JP3240403B2 - Waste plastic pyrolysis oil conversion system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION As one of effective uses of waste plastics, there is a method in which waste plastics are thermally decomposed and used as oil. The oil obtained by the pyrolysis includes a wide variety of oils, from low-boiling oil in gaseous state at room temperature to high-boiling oil in liquid or solid form.

[0002] The present invention is directed to a waste equipment provided with an apparatus for selectively reducing the molecular weight of only high-boiling oil contained in cracked oil produced by the thermal cracking of waste plastic to increase the recovery rate of medium-boiling oil. Plastic pyrolysis oil
Regarding the stem .

[0003]

2. Description of the Related Art In the thermal decomposition method of waste plastics, oils having a wide range of boiling point distributions are produced. However, high boiling point oils cause problems such as clogging of pipes and solidification of the pipes themselves. There is a need to. As a method for reducing the molecular weight of the high-boiling oil, there is a method in which a packed layer of a catalyst for reducing the molecular weight (such as silica or alumina) is provided in the middle of a pipe.

[0004] However, in this method, even a medium boiling oil or a low boiling oil is gasified with a low molecular weight, so that the recovery rate of the medium boiling oil is reduced, and furthermore, there is a problem of clogging of the pipe due to the installation of the catalyst packed bed. And so on.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to selectively remove only high-boiling oils and low-molecular-weight oils in order to avoid the above-described problems of lowering the recovery rate of medium-boiling oils and preventing blockage of pipes due to the installation of a catalyst layer. Equipped with a device for depolymerizing high boiling oil in pyrolysis products of waste plastics
An object of the present invention is to provide a waste plastic pyrolysis oil conversion system .

[0006]

DISCLOSURE OF THE INVENTION A waste plus according to the present invention
The Tic Pyrolysis Oil Conversion System has been devised to achieve the above-mentioned purpose, and is used to thermally decompose waste plastic.
High boiling point oil (oil that becomes waxy at room temperature) from cracking kettle and gaseous cracking oil coming from pyrolysis kettle
Tank that condenses the oil, a catalyst that is filled in the condensation tank and reduces the molecular weight of the condensed high-boiling oil to medium-boiling oil (oil that is liquid at room temperature), and a catalyst that is not depolymerized on the catalyst packed bed.
The high boiling oil which remains or those that an oil return pipe for returning to the thermal decomposition kettle.

[0007] As the catalyst, zeolite, silica
Alumina, silica / magnesia, activated clay and the like are preferably used. These may be used alone or in combination of two or more. The catalyst may carry a platinum group element as needed. The shape of the catalyst is granular (diameter 1 to 50).
mm), a honeycomb shape, a plate shape, or the like. Examples of the honeycomb-shaped catalyst include a catalyst in which silica / alumina is held in a honeycomb-shaped monolith block formed by alternately laminating corrugated ceramic paper and flat ceramic paper.

[0008] The condensing tank is preferably provided with a stirring means for stirring oil accumulated under the catalyst packed bed. As the stirring means, for example, a stirring blade is provided at the bottom of the condensing tank, or an oil circulation pipe for extracting condensed oil to the outside of the tank from below the catalyst packed bed of the condensing tank and returning it to the top of the catalyst packed bed. The stirring blade has a shape such that oil can be circulated and stirred up and down.

The condensing tank is provided with a heating means for heating the catalyst packed bed. As the heating means, for example, a heating furnace or an electric heater is provided around the catalyst packed bed. It is also possible to use waste heat from the heating furnace of the waste plastic pyrolysis oven. The heating temperature of the catalyst packed bed is preferably 20
0-350 ° C.

[0010] A wire mesh for suppressing the floating of the particulate catalyst is mounted on the catalyst packed layer. The wire mesh prevents the granular catalyst from floating from the catalyst packed bed and flowing out of the oil cracker into the pyrolysis tank.

An extraction pipe for extracting condensed oil in the condensing tank is provided at the bottom of the condensing tank. With this extraction pipe, all the condensed oil in the condensation tank can be extracted at the end of operation or in an emergency. This condensed oil is preferably returned to the pyrolysis kettle.

[0012] side of the condensing tank, replacement port for catalyst replacement is provided. With this replacement port, the catalyst packed bed can be easily replaced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be specifically described by the following examples.

[0014] In Embodiment 1 FIG. 1 is pyrolyzed by Yuka decomposition oil waste plastics charged into the pyrolysis kettle (1), including here in a wide variety of oil from the low-boiling oil to high boiling point oil. This cracked oil is sent from the top of the pyrolysis tank (1) to the upper part of the condensing tank (3) via the conduit (2). The condensing tank (3) is kept at a constant temperature. Of the cracked oil coming from the pyrolysis kettle (1),
Only high-boiling oils having a boiling point higher than that temperature (oils that become waxy at room temperature) are condensed at this temperature, and medium- and low-boiling oils having a boiling point lower than that temperature are not condensed. The medium / low boiling point oil is further condensed and recovered by a downstream condenser (not shown). Condenser (3)
As a result, the high-boiling oil condenses on the upper surface of the later-described catalyst packed bed (4).

A flue (11) is provided on the outer periphery of the condensing tank (3) for passing exhaust heat from the heating furnace of the waste plastic pyrolyzer, and the entire condensing tank (3) is maintained at about 300 ° C. ing.

From the center to the lower end of the height of the condensing tank (3), a catalyst for reducing the molecular weight of the condensed high-boiling oil to medium-boiling oil is filled. This catalyst has a particle size of about 30 mm.
Is ruthenium supported on granular silica-alumina. By this catalytic action, the condensed oil (high-boiling oil) is degraded into a gas (medium / low-boiling oil), which merges with the medium / low-boiling oil that has not been condensed in the condenser (3). (Not shown) for condensation and recovery.

At the bottom of the condensing tank (3), a stirring blade (5) is provided below the catalyst packed bed (4), and is driven to rotate by a motor (6). The stirring blade (5) has a shape capable of circulating and stirring oil up and down, and the reaction is promoted by the stirring blade (5).

An oil return pipe (7) for returning the high-boiling oil remaining without being depolymerized on the catalyst packed bed to the vicinity of the bottom of the pyrolysis tank (1) is provided slightly in the catalyst packed bed of the condensation tank (3). It is located near the bottom of the pyrolysis pot (1) from above. A wire mesh (8) for holding the granular catalyst is mounted on the catalyst packed bed so that the particulate catalyst together with the remaining high boiling point oil does not flow into the oil return pipe (7). A drain pipe (9) is provided at the bottom of the condenser tank (3) so that all condensed oil in the condenser tank (3) can be drained at the end of operation or in an emergency.
The other end of (9) is connected near the bottom of the pyrolysis kettle (1).

On the side of the condensing tank (3), a replacement port (10) for catalyst replacement is provided. With this replacement port (10),
The catalyst packed bed (4) can be easily replaced.

[0020] In Embodiment 2 FIG. 2, instead of providing the stirring blade at the bottom of the condensing tank (3), over the catalyst-packed layer by extracting condensed oil from below into Sogaibu catalyst-packed layer of the condensing tank (3) There is provided an oil circulation pipe (12) for returning the oil circulation pipe. Other configurations are the same as those of the first embodiment.

[0021]

EFFECT OF THE INVENTION Waste plastic pyrolysis oil according to the present invention
The system is configured as described above, so it is possible to selectively reduce the molecular weight of only high-boiling oil, and as a result, it is possible to effectively reduce the recovery rate of medium-boiling oil and block pipes due to the installation of a catalyst layer. Can be avoided.

[Brief description of the drawings]

FIG. 1 shows waste plastic heat fraction according to Embodiment 1 of the present invention.
It is a vertical sectional view showing an oil removal system .

FIG. 2 is a vertical sectional view of a lower part of a condensing layer according to a second embodiment of the present invention.

[Explanation of symbols]

 1: Pyrolysis furnace 2: Conduit 3: Condensation tank 4: Catalyst packed bed 5: Stirrer blade 7: Oil return pipe 8: Wire mesh 9: Extraction pipe 10: Replacement port 11: Flue 12: Oil circulation pipe

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-90281 (JP, A) JP-A-6-271868 (JP, A) JP-A-6-220458 (JP, A) JP-A-7-90 268354 (JP, A) JP-A-7-166170 (JP, A) JP-A-5-345894 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10G 1/10 ZAB B01J 23/40 B01J 23/46 301 B09B 3/00 C10G 11/02

Claims (1)

(57) [Claims] 1. A pyrolysis pot for pyrolyzing waste plastic
And a condensing tank for condensing high-boiling oil from the gaseous cracking oil coming from the pyrolysis tank, and a catalyst filled in the condensing tank and for decondensing the high-boiling oil into medium-boiling oil. When,
The high boiling oil which remains without being depolymerized over a catalyst-packed layer and an oil return pipe for returning to the thermal decomposition kettle, catalyst
But zeolite, silica-alumina, silica-magnesi
A, activated clay, a mixture of two or more of these, platinum
Selected from the group consisting of those carrying a group III element
Waste plastic pyrolysis and oiling system having a granular, honeycomb or plate shape .