JP2001072795A - Method of treating waste plastic containing flame retardant components - Google Patents

Abstract

(57) [Problem] To efficiently and surely separate and collect a plastic component and a flame retardant component from waste plastic, respectively, and preferably to effectively use a part of the treated waste plastic. SOLUTION: A waste plastic containing a flame retardant component is immersed in an organic solvent heated to 100 to 300 ° C to separate the waste plastic into a plastic component and a flame retardant component, and the separated plastic component and flame retardant component are separated. Each is characterized by being recovered from an organic solvent. Preferably, the plastic component recovered from the organic solvent is crushed to be processed into a furnace fuel and / or iron source reducing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating waste plastics containing a flame retardant component, and more particularly, to home appliances,
The present invention relates to a treatment method for separating plastic waste containing a flame retardant component used for OA equipment, toner and the like into a plastic component and a flame retardant component.

[0002]

2. Description of the Related Art In recent years, synthetic resins such as plastics have been increasing as industrial wastes and general wastes, and the treatment thereof has become a serious social problem including environmental protection. In particular, various properties of plastics (polyethylene, polypropylene, vinyl chloride, polystyrene, polycarbonate, etc.) are used for home appliances such as televisions and OA equipment, and these plastics have heat resistance and flame retardancy. In order to increase the flame retardant component such as an organic halogen compound (for example, tetrabromobisphenol A (TBA), decabromodiphenyl oxide (D
BDPO)).

When these waste plastics are incinerated, there are problems such as damage to the furnace wall of the incinerator due to the high calorific value of the plastics generated during combustion. To avoid this, dedicated incineration equipment is required. Become. In addition, when plastic is burned, corrosive gas (such as hydrogen chloride) derived from plastic-containing components is generated, and dust contained in waste gas contains harmful metals such as zinc and lead. Special equipment is required to detoxify harmful substances in corrosive gases and dust. In addition, waste plastics containing flame retardant components, in particular, have a problem in that when they are incinerated, harmful organic halogen compounds such as dioxin are generated.In recent years, the impact of this harmful substance on the environment has become a major social problem. is there.

[0004]

Conventionally, as a method of separating waste plastics, a method of mechanically crushing waste plastics to separate and collect them separately has been known. However, waste plastics containing a flame retardant component have been known. Due to its nature, it is difficult to separate the flame retardant component and the plastic component even by mechanical crushing. For this reason, at present, many waste plastics are disposed of in landfills. However, dumping of waste plastic causes deterioration of the land at the landfill site, and is not desirable from the viewpoint of environmental protection. In addition, recently, the shortage of landfill sites has become serious, There is a long-awaited desire to develop a mass processing method.

Accordingly, an object of the present invention is to solve such problems of the prior art, and to provide a method for treating waste plastic which can efficiently and surely separate and collect a plastic component and a flame retardant component from waste plastic. Is to do. Another object of the present invention is to provide a method for treating waste plastic that can effectively utilize a part of the treated waste plastic.

[0006]

The features of the present invention for solving such a problem are as follows. [1] A waste plastic containing a flame retardant component is immersed in an organic solvent heated to 100 to 300 ° C. and separated into a plastic component and a flame retardant component, and the separated plastic component and the flame retardant component are separated from each other. A method for treating waste plastic containing a flame retardant component, wherein the waste plastic is recovered from an organic solvent.

[2] The method for treating waste plastic according to the above [1], wherein the plastic component recovered from the organic solvent is crushed to be processed into a furnace fuel and / or iron source reducing agent. A method for treating waste plastic containing a flame retardant component.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the processing method of the present invention will be described below. In the method for treating waste plastic of the present invention, 1
Waste plastic containing a flame retardant component is immersed in an organic solvent heated to 00 ° C. to 300 ° C. to separate the waste plastic into a plastic component and a flame retardant component. Collect from

There are no particular restrictions on the waste plastics to be treated according to the present invention, for example, polystyrene, polyethylene, polypropylene, polycarbonate, ABS, P
It is a waste plastic containing one or more types such as MMA. The melting point (softening point) of these waste plastics varies depending on the resin, but is usually 100 to 200 ° C, and the decomposition start temperature is 300 ° C or higher. Representative flame retardant components contained in these waste plastics include, for example, tetrabromobisphenol A (TBA, melting point: 180
° C), decabromodiphenyl oxide (DBDPO,
Organic flame retardants such as octabromodiphenyl oxide (OBDPO, melting point: 70 to 150 ° C.). Usually, these flame retardant components have a specific gravity of 1.
5 or more. In addition, some include an inorganic flame retardant and a flame retardant auxiliary (for example, antimony trioxide) in addition to the organic flame retardant component.

In the present invention, the organic solvent used for treating the waste plastic exists as a liquid at the treatment temperature (100 to 300 ° C.) of the waste plastic containing the flame retardant component, and almost decomposes at this treatment temperature. It is necessary that the properties such as viscosity do not change without any change. Further, as the organic solvent, the separated plastic component is dissolved in the organic solvent at the processing temperature or in a state of being suspended in the organic solvent in some cases (in a state of being suspended in a solid state and / or a liquid state). On the other hand, it is desirable that the flame retardant component be sedimented and separated in the organic solvent. Therefore, the organic solvent is preferably one having a lower specific gravity than the flame retardant component. Among them, particularly preferred is one that shows compatibility with the plastic component and dissolves the plastic component. From such a viewpoint, as a suitable organic solvent, an organic solvent containing a paraffinic hydrocarbon and / or an olefinic hydrocarbon as a main component and containing an oxygen-containing hydrocarbon is particularly preferable. Examples include edible oils, waste oils such as waste solvents, kerosene, and the like, and one of these can be used alone or as a mixture of two or more.

The form in which the plastic component separated from the flame retardant component is present in the organic solvent may be a form in which the plastic component is dissolved in the organic solvent at the processing temperature, or a form in which the plastic component is not dissolved but suspended in the organic solvent (solid And / or liquid form), and both forms may coexist, but preferably dissolved in an organic solvent if possible. Although the viscosity of the organic solvent changes with the dissolution of the plastic component, the organic solvent in which the plastic is dissolved can be regenerated because the dissolved plastic component can be removed by a method such as heat distillation.

In order to properly separate waste plastic into a plastic component and a flame retardant component in an organic solvent, the temperature condition of the organic solvent is adjusted by melting the plastic component contained in the waste plastic and decomposing it into a gaseous state by thermal decomposition. It is necessary to set the temperature condition such that no product is generated and the flame retardant component contained in the waste plastic is not decomposed or volatilized. The temperature condition (heating temperature) of this organic solvent differs to some extent depending on the properties of the plastic, etc.
The temperature may be set to 00 ° C, preferably 100 to 200 ° C. The waste plastic is immersed in an organic solvent heated to such a temperature, and the waste plastic is combined with a plastic component and a flame retardant component (organic bromine compound, inorganic compound, etc.). To separate.

The reaction in which chlorine contained in vinyl chloride is desorbed as hydrogen chloride gas starts at about 200 ° C.
Finish at about 350 ° C. Therefore, under the above temperature conditions, it is possible to remove chlorine in vinyl chloride contained in waste plastic. Hydrogen chloride gas desorbed from vinyl chloride can be recovered as hydrochloric acid, for example, in a hydrochloric acid recovery device, or can be neutralized with an alkali.

The processing time (immersion time) of the waste plastic in the organic solvent is about 1 to 30 minutes, preferably 5 to 20 minutes.
It is appropriate to set it to about a minute. The processing pressure may be in the range of normal pressure or the autogenous pressure of the organic solvent at the processing temperature. For this reason, a special mechanism such as an airtight mechanism and a valve in the processing tank is not required, and the processing apparatus can have a simple device configuration. Note that the atmosphere in which the waste plastic is immersed in the organic solvent is an inert gas (nitrogen, argon, etc.) in order to prevent oxidation of plastic components in the organic solvent, combustion of volatile components and the like, or generation of dioxin and the like. It is preferable to use a non-oxidizing gas atmosphere such as a gas atmosphere.

The plastic component and the flame retardant component separated in the organic solvent are each recovered from the organic solvent. Among these, the separated form of the plastic component in the organic solvent may be either dissolved in the organic solvent, or suspended (solid and / or liquid) in the organic solvent, or These are coexisting. When the plastic component is in the above-mentioned state, the organic solvent and the plastic component can be separated by a distillation apparatus of, for example, heating distillation or reduced pressure distillation. Also, when the plastic component is in the above state,
For example, when a part or all of the plastic component is in a liquid state and suspended in an organic solvent, the organic solvent is solidified by solidifying the organic solvent as necessary to form a solid phase (solid or semi-solid). After cooling to a temperature at which the organic solvent and the plastic component can be separated by a solid-liquid separator such as a filter press, a screen press, and a centrifuge.

If the plastic component in the organic solvent is in the coexisting state described above, for example, if a part or all of the plastic component is in a liquid state and suspended in the organic solvent, it is optional. After cooling the organic solvent to a temperature at which the liquid plastic component solidifies to a solid phase (solid or semi-solid), the organic solvent and the plastic component are separated by the solid-liquid separation device, and then heated. distillation,
The plastic component dissolved in the organic solvent can be separated by a distillation apparatus such as vacuum distillation.

Further, since the flame retardant component is settled and separated in an organic solvent, it can be separated from the organic solvent by a solid-liquid separation device such as a filter press, a screen, a centrifuge, and a vibrating sieve. Since the inorganic flame retardant has very low solubility in an organic solvent and has a higher specific gravity than an organic solvent, it is also sedimented and separated in an organic solvent and separated and recovered in the same manner as a flame retardant component. You.

The plastic component recovered as described above does not contain a halogen component (chlorine or bromine) which is a source of corrosive gas or dioxin, and therefore, has a fuel and / or a fuel for a furnace such as a blast furnace. It can be used as an iron source reducing agent. In this case, the plastic component recovered from the organic solvent is crushed into a shape suitable for the raw material of the furnace, and processed into a fuel and / or iron source reducing agent for the furnace.

FIG. 1 is a flowchart showing one embodiment of the present invention. In the figure, 1 is a processing device (separation reactor), 2
Is a separation device for separating an organic solvent and a plastic component, 3 is a separation device for separating an organic solvent and a flame retardant component, 4 is an organic solvent tank, 5 is a crushing treatment device, and 6 is a generated gas treatment device. It is. In the embodiment shown in FIG. 1, the organic solvent filled in the processing apparatus 1 is heated to the above-described temperature, and waste plastic containing a flame retardant component is supplied to the organic solvent and subjected to immersion processing.

The waste plastic immersed in the organic solvent in the processing apparatus 1 is separated into a plastic component and a flame retardant component. As described above, the form of the separated plastic component in the organic solvent is one of a state of being dissolved in the organic solvent, a state of being suspended in the organic solvent, and a state of coexistence thereof. Further, the flame retardant component is settled and separated in the organic solvent.

For this reason, the organic solvent containing the plastic component in the processing device 1 is supplied to the separation device 2 by a suitable supply means, and the plastic component is separated and recovered from the organic solvent. The organic solvent containing the sedimented and separated flame retardant component is also supplied to the separation device 3 by an appropriate supply means, and the flame retardant component is separated and recovered from the organic solvent.

When the plastic component is present in the organic solvent in the above-described form, for example, the separation device 2 may be constituted by a distillation device that separates the plastic component from the organic solvent by a treatment such as heat distillation or vacuum distillation. Yes, but not limited to this. When the plastic component is present in the organic solvent in the above-described form, for example, the separation device 2 is configured by a solid-liquid separation device such as a filter press, a screen, a centrifugal separator, and a vibrating sieve. If a part or all is suspended in an organic solvent in a liquid state, the organic solvent is cooled to a temperature at which the liquid plastic component solidifies to a solid phase (solid or semi-solid) if necessary. After that, the plastic component can be separated from the organic solvent by the solid-liquid separation device, but is not limited thereto.

When the plastic component in the organic solvent coexists with the above, for example, the solid-liquid separation device and the distillation device for performing heating distillation, reduced pressure distillation and the like are provided as the separation device 2. If some or all of the plastic component is suspended in an organic solvent in a liquid state, the organic solvent may be solidified by solidifying the organic solvent into a solid phase (solid or semi-solid) if necessary. After cooling to a certain temperature, the organic solvent and the plastic component are separated by the solid-liquid separation device, and then the plastic component dissolved in the organic solvent is separated by the distillation device. The separation device 3 for separating an organic solvent and a flame retardant component.
Can be constituted by a solid-liquid separation device such as a filter press, a screen, a centrifuge, and a vibrating sieve, but is not limited thereto.

The organic solvent separated from the plastic component and the flame retardant component by the separation devices 2 and 3 is sent to the organic solvent tank 4 and is circulated to the treatment device 1. The plastic component separated from the organic solvent is crushed by the crushing device 5 to a particle size that can be put into a furnace such as a blast furnace. The crushing device 5 may be a single-shaft crusher, a two-shaft crusher, or the like, regardless of its type, as long as it can crush plastic to a particle size that can be put into a furnace.

The gas generated in the processing apparatus 1 is sent to a generated gas processing apparatus 6, where it is rendered harmless. For example, when the generated gas contains hydrogen chloride,
It is preferable to provide a hydrochloric acid recovery device for recovering hydrogen chloride as hydrochloric acid or a neutralization device for neutralizing hydrogen chloride with alkali. Further, the generated gas treatment device 6 may be provided with a combustion furnace for burning the generated gas, and provided with the hydrochloric acid recovery device or the neutralization treatment device for detoxifying hydrogen chloride downstream thereof. May be.

[0026]

[Example 1] Polystyrene resin 50 containing 20% by weight of tetrabromobisphenol A as a flame retardant component and 4% by weight of antimony trioxide as a flame retardant aid component.
g was immersed for 15 minutes in 500 ml of kerosene (initial runoff temperature 165 ° C.), an organic solvent heated to 150 ° C., and then a plastic component, a flame retardant component, and a flame retardant auxiliary component were recovered from the organic solvent, respectively. Then, the recovery rates of the plastic component, the flame retardant component and the flame retardant auxiliary component were determined. At the same time, the decomposition rate of plastic was determined from the components of the generated gas, and the content of bromine (bromine derived from the flame retardant component) in the recovered plastic component was measured. Table 1 shows the results.

The recovery of the plastic component from the organic solvent is carried out by taking out the organic solvent in which the plastic component is dissolved, and subjecting the same to a vacuum evaporator to separate the plastic component dissolved in the organic solvent. The amount of plastic recovered was measured to determine the recovery of plastic components. Further, the flame retardant component and the flame retardant auxiliary component precipitated in the organic solvent were subjected to solid-liquid separation using a filter press together with the organic solvent to separate the flame retardant component and the flame retardant auxiliary component.

[Inventive Example 2] An organic solvent obtained by heating 50 g of a polystyrene resin containing 15% by weight of decabromodiphenyl oxide as a flame retardant component and 3% by weight of antimony trioxide as a flame retardant aid component was heated to 150 ° C. After performing a treatment of immersing in 500 ml of kerosene (initial flowing temperature: 165 ° C.) for 15 minutes, a plastic component, a flame retardant component, and a flame retardant auxiliary component are respectively recovered from the organic solvent in the same manner as in Example 1 of the present invention. The recovery rates of the plastic component, the flame retardant component and the flame retardant auxiliary component were determined. At the same time, determine the decomposition rate of plastic from the components of the generated gas,
The content of bromine (bromine derived from the flame retardant component) in the recovered plastic component was measured. Table 1 shows the results.

[Invention Example 3] An organic solvent obtained by heating 50 g of a polystyrene resin containing 15% by weight of decabromodiphenyl oxide as a flame retardant component and 3% by weight of antimony trioxide as a flame retardant aid component to 130 ° C. After performing a treatment of immersing in 500 ml of kerosene (initial flowing temperature: 165 ° C.) for 25 minutes, a plastic component, a flame retardant component and a flame retardant auxiliary component are respectively recovered from the organic solvent in the same manner as in Example 1 of the present invention. The recovery rates of the plastic component, the flame retardant component and the flame retardant auxiliary component were determined. At the same time, determine the decomposition rate of plastic from the components of the generated gas,
The content of bromine (bromine derived from the flame retardant component) in the recovered plastic component was measured. Table 1 shows the results.

According to Table 1, by treating the waste plastic by the method of the present invention, the plastic component and the flame retardant component (and the flame retardant auxiliary component) can be respectively recovered at a high recovery rate. It can be seen that the amount of bromine in the recovered plastic can be extremely low. Therefore, the separated and recovered plastic component can be suitably used as a fuel for a furnace such as a blast furnace and / or an iron source reducing agent.

[0031]

[Table 1]

[0032]

As described above, according to the present invention, the plastic component and the flame retardant component can be efficiently and reliably separated and recovered from the waste plastic, respectively. Therefore, the flame retardant separated from the waste plastic can be obtained. A plastic component containing no component can be incinerated without generating harmful substances such as dioxin or an organic bromine compound causing corrosion, or can be used as a furnace fuel or an iron source reducing agent. Further, it becomes possible to efficiently recover the flame retardant component and the flame retardant auxiliary component from the waste plastic.

Further, according to the invention of claim 2 of the present application, the plastic component separated from the waste plastic can be appropriately used as a furnace fuel or an iron source reducing agent. Harmful substances and organic bromine compounds which cause corrosion can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a flow of an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing apparatus, 2, 3 ... Separation apparatus, 4 ... Organic solvent tank, 5 ... Crushing processing apparatus, 6 ... Generated gas processing apparatus

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Hiroba 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Tatsuro Ariyama 1-1-2 Marunouchi, Chiyoda-ku, Tokyo No. Nippon Kokan Co., Ltd. F-term (reference) 4F070 AA07 AA08 AA13 AA15 AA18 AA32 AA50 AB09 AB23 AB26 AC32 AC35 AE28 BA02 BA04 BB05 DA43 DC11 4F301 AA15 AB01 CA04 CA09 CA14 CA33 CA65 CA72 4H015 AA02 AA12 CA12 CB12

Claims (2)

[Claims] 1. A waste plastic containing a flame retardant component is immersed in an organic solvent heated to 100 to 300 ° C. and separated into a plastic component and a flame retardant component, and the separated plastic component and the flame retardant component are separated. Each of which is recovered from an organic solvent. 2. The waste plastic containing a flame retardant component according to claim 1, wherein the plastic component recovered from the organic solvent is crushed to be processed into a furnace fuel and / or an iron source reducing agent. Processing method.