JP3596173B2 - How to make plastic oil - Google Patents

Description

【００４３】
表１の結果から、水蒸気を導入した場合に油化促進効果が高いことがわかる。また固体酸触媒を用いると、さらに油化促進効果が高いことがわかる。[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for converting a plastic, particularly a mixed plastic containing polyolefin and polystyrene, into oil by subjecting it to thermal decomposition to obtain an oily substance.
[0002]
[Prior art]
A method of using a solid acid catalyst such as silica-alumina, zeolite, or the like as a method for thermally decomposing a plastic to oil is known (for example, JP-A-48-967, JP-A-48-43075, and JP-A-59-43075). No. 111815). Such a solid acid catalyst is said to be highly effective in oiling plastics containing polyolefins such as polyethylene and polypropylene.
[0003]
However, in the conventional method, the catalytic activity of the solid acid catalyst cannot be said to be sufficient, and the oiling rate is insufficient. In particular, when a mixed plastic containing polystyrene in a plastic containing a polyolefin such as polyethylene or polypropylene is oiled, the activity of the catalyst is reduced, so that the oil cannot be efficiently oiled.
[0004]
Japanese Patent Application Laid-Open No. 49-20284 discloses that when a mixture of polyethylene, polystyrene, polypropylene and vinyl chloride having a ratio of 3/3/2/2 is made into oil using Kanuma soil as a catalyst, polyethylene, polypropylene It is shown that the activity of the catalyst is lower than in the case of sole oilification. The catalyst with reduced activity has carbon adhered to its surface, and a method of regenerating the deteriorated catalyst by firing at 600 ° C. is described.
[0005]
On the other hand, Japanese Patent Application Laid-Open No. 6-220458 discloses that, when converting polystyrene into oil, the melt is pyrolyzed to separate and remove gas components, and then the oil is gasified in a heating furnace and brought into contact with a catalyst to reduce lightness. The method of conversion is shown. In this method, a light gas component generated in the first thermal decomposition is removed to prevent the gas component from being further decomposed by the catalyst into lighter components, thereby reducing the amount of oily substances produced. For this reason, no consideration is given to a reduction in the activity of the catalyst during the oiling of the mixed plastic.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to propose a method of oiling a plastic that can efficiently oilify, particularly a method of oiling a plastic that can efficiently oilify a mixed plastic containing polystyrene in addition to polyolefin. is there.
[0007]
[Means for Solving the Problems]
The present invention is the following method for oiling plastic.
(1) In a method for producing an oily substance by thermally decomposing a plastic , the degree of crystallinity determined by the following formula (1) from the intensity of a diffraction line spectrum measured by a powder X-ray diffraction method is 5% or less. Wherein the weight ratio (SiO ₂ / Al ₂ O ₃ ) of silica to alumina is 90/10 to 65/35 and the acid value is 0.4 mg KOH / g or less. A method for converting a plastic into oil, comprising performing thermal decomposition while supplying water to a reaction system in the presence of an alumina catalyst .
Crystallinity = [S ₁ / (S ₁ + S ₂ )] × 100 (%) … (1)
(In the formula, S ₁ is the area of the spectrum whose diffraction angle 2θ is in the range of 22 to 42 degrees, and S ₂ is the area of the spectrum whose diffraction angle 2θ is in the range of 20 to 70 degrees.)
(2) synthetic silica-alumina catalyst, silica and the weight ratio of alumina plastic oil of the (1), wherein the (SiO ₂ / Al ₂ O ₃₎ is 80 / 20-70 / 30 Method.
(3) The method according to (1) or (2 ), wherein the synthetic silica-alumina catalyst has an acid value of 0.1 mgKOH / g or less.
(4) The method according to any one of the above (1) to (3) , wherein the synthetic silica-alumina catalyst has a specific surface area of 400 m ² / g or more.
(5) The method according to any one of the above (1) to (4) , wherein the thermal decomposition of the plastic is performed in a range of 150 to 600 ° C.
(6) The method according to any one of the above (1) to (5) , wherein the plastic is a mixed plastic containing polyolefin and polystyrene.
[0008]
The plastic to be oiled in the present invention is not particularly limited, and may be any of a thermoplastic resin or a thermosetting resin, but those containing a polyolefin, particularly those containing a polyolefin as a main component are suitable as the target. I have.
Examples of the thermoplastic resin include polyolefin (PO) such as polyethylene (PE) and polypropylene (PP), polystyrene (PS), high-impact polystyrene (HIPS), ABS resin, ethylene-vinyl acetate copolymer resin (EVA), Examples include vinyl chloride (PVC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA, nylon), and polycarbonate (PC). Examples of the thermosetting resin include a phenol resin, a melamine resin, a urea resin, an alkyd resin, and polyurethane (PU). These plastics may be used alone or as a mixture of two or more.
[0009]
Among the above plastics, polyolefins such as polyethylene and polypropylene and mixtures thereof, or these polyolefins are 60 to 99% by weight, preferably 70 to 90% by weight, and polystyrene 40 to 1% by weight, preferably 30 to 10% by weight. A mixture of plastics containing (a mixed plastic) is preferred.
[0010]
Examples of plastics to be oiled include waste plastics contained in municipal waste, industrial waste, and the like. Such waste plastics are generally discharged in a state in which various plastics are mixed, but such mixed plastics may be sorted out in advance, or may be directly oiled without being sorted out.
[0011]
Plastics to be oiled include waxes, rubbers, elastomers, and the like, in addition to those classified as so-called resins. Specific examples thereof include the following.
-Ethylene waxy polymer or grease-like polymer.
-A propylene-based wax-like polymer or grease-like polymer, for example, atactic polypropylene.
A synthetic rubber, for example, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), styrene-butadiene copolymer rubber (SBR), butadiene-acrylonitrile copolymer rubber (NBR), Chloroprene rubber (CR), polyisoprene rubber (IR), butyl rubber (IIR), polybutadiene rubber (BR) and cross-linked products (vulcanizates) thereof, thermoplastic elastomers, for example, ethylene-propylene-non-conjugated diene copolymer rubber / Partially cross-linked products of polyethylene compositions, styrene-butadiene copolymer hydrides, and synthetic "hydrocarbon resins" such as "petroleum resins".
[0012]
In the method of the present invention, to use a solid body acid catalyst.
The solid acid catalysts is a solid having acidic, that having a function of promoting lightening plastic (low molecular weight) in a heated state.
[0014]
This onset Ming as a solid acid catalyst, using a solid acid catalyst of silica-alumina. The catalyst is a catalyst composed mainly of silica-alumina, specifically a amorphous or low-crystalline synthetic silica-alumina.
[0015]
Silica-alumina is a composite oxide of silica and alumina, also referred to as aluminosilicate, clay naturally occurring, including mineral and synthetic zeolites such as synthetic silica of amorphous as a solid acid catalyst in the present invention - to use the alumina. In particular, from the intensity of the diffraction line spectrum measured by the powder X-ray diffraction method, the degree of crystallinity determined by the above formula (1), that is, the range of the diffraction angle 2θ seen in the chart measured by the powder X-ray diffraction method, spectrum area in the range of 22 to 42 degrees (S _1), and the area in the range of diffraction angle 2θ is in the range of 20 to 70 degrees spectrum (S _2), is determined by the equation (1) crystals degree is 5% or less, preferably 1% or less, the weight ratio of silica to alumina _{(SiO 2 / Al 2 O 3} ) is (90/10) - (65/35), preferably (80/20 ) To (70/30) and a synthetic silica-alumina having an acid value of 0.4 mgKOH / g or less, preferably 0.1 mgKOH / g or less. Further, among such synthetic silica-aluminas, silica-alumina having a specific surface area of 400 m ² / g or more, preferably 500 m ² / g or more, as measured by the BET method, is desirable.
[0016]
The synthetic silica-alumina catalyst, wherein at Property values can be used those in earlier Kihan circumference, wherein the physical property value is silica-alumina which are all preferred range and most preferred. But there the particular physical properties are preferred ranges, and other physical properties can be used as preferred silica-alumina is in said range.
[0019]
In order to convert a plastic into oil by the method of the present invention, the plastic is thermally decomposed while supplying water to a reaction system. This speeds up the oiling of the plastics and produces an oil. As a method for supplying water to the reaction system, it is preferable to continuously or intermittently supply steam into the reactor, but it is preferable to supply liquid water into the reactor to generate steam in the reactor. It may be. These may be combined.
In the method of the present invention, when catalytic pyrolysis in the presence of the solid acid catalyst while supplying water to the reaction system, Yuka rate (degradation rate) may turn faster.
[0020]
When water or liquid water is continuously supplied into the reactor, the supply amount of water is 0.1 to 1000 μl / min, preferably 1 to 100 μl / min in terms of liquid water per 1 g of the raw material plastic. It is desirable to supply in the amount of. In the case of intermittent supply, it is preferable to introduce such that the averaged amount is the same as the above as a continuous supply.
In addition, water mixed in the cracked oil obtained by the method of the present invention can be removed by oil-water separation, dehydration treatment or the like as necessary.
[0021]
It is desirable to set the decomposition temperature of the plastic at 150 to 600 ° C, preferably 250 to 500 ° C, and the reaction time at 0.1 min to 5 hr. The atmosphere of the reaction system may be any atmosphere as long as the reaction is not hindered. For example, the decomposition can be performed in a nitrogen atmosphere.
The amount of solid acid catalysts is 0.01 to 20 wt% with respect to the plastic, preferably desirable to 0.1 to 10 wt%.
[0022]
The reactor used for the thermal decomposition of the plastic may be any type such as a tank type, a screw type, a pipe type and the like. As a specific example of the decomposition reaction device, a plastic to be oiled is heated to 150 to 600 ° C., preferably 250 to 500 ° C. in a tubular decomposition furnace provided with a conveying screw and steam supply means in the tube. There is a device provided with a mechanism. Since this type of decomposition reactor has a continuous decomposition capability, it is suitable for a processing facility where a large amount of plastic is constantly (continuously) accumulated.
[0023]
In the method of the present invention, the plastic is pyrolyzed while supplying water to the reaction system, so that the plastic can be efficiently converted to oil. In particular, even when a mixed plastic containing polystyrene in addition to polyolefin is oiled, the oil can be efficiently oiled.
[0024]
The oil obtained by the method of the present invention can be used for fuels, raw materials, and any other uses. The solid acid catalyst may be mixed with the oily substance, but may be separated and collected for reuse.
[0025]
【The invention's effect】
The method for converting a plastic to oil according to the present invention is a method for producing an oily substance by thermally decomposing a plastic, wherein the crystallization obtained by the calculation formula (1) from the intensity of the diffraction line spectrum measured by the powder X-ray diffraction method. degrees is a less than 5% synthetic silica-alumina catalyst, the weight ratio of silica to alumina _{(SiO 2 / Al 2 O 3} ) is 90 / 10-65 / 35, acid value of 0.4 mgKOH / g Since plastic is thermally decomposed while supplying water to the reaction system in the presence of the following synthetic silica-alumina catalyst, even if the plastic is a mixed plastic containing especially polyolefin and polystyrene, it is efficiently oiled. be able to.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, examples of the present invention will be described.
Example 1
As the solid acid catalyst, silica-alumina [manufactured by Sekiyu Kasei Kogyo Co., Ltd., silica-alumina HA, crystallinity = 0% determined by the above formula (1), weight ratio of SiO ₂ / Al ₂ O ₃ = 71 / 29, acid value = 0 mgKOH / g, surface area measured by BET method = 510 m ² / g], and then pulverized to fractionate particles having a particle size of 18 to 50 mesh. The acid value of silica / alumina was determined by adding 50 ml of water to 1 g of the catalyst, boiling for 30 minutes with stirring, filtering, and titrating the filtrate with a 0.01 mol KOH aqueous solution.
[0027]
5 g of high-density polyethylene, 2 g of polypropylene, and 3 g of polystyrene were placed in a quartz reactor having a capacity of 200 ml with a distillate receiver, and the inside of the reactor was replaced with nitrogen. After heating to about 350 ° C. under normal pressure, 0.1 g of the above silica-alumina catalyst was added.
[0028]
Next, the water was heated to steam and introduced into the reactor. The introduction of steam was performed as liquid water at a rate of 50 μl / min.
The temperature of the reactor was raised to 430 ° C., and a catalytic cracking reaction was carried out until 8 ml of the cracked oil was distilled off, and the resultant was divided by a required time to obtain an average distillation rate. As a result, the average distillation speed was 1.07 ml / min. The weight of the cracked oil was 7.2 g, and the amount of the residue remaining in the reactor was 2.4 g.
[0029]
Example 2
The procedure was performed in the same manner as in Example 1 except that the catalyst addition temperature was changed to 300 ° C., and the introduction rate of water vapor was changed to 25 μl / min as liquid water. Table 1 shows the results.
[0030]
Example 3
Example 1 was repeated except that the raw material plastic was changed to a plastic containing 7 g of high-density polyethylene and 3 g of polypropylene, and the introduction rate of water vapor was changed to 25 μl / min as liquid water. Table 1 shows the results.
[0031]
Example 4
Example 1 was carried out in the same manner as in Example 1, except that 0.1 g of a catalyst obtained by treating silica alumina HA with a 1.0 mol / l Cu (NO ₃ ) ₂ solution was used instead of silica alumina HA. Table 1 shows the results.
[0032]
Comparative Example 1
The procedure was performed in the same manner as in Example 1, except that 0.1 g of Kanuma Dou Pumice was used as a catalyst instead of silica alumina HA. Table 1 shows the results.
[0033]
Example 5
The same operation as in Example 1 was performed except that 10 g of polystyrene was used as a raw material plastic and the amount of the catalyst was changed to 0.2 g. Table 1 shows the results.
[0034]
Comparative Example 2
The same operation was performed as in Example 1 except that no catalyst was used. Table 1 shows the results.
[0035]
Comparative Example 3
The same operation as in Example 1 was performed except that 0.3 g of the same silica-alumina catalyst as in Example 1 was used and no steam was introduced. As a result, the average distillation rate was 0.47 μl / min, the weight of the cracked oil was 6.7 g, and the amount of the residue remaining in the reactor was 2.6 g.
[0036]
Comparative Example 4
The procedure was performed in the same manner as in Example 3 except that no steam was introduced. Table 1 shows the results.
[0037]
Comparative Example 5
Example 1 was repeated except that no catalyst was used and no steam was introduced. Table 1 shows the results.
[0038]
Comparative Example 6
The same operation as in Example 3 was performed except that no catalyst was used and no steam was introduced. Table 1 shows the results.
[0039]
Comparative Example 7
The same operation as in Example 4 was performed except that no steam was introduced. Table 1 shows the results.
[0040]
Comparative Example 8
The same procedure was performed as in Comparative Example 1 except that no steam was introduced. Table 1 shows the results.
[0041]
Comparative Example 9
The procedure was performed in the same manner as in Example 5 , except that no steam was introduced. Table 1 shows the results.
[0042]
[Table 1]

[0043]
From the results in Table 1, it can be seen that the effect of promoting oiling is high when steam is introduced. In addition, it can be seen that the use of a solid acid catalyst further enhances the effect of promoting oiling.

Claims (6)

In a method for producing an oily substance by pyrolyzing a plastic, a synthetic silica having a crystallinity of 5% or less determined by the following formula (1) from the intensity of a diffraction line spectrum measured by a powder X-ray diffraction method: An alumina catalyst, wherein the weight ratio (SiO ₂ / Al ₂ O ₃ ) of silica to alumina is 90/10 to 65/35 and the acid value is 0.4 mgKOH / g or less; A method for liquefying plastics, comprising performing thermal decomposition while supplying water to a reaction system in the presence of water.
Crystallinity = [S ₁ / (S ₁ + S ₂ )] × 100 (%) … (1)
(In the formula, S ₁ is the area of the spectrum whose diffraction angle 2θ is in the range of 22 to 42 degrees, and S ₂ is the area of the spectrum whose diffraction angle 2θ is in the range of 20 to 70 degrees.) The synthetic silica-alumina catalyst uses a weight ratio of silica to alumina (SiO _Two / Al _Two O _Three ) Is from 80/20 to 70/30. 3. The method according to claim 1, wherein the synthetic silica / alumina catalyst has an acid value of 0.1 mg KOH / g or less. The synthetic silica / alumina catalyst has a specific surface area of 400 m. ^Two The method according to any one of claims 1 to 3, wherein the amount is not less than / g. The method according to any one of claims 1 to 4, wherein the thermal decomposition of the plastic is performed in a range of 150 to 600C. 6. The method according to claim 1, wherein the plastic is a mixed plastic containing polyolefin and polystyrene.