Process and equipment for preparing high-performance regenerated rubber through low-temperature cracking of waste tires

Abstract

The invention relates to the technical field of high polymer materials and engineering, in particular to a process and equipment for preparing high-performance regenerated rubber through low-temperature cracking of waste tires. Firstly, the waste tires are subjected to novel multi-stage crushing, magnetic separation and cyclone separation, then subjected to ultrasonic soaking with a composite activating agent containing graphene quantum dots, dried and then put into a cracking kettle; the method comprises the following steps: adding a composite catalyst containing a carbon nanotube supported noble metal, cracking at low temperature under the protection of nitrogen, carrying out solid-liquid separation by virtue of a centrifugation-filtration integrated technology, and treating a liquid product by combining molecular distillation and reduced pressure distillation. The equipment comprises a plurality of functional devices, can accurately control temperature and pressure, and realizes efficient preparation. According to the method, pretreatment is more efficient, activation is more sufficient, the catalyst effect in the cracking process is high, the aftertreatment separation and recycling effect is good, the performance of the prepared regenerated rubber is greatly improved, the method is widely applied to the fields of tires, rubber products and road paving, and environment-friendly treatment and resource recycling of waste tires can be achieved.

Description

Technical Field

[0001] The invention relates to the field of polymer materials and engineering technology, and in particular to a process and equipment for preparing high-performance recycled rubber by low-temperature pyrolysis of waste tires. Background Art

[0002] With the booming development of the automobile industry, the number of waste tires is increasing day by day, becoming an environmental problem that needs to be solved urgently. According to statistics, more than 1.5 billion waste tires are generated worldwide each year, and this number continues to rise. Waste tires are difficult to degrade naturally. Long-term accumulation not only occupies a large amount of land resources, but also easily causes fires and breeds mosquitoes, posing a serious threat to the ecological environment and human health.

[0003] At present, the main methods of handling waste tires are landfill, incineration and recycling. Landfill is simple and direct, but it takes up a huge amount of land space, and the chemicals in the tires may seep into the soil and groundwater, causing environmental pollution; although incineration can achieve a certain degree of reduction, it will produce a large amount of harmful gases, such as sulfur dioxide, nitrogen oxides and polycyclic aromatic hydrocarbons, which will aggravate air pollution and do not meet environmental protection requirements.

[0004] In contrast, recycling is considered the most promising treatment method. However, the traditional process for preparing recycled rubber from waste tires has many defects. In the pretreatment stage, conventional crushing methods are inefficient and energy-intensive, making it difficult to evenly crush tire particles to the ideal particle size, affecting subsequent reactions. Magnetic separation and dust separation technologies are also not advanced enough to completely remove metal and dust impurities, which reduce the quality of recycled rubber.

[0005] In the cracking process, traditional processes often use high-temperature cracking, which not only consumes a lot of energy, but also causes excessive cracking of rubber molecules, resulting in poor performance of the recycled rubber. Ordinary catalysts are not active enough to effectively promote the breakage and recombination of rubber molecular chains, making it difficult for key performance indicators such as tensile strength, elongation at break and wear resistance of recycled rubber to reach ideal levels.

[0006] The post-processing stage is also full of problems. The traditional solid-liquid separation technology is inefficient and the separation is not thorough, resulting in too much liquid impurities remaining in the recycled rubber, affecting product quality. During the distillation separation process, the recovery rate of light oil and cracking gas is low, resulting in a waste of resources.

[0007] In addition, the existing waste tire processing equipment also has many drawbacks. The temperature control accuracy of the cracking reactor is poor, and it is impossible to ensure that the reaction is carried out in the optimal temperature range; the equipment is not well sealed, which is easy to cause gas leakage, which not only poses a safety hazard, but also affects the reaction effect; the overall automation of the equipment is low, requiring a lot of manual operation, which increases production costs and makes it difficult to improve production efficiency.

[0008] Facing the increasing demand for waste tire treatment and strict environmental protection requirements, it is urgent to develop a process and equipment that are efficient, environmentally friendly, and can prepare high-performance recycled rubber. This not only helps to solve the environmental problems caused by waste tires but also enables the recycling of resources, with important economic and social value. Summary of the Invention

[0009] (I) Technical Problems to be Solved

[0010] In view of the deficiencies of the prior art, the present invention provides a process and equipment for preparing high-performance recycled rubber by low-temperature pyrolysis of waste tires.

[0011] (II) Technical Solutions

[0012] A process and equipment for preparing high-performance recycled rubber by low-temperature pyrolysis of waste tires, the process comprising the following steps:

[0013] Pretreatment: The waste tires are crushed to a particle size of 1 - 5 cm, metal impurities are removed by high-gradient magnetic separation technology with a magnetic separation intensity of 5 - 8 T, and dust impurities are removed by a cyclone separator. Then, the tire particles are soaked in a composite activator solution with a mass fraction of 3% - 8% for 2 - 4 h, during which ultrasonic assistance treatment is carried out with a frequency of 20 - 40 kHz and a power of 100 - 300 W; the composite activator consists of an organosilane coupling agent and nano-zinc oxide in a mass ratio of 2:1, and 0.5% - 1.5% of graphene quantum dots; the siloxane group in the organosilane coupling agent undergoes a condensation reaction with the hydroxyl groups on the tire surface, nano-zinc oxide undergoes chemical adsorption with rubber molecules, and graphene quantum dots form π-π stacking interactions with rubber molecules. The reaction formula is as follows:

[0014]

[0015] Low-temperature pyrolysis: The pretreated tire particles are put into a pyrolysis reaction kettle, and a composite catalyst accounting for 2% - 5% of the mass of the tire particles is added. The composite catalyst consists of nano-titanium dioxide and cobalt acetate (Co(CH3COO)2) as a transition metal salt in a mass ratio of 3:2, and platinum / carbon nanotube (Pt / CNT) supported on carbon nanotubes. Under a nitrogen protection atmosphere, the temperature in the reaction kettle is raised to 300 - 350 °C, and pyrolysis is carried out at this temperature for 3 - 5 h. The specific reaction formula is as follows:

[0016]

[0017] Post-treatment: A new type of centrifugal - filtration integrated solid - liquid separation technology is adopted to carry out solid - liquid separation of the reaction product to obtain high-performance recycled rubber with a particle size of 0.1 - 0.5 mm;

[0018] Equipment: The low-temperature cracking equipment includes a tire crushing device, a magnetic separation device, a cyclone separation device, a soaking pool, a cracking reactor, a solid-liquid separation device, a distillation device, a nitrogen supply system, and a heating system, which are connected in sequence; the cracking reactor adopts a double-layer jacket structure, with the inner layer being the reaction chamber and the outer layer being the heating medium channel, and the heating medium is a new type of heat-conducting oil.

[0019] Preferably, in the pretreatment step, the soaked tire particles are first preliminarily dried in a microwave drying equipment with a microwave power of 300 - 500W and a drying time of 5 - 10 minutes, and then placed in an oven at 60 - 80°C for 1 - 2 hours to remove the excess moisture and activator solution on the surface.

[0020] Preferably, before using the composite catalyst, nano-titanium dioxide, transition metal salts, and carbon nanotube-supported noble metals need to be ball-milled in a planetary ball mill at a rotation speed of 800 - 1200 revolutions per minute for 3 - 5 hours, and a dispersant accounting for 1% - 3% of the total mass is added during the ball-milling process.

[0021] Preferably, in the low-temperature cracking step, the pressure inside the reactor is controlled at 0.1 - 0.3MPa. The pressure inside the reactor is monitored in real time through a pressure sensor, and the flow rate of the nitrogen supply system is automatically adjusted through an intelligent pressure control system to maintain the pressure stability, and the pressure fluctuation is controlled within ±0.01MPa.

[0022] Preferably, during the post-treatment of the recycled rubber, a two-stage crushing process is adopted for crushing. First, the solid product is crushed to a particle size of 1 - 3mm by a coarse crusher, and then further crushed to 0.1 - 0.5mm by a colloid mill. The crushing time of the coarse crusher is 10 - 20 minutes, and the crushing time of the colloid mill is 20 - 40 minutes; for screening, a multi-layer vibrating screen is used, and the mesh numbers of the sieve meshes are 30 meshes, 40 meshes, and 60 meshes respectively.

[0023] Preferably, an efficient condenser is provided at the top of the distillation device, which adopts a spiral tube condensation structure. The cooling medium is low-temperature brine, and the temperature is controlled at -10 - 0°C. The condensed light oil is collected in an oil storage tank with a liquid level monitoring device, and the cracked gas is stored in a gas storage tank with a pressure monitoring device after being compressed.

[0024] Preferably, for the high-performance recycled rubber prepared by the process according to any one of the above, after testing, the tensile strength of this recycled rubber is increased by 40% - 60% compared with traditional recycled rubber, the elongation at break is increased by 30% - 50%, and the abrasion resistance is increased by 50% - 70%.

[0025] Preferably, for the applications of the high-performance recycled rubber in the fields of tire manufacturing, rubber product production, and road paving materials as described in the previous item, in tire manufacturing, using this recycled rubber can reduce the rolling resistance of the tire by 20%-30% and improve fuel economy; in rubber product production, it can increase the service life of the product by 30%-50%; in road paving materials, it can enhance the rutting resistance and anti-aging performance of the road and extend the service life of the road by 40%-60%.

[0026] (III) Beneficial technical effects

[0027] Compared with the existing technologies, the beneficial effects of the present invention are as follows:

[0028] 1. The novel multi-stage crushing device combines the principles of shear and impact crushing, greatly improving the crushing efficiency. The high-gradient magnetic separation technology can almost completely remove metal impurities, and the cyclone separator effectively removes dust. The graphene quantum dots added in the composite activator enhance the interaction between rubber molecules, and the ultrasonic-assisted soaking makes the activation more sufficient, laying a good foundation for the subsequent cracking reaction.

[0029] 2. The carbon nanotube-supported noble metals in the composite catalyst provide additional active sites, and cooperate with nano-titanium dioxide and transition metal salts to promote the reasonable breaking and recombination of rubber molecular chains. The precise temperature and pressure control system and the protection of high-purity nitrogen ensure that the reaction proceeds under the best conditions and improve the performance of the recycled rubber.

[0030] 3. The novel centrifugal-filtration integrated solid-liquid separation technology greatly improves the separation efficiency and effect, reducing the impurity residue. The combination of molecular distillation and vacuum distillation effectively recovers light oil and cracking gas, realizing the maximum utilization of resources.

[0031] 4. The novel heat transfer oil improves the heat transfer efficiency. The intelligent heating system precisely controls the temperature within ±1°C to ensure the stability of the reaction. The high-precision pressure control and the supply of high-purity nitrogen guarantee the stability of the reaction environment. The two-stage crushing and multi-layer vibrating screen screening process make the particle size of the recycled rubber more uniform.

[0032] 5. The finally prepared high-performance recycled rubber performs excellently in various properties, with a significant improvement in tensile strength, elongation at break, and abrasion resistance. In practical applications, it can be used in tire manufacturing to reduce rolling resistance and improve fuel economy; in rubber product production, it can extend the service life; in road paving, it can enhance the road performance and extend the service life of the road. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is the process flow chart of the low-temperature cracking of waste tires to prepare high-performance recycled rubber proposed by the present invention;

[0034] Figure 2It is a line chart comparing the cracking gas recovery rates of the examples and the comparative examples;

[0035] Figure 3 It is a column chart comparing the light oil recovery rates of the examples and the comparative examples;

[0036] Figure 4 It is a chart comparing the tensile strength and elongation at break of the examples and the comparative examples. Detailed implementation manners

[0037] Example 1

[0038] Pretreatment: Select 100 kg of waste tires and crush them using a new type of multi-stage crushing device; the device first performs preliminary crushing of the tires through shear crushing, and then further refines them using impact crushing, finally obtaining tire particles with a particle size of 1 - 3 cm; then, use a high-gradient magnetic separation device to remove metal impurities, and the magnetic separation intensity is set to 6 Tesla. After two magnetic separation operations, almost all metal impurities in the tire particles can be removed; subsequently, remove dust impurities through a cyclone separator. After detection, the dust removal rate reaches 98%; put the treated tire particles into an immersion tank, and the immersion tank is filled with a composite activator solution with a mass fraction of 5%; the composite activator is composed of an organosilane coupling agent (KH570) and nano-zinc oxide mixed in a mass ratio of 2:1, and 1% of graphene quantum dots are added at the same time; during the immersion process, turn on the ultrasonic device, the ultrasonic frequency is set to 30 kHz, the power is 200 W, and the immersion time is 3 hours; after the immersion is completed, take out the tire particles, first put them into a microwave drying device for preliminary drying, the microwave power is 400 W, the drying time is 8 minutes, and then transfer them to an oven at 70 °C for drying for 1.5 hours;

[0039] Preparation of the composite catalyst: Weigh 30 g of nano-titanium dioxide, 20 g of cobalt acetate, and 10 g of noble metal supported on carbon nanotubes (Pt / CNT) according to the mass ratio, and then add 2% of polyvinylpyrrolidone (PVP) by total mass as a dispersant; put these components into a planetary ball mill and ball mill at a speed of 1000 revolutions per minute for 4 hours to fully mix and homogenize the components to obtain the composite catalyst;

[0040] Low-temperature cracking: Transfer the pretreated tire particles to a cracking reaction kettle, and add a composite catalyst accounting for 3% of the mass of the tire particles; the reaction kettle is connected to a nitrogen supply system. First, introduce nitrogen to displace the air in the kettle, and then continuously introduce nitrogen to maintain an inert atmosphere. The nitrogen purity is 99.99%; use the heating system to raise the temperature in the reaction kettle to 320 °C at a heating rate of 4 °C / min, and maintain this temperature for 4 hours for the cracking reaction; during the cracking process, use a pressure sensor to monitor the pressure in the reaction kettle in real time, and use an intelligent pressure control system to adjust the nitrogen flow rate to stably control the pressure at 0.2 MPa, and the pressure fluctuation is controlled within ±0.01 MPa;

[0041] Post-treatment: After the cracking reaction is completed, a centrifugation-filtration integrated device is used to separate the solid and liquid of the reaction product. The separation speed of the device is set at 4000 revolutions per minute, and the separation time is 30 minutes. The separated solid product is first crushed by a coarse crusher for 15 minutes to make the particle size reach 1 - 3 mm, and then further crushed by a colloid mill for 30 minutes to obtain recycled rubber with a particle size of 0.1 - 0.5 mm. After that, a multi-layer vibrating screen is used for screening, and the mesh numbers of the sieve are 30 meshes, 40 meshes, and 60 meshes respectively, and qualified recycled rubber products are classified and screened out. The liquid product enters a distillation device in which a molecular distillation tower and a vacuum distillation tower are connected in series for treatment. The molecular distillation temperature is set at 100 °C, and the vacuum degree is 5×10 -3 Pa, the vacuum distillation temperature is 150 °C, and the vacuum degree is 0.06 MPa. The high-efficiency condenser at the top of the tower adopts a spiral tube condensation structure, and the cooling medium is low-temperature brine at a temperature of -5 °C to cool the distilled light oil and cracking gas to room temperature. The condensed light oil is collected in an oil storage tank with a liquid level monitoring device, and the cracking gas is stored in a gas storage tank with a pressure monitoring device after compression;

[0042] Performance testing: The prepared recycled rubber is subjected to performance testing, with a tensile strength of 18 MPa and an elongation at break of 500%.

[0043] Example 2

[0044] Pretreatment: Take 120 kg of waste tires and crush them to a particle size of 2 - 4 cm using a new type of multi-stage crushing device. The high-gradient magnetic separation intensity is set at 7 Tesla. After three magnetic separations, the metal impurity removal rate reaches 99.5%. A cyclone separator removes dust impurities, and the dust removal rate is 98.5%. The tire particles are soaked in a 6% compound activator solution by mass, with an ultrasonic frequency of 35 kHz and a power of 250 W for 3.5 hours. After soaking, they are first dried by microwave with a microwave power of 450 W for 9 minutes, and then dried in an oven at 75 °C for 1.8 hours;

[0045] Preparation of composite catalyst: Weigh 36 g of nano-titanium dioxide, 24 g of cobalt acetate, and 12 g of carbon nanotube-supported noble metal (Pt / CNT), add 2.5% of PVP by total mass, and ball-mill in a planetary ball mill at a speed of 1100 revolutions per minute for 4.5 hours;

[0046] Low-temperature cracking: Add the pretreated tire particles to the cracking reaction kettle, and add a composite catalyst accounting for 3.5% of the mass of the tire particles. After replacing the air with nitrogen, keep the nitrogen purity at 99.99%, and raise the temperature to 330 °C at a heating rate of 4.5 °C / min for 4.5 hours of cracking reaction. During the reaction, the pressure is controlled at 0.22 MPa, with a fluctuation of ±0.01 MPa;

[0047] Post-treatment: During solid-liquid separation, the rotational speed of the centrifugal-filtration integrated equipment is 4,200 revolutions per minute, and the separation time is 35 minutes. The solid product is first crushed by a coarse crusher for 18 minutes and then by a colloid mill for 35 minutes. It is screened by a multi-layer vibrating screen with mesh numbers of 30, 40, and 60. During distillation, the molecular distillation temperature is 105°C, and the vacuum degree is 6×10 -3 Pa, the vacuum distillation temperature is 160°C, and the vacuum degree is 0.07 MPa. The cooling medium temperature of the condenser is -8°C;

[0048] Performance testing: The tensile strength of the recycled rubber prepared in Example 2 is 19 MPa, and the elongation at break is 520%.

[0049] Example 3

[0050] Pretreatment: Select 80 kg of waste tires and crush them into particles with a particle size of 1 - 5 cm by a new type of multi-stage crushing device. The high-gradient magnetic separation intensity is 5 Tesla, and the removal rate of metal impurities after two magnetic separations is 99%. The dust removal rate of the cyclone separator reaches 97.5%. The tire particles are soaked in a 4% compound activator solution by mass, with an ultrasonic frequency of 25 kHz and a power of 150 W for 2.5 hours. After soaking, the microwave drying power is 350 W for 7 minutes, and then dried in an oven at 65°C for 1.2 hours;

[0051] Preparation of composite catalyst: Weigh 24 g of nano-titanium dioxide, 16 g of cobalt acetate, and 8 g of carbon nanotube-supported noble metal (Pt / CNT), add 1.5% of PVP by total mass, and ball mill in a planetary ball mill at a rotational speed of 900 revolutions per minute for 3.5 hours;

[0052] Low-temperature pyrolysis: Add the pretreated tire particles into the pyrolysis reactor, and add a composite catalyst accounting for 2.5% of the mass of the tire particles. After nitrogen replacement, heat up to 310°C at a heating rate of 3.5°C / min and carry out pyrolysis reaction for 3.5 hours. The pressure is controlled at 0.18 MPa, with a fluctuation of ±0.01 MPa, and the nitrogen purity is 99.99%;

[0053] Post-treatment: The rotational speed of the solid-liquid separation equipment is 3,500 revolutions per minute, and the separation time is 25 minutes. The solid product is crushed by a coarse crusher for 12 minutes and then by a colloid mill for 25 minutes. It is screened by a multi-layer vibrating screen with mesh numbers of 30, 40, and 60. During distillation, the molecular distillation temperature is 95°C, and the vacuum degree is \(4×10^{-3}\) Pa, the vacuum distillation temperature is 140°C, and the vacuum degree is 0.05 MPa. The cooling medium temperature of the condenser is -3°C;

[0054] Performance testing: The tensile strength of the recycled rubber prepared in Example 3 is 17 MPa, and the elongation at break is 480%. Comparative example

[0055] Pretreatment: 100kg of waste tires were taken and crushed by traditional crusher. The particle sizes varied, and the average particle size was about 5cm. Ordinary magnetic separation equipment was used to remove metal impurities, and the metal impurities remained relatively large, about 5%. A simple bag dust removal method was used to remove dust, and the dust removal rate was only 80%. The tire particles were soaked in an activator solution containing only organic silane coupling agent (KH570) and nano zinc oxide, with a mass fraction of 3%. No ultrasonic assistance was used during the soaking process, and the soaking time was 2 hours. After soaking, they were dried in an oven at 50°C for 2 hours.

[0056] Preparation of composite catalyst: nano-titanium dioxide and cobalt acetate were weighed in a mass ratio of 3:2, without adding carbon nanotube-supported noble metals and dispersants, and ball-milled in an ordinary ball mill at a speed of 500 rpm for 2 hours;

[0057] Low temperature pyrolysis: the pretreated tire particles were placed in a common pyrolysis reactor, and the composite catalyst accounting for 2% of the tire particle mass was added; the reactor was not connected to a nitrogen protection system and was heated directly in the air; the temperature was raised to 380°C at a heating rate of 6°C / min, and the pyrolysis reaction was carried out for 3 hours; the pressure was not effectively controlled during the reaction process;

[0058] Post-processing: The solid-liquid separation was carried out by using the traditional centrifugal separation equipment, the separation speed was 2000 rpm, the separation time was 40 minutes, the separation effect was not good, and the solid product still contained a lot of liquid impurities; the solid product was directly crushed by ordinary pulverizer without grading and screening.

[0059] Comparison table of recycled rubber properties between examples and comparative examples:

[0060] Sample Example 1 Example 2 Example 3 Comparative Example Tensile strength (MPa) 18 19 17 12 Elongation at break (%) 500 520 480 400 Proportion of abrasion resistance improvement 60％ 65％ 55％ -

[0061] Conclusion: This table intuitively shows the difference between the embodiment and the comparative example in the performance of recycled rubber. The tensile strength, elongation at break and wear resistance improvement ratio of the embodiment are significantly better than those of the comparative example, indicating that the patented process is effective in improving the performance of recycled rubber.

[0062] Comparison table of process parameters and resource recovery of examples and comparative examples:

[0063] Sample Example 1 Example 2 Example 3 Comparative Example Cracking temperature (°C) 320 330 310 380 Cracking time (h) 4 4.5 3.5 3 Light oil recovery rate 85％ 88％ 82％ 60％ Cracked gas recovery rate 80％ 82％ 78％ 55％

[0064] Conclusion: This table compares the process parameters and resource recovery of the embodiment and the comparative example. The embodiment achieves a higher recovery rate of light oil and cracking gas at a lower cracking temperature and a suitable cracking time, which reflects the advantages of the patented process in energy saving and resource recovery.

[0065] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires, characterized in that, The process includes the following steps: Pretreatment: The waste tires are crushed to a particle size of 1 - 5 cm, and the metal impurities are removed by high-gradient magnetic separation technology with a magnetic separation intensity of 5 - 8 T. Then, the dust impurities are removed by a cyclone separator. After that, the tire particles are soaked in a composite activator solution with a mass fraction of 3% - 8% for 2 - 4 h, during which ultrasonic assistance treatment is carried out with a frequency of 20 - 40 kHz and a power of 100 - 300 W. The composite activator consists of an organosilane coupling agent and nano-zinc oxide with a mass ratio of 2:1, and 0.5% - 1.5% of graphene quantum dots. The siloxane group in the organosilane coupling agent undergoes a condensation reaction with the hydroxyl groups on the tire surface, the nano-zinc oxide undergoes chemisorption with the rubber molecules, and the graphene quantum dots form π-π stacking interactions with the rubber molecules. The reaction formula is as follows: Low-temperature pyrolysis: The pretreated tire particles are put into a pyrolysis reactor, and a composite catalyst accounting for 2% - 5% of the mass of the tire particles is added. The composite catalyst consists of nano-titanium dioxide and transition metal salt cobalt acetate Co(CH3COO)2 with a mass ratio of 3:2, and carbon nanotube-supported noble metal Pt / CNT. Under a nitrogen protection atmosphere, the temperature in the reactor is raised to 300 - 350 °C and pyrolyzed at this temperature for 3 - 5 h. The specific reaction formula is as follows: Post-treatment: A new centrifugal-filtration integrated solid-liquid separation technology is used to separate the reaction products into solid and liquid phases, obtaining high-performance recycled rubber with a particle size of 0.1 - 0.5 mm. Equipment: The low-temperature pyrolysis equipment includes a tire crushing device, a magnetic separation device, a cyclone separation device, a soaking pool, a pyrolysis reactor, a solid-liquid separation device, a distillation device, and a nitrogen supply system and a heating system connected in sequence. The pyrolysis reactor adopts a double-layer jacket structure, with the inner layer being the reaction chamber and the outer layer being the heating medium channel, and the heating medium is a new type of heat-conducting oil.

2. The process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires according to claim 1, characterized in that, In the pretreatment step, the soaked tire particles are first preliminarily dried in a microwave drying equipment with a microwave power of 300 - 500 W and a drying time of 5 - 10 minutes, and then put into an oven at 60 - 80 °C for drying for 1 - 2 hours to remove the excess moisture and activator solution on the surface.

3. The process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires according to claim 1, characterized in that, Before using the composite catalyst, nano-titanium dioxide, transition metal salt, and carbon nanotube-supported noble metal need to be ball-milled in a planetary ball mill at a rotation speed of 800 - 1200 revolutions per minute for 3 - 5 hours, and a dispersant accounting for 1% - 3% of the total mass is added during the ball-milling process.

4. The process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires according to claim 1, characterized in that, In the low-temperature pyrolysis step, the pressure in the reactor is controlled at 0.1 - 0.3 MPa. The pressure in the reactor is monitored in real time through a pressure sensor, and the flow rate of the nitrogen supply system is automatically adjusted through an intelligent pressure control system to maintain the pressure stability, and the pressure fluctuation is controlled within ±0.01 MPa.

5. The process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires according to claim 1, characterized in that, During the post-treatment process of the recycled rubber, two-stage crushing process is adopted for crushing. First, a coarse crusher is used to crush the solid product to a particle size of 1-3 mm, and then a colloid mill is used to further crush it to 0.1-0.5 mm. The crushing time of the coarse crusher is 10-20 minutes, and the crushing time of the colloid mill is 20-40 minutes. Screening is carried out using a multi-layer vibrating screen, and the mesh numbers of the sieve meshes are 30 mesh, 40 mesh and 60 mesh respectively.

6. The process and equipment for preparing high-performance recycled rubber by low-temperature cracking of waste tires according to claim 1, characterized in that, A high-efficiency condenser is provided at the top of the distillation device, which adopts a spiral tube condensation structure. The cooling medium is low-temperature brine, and the temperature is controlled at -10-0 °C. The condensed light oil is collected in an oil storage tank equipped with a liquid level monitoring device, and the cracked gas is stored in a gas storage tank equipped with a pressure monitoring device after compression.

7. A high-performance recycled rubber prepared by the process according to any one of claims 1-6, characterized in that, After testing, the tensile strength of this recycled rubber is increased by 40%-60% compared with traditional recycled rubber, the elongation at break is increased by 25%-50%, and the wear resistance is increased by 50%-70%.

8. Use of the high-performance recycled rubber according to claim 7 in the fields of tire manufacturing, production of rubber products, and road paving materials, characterized in that, In tire manufacturing, using this recycled rubber can reduce the rolling resistance of the tire by 20%-30% and improve fuel economy; in the production of rubber products, it can increase the service life of the products by 30%-50%; In road paving materials, it can enhance the rutting resistance and anti-aging performance of the road, and extend the service life of the road by 40%-60%.

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