CZ31153U1 - A device for the production of aromatic hydrocarbons by molecular destruction and polymer reforming - Google Patents

Description

The proposed technical solution relates to a plant for the production of aromatic hydrocarbons by the method of reforming polymeric raw materials using rectification and molecular restructuring.

BACKGROUND OF THE INVENTION

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

With the rapid increase of polymeric wastes (plastics, tires) in the world and as a result of the increase in the amount of secondary polymeric raw materials, it becomes economically profitable to produce liquid aromatic hydrocarbons from these materials. The raw material so produced is saturated with aromatic hydrocarbons more than the petroleum fraction and is therefore a very valuable raw material for the refining and chemical industries.

Recovery of hydrocarbons from plastic waste appears to be an economically and environmentally friendly method according to the state of the art. This means that it will heat up to a very high temperature without air (oxygen). The condensation of the gasified plastic waste produces an oil which can be used, for example, as a fuel for diesel internal combustion engines.

An apparatus and process for the recycling of plastics by the hydrocarbon recovery method is described, for example, in JP2015057500. The disadvantage of the device described here is, in particular, its low operational safety resulting from its construction. As a result, it is known from practice that molten plastic waste and plastic gases ignite in non-standard operating modes.

The deficiencies described are solved by a device for continuous recycling of plastics known from the Czech utility model No. 29890. This device is operationally safe, but its construction allows simple distillation of gasified plastic waste. Since plastic waste is inherently variable in composition, the resulting oil may have variable composition or quality.

The essence of the technical solution

The essence of the proposed technical solution is the construction of a device for the production of aromatic hydrocarbons by molecular destruction and polymer reforming. The apparatus comprises a press and / or feed opening for charging the feed polymer feedstock into the reactor. The choice of the element for the input of the polymer input raw material is given by its composition. In particular, it is suitable to feed the press with a soft, compressible polymer feedstock. The feed opening is then particularly useful for the hard, non-compressible polymer raw material.

The reactor has an inlet zone and a heat zone. The thermal zone consists of a preparatory thermal zone, a molecular destruction zone and a reforming zone, the boundary of which is blurred and may partially overlap, depending on the current operating mode of the plant. The reactor inlet zone is cooled and / or thermally insulated from the reactor thermal zone. This is due to the maintenance of the solid (non-molten) plug of the feed polymer feedstock. This ensures that the internal environment of the reactor is hermetic to the atmosphere, so that the polymer melt does not come into contact with the external atmosphere. The inlet zone is provided with a plurality of protrusions on the inner surface to maintain the desired thermal regime of the polymer feedstock. In particular, ribs extending into the profile of the polymer treated with the raw material appear to be advantageous. These fins help to cool the solid plug of the feedstock polymer introduced throughout its cross-section, since the polymers being processed are a good thermal insulator. Thus, the temperature control (cooling) of the inlet zone envelope may not safely ensure a sufficiently low temperature in the center of the rigid plug in all modes.

-1 CZ 31153 Ul

The inner cross section of the inlet zone and the pre-treatment heat zone increases from the press and / or feed opening towards the molecular destruction zone. This is to avoid blockage of the input polymer feedstock, or to loosen the rigid plug for easier processing.

At least the molecular destruction zone is internally provided with a variable speed screw conveyor to convey solid residues from the molecular destruction zone to the cooled conveyor system. The refrigerated conveyor system is adapted to prevent the hydrocarbon steam-gas mixture from entering the atmosphere and vice versa. As a rule, it comprises a siphon passage with a rigid plug formed by cooled solid residues, so that the outside atmosphere is prevented from entering the reactor interior, respectively. to release the steam-gas mixture into the atmosphere. The cooled conveyor system may be provided with a double, actively cooled jacket.

At least the preparatory heat zone and the molecular destruction zone are provided with a heating system. The heating system can be provided with an active flue gas duct so that the power of the plant can be controlled effectively (in addition to the heating intensity). Above the reforming zone, a rectifying block with adjustable temperature regime is connected to the reactor. In particular, it may be provided with a double jacket which is actively cooled. The rectification block is provided in the upper part with at least one outlet of the steam-gas mixture of a predefined temperature. The drain is connected to the upper part of the connected cooling tower via a compensating coupling. The expansion joint is used to compensate for thermal expansion / contraction of the pipeline. The lower end of the cooling tower is provided with a siphon passage where the condensed liquid fraction is temporarily captured. The siphon passage ensures that a certain overpressure is maintained throughout the device. Under the siphon passage, a manifold tank is connected to the piping, which is equipped with a gas and liquid fraction outlet.

In particular, one possible specific embodiment of the device may be useful for treating a polymer feedstock having a melting point below about 700 ° C. Such a raw material will in particular be plastic waste. In this case, the pre-heat zone is provided with a plurality of protrusions on the inner surface to maintain the desired heat regime being processed by the polymer of the feedstock. In particular, it may be a system of ribs that help to heat the feed polymer raw material throughout its volume. The pre-heat zone is oriented such that the bottom edge of the exit opening of the pre-heat zone is higher than the bottom edge of the entrance opening of the pre-heat zone. Thanks to this technical feature, resp. resulting from the orientation of the preparation heat zone slightly upwards, the solid plug in the reactor inlet zone is at least partially below the surface of the melt polymer formed. This limits the direct contact of the rigid plug with the most warm top of the polymer melt. This helps to maintain a rigid plug, which prevents the polymer melt from leaking into the press and leaking into the environment.

The exit zone of the pre-heat zone is connected to the reactor main body. The longitudinal axis of the reactor main body, corresponding to the axis of rotation of the screw conveyor situated in the molecular destruction zone and in the reforming zone, is at an angle between the horizontal and the vertical.

The upper portion of the reactor main body is provided on its side jacket on the side adjacent to the ground with an orifice with expanding solid residue conduction into the cooled conveyor system. Expansion of the cable cross-section is necessary to prevent blockage of solid residues and its blockage. The upper part of the reactor main body is provided on the side remote from the ground with at least one opening for connecting the rectification block.

Another possible embodiment of the device may be particularly useful for treating a polymer feedstock having a melting point greater than about 700 ° C. Such a raw material will in particular be rubber mixed waste in the form of crushed tires. In this case, the screw conveyor situated in the molecular destruction zone and in the preparatory heat zone has an axis of rotation in common with the longer axis of the reactor main body. This axis is horizontal. The pre-treatment zone is situated below the inlet zone in the front of the main reactor body.

In the pre-heat zone there is a baffle above to determine the maximum layer thickness of the feedstock polymer and at least partially prevent backflow of the steam-gas mixture polymer into the inlet opening of the pre-heat zone.

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CZ 31153 Ul

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 central part of the main body. The rear of the reactor main body is provided with an orifice with expanding solid residue conduction into the cooled conveyor system. This opening may be both adjacent to the ground in the cladding and at the base of the reactor main body. At least one opening for the rectification block connection is situated at the highest point of the main body shell.

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

The heating system is preferably designed to include hot air distributions without direct flame contact with the reactor wall. This avoids local overheating and combustion of the polymer melt within the reactor. This can be achieved by placing a flame shroud in the hot air distribution system between the flame source and the reactor wall. In particular, a flame shrinkage barrier means a commonly known barrier with openings or openings. grid or mesh.

Due to its construction, the device enables safe and efficient operation of the described method in a zone of slight overpressure. This is achieved by a rigid plug of the input polymer of the raw material on the inlet side and siphon passages on the outlet side. It is a low-pressure device with an overpressure of approximately 0.1 bar (10kPa).

Among the advantages of the described apparatus are, in particular, safety, high yield of end products from the feed polymer feedstock, simple operation and low operating costs.

A process for producing aromatic hydrocarbons by molecular destruction and reforming of polymers can be performed on the apparatus described. Molecular destruction refers to the breakdown of heavy polymer molecules. Reforming polymers here means changing the structure of more than 65% of the hydrocarbon mixture hydrocarbons to aromatic hydrocarbons. The method comprises a process of heating the feed polymer, a process of molecular destruction of the polymers, and a rectification process. In particular, the polymeric raw material may be a secondary plastic or rubber waste.

In the first step of the process, the feed polymer feedstock of known chemical composition, with a defined maximum fraction, is charged to the reactor. Depending on the particular embodiment resulting from the feedstock polymer composition, the insertion can be carried out by a press and / or by gravity. The polymer feedstock may be mixed with a maximum of 20 wt. % of the catalyst to be treated, based on the total weight of the feed polymer to be treated. This means that up to 20 kg of catalyst can be used for every 100 kg of polymer feedstock. The purpose of the catalyst, if used, is to improve the physical and chemical processes of the process. The choice of possible use and the amount of catalyst depends on the composition of the polymer feedstock.

The insertion is carried out in a reactor having an inlet zone and a heat zone. The thermal zone consists of a preparatory zone and a zone of molecular destruction. The reactor inlet zone is cooled and / or thermally insulated from the reactor thermal zone. This is due to the maintenance of the solid (non-molten) plug of the feed polymer feedstock. This ensures that the internal environment of the reactor is hermetic to the atmosphere, so that the polymer melt does not come into contact with the external atmosphere.

In the reactor pre-heat zone, the feed polymer feedstock is heated to a maximum of 450 ° C at a heating rate of 4 to 15 ° C / min. The choice of heating rate is given mainly by the composition of the feed polymer and the desired result of the entire production. Subsequently, the resulting polymer melt is further heated in a zone of molecular destruction at a maximum temperature of 700 ° C, where a process of molecular destruction takes place, where appropriate with the participation of catalysts.

The molecular destruction formed by the polymeric steam-gas mixture at elevated pressure enters the reforming zone, which is located above the solid residues from the molecular destruction. Solid residues are transported from the molecular destruction zone to a cooled conveyor system by means of a screw conveyor. Solid residues are especially 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 hydrocarbon steam-gas mixture from entering the atmosphere and vice versa. As a rule, it comprises a siphon passage with a rigid plug formed by cooled solid residues, so that the outside atmosphere is prevented from entering the reactor interior, respectively. to release the steam-gas mixture into the atmosphere. The cooled conveyor system may be provided with a double, actively cooled jacket.

The hydrocarbon steam-gas mixture enters from the reforming zone into a rectifying block with a controlled temperature regime, from whose upper part the steam-gas mixture of a predefined temperature is discharged. The liquefied fraction flows back to the reforming zone for reprocessing.

In the downstream cooling tower, the lower end of which is provided with a siphon passage, the steam-gas mixture partially condenses. A gas fraction and a liquid fraction are separated in the downstream distribution tank. The gaseous fraction and the liquid fraction of aromatic hydrocarbons, as the final product of the entire process, are pumped from the distribution tank for further processing.

Described technology:

- produces a precious and industrial product;

- Disposes of non-recyclable polymers, thereby protecting the environment.

Clarification of 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 detail of part of the apparatus of FIG. 1, showing some reactor zones;

FIG. 3 is a schematic view of a device with a main body having a horizontally oriented long axis;

FIG. 4 is a detail of part of the apparatus of FIG. 3, indicating some reactor zones;

FIG. 5 shows a detail of a part of a device provided with a chute.

Exemplary implementation of the technical solution

Example 1

An exemplary embodiment of the apparatus includes a press 1 for introducing polymer feedstock into the reactor

2. The reactor 2 has an inlet zone 21 and a heat zone 22. The heat zone 22 is comprised of a preparatory heat zone 23, a molecular destruction zone 24, and a reforming zone 25.

The inlet zone 21 of the reactor 2 is cooled and thermally insulated from the thermal zone 22 of the reactor 2. The inlet zone 21 is provided on the inner surface with a set of protrusions 10 to maintain the desired thermal regime (cooling) of the polymer feedstock being processed. The protrusions 10 are here in the form of longitudinal ribs. The internal cross-section of the inlet zone 21 and the pre-treatment heat zone 23 increases from the press 1 towards the molecular destruction zone 24. The pre-treatment zone 23 is provided on the inner surface with a plurality of protrusions 10 to maintain the desired thermal regime (heating) of the polymeric feedstock being processed. The protrusions 10 are here in the form of longitudinal ribs. The pre-heat zone 23 is oriented so that the lower edge of the pre-heat port 13 of the pre-heat zone 23 is higher than the bottom edge of the pre-heat port of the pre-heat zone 23. The main body 14 of the reactor 2, corresponding to the axis of rotation of the screw conveyor 3 situated in the molecular destruction zone 24 and in the reforming zone 25, is an angle between the horizontal and the vertical. The variable speed screw conveyor 3 is used to convey solid residues from the molecular destruction zone 24 to the cooled conveyor system 4. To this end, the upper part of the reactor main body 14 is provided with an opening extending on its side jacket on the ground side. By means of a guide to the solid residue, which flows into the conveyor system 4. The conveyor system 4 is adapted to prevent the penetration of the hydrocarbon steam-gas mixture into the atmosphere, and vice versa. The conveyor system 4 is provided with a system of variable speed worm conveyors inside and operates on the siphon principle.

The preparatory heat zone 23 and the molecular destruction zone 24 are provided with a heating system 11. Here, it also partially affects the reforming zone 25. The heating system 1T comprises hot air distributions without direct flame contact with the reactor wall 2. In the hot air distributions, a flame shroud is located between the flame source and the reactor wall 2 in the form of a commonly known grid.

Above the reforming zone 25, a rectifying block 5 with a controllable temperature mode is connected to the reactor 2 on the ground remote side. The rectification block 5 is provided in the upper part with at least one outlet of the steam-gas mixture of a predefined temperature. This drain is connected via a compensating coupling 9 to the upper part of the downstream cooling tower 6. The lower end of the cooling tower 6 is provided with a siphon passage 7. Below the siphon passage 7 a manifold tank 8 is connected to the piping. The distribution tank 8 is provided with technical means for controlling the temperature of the internal volume, here in the form of a conventional cooling device.

An exemplary embodiment of the device is shown in Figures 1 and 2.

Example 2

An exemplary embodiment of the apparatus comprises a press 1 for feeding a feed polymer feedstock into the reactor 2. The reactor 2 has an inlet zone 21 and a heat zone 22. The heat zone 22 is formed by a preparatory heat zone 23, a molecular destruction zone 24 and a reforming zone 25.

The inlet zone 21 of the reactor 2 is cooled and thermally insulated from the thermal zone 22 of the reactor 2. The inlet zone 21 is provided on the inner surface with a set of protrusions 10 to maintain the desired thermal regime treated by the feedstock polymer. The protrusions 10 are here in the form of longitudinal ribs. The internal cross-section of the inlet zone 21 and the pre-treatment heat zone 23 increases from the press 1 towards the molecular destruction zone 24.

The molecular destruction zone 24 and the preparatory heat zone 23 are internally provided with a variable speed screw conveyor 3. In the pre-heat zone 23, a baffle 16 is located from above to determine the maximum thickness of the feedstock polymer layer and at least partially prevent backflow of the steam-gas mixture polymer into the inlet opening of the pre-heat zone 23. The screw conveyor 3 has a pivot axis common to the longer axis of the reactor main body 14 wherein the axis is horizontal. The pre-treatment zone 23 is situated below the inlet zone 21. The screw conveyor 3 serves, among other things, to convey solid residues from the molecular destruction zone 24 to the cooled conveyor system 4. This is done so that the rear part of the reactor main body 14 is provided with The refrigerated conveyor system 4 is adapted to prevent the hydrocarbon steam-gas mixture from entering the atmosphere, and vice versa. The conveyor system 4 is provided with a system of variable speed worm conveyors inside and operates on the siphon principle.

The preparatory heat zone 23 and the molecular destruction zone 24 are provided with a heating system 11. The heating system 11 comprises hot air distributions without direct flame contact with the reactor wall 2. In the hot air distributions, a flame precipitating baffle in the form of a commonly known grid is situated between the flame source and the reactor wall 2. The main body 14 has an oval cross-section with a horizontal bottom, the ends of the main body 14 having a lower height and a smaller cross-sectional area than the central part of the main body 14.

Above the reforming zone 25, a rectifying block 5 with a controllable temperature mode is connected to the reactor 2 at the highest point of the jacket of the main body 14. The rectification block 5 is provided in the upper part with at least one outlet of the steam-gas mixture of a predefined temperature. This drain is connected via a compensating coupling 9 to the upper part of the adjacent cooling tower 6. The lower end of the cooling tower 6 is provided with a siphon passage 7. Below the siphon passage 7, a manifold 8 is provided on the pipeline. . The distribution tank 8 is provided with technical means for controlling the temperature of the internal volume, here in the form of a conventional cooling device.

An exemplary embodiment of the device is shown in FIGS. 3 and 4.

Example 3

The exemplary embodiment of the apparatus differs from Example 2 in the manner of loading the feed polymer polymer. In this case, it is a rubber rubble of used tires with a different ratio of metal and fabric admixtures, loaded without pressing. As a result, it is more advantageous to load the device in a gravitational manner. For this purpose, the device is provided with a chute 15 instead of a press 15. The chute 15 is provided with an inlet zone 21 with a vertical orientation. It includes a transfer chamber provided with a cap on its upper and lower parts, the operation of these caps being independent of each other. When transporting the feed polymer feed to the feed opening 15, at least one of the shutters is always closed, thereby ensuring the hermetically sealed interior of the reactor 2 from the inlet side.

An exemplary embodiment of the device is shown in Fig. 5.

Claims (16)

Apparatus for the production of aromatic hydrocarbons by molecular destruction and polymer reforming, characterized in that it comprises a press (1) and / or a feed opening (15) for charging a feed polymer feedstock into a reactor (2) having an inlet zone (21) and a heat zone (22), wherein the heat zone (22) is formed by a heat treatment zone (23), a molecular destruction zone (24) and a reforming zone (25), wherein the inlet zone (21) of the reactor (2) is cooled and / or thermally insulated a thermal zone (22) of the reactor (2), wherein the inlet zone (21) is provided on the inner surface with a plurality of protrusions (10) to maintain the desired thermal regime processed by the feedstock polymer; from the press (1) and / or the feed opening (15) towards the molecular destruction zone (24), at least the molecular destruction zone (24) is provided with a screw conveyor (3) with a at a reversible speed for conveying solid residues from the molecular destruction zone (24) to a cooled conveyor system (4) adapted to prevent the hydrocarbon gas turbine mixture from entering the atmosphere, and vice versa, wherein at least the preparatory thermal zone (23) and the molecular destruction zone (24) are provided a heating system (11) above the reforming zone (25) is connected to the reactor (2) with a temperature controllable rectification block (5) provided at the top with at least one outlet of a predetermined temperature steam-gas mixture, which outlet is via a compensating coupling (9) ) is connected to the upper part of the adjoining cooling tower (6), the lower end of which is provided with a siphon passage (7), and below the siphon passage (7) a manifold tank (8) is provided. Apparatus for the production of aromatic hydrocarbons by molecular destruction and polymer reforming according to claim 1, characterized in that the preparation heat zone (23) is provided on the inner surface with a set of protrusions (10) to maintain the desired thermal regime treated by the polymer of the feedstock. 31153 U1, wherein the pre-heat zone (23) is oriented so that the lower edge of the pre-heat exit zone (13) is higher than the bottom edge of the pre-heat entry zone (12), the outlet ( 13) of the preparatory heat zone (23) is connected to the main body (14) of the reactor (2), wherein the longitudinal axis of the main body (14) of the reactor (2) corresponding to the axis of rotation of the screw conveyor (3) situated in the molecular destruction zone (24) and in the reforming zone (25), at an angle between the horizontal and the vertical, the upper portion of the main body (14) of the reactor (2) is provided at its side mantle on the side adjacent to the ground with an orifice with expanding solids to the cooled conveyor system (4). ) and the upper part of the main body (14) of the reactor (2) is provided on the side remote from the ground with at least one opening for connecting the rectification block (5). Apparatus for the production of aromatic hydrocarbons by molecular destruction and polymer reforming according to claim 1, characterized in that the screw conveyor (3) situated in the molecular destruction zone (24) and in the preparatory heat zone (23) situated below the inlet zone (21) 1), has an axis of rotation in common with the longer axis of the main body (14) of the reactor (2), the axis being horizontal, a baffle (16) situated from above in the preparatory heat zone (23) to determine the maximum thickness of the feedstock polymer layer and at least partially avoid backward penetration of the steam-gas mixture polymer into the inlet opening of the preparatory heat zone (23) the main body (14) has an oval cross-section with a horizontal bottom, the ends of the main body (14) having a lower height and less cross-sectional area than the middle part of the main body (14) the main body (14) of the reactor (2) is provided with an expanding opening by guiding the solid residues into the cooled conveyor system (4) at the highest point of the housing of the main body (14), at least one opening for connecting the rectification block (5) is situated. Apparatus for producing aromatic hydrocarbons by molecular destruction and reforming of polymers according to any one of the preceding claims, characterized in that the distribution tank (8) is provided with a technical means for controlling the temperature of the internal volume. Apparatus for producing aromatic hydrocarbons by molecular destruction and polymer reforming according to any one of the preceding claims, characterized in that the heating system (11) comprises hot air distributions without direct flame contact with the reactor wall (2). Apparatus for the production of aromatic hydrocarbons by molecular destruction and polymer reforming according to claim 5, characterized in that a flame barrier is situated in the hot air distribution system between the flame source and the reactor wall (2). 5 drawings -7EN 31153 Ul List of reference marks: 1 - Nov. 2 - reactor 21 - reactor inlet zone 22 - reactor thermal zone 5 23 - Reactor heat preparation zone 24 - Molecular destruction zone 25 - Reforming Zone 3 - screw conveyor 4 - conveyor system 10 5 - rectification block 6 - cooling tower 7 - siphon passage 8 - distributor tank 9 - compensating coupling 15 Dec 10 -output 11 - heating system 12 - preparation zone inlet 13 - exit port of the preparation zone 14 - main reactor body 20 May 15 - feed opening 16 - bulkhead.