plastic is desorbed from the plastic, and hydrogen chloride gas is generated. Lead to 17, NaO
It was washed and neutralized with an aqueous NaOH solution supplied from the H supply line 19.

Then, the mixture of the molten plastic and pyrolysis oil was supplied to the pyrolysis tank 13 and circulated between the heating furnace 14 and the temperature to 380 to 420 ° C.
By the operation up to this point, about 26 kg /
The pyrolysis oil vapor of h was generated. This pyrolyzed oil vapor was introduced into the dehydrochlorination tank 18 at a temperature of 300 ° C. filled with alumina particles to convert the hydrogen chloride in the pyrolyzed oil vapor into aluminum chloride. At this time, since aluminum chloride to be converted is generated in a gas state, the voids between the alumina particles are not blocked by the reaction product,
On the contrary, the reaction proceeds in the direction in which the alumina on the particle surface is consumed and consumed to increase the voids between the particles, and the pressure loss of the alumina particle packed bed is not increased. Furthermore, since the solid content in the pyrolyzed oil vapor adhering to the surface of the alumina particles is small, the operating state can be stably maintained.

Then, the thermal cracked oil vapor thus treated was introduced into the catalytic cracking tank 15. In the catalytic cracking tank 15, a zeolite-based catalyst and a pyrolysis oil vapor were brought into contact with each other under predetermined conditions, and a waste plastic oil product such as kerosene, gasoline, light oil was produced by catalytic cracking using the zeolite-based catalyst. At this time, aluminum chloride in the pyrolyzed oil vapor has less activity-inhibiting effect on the zeolite-based catalyst than hydrogen chloride, so that it is possible to oilize the waste plastic material without lowering the efficiency of catalytic cracking. it can. Next, the vapor of the waste plastic oil product was condensed and cooled by the cooler 16 for the pyrolysis oil vapor to separate it into the desired liquefied waste plastic oil product and decomposed gas.

Next, the waste plastic oilification product containing aluminum chloride treated in the waste plastic oilification treatment facility 10 as described above is stored in the produced oil storage tank 22. Then, a predetermined amount of the waste plastic oil product (about 18
(kg) is supplied to a washing tank 25 having a diameter of 0.4 m and a depth of 0.4 m for the oily product holding portion. At this time, the concentrations of aluminum chloride and hydrogen chloride in the waste plastic oil product before treatment in the cleaning tank 25 are several tens p respectively.
It was several thousand ppm from pm and several tens to several hundreds ppm. Next, about 18 kg of water is charged into the cleaning tank 25, and the stirring blade 24 is rotated at a predetermined rotation speed by the motor 23 at room temperature in the cleaning tank 25 and is held for about 30 minutes. The waste plastic oil product was washed. In this washing treatment, it is preferable to maintain the weight ratio of water and waste plastic oil product at 0.5 to 1.5 and mix them under room temperature conditions in order to maintain the washing efficiency. . Then, the mixed treatment product after the washing is introduced into the oil-water separation tank 26, and left standing for about 20 minutes to separate it into upper and lower parts due to the difference in specific gravity between water and oil, and then the upper layer is produced oil (waste plastic oil product). And the lower layer was extracted as a washing liquid. At this time, the concentrations of aluminum chloride and hydrogen chloride in the produced oil taken out from the upper layer were both below the specified amounts. A part of the cleaning liquid extracted from the oil / water separation tank 26 is collected and stored in the cleaning liquid storage tank 27,
In the next cleaning process, the stored cleaning liquid can be used. Here, the cleaning liquid can be repeatedly used until the concentration of aluminum chloride in the cleaning liquid is concentrated to the extent of exceeding several thousands ppm.

Since the waste plastic oil product obtained as described above has a low content of aluminum chloride, hydrogen chloride and the like, it causes quality problems when used as gasoline, kerosene, gas oil and the like. It never happens. Further, since the hydrogen chloride is converted to aluminum chloride and catalytically decomposed by using the zeolite-based catalyst, the production efficiency can be maintained without inhibiting the activity of the zeolite-based catalyst. Furthermore, since the structures of the cleaning tank 25 and the oil / water separation tank 26 are relatively simple and expensive chemicals are not used, the facility cost, running cost, and maintenance cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an aluminum chloride removing apparatus applied to a method for removing aluminum chloride from a waste plastic oil product according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of the waste plastic oil treatment facility.

FIG. 3 is a configuration diagram of a waste plastic oil conversion treatment facility according to a conventional example.

[Explanation of symbols]

10 Waste Plastic Oil Treatment Equipment 11 Extruder 12 Raw Material Mixing Tank 13 Pyrolysis Tank 14 Heating Furnace 15 Contact Cracking Tank 16 Pyrolysis Oil Vapor Cooler 17 Washing Tower 18 Dehydrochlorination Tank 19 NaOH
Supply line 21 Aluminum chloride removing device 22 Oil storage tank 23 Motor 24 Stirring blade 25 Washing tank 26 Oil-water separation tank 27 Washing liquid storage tank

Claims (1)

[Claims] 1. A waste plastic obtained by passing a thermal decomposition product of a waste plastic material through a dehydrochlorination tank in which alumina particles are placed to perform dehydrochlorination treatment, and then catalytically decomposing this by a zeolite-based catalyst. A method for removing aluminum chloride from an oiled product, wherein the waste plastic oiled product is mixed with water or an alkaline solution such as calcium hydroxide and stirred, and then the waste plastic oiled product and aluminum chloride are mixed in the next step. A method for removing aluminum chloride from a waste plastic oil product, which comprises separating an aqueous solution or a waste plastic oil product and a solution containing a chloride and an aluminum compound.