HUP0600863A2 - Method and apparatus for thermic cracking of scrap rubber and other organic materials - Google Patents

Description

It condenses the gases and vapors generated in the equipment in a simple device. It does not include a solution for the utilization of the generated by-products (coal, steel).

Hungarian invention application number P0302916 proposes a horizontal drum reactor for the pyrolysis of waste rubber, condenses the materials generated during pyrolysis, and sells the resulting carbon after grinding. The technology works with very poor thermal energy utilization, heating is done with heated flue gas by transferring the thermal energy to the ground rubber waste through the reactor wall. The extracted hydrocarbons are produced in a random composition, and the degradation processes are difficult to control.

Recognizing the shortcomings of the known technological arrangements and operational units, we set ourselves the goal of designing a complex technological equipment with a more economical energy balance than before, as well as the reactors required for technological operations, which is suitable for the complex processing of organic materials and waste, primarily tires, as well as rubber and plastic. Furthermore, we set ourselves the goal of designing the processing process in such a way that it can be easily changed, with which the composition of the material generated in waste disposal can be better controlled and guided towards the desired end product.

The set goal is achieved on the one hand by carrying out the operational steps based on thermal decomposition and the operational step relevant for heat transfer in operationally separate reactors, and on the other hand by designing the reactors according to the different operational steps. This allows the thermal decomposition process to be carried out not only under more favorable conditions in terms of energy consumption, but also by better controlling the substances generated in the chemical process in a direction that results in a more affordable product.

The invention relates to a reactor suitable for the thermal decomposition of organic materials and waste, primarily tires, rubber and plastic.

The invention also relates to a reactor for producing activated carbon.

The invention further relates to a cooling device suitable for cooling artificial coal and/or carbon black.

The invention also relates to a chemical technological device for the complex processing of organic materials and waste, primarily tires and rubber and plastic.

The reactor body according to the invention is equipped with a drive, agitator, a screw for mixing and conveying, a pre-mixing chamber with fuel oil and/or flue gas feed, a heating unit and a carbon dioxide feeder, a reactor gas nozzle, a raw material feed nozzle, a flue gas nozzle, an air nozzle and a soot removal nozzle. A special mixing device is designed inside the reactor body in such a way that its centrally located, vertical screw serves as a recirculation mixer, on which two pairs of mixing elements are mounted on the same axis. The reactor body is also equipped with a horizontal screw extending through the lower third of the body. The horizontal screw is designed as a single unit containing two oppositely arranged sections with the same direction of rotation

We use a frequency-controlled motor to drive the mixers, which allows us to advantageously empty the reactor and also advantageously influence the material flow within the reactor.

An infrared burner connected to the prechamber is installed to heat the reactor. The infrared burner is optionally combined with a tubular reactor for subsequent pyrolysis.

The reactor for producing activated carbon according to the invention has a similar design to the reactor for thermal decomposition, with the difference that it has a nitrogen feed port, a pyrolysis gas port, a carbon black feed port, a steam injection port and an activated carbon collector port.

The cooling device suitable for cooling artificial coal and/or carbon black according to the invention has a similar design to the above-mentioned reactors, with the difference that it is equipped with an artificial coal feeding nozzle, a hot air nozzle, an air blowing nozzle and a carbon removal nozzle. The cooling device preferably incorporates a liquid cooler. The thermal energy of the liquid cooler, when conducted through a heat exchanger, also provides an opportunity to further reduce energy consumption. The air used for heating the reactors can be preheated in the cooling device, and this heat can also be used to preheat and maintain the temperature of the raw material.

The chemical technological equipment for the complex processing of organic materials and wastes, primarily tires and rubber and plastic, according to the invention has a reactor for thermal decomposition, a reactor for the production of activated carbon, and a cooling device suitable for cooling activated carbon and/or activated carbon.

A possible embodiment of the reactors according to the invention is illustrated in the figures:

Figure 1 shows a cross-section of a cracking reactor;

Figure 2 shows a cross-section of an activation reactor designed to activate carbon black or soot produced in a thermal decomposition process;

Figure 3 shows a cross-section of an apparatus for cooling carbon black or soot;

Figure 4 is a schematic representation of a complex technological device.

Figure 1 shows a possible design of a reactor suitable for thermal decomposition operating at near atmospheric pressure or less. The reactor body 1, equipped with a reactor gas port 9, a raw material feed port 10, a flue gas port 11, a soot removal port 12 and closing fittings, has 2 mixing elements driven by a gear 13, a vertical screw 3 designed as a recirculation mixer, a horizontal screw 4, a carbon dioxide feeder 8, an air port 26 and is also equipped with a heating unit. The mixers are driven by a frequency-controlled gear 13. The heating unit is preferably a premixing chamber burner 5, which is assembled with an infrared burner 6. A fuel gas feed 24 and a fuel oil feed 25 are connected to the premixing chamber 5. In the pre-mixing chamber 5, a perfectly burning mixture is produced from gaseous or liquid fuel through the connected feed, which covers the heat required for the reaction. The combustion product of the fuel that can be burned with perfect combustion can be led out through the combustion product stub 11 and passed through the spaces for preheating and maintaining the temperature of the raw materials and connected directly to the chimney. The infrared burner 6 enables efficient heat transfer on the one hand, but at the same time it also advantageously prevents the heating flame from directly contacting and burning the decomposition product of the thermal decomposition of the waste. The infrared burner 6 made of silicon carbide is preferably suitable as a heating unit, which enables energy-saving heat transfer and at the same time separates the combustion reaction and the thermal decomposition reaction from each other. In the lower third of the reactor body 1, a horizontal screw 4 extending through the reactor body 1 is formed, which has two sections with opposite correspondence and the same direction of rotation. The two sections with opposite correspondence are formed as a single unit. This is advantageous for mixing and discharge.

One pair of mixing elements 2 of the cracking reactor is preferably mounted near the inner wall of the reactor body 1, and the other pair of mixing elements 2 is mounted near the vertical screw 3, which ensures favorable flow within the reactor body 1.

The infrared burner 6 is combined with a pyrolysis tube reactor 7 for post-pyrolysis. This design of the heating unit advantageously allows for parallel thermal decomposition reactions, especially pyrolysis.

The gaseous components of the thermal decomposition leave the reaction space at the reactor gas stub 9. The reactor gas stub 9 is connected to conventional technological equipment for the purification, separation and further processing of the decomposition products. The pyrolysis tube reactor 7 is closely integrated with the heating element. Thus, with little heat loss, we can further decompose those components of the decomposition product leaving the cracking reactor that require further decomposition.

The parts of the cracking reactor that come into direct contact with the feedstock are made of high nickel, non-austenitizing steel. When using two horizontal screws 4 driven by frequency-controlled gears 13, not only can the discharge operation time be reduced, but also the possibility of the non-Newtonian viscous feedstock, most often containing rubber, sticking can be reduced. With this design, the feedstock is mixed better within the entire reactor volume than before.

Figure 2 shows a preferred embodiment of a reactor for activating carbon and/or carbon black. Figure 2 shows a carbon activating reactor for further processing carbon produced in a cracking reactor, which is a carbon activating reactor formed with a reactor body 1 operating at atmospheric or, more preferably, subatmospheric pressure. The reactor shown in Figure 2 is designed very similarly to the cracking reactor shown in Figure 1. The carbon activating reactor has a heating unit designed similarly to the cracking reactor shown in Figure 1, and the heating unit of the cracking reactor shown in Figure 1 combined with the pyrolysis tube reactor 7 can be used for this purpose. The carbon activating reactor has a mixing element 2 of the same design as the cracking reactor, a centrally located vertical screw 3 designed as a recirculation mixer, and a horizontal screw 4. As can be clearly seen in the figure, the reactor for activating artificial carbon has a nitrogen feed port 14, a pyrolysis gas port 15, a carbon black feed port 16, a steam inlet port 17, an air port 26 and an activated carbon collector port 23.

The 5 pre-mixing chamber 6 infrared burner can be operated economically. In addition to the commonly used heating gas and heating oil, materials unsuitable for further processing, possibly derived from pyrolysis, as well as cracked gas and cracked oil, can also be burned in it. The combustion product 11 can be led through technological facilities for preheating and maintaining temperature directly into a chimney without requiring further disposal through a flue gas stub.

The pyrolysis tube reactor 7 is preferably made of a non-austenitizing steel alloy with a high nickel content.

Figure 3 shows a preferred combined liquid and air coolant cooling device for cooling a type of coal. The reactor designed to perform the thermal operation shown in Figure 3 is suitable for cooling both the coals produced in the cracking reactor and the coals produced in the coal activation reactor. The mechanical design of the reactor is similar to the design of the cracking reactor shown in Figure 1 and the coal activation reactor shown in Figure 2 with the difference that instead of heating units, cooling components are installed in the reactor. The cooling device is preferably a cooling device operating at atmospheric pressure or above atmospheric pressure. The cooling device includes mixing elements 2 within the reactor body 1, and a vertical screw 3 centrally positioned as a recirculation mixer, and a horizontal screw 4. The cooling device has a coal feed port 22, an air inlet port 19, a hot air port 18, a coal removal port 20 and a spiral liquid heat exchanger 21. The liquid cooler 21 is designed in such a way that the device is also preferably suitable for preheating air. The mixing elements of the cooling device, which are of the same design as the mixing elements of the cracker and coal activation reactor, are driven by a frequency-controlled gear 13.

The liquid heat exchanger 21 suitable for the complex technological equipment can be advantageously designed when it is designed as a liquid cooling coil within the reactor body 1, which also includes a space suitable for preheating air.

When the horizontal screw 4 with opposite gears is driven by two frequency-controlled gears 13, the cooling operation time can be advantageously reduced and the removal of the finished product can be made simpler.

Figure 4 is a schematic diagram of a complex technological process flow chart, which describes a schematic design of a complex technological plant that can be formed by a possible connection of the cracking reactor according to Figure 1, the activated carbon reactor according to Figure 2 and the cooling plant according to Figure 3. Although the equipment of the auxiliary operating circuits is only schematically indicated in the figure, an essential feature of the figure is that no technological equipment or material flow for catalyst treatment is shown. Namely, an important advantage of the complex technology is that there is no catalyst processing step and no separate material flow for catalyst treatment and regeneration due to the choice of suitable structural materials.

The schematic flow chart of the complex technology (Figure 4) only describes the connection of the cracking reactor, the activated carbon reactor and the proposed cooling device, with the commonly used technological equipment and the connection points indicated.

The cracking reactor shown on the left side of Figure 4 is connected to the raw material feed port 10 with the raw material feed device 27. The soot removal port 12 of the cracking reactor is connected to the carbon feed port 22 of the cooling device. The carbon removal port 20 of the cooling device is connected to the finished product processing line 28. The raw material feed tank 27 and the cracking reactor are also connected to the chimney 29 through the flue gas port. The hot air port 18 of the cooling device is connected to the air port 26 of the cracking reactor.

In the case of the above coupling method, the solid end product is carbon. Carbon can also be converted into activated carbon. In this case, the coupling method shown on the right side of Figure 4 comes into effect.

The carbon black feed port 16 of the activated carbon reactor branches off from the finished product processing line 28 and the flue gas port 11 is connected to the chimney 29. The activated carbon collection port 23 is connected to the carbon feed port 22 of the cooling device for cooling the solid phase product. The hot air port 18 of the cooling device is connected to the air port 26 of the activated carbon reactor and the carbon collection port 20 is connected to the finished product processing line 28.

In the case of the switching mode shown on the left side of Figure 4, the complex technological process is as follows:

Before charging, the oxygen content in the cracking reactor is reduced by carbon dioxide fed through the carbon dioxide feeder 8. The cracking reactor can be charged with a raw material that has been chopped to size and preheated via a raw material feeding device 27. The heating unit described in Figures 1 and 2 is used to heat the cracking reactor and preheat it if necessary. The heat of the reactor operating in parallel can also be used to preheat the cracking reactor and, if applicable, the reactor for activating the artificial coal. This heat can also come from the cooling device according to Figure 3. In the pre-mixing chamber 5, mixtures can also be produced from conventional fuels that can be completely burned. In the pre-mixing chamber 5, the components of the thermal decomposition such as cracked oil and cracked gas can also be used to produce the energy required for decomposition. The oil or gas is fed into the pre-mixing chamber 5 via the fuel oil feed 25 or the fuel gas feed 24.

After the filling is completed, the temperature is raised and the reactor charge is cracked by operating the heating elements, preferably using three heating units. The heat energy released at the flue gas stub of the reactor 11 can be advantageously used to preheat the raw material and preferably to maintain it at 150 °C. This is also an advantageous temperature because in this way the possibility of self-ignition can be eliminated and the thermal decomposition heat energy requirement can be reduced by intermittent mixing. The cracking is carried out with the continuous and controlled operation of the 3 vertical screw, the 4 horizontal screw and the 2 mixing elements at 200 - 1200 °C, preferably 350 - 600 °C. The cracking is carried out at near atmospheric pressure or at reduced atmospheric pressure. The various polymers can be cracked advantageously in the pressure range of 0.2 - 2 bar.

During cracking, special attention must be paid to the sticking of the feedstock inside the reactor. Sticking of the feedstock is especially harmful when cracking a mixture of inhomogeneous material composition, such as tire shreds surrounded by rubber. A feedstock that sticks to the structural elements of the reactor for a long time is not beneficial in terms of the composition of the reactor gas generated during thermal decomposition.

By properly operating the frequency-controlled motors of the 13 drives, an effective flow can be maintained within the entire reactor volume. By using the frequency-controlled motor-driven 13 drives, the felt-like formation of the steel wire from the tire can be advantageously reduced, and smaller felt-like aggregates can be broken up. This is also an advantageous design because in the event of the formation of wire aggregates, the operation in the reactor does not necessarily have to be stopped. The formation of metallic felt-like formations can be remotely detected outside the reactor body 1.

The air port 26 of the cracking reactor is kept closed during normal operation and the gas composition in the reactor is continuously monitored. In the event of an emergency shutdown, the air port 26 can also be used for extinguishing agent flooding.

The long-chain (mostly liquid phase) fraction of the mixture leaving through the reactor gas stub 9 can be processed directly, or preferably it can be pyrolyzed into shorter-chain materials in the pyrolysis tube reactor 7 integrated with the infrared burner 6. In the pyrolysis tube reactor 7 integrated with the infrared burner 6, it is possible to process in stages cracked oils and products of the thermal decomposition reaction that are produced in relatively small quantities. When several pyrolysis tube reactors 7 integrated with the infrared burners 6 are installed in the reactor body 1, several pyrolysis processes can be carried out simultaneously in parallel.

When cracking is completed, the reactor gas port 9 is closed. The solid phase residue of cracking can be removed from the reactor through the soot removal port 12 by reversing the direction of rotation of the gear 13. A frequency-controlled motor-driven gear 13 is advantageously used for such tasks, since the direction of rotation can also be easily changed with the frequency-controlled gear 13. An oxygen-free environment is ensured during removal and storage.

After unloading, we can perform thermal decomposition of another batch of raw material in the cracking reactor.

During storage, the artificial coal is placed in the cooling device, where it is cooled to 250 -350 °C, preferably below 300 °C.

Depending on the raw material used, the carbon black is passed through the separator of the finished product processing line 28, if necessary, and the metallic residue can be removed from it, which can also be sold separately. The carbon black is cooled in the cooling device. The hydrocarbon-rich product leaving the reactor gas stub 9 can be processed with further operations and sold as both chemical raw materials and as an energy source. The carbon black can also be sold as a separate end product.

The switching method shown on the right side of Figure 4 is used to produce activated carbon.

The carbon black produced in the cracking reactor, which is of a carbon black composition, is fed from the carbon black storage of the finished product processing line 28 into the carbon black activation reactor through the carbon black feed stub. Before and during the loading, the carbon black activation reactor is checked for oxygen freedom. During the loading period and during the activation holding period, the activation is carried out with nitrogen, and after the holding period, the activation is carried out with a different, preferably 75/25 ratio steam/nitrogen mixture. From the loading to the collection of the finished product, the material fed into the reactor is mixed by operating the 2 mixing elements, the 3 vertical screw and the 4 horizontal screw. After the filling is completed, the activated carbon reactor is heated to 600 - 1000 °C, preferably 800 - 850 °C, by burning the fuel mixture mixed in the pre-mixing chamber 5 in the infrared burners 6. In the meantime, the reactor pressure is kept at a value lower than atmospheric pressure, preferably at a pressure of 0.1 - 0.5 bar. For the production of high-quality activated carbon, it is particularly preferable to maintain a uniform pressure value, which is important from the point of view of the quality of the material produced in the activation step. During activation, a nitrogen flow of 10 - 1000 dm ³ /min, preferably nearly 100 dm ³ /min, is maintained in the reactor during the heating period and for the 60 - 600 minute, preferably nearly 2-3 hour, temperature holding time at 850 °C. The gas components leaving the pyrolysis gas stub 15 can be used as a fuel after condensation or as a chemical raw material after further operations. After the heat retention period has elapsed, the nitrogen atmosphere is preferably replaced with a 75/25 steam/nitrogen mixture, the flow rate of which is the same as the flow rate of the nitrogen gas. At this time, the flow rate of the nitrogen gas is preferably reduced to approximately 80 dm ³ /min, and steam is generated by adding 300 - 800 cm 3 /min, preferably approximately 450 cm 3 /min of water to the system with a peristaltic pump. This amount of water corresponds to approximately 600,000 cm 3 /min of steam at 20 °C and 1 atm pressure. The water steam addition is maintained at approximately 850 °C for a further period of time, preferably approximately two hours. Then the temperature is raised to 900 - 1200 °C, preferably 925 - 950 °C. After the activation is completed, both the nitrogen and water feed are stopped and the pyrolysis gas port 15 is closed, and the activated carbon is discharged into the cooling device via the horizontal screw 4 through the activated carbon collection port 23. Cooling is carried out to 250 -350 °C, preferably below 300 °C, with the exclusion of oxygen. After cooling, the activated carbon is processed on the finished product processing line 28.

The heating unit of the cracker and the activated carbon reactor, as well as the liquid and air cooling circuits of the cooling device, can be connected to additional technological equipment, thereby reducing the energy demand of the complex technology.

In the case of a solution where several pyrolysis tube reactors 7 with integrated infrared heating zones 6 are installed within the reactor bodies 1 of the cracking and carbon activation reactors, then several pyrolysis processes can be carried out simultaneously, which can even have different raw materials. Therefore, different cracked oils and cracked gases can be processed in parallel.

With the reactors and technological equipment according to the invention, we can convert polymers and organic wastes shredded to a size of 1 - 10 cm in an energy-saving manner, preferably rubber shredded to a size of 2 - 8 cm, tires shredded to a size of 2 - 6 cm and various synthetic clays shredded to a size of 2 - 8 cm, such as various polyethylenes, polypropylenes, polystyrenes, polyamides and other plastics and mixtures thereof classified according to material quality. With the solution according to the invention, we can extract chemical raw materials and fuels from waste, the energy requirement of the solution can be reduced by using waste heat. The complex technological equipment can also be made suitable for the thermal decomposition of different raw materials with appropriate control.

The pre-mixing chamber infrared burner design is not only a favorable design from an energetic point of view, but also has the additional advantage that the investment requirement and maintenance of thermal decomposition are more favorable. In the flue gas circuit, it is not necessary to establish and operate a technological investment that is otherwise customary for the treatment and disposal of additional flue gas components formed in addition to carbon oxides.

The inventive solution of the stirring allows felt-like formations that cause the stirring to stop, or in extreme cases, to break, to the extent that the reaction can be continued without stopping, even when the reactor is operating.

Therefore, the above design of mixing is more favorable than previously known solutions, both energetically and in terms of thermal decomposition yield.

Claims (14)

Patent claims 1. Kraków reactor for thermal decomposition of organic materials and waste, primarily tires, rubber and plastic, which has a reactor body (1) equipped with a drive (13), mixing elements (2), a screw for mixing and conveying, a pre-mixing chamber (5), a heating unit and a carbon dioxide feeder (8), a reactor gas nozzle (9), a raw material feeding nozzle (10), a flue gas nozzle (11), an air nozzle (26) and a soot removal nozzle (12), and furthermore a known fuel gas feed (24) and/or fuel oil feed (25) are connected to the pre-mixing chamber (5), which is characterized by a vertical screw (3) centrally located in the interior of the reactor body (1), designed as a recirculation mixer, on which two pairs of mixing elements (2) are mounted on the same axis and a horizontal screw extending through the lower third of the reactor body (1) It has a screw (4), a runner unit consisting of a pre-mixing chamber (5), an infrared burner (6) and a pyrolysis tube reactor (7) integrated with the infrared burner (6). 2. A reactor for the production of activated carbon using activated carbon, comprising a reactor body (1) equipped with a drive (13), mixing elements (2), a screw for mixing and conveying, a pre-mixing chamber (5), a heating unit and a nitrogen feed port (14), a pyrolysis gas port (15), a soot feed port (16), a flue gas port (11), an air port (26), a water vapor injection port (17), an activated carbon collection port (23), and a known fuel gas feed (24) and/or fuel oil feed (25) connected to the pre-mixing chamber (5), characterized by a vertical screw (3) centrally located in the interior of the reactor body (1), designed as a recirculation mixer, on which two pairs of mixing elements (2) are mounted on the same axis and a horizontal screw extending through the lower third of the reactor body (1). It has a screw (4), a runner unit consisting of a pre-mixing chamber (5), an infrared burner (6) and a pyrolysis tube reactor (7) integrated with the infrared burner (6). 3. Reactor according to claims 1 or 2, characterized in that the infrared burner (6) is made of silicon carbide or nickel-silicon carbide suitable for combined firing. 4. A reactor according to any one of claims 1 to 3, characterized in that its structural elements in direct contact with the heated raw material are made of high nickel-containing and non-tempering steel. 5. Cooling device for cooling carbon black and/or soot, comprising a reactor body (1) equipped with a drive (13), mixing elements (2), a screw for mixing and conveying, a reactor gas nozzle (9), a carbon feed nozzle (22), a hot air nozzle (18), an air injection nozzle (19), a carbon removal nozzle (20) and a heat exchanger (21), characterized in that the reactor body (1) has a screw (3) centrally located in the interior, designed as a recirculation mixer, on which two pairs of mixing elements (2) are mounted on the same axis and a horizontal screw (4) extending through the lower third of the reactor body (1). 6. The device according to any one of claims 1, 2 and 5, characterized in that one pair of mixing elements (2) is located near the inner wall of the reactor body (1), and the other pair of impacting elements (2) is located near the vertical screw (3). 7. The device according to any one of claims 1, 2 and 5, characterized in that the horizontal screw (4) is designed as a single unit comprising two oppositely aligned sections with the same direction of rotation. 8. A cooling device according to claim 5, characterized in that it has a liquid heat exchanger (21) which is designed as a cooling coil. 9. The device according to any one of claims 1-8, characterized in that its drive (13) is of frequency-controlled design. 10. The device according to any one of claims 1 and 2, characterized in that it has a flue gas stub (11) which is assembled with a preheating raw material tank (27). 11. Apparatus according to claim 5, characterized in that it has a hot air nozzle (18) which is integrated with a preheating raw material tank (27). 12. Technological equipment for processing organic materials and waste, primarily tires and rubber and plastic complexes, having one or more reactors, cooling equipment, raw material feeding equipment (27) and finished product processing line (28), characterized in that it has a cracking reactor according to claim 1 and a carbon activation reactor according to claim 2, and a cooling equipment according to claim 5. 13. Technological apparatus according to claim 12 for the thermal decomposition of organic materials and waste, primarily tires and rubber and plastic, characterized in that it has a cracking reactor according to claim 1 and a cooling device according to claim 5. 14. Technological equipment according to claim 12 for processing artificial carbon generated during the processing of organic materials and waste, primarily tires, rubber and plastic, characterized in that it has an artificial carbon activation reactor according to claim 2 and a cooling device according to claim 5.