SK500242021U1 - Equipment for production of hydrocarbons in liquid form by method of thermal decomposition and reforming of polymeric materials - Google Patents

Abstract

Described is a device for decomposition and reforming of polymeric raw materials, which consists of a preparation chamber (2), reactor (3), rectification block (4) with adjustable temperature regime, cooling tower (5) and distribution tank (6) equipped with gas fraction discharge and liquid fraction. The reactor (3) contains an inlet zone, which also serves as a zone of molecular destruction and gasification, a reforming zone and a transition zone to the rectification block. At least the molecular destruction zone is equipped with a heating system (7). The entire reactor (3) is equipped inside along its entire longitudinal axis with a helical conveyor for conveying solid residues from the molecular destruction zone to the connected refrigerated conveyor system (8).

Description

The proposed technical solution relates to equipment for the production of hydrocarbon liquid (artificial oil) by the method of thermal decomposition and reforming of polymeric raw materials using reactive distillation.

Prior art

Thermal decomposition or thermolysis (historically, the term pyrolysis is more commonly used) is chemical decomposition caused by heat.

Reactive distillation is a process in which hot pyrolytic vapors can condense and return to the main pyrolysis chamber - the reactor, if the correct length of the carbon chain is not reached, thus greatly increasing the quality of the output liquid fraction.

The process by which a flowing boiling liquid and steam flowing in opposite directions (countercurrent of both phases) meet together in a vertical tower apparatus is called rectification, essentially rectification is countercurrent distillation.

Thus, reactive distillation is carried out by connecting the rectification tower to the reactor body in the vertical plane, and in this way we ensure the return of condensates from the rectification tower to the reactor to the zone of molecular decomposition (destruction).

Reforming is a technology in chemistry that modifies the molecular structure of hydrocarbons to change its properties. Usually, reforming is used to produce aromatic hydrocarbons from some petroleum fractions.

With the rapid increase in polymer waste (plastics, tires) in the world and as a result of the increase in the amount of secondary polymer raw materials, it is becoming economically profitable to produce liquid hydrocarbons from these materials. The raw material produced in this way is saturated with aromatic hydrocarbons more than petroleum fractions (it can also be 70%), and is therefore a very valuable raw material for the refining and chemical industries.

The recovery of hydrocarbons from plastic waste appears to be an economically and ecologically very favorable method according to the state of the art. This means that it heats up to a high temperature without the access of air (oxygen). Condensation of the gasified plastic waste produces a liquid fraction which can be used, for example, as a fuel for diesel internal combustion engines or a raw material for the refining and chemical industries, for example for the production of diluents.

The apparatus and process for recycling plastics by the hydrocarbon recovery method is described e.g. in JP2015057500. The disadvantage of the device described here is in particular its low operational safety, which results from its construction. Thanks to this, cases are known from practice where molten plastic waste and plastic gases have ignited in non-standard operating modes.

The described shortcomings are solved by the device for continuous recycling of plastics known from the Czech utility model no. 29890. This plant is operationally safe, but its construction allows easy distillation of gaseous plastic waste. Due to the fact that plastic waste has a variable composition by its nature, the resulting oil can also have a variable composition or quality.

The essence of the technical solution

The essence of the technical solution is a device for the production of hydrocarbons in the form of a liquid by the method of thermal decomposition and reforming of polymeric raw materials using reactive distillation, which has a rectification block with a controllable temperature regime connected to the reactor above the reforming zone. The rectification block is equipped in the upper part with at least one outlet of the steam-gas mixture with a predefined temperature, the outlet being connected via a compensating coupling to the upper part of the adjoining cooling tower, the lower end of which is provided with a siphon passage. Below the siphon passage, a distribution tank is connected to the seal, equipped with a discharge of the gaseous fraction and the liquid fraction, the essence of which is that it contains a preparation chamber for the supply of the input polymeric raw material. The reactor comprises an inlet zone which also serves as a zone of molecular destruction and gasification, a zone of reforming and a zone of transition to the rectification block, at least the zone of molecular destruction being equipped with a heating system. The entire reactor is equipped along along the entire longitudinal axis of the reactor with a speed-adjustable helical conveyor for transporting solid residues from the molecular destruction zone to an connected refrigerated conveyor system adapted to prevent the penetration of hydrocarbon mixture hydrocarbons into the air, and vice versa.

A preferred embodiment describes a device, the rectification block of which is vertically connected to the reactor body, for ensuring the gravitational return of condensate from the rectification block to the reactor, in particular to the zone of molecular decomposition.

In another preferred embodiment, a device is provided, the preparation chamber comprising from two

SK 50024-2021 U1 into five thermal zones for controlled pre-heating of the input raw material and a spiral conveyor for the movement of the raw material from the inlet to the outlet, while its diameter to the outlet part increases.

The essence of the proposed technical solution is the construction of equipment for the production of liquid hydrocarbons by thermal decomposition (molecular destruction) and polymer reforming. The device comprises a hopper for inserting the input polymeric raw material into the preparation chamber and further into the reactor. The choice of the element for the input of the input polymeric raw material is given by its composition. Crushed plastic or rubber waste is assumed under the input polymer raw material.

The reactor has a zone of molecular destruction and gasification of the hydrocarbon mixture (formation of steam-gas mixture - PPS) and a reforming zone, while their boundary is blurred and they can partially overlap each other depending on the current operating mode of the plant. The temperatures ensuring the condensation of the steam-gas mixture in the inlet part of the preparation chamber ensure the airtightness of the internal environment of the reactor towards the air, so that the steam-gas mixtures do not come into contact with the external atmosphere. Homogenization of the mixed raw material takes place in the preparation chamber, mixed with a catalyst / neutralizer (for plastics), air removal. The rubber (tire) preparation chamber will have a slight inclination towards the reactor to allow a molten plasticizer to flow into the reactor, which begins to melt from 150 ° C.

From the inlet zone of the preparation chamber, the raw material is supplied by a rotating screw to the outlet of the preparation chamber with simultaneous heating, and when it has already reached a certain temperature, gravity falls through the opening into the reactor.

The internal cross-section of this hopper towards the zone of molecular destruction increases. This is to avoid blocking the input polymer feedstock.

The entire reactor is equipped internally with a screw conveyor with adjustable speed for the transport of solid residues from the molecular destruction zone and the reforming zone to the cooled conveyor system. The refrigerated conveyor system is adapted to prevent the penetration of the hydrocarbon steam-gas mixture into the air, and vice versa. As a rule, it contains a siphon passage with a solid plug formed by cooled solid residues, so that the access of the external atmosphere to the interior of the reactor, resp. to leak the gas-gas mixture into the air. The refrigerated conveyor system can be provided with double, actively cooled plastic.

The molecular destruction zone is equipped with a heating system. The heating system can be equipped with active flue gas extraction, which makes it possible (in addition to the intensity of self-heating) to effectively control the performance of the device. Above the reforming zone, a rectification block (reactive distillation block) with a controllable temperature regime is connected to the reactor. In particular, it can be equipped with a double plastic which is actively cooled. The rectification block is equipped in the upper part with at least one outlet of the steam-gas mixture with a predefined temperature. The drain is connected to the upper part of the adjoining cooling tower via a pipe via a compensating coupling. The compensating coupling is used to compensate for thermal expansion / contraction of the pipe. The lower end of the cooling tower is equipped with a siphon passage, where the condensed liquid fraction is temporarily captured. The siphon passage ensures that a certain overpressure is maintained in the entire device. Below the siphon passage, a distribution tank is connected to the pipeline, equipped with the discharge of the gaseous fraction and the liquid fraction. From the distribution tank, the gas proceeds to the gas scrubber, where it is cleaned of mechanical impurities, condensing and hall elements.

One of the possible specific embodiments of the device can be usable in particular for processing a polymeric raw material having a melting point lower than 400 ° C. In practice, such a raw material will be mainly plastic waste.

The outlet of the preparation chamber opens into the main body of the reactor. The longitudinal axis of the main body of the reactor, corresponding to the axis of rotation of the screw conveyor situated in the zone of molecular destruction and in the zone of reforming, is at an angle between the horizontal and the vertical.

The upper part of the main body of the reactor is provided on its side shell on the side adjacent to the ground with an opening with an expanding conduction of solid residues into the cooled conveyor system. The widening of the line cross-section is in order to prevent the blocking of solid residues and its clogging. The upper part of the main body of the reactor is provided on the side remote from the ground with at least one opening for the connection of a rectification block.

Another possible specific embodiment of the device can be particularly useful for processing crushed tires. In this case, the feedstock falls into the reactor on a spiral conveyor inside the reactor. This helical conveyor has an axis of rotation in common with the longer axis of the reactor main body. This axis is almost horizontal, going slightly up to the outlet end of the reactor.

In the preparation heat zone at the beginning of the reactor, a compartment is located from above to determine the maximum layer thickness of the polymer feedstock to be treated and to at least partially prevent the polymer vapor mixture from penetrating back into the feed heat zone inlet.

The main body has an oval cross-section with a horizontal bottom, the ends of the main body having a lower height and a smaller cross-sectional area than the middle part of the main body. The rear part of the main body of the reactor is provided with an opening with an expanding conduit of solid residues into the cooled conveyor system. This opening may be, either adjacent to the ground in the peripheral shell, as well as at the base (rear cover) of the main body.

SK 50024-2021 U1 reactor. At least one opening for connecting the rectification block is situated at the highest point of the main body shell.

Depending on the intended place of use of the device, the distribution tank can be equipped with technical means for regulating the temperature of the internal volume. By cooling or heating the internal volume, a constant defined temperature of the gaseous fraction and the liquid fraction is ensured. This temperature stability prevents the undesired passage of the gaseous fraction into the liquid fraction (and vice versa), regardless of the temperature outside the distribution tank. Said technical means may, for example, be in the form of a heated or cooled double jacket of a distribution tank or a heat exchanger within its volume.

The heating system is preferably designed to include hot air distribution without direct contact of the flame with the reactor wall. This prevents local overheating and overburning of the polymer melt inside the reactor. This can be achieved by placing a flame collision compartment in the hot air distribution between the flame source and the reactor wall. By flame precipitation compartment is meant in particular a commonly known compartment with openings, resp. grid or mesh.

Due to its construction, the device enables safe and efficient implementation of the described method in the zone of slight overpressure. This is achieved by a rigid stopper of the polymeric feedstock in the preparation chamber on the inlet side and by siphon transitions on the outlet side. It is a low-pressure device where the overpressure is 0.1-0.3 bar (10-30 kPa).

The advantages of the described device include in particular safety, high yield of end products from the input polymer raw material, simple operation and low operating costs.

A process for producing a hydrocarbon liquid using thermal decomposition (molecular destruction) and polymer reforming can be carried out on the described apparatus. By molecular destruction is meant the decomposition (breaking) of heavy polymer molecules. Polymer reforming here means a change in the structure of more than 65% of the hydrocarbons of the steam-gas mixture to aromatic hydrocarbons. The method includes a process for heating the polymeric feedstock, a thermal decomposition-molecular destruction of the polymer process, and a rectification process. The polymeric raw material here can in particular be secondary processed plastic or rubber waste.

In the first step of the process, the input polymer feedstock of known chemical composition, with a defined maximum fraction, is introduced into the reactor. Depending on the particular embodiment resulting from the composition of the polymeric feedstock, the loading can take place via a preparation chamber and / or by gravity. The polymeric feedstock may be blended with a maximum of 10% by weight. of catalyst / neutralizer, based on the total weight of the polymer feedstock to be treated. This means that up to 10 kg of catalyst can be used for every 100 kg of polymeric feedstock. The purpose of the catalyst, if used, is to improve the physical and chemical processes of the process carried out. The choice of possible use and amount of catalyst depends on the composition of the polymeric feedstock.

The loading takes place in a reactor having a preparation zone, a molecular destruction zone and a reforming zone. The airtightness of the internal environment of the reactor against the air is ensured, so that the polymer melt does not come into contact with the external atmosphere.

In the zone of molecular destruction of the reactor in the case of plastics, the thermally prepared polymer feedstock is rapidly heated to a maximum temperature of 600 ° C. Subsequently, a steam-gas mixture is formed, the process taking place here with the possible participation of catalysts.

In the preparation heat zone of the tire reactor, the feed polymer feedstock is heated to a maximum temperature of 450 ° C at a heating rate of 4 to 15 ° C / min. The choice of heating speed is given mainly by the composition of the input polymer raw material and the desired result of the whole production. Subsequently, the polymer melt formed is further heated in the molecular destruction zone at a maximum temperature of 600 [deg.] C., whereupon the molecular destruction process takes place, with the possible participation of catalysts.

The vapor-gas mixture formed by molecular destruction with increased pressure enters the reforming zone, which is located above the solid residues from molecular destruction. The solid residues are conveyed from the molecular destruction zone to the refrigerated conveyor system by means of a screw conveyor. Solid residues are in particular carbonaceous solid residues, polymeric fillings or foreign bodies, such as stones, sand, metal parts and the like. The refrigerated conveyor system is adapted to prevent the penetration of the hydrocarbon steam-gas mixture into the air, and vice versa. As a rule, it contains a siphon passage with a solid plug formed by cooled solid residues, so that the access of the external atmosphere to the interior of the reactor, resp. to leak the gas-gas mixture into the air. The refrigerated conveyor system can be equipped with a double, actively cooled jacket.

The hydrocarbon steam-gas mixture enters from the reforming zone into the rectification unit with a controllable temperature regime, from the upper part of which the steam-gas mixture with a predefined temperature is discharged. The liquefied fraction flows back to the reforming zone for reprocessing.

In the adjoining cooling tower, the lower end of which is equipped with a siphon passage, the steam-gas mixture partially condenses. In the subsequent distribution tank, the gaseous fraction and the liquid fraction are separated. From the distribution tank, the gaseous fraction and the liquid fraction of hydrocarbons are as final

SK 50024-2021 U1 product of the whole process, pumped for further processing.

Described technology:

- produces the product required by the industry;

- recycles non-recyclable polymers, thus protecting the environment.

Overview of figures in the drawings

An exemplary embodiment of the proposed solution is described with reference to the drawings, in which FIG. 1 is a schematic view of a device with a main body having an inclined longer axis;

FIG. 2 is a schematic view of the device from the side of the distribution tank;

FIG. 3 is a schematic view of the device from above.

Examples of embodiments

Example 1

An exemplary embodiment of the device shown in FIG. 1, 2 and 3 comprises a preparation chamber 2 with a screw for feeding the input polymeric feedstock into the reactor 3. The reactor 3 has a helical conveyor inside for moving the solid parts of the feedstock. The axis of rotation of the screw conveyor corresponds to the longitudinal axis of the reactor. Reactor 3 has an inlet zone which immediately passes into the molecular destruction zone. Furthermore, reactor 3 has a reforming zone.

The molecular destruction zone is equipped with a heating system 7. The heating system 7 comprises hot air distributions without direct contact of the flame with the wall of the reactor 3. In the hot air distributions there is a condensing trap in the form of a commonly known grid between the flame source and the wall of the reactor 3.

Above the reforming zone, a rectification block 4 with a controllable temperature regime is connected to the reactor 3 on the side remote from the ground. The rectification block 4 is equipped in the upper part with at least one outlet of the steam-gas mixture with a predefined temperature. This outlet is connected via a compensating coupling to the upper part of the adjoining cooling tower 5. The lower end of the cooling tower 5 is provided with a siphon passage. Below the siphon passage, a distribution tank 6 is connected to the pipeline, equipped with the discharge of the gaseous fraction and the liquid fraction. The distribution tank 6 is equipped with technical means for regulating the temperature of the internal volume, here in the form of a commonly known cooling device. Solid carbon residues are transported from the molecular destruction zone by means of a screw conveyor to a refrigerated conveyor system 8. A carbon-enriched raw material mix (semi-coke and ash) is formed, which after processing (sorting and pelleting) can be used as an ecological fuel.

SK 50024-2021 U1

List of reference marks

- Inlet opening

- Preparation chamber

3 - Reactor

- Rectification block

- Cldadiaca tower

- Distribution tank

- Heating system

8 - Refrigerated conveyor system

- Gas scrubber

Claims (3)

An apparatus for the production of hydrocarbons in the form of a liquid by the method of thermal decomposition and reforming of polymeric raw materials using reactive distillation, which has a rectification block (4) connected to the reactor (3) with a controllable temperature regime above the reforming zone, wherein the rectification block (4) is the upper part is equipped with at least one outlet of the steam-gas mixture with a predefined temperature, the outlet being connected via a compensating coupling to the upper part of the adjoining cooling tower (5), the lower end of which is equipped with a siphon passage. ) equipped with a discharge of the gaseous fraction and the liquid fraction, characterized in that it comprises a preparation chamber (2) for feeding the polymeric feedstock, the reactor (3) comprising an inlet zone which also serves as a molecular destruction and gasification zone, reforming zone and transition zone to the rectification block, where at least the zone of molecular destruction is equipped with a system ( 7) heating, and wherein the whole reactor (3) is equipped inside along its entire longitudinal axis with a speed-adjustable helical conveyor for transporting solid residues from the molecular destruction zone to an connected refrigerated conveyor system (8) adapted to prevent hydrocarbon mixture hydrocarbons from entering and vice versa. Device according to claim 1, characterized in that the rectification block (4) is vertically connected to the reactor body (3), to ensure the gravitational return of condensate from the rectification block to the reactor, in particular to the molecular decomposition zone. Apparatus according to claim 1, characterized in that the preparation chamber (2) comprises from two to five thermal zones for controlled pre-heating of the feedstock and a helical conveyor for moving the feedstock from inlet to outlet, its diameter increasing to outlet.