BG2251U1 - Installation for low temperature pyrolysis of waste plastic materials with the addition of waste oils and greases - Google Patents

Abstract

The utility model concerning an installation for low temperature pyrolysis of a mixture of waste plastic materials with the addition of waste oils and greases is related to the processing industry, in particular to the preparation of low molecular weight hydrocarbons by means of low temperature pyrolysis of high molecular weight hydrocarbons. The problems with low temperature pyrolysis of waste plastic materials are the uneven heating of the initial raw material, incomplete course of the pyrolysis reactions, release of a large amount of solid particles in the pyrolysis gas and oil, and difficulty in the separation of the solid residue. The solution to the mentioned problems lies in the addition of waste oils and greases to the initial raw material of waste plastic products. During the pyrolysis of the resulting initial raw material mixture, the destruction reactions occur evenly in the entire volume. The attraction of solid particles from the pyrolysis gas is reduced and the separation and processing of the solid pyrolysis residue is facilitated. 1 claim, 1 figure

Description

Field of the art

The useful model refers to a low-temperature pyrolysis plant for a mixture of waste plastics with the addition of waste oils and shakes in the chemical processing industry, in particular to the production of low-molecular hydrocarbons by low-temperature pyrolysis of high molecular hydrocarbons.

State of the art

All plastics have low thermal conductivity. When subjected to pyrolysis, the plastics are heated extremely slowly and unevenly. This leads to partial pyrolysis of the starting mixture in the pyrolysis reactor. The mixture located in the immediate vicinity of the reactor's heating zones is more pyrolyzed than the mixture away from the heating zones. The resulting solid residue near the heating zones isolates the remainder of the feed mixture and prevents pyrolysis reaction throughout the mixture.

The disadvantage of this type of process is the need for small volume reactors and a large heating surface. When increasing the volume of the reactor, a residue of unprocessed feedstock is obtained, which solidifies in a monolithic block and there is a need to stop the purification reactor.

Pyrolysis oils, pyrolysis gas and a solid carbon residue are obtained by pyrolysis of waste plastics. The installations used are periodically active and their operation is expressed in the charging, heating of the raw material in the absence of oxygen. As a result of the temperature, the high molecular compounds are disrupted in low molecular weight. Upon completion of the pyrolysis process, the reactor is allowed to cool, the solid residue is removed and recharged for a new cycle. The primary pyrolysis gas produced in the reactor is passed to the next apparatus. During its cooling, pyrolysis oils and pyrolysis gas are released. Up to now, existing plants with the solid residue are removed from the reactor as a carbide solid. This leads to the need for immediate cooling to prevent ignition and dusting. In plastic pyrolysis installations, rotary reactors or agitator reactors are used. It is necessary to mix the starting mixture very intensively in order to avoid partial pyrolysis around the heating zones. The agitators and rotary reactors used are equipped with powerful electric motors and gearboxes. This leads to an increase in energy costs.

There are no known continuous low-temperature pyrolysis plants for waste plastics with the addition of waste oils and greases.

Technical nature of the utility model

The purpose of the utility model is to create a low-temperature pyrolysis plant for waste plastics with the addition of waste oils and greases.

The installation for low-temperature pyrolysis of waste plastics with the addition of waste oils and greases includes an input raw material hopper attached to a screw auger connected by means of a separating valve and a screw auger with a pyrolysis reactor. The reactor is equipped with a mechanical stirrer and a waste-oil supply nozzle, connected to the upper part by a scrubber by means of a non-return auger and a pipeline which is connected to another scrubber by means of a pipeline, the second scrubber being connected to the upper part by means of a pipeline buffer court. The buffer tank by means of filters is connected to a gas duct which is connected by a pipeline to another buffer vessel connected in series with a collector, a burner and a combustion chamber attached to the reactor, the lower part of the reactor being connected through a discharge auger to a discharge screw connected to solid residual vessel.

With the addition of waste oils and greases, the heat transfer in the feed mixture increases, thereby achieving uniform heating of the mixture throughout the volume.

The use of catalysts in pyrolysis reactions is poorly documented, since, after the reaction has been completed, catalysts

The 2251 ulcer can not be separated from the solid residue although it remains unchanged after the end of the reaction.

By adding waste oils and shakes to the feed mixture, it is possible to add zeolite catalyst in extremely small quantities and low cost. The remainder of the catalyst in the solid residue is in negligible amounts. The course of the pyrolysis reaction is uniform over the entire volume of the mixture. Keeping the technological process in the reactor is facilitated and allows the maintenance of constant parameters.

With the addition of waste oils and greases, the need for intensive stirring and breaking of the feed mixture is dropped and it is possible to use a mechanical stirrer with a rotational speed of up to 6 vol. / Hr. The pyrolysis reaction proceeds evenly throughout the volume.

Reduced release of solids (soot) in the primary pyrolysis gas is achieved in the plant. When adding waste oils and greases to the feedstock, the pyrolysis process proceeds evenly throughout the volume. Primary pyrolysis gas separation is a constant in volume ratio throughout the process. Since pyrolysis is low temperature - up to 450 ° C some of the components of waste oils and greases do not completely pyrolyze but evaporate. Immediately afterwards, they condense in the space above the reaction mixture, and the carbon nuclei (carbon black) are the condensation cores. The formed droplets are returned to the reaction mixture. This contributes to the very small amount of solid particles leaving the reactor with the primary pyrolysis gas.

Co-pyrolysis of waste plastics with the addition of waste oils and greases results in a thermoplastic starting material which allows molding, e.g. in the form of briquettes and facilitates further use.

An explanation of the attached figure

Figure 1 is a schematic view of the waste pyrolysis plant with the addition of waste oils and greases.

Examples of performance model implementation

The waste pyrolysis plant with the addition of waste oils and greases consists of the following modules:

- Input / output devices for input of the raw material and removal of the products

- Pyrolysis reactor

- Contact capacitor - a system of two scrubbers

- Gas tract

- Control system

All the apparatuses included in the installation and the connections between them are noted in the flow diagram of Fig. 1. The raw material is poured into the inlet hopper 1 and transferred to a reactor 5 via a screw auger system. Waste plastics must be crushed into small pieces up to 40 mm and the content of other substances and impurities should not exceed 5%. Depending on the condition, the waste greases are transferred by a screw auger 2. The waste oils are fed by a dosing pump directly into the reactor 5. By means of auger 2, the raw material passes through the valve 3 into the auger 4. The auger turns 2 are adjusted so that the plant an optimal amount of raw material is consumed. This ensures a constant supply of raw material and prevents the entry of oxygen into the system. This is accomplished by means of a valve 3. The reactor 5 is filled with a liquid obtained in the catalytic process by first melting the feedstock. A mechanical stirrer 6 is mounted in the reactor 5 for homogenization. The mixture is heated rapidly to a temperature of 380-400 ° C, and its thermal decomposition begins. In this shock heat, mainly liquid fractions or so-called " pyrolysis oils. They interact with the catalyst and further break down the hydrocarbon bonds. As a result, primary pyrolysis gas exiting the reactor through device 11 is formed. The temperature in the pyrolysis reactor 5 is maintained by a combustion system consisting of a high temperature combustion chamber 8 and a burner 7. The system is adapted to burn the purified pyrolysis gas. The combustion is carried out without emitting harmful emissions of gases due to the high temperature combustion in the chamber 8. From the lower part of the reactor 5, the solid residue is removed due to its higher density and is removed by means of a screw 13. The turns of this auger are adjusted according to the level of the reaction mixture in a reactor

2251 ul

5. From the auger 13, the heavy ingredients, by means of auger 14, are discharged into a vessel 15 which simultaneously cools the solids and provides a hydraulic outlet for the outlet. The steam gas mixture of the primary pyrolysis gas is removed from the reactor 5 in the auger capacitor 11 by a line. There is the condensation of the heaviest fraction with a condensation temperature above 350 ° C, which is returned back to reactor 5. The non-condensed vapors pass into a scrubber through a tubular line where it condenses the average pyrolysis fraction (impregnation oil). Residual vapors after scrubber 16 pass into a scrubber 19 along a tubular line. It condenses the so-called. slightly pyrolytic oil. The temperature control in scrubbers 16 and 19 is automatic by means of circulation pumps 20 and coolers 18 and 21. Residual non-condensable gases after scrubber 19 are introduced via a tubular line into a buffer vessel 22 that also acts as a dropper. Buffer vessel 22 is connected to a gas line 23. A line 25 and 26 are mounted on the line between the buffer vessel 22 and the gas duct 23 for catching the finest drops of gas. Piston 23 is connected to a conduit to a second buffer vessel 24 and from there to a conduit to a collector 9 and a burner 7. Flow through the entire gas tract from reactor 5 to a burner 7 is maintained by a gas 23 and from the reactor to the gas path 23 the tread is below vacuum, and from the gas 23 to the burner 7 is under pressure. Upon initial startup of the preheating system, propane-butane gas from a gas bottle 10 is connected, which is connected to a collector 9.

Claims (1)

Claims An installation for low-temperature pyrolysis of waste plastics with the addition of waste oils and greases, characterized in that it comprises an inlet hopper (1) for raw material attached to a screw auger (2) connected by means of a separating valve (3) and an insertion screw (5) is connected to a scrubber (16) by means of a reciprocating auger (11) and a conduit (5) connected to the pyrolysis reactor (5) and the scrubber (16) is connected to a scrubber (19) with a pipeline, the scrubber (19) a pipeline at its upper part is connected to a buffer vessel (22) which is connected to a gas duct (23) by means of filters (25 and 26), which is connected to a buffer vessel (24) connected in series with a collector (9) a burner (7) and a combustion chamber (8) attached to the reactor (5), the reactor (5) being connected to the outlet screw (13) ).