JPS5913273B2 - How to pyrolyze old tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for pyrolyzing old tires, which results in pyrolysis products, a mixture of gas and oil vapor having a wide boiling point range.

In the conventional method for thermally decomposing old tires, the decomposition products are directly cooled and condensed using a heat exchanger, so clean light oil or heavy oil with a high flash point cannot be obtained.

Therefore, the oil obtained by the conventional method has a low flash point, is dangerous, and is dirty, making it difficult to use as a fuel.

Moreover, if a distillation device is not installed, the produced oil as described above must be further passed through the distillation device.
This required a large amount of extra heat energy and was not economically desirable.

The present invention provides easy operation adjustment in the pyrolysis process, easy recovery of char, easy fractional recovery of high quality light oil and heavy oil in the fractionation process, and thermoeconomics. The purpose of this invention is to provide an excellent method for pyrolyzing old tires.

That is, in the present invention, by using a pyrolysis furnace that has an internal screw transfer device and heats from the outside, adjustment is easy, and it can be used in a distillation column having two or more fractionation stages. By directly introducing high-temperature pyrolysis steam and performing fractional distillation, it is possible to reliably perform fractional distillation into clean light oil and heavy oil, and also to remove the sensible heat and condensation heat of the pyrolysis steam. By utilizing this, there is no need to use a large amount of separate heat source, and one embodiment thereof will be described with reference to the drawings.

The figure schematically shows an apparatus suitable for carrying out the method of the invention.

Referring to FIG. 1, a case will be described below as an embodiment of the present invention in which old tires are thermally decomposed to produce carbon, heavy fuel oil, naphtha, cracked gas, etc.

The pyrolysis device consists of a hopper 2 that receives old tires 1 crushed into appropriate sizes, a screw set transfer device 3 that takes out the crushed tires from the bottom of this hopper 2 and transfers them, and a screw-based transfer device 3 that takes out the crushed tires from the bottom of the hopper 2 and transfers them. A pyrolysis furnace 4 that receives heat from the furnace and heats and decomposes it, a burner 5 that heats the furnace 4 from the outside, a transfer pipe 6 that takes out the gaseous decomposition products at high temperature, and a pyrolysis furnace that receives and cools the gaseous decomposition products. a multistage fractional distillation column 7 that performs condensation and fractional distillation; a cooling condenser 8 that receives the gas at the top of the distillation column 1 and the gaseous low-boiling oil vapor and condenses the latter by cooling it; A receiving tank 9 that receives and separates condensed oil and gas, a pump 10 that returns part of this oil to the top of the distillation column 1 and sends out the other part as a product, and extracts heavy oil flowing down to the bottom of the distillation column 1. It consists of a pump 11 that pumps out water.

That is, the tire 1 crushed to an appropriate size is put into a hopper 2, and a certain amount is taken out from the bottom of the hopper 2 by a transfer device 3 and sent to a pyrolysis furnace 4.

Then, the tire 1 is heated to 500°C or higher in this pyrolysis furnace, and the tire 1 is pyrolyzed to produce char mainly composed of metal and carbon blank, gas containing hydrogen and methane, and oil vapor. do.

Of these, char falls from the end of the cracking furnace 4 and is discharged as shown by arrow 12.

Further, the gas and oil vapor are introduced into the distillation column 1 through the transfer pipe 6 in a high temperature state.

In this distillation column γ, low-temperature light oil condensed in a cooling condenser 8 connected to the top passes through a receiving tank 9 and a pump 10, a part of which is returned to the vicinity of the top, and flows down inside the column T. I'll come.

The high-temperature oil vapor introduced from the pyrolysis furnace 4 is cooled by this flowing down oil, and the heavy components condense and flow down to the bottom, while at the same time some of the light oil that has flowed down from the top evaporates. .

That is, in the upper half of the distillation column 7, the light oil vapor gas rises and comes into contact with the light oil flowing down from the top, causing the heavy components to almost completely flow down to the bottom, leaving only the light oil and gas at the top. Make sure to take it out.

On the other hand, in the lower half of the distillation column 1, the heavy oil condensed and flowing down is brought into contact with a small amount of steam (see arrow 13) blown into the bottom of the column, so that the light oil remaining in the heavy oil is almost completely removed from the steam. The oil is evaporated to 100% and extracted from the bottom of the tower using a pump 11 as heavy oil with a high flash point and substantially no light oil content.

Note that arrow 14 indicates the extraction of heavy oil, arrow 15 indicates extraction of light oil, and arrow 16 indicates extraction of gas.

By performing such thermal decomposition, the decomposition products are precisely fractionated into heavy oil and light oil without using a large amount of heat other than the heat required for thermal decomposition, and the decomposition products are separated into heavy oil and light oil with a high flash point. It can be divided into heavy oil and clean light oil.

Therefore, in the pyrolysis treatment of used tires, the present invention uses a pyrolysis furnace having a set of screw transfer devices inside to pyrolyze the shredded tires, so that the shredded tires can be reliably transferred. It is carried out continuously, the transfer rate can be easily adjusted, thermal decomposition can be carried out under optimal conditions, and the produced char can be easily recovered.

In addition, high-temperature pyrolysis vapor is introduced in its high-temperature state into a distillation column having multiple fractionation stages, and the sensible heat and condensation heat of the pyrolysis vapor are used as the main heat source required for fractionation. Since the oil is fractionated into light oil and heavy oil, these can be precisely fractionated.

That is, in order to obtain a light oil component with a high flash point, the amount of light oil component to be extracted can be maximized, and furthermore, a clean light oil component that does not contain heavy oil components can be extracted.

In addition, by using the sensible heat and condensation heat of pyrolysis steam, there is no need to use a large amount of separate heat source, which is not only extremely advantageous in terms of thermoeconomics. Since it can be placed at the top of the distillation column downstream, the effects of the present invention, such as less dirt than in the case of direct cooling, are extremely significant.

[Brief explanation of drawings]

The figure is an explanatory diagram of an embodiment of the present invention. 1...Shredded old tires, 2...Hopper, 3...Transfer device, 4...Pyrolysis furnace, 5... Burner, 6...Transfer pipe, 7
... Distillation column, 8 ... Condenser, 9 ...
...Receiving tank, 10, 11...Pump.

Claims (1)

[Claims] 1. In the pyrolysis treatment of old tires, a step of crushing the old tires into shredded tires, a step of supplying the shredded tires to the starting end of a pyrolysis furnace having a set of screw transfer devices inside, and a step of crushing the shredded tires. While the tires are moving through the pyrolysis furnace, the pyrolysis furnace is heated from the outside to pyrolyze the tires into char containing carbon blank as a main component, gas containing hydrogen and methane, and oil vapor. a step of discharging the char from the end of the pyrolysis furnace; a step of introducing the gas and oil vapor at high temperature into an intermediate section of a multi-stage distillation column; A step in which gas and low-boiling point oil vapor are introduced into a cooling condenser from the top and condensed; a T plug that separates the gas from the light oil condensed in the condenser; and a T-plug that separates the light oil of the separated low temperature. A step of returning a portion to near the top of the distillation column and taking out the remaining low-temperature light oil; It consists of a step of cooling high-temperature oil vapor to condense heavy oil and extracting the condensed heavy oil from the bottom of the distillation column, and in which the heat is used as the main heat source necessary for fractional distillation in the distillation column. Sensible heat and condensation of decomposition steam; A method for pyrolyzing old tires characterized by the use of heat.