A tire wastewater oil extraction and resource utilization system

Abstract

The present application belongs to the field of environmental protection and resource recycling technology, and particularly relates to a tire wastewater oil extraction and resource utilization system. The system comprises an adsorption tower, the adsorption tower is connected with a dry distillation furnace through a water removal screw, the dry distillation furnace is connected with a post-cooler through a primary cooler; the primary cooler is connected with an oil pump through an oil-water separation system; the dry distillation furnace is connected with a pressure tank through a regenerator, the pressure tank is connected with the adsorption tower; the regenerator is connected with a ceramic fiber filter through a cyclone separator, the ceramic fiber filter is connected with an alkali washing and acid removal tower through an RTO, and the alkali washing and acid removal tower is connected with an induced draft fan. The present application realizes closed loop operation of "adsorption-oil extraction-activation-reuse", and has the comprehensive advantages of oil recovery, activated carbon regeneration and clean emission.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection and resource recycling technology, specifically relating to a tire wastewater oil extraction and resource utilization system. Background Technology

[0002] Tire production and cleaning processes generate large amounts of oily wastewater containing recyclable oils. Traditional treatment methods often employ flocculation, flotation, or activated carbon adsorption, but these methods tend to focus only on achieving emission standards while neglecting the resource value of the oil. If activated carbon becomes saturated and is not properly treated, it can cause secondary pollution. If an effective method can be used to extract and recover the oil from the wastewater while simultaneously regenerating the activated carbon, it can reduce hazardous waste treatment costs and yield oil byproducts, resulting in significant economic and environmental benefits. Therefore, this invention provides a wastewater treatment and resource recovery system with oil extraction as its core. Summary of the Invention

[0003] In view of the above-mentioned deficiencies of the prior art, the present invention provides a tire wastewater oil extraction and resource utilization system.

[0004] The technical solution of this invention is as follows: A tire wastewater oil extraction and resource utilization system includes an adsorption tower, which is connected to a distillation furnace via a dewatering spiral, and the distillation furnace is connected to an aftercooler via a primary cooler; the primary cooler is connected to an oil pump via an oil-water separation system. The distillation furnace is connected to the alkali washing and deacidification tower, and the alkali washing and deacidification tower is connected to the induced draft fan.

[0005] The pyrolysis furnace is connected to the regeneration furnace, and the remaining activated carbon after pyrolysis enters the regeneration furnace; the regeneration furnace is connected to the cyclone separator, and the flue gas generated in the regeneration furnace enters the cyclone separator.

[0006] The filtered flue gas enters the RTO; the RTO is connected to the alkaline washing and deacidification tower, and the flue gas after catalytic combustion in the RTO enters the alkaline washing and deacidification tower, with alkaline solution entering the alkaline washing and deacidification tower; the alkaline washing and deacidification tower is connected to the induced draft fan, and the flue gas purified by the alkaline washing and deacidification tower is discharged into the air by the induced draft fan.

[0007] The primary cooler is connected to the aftercooler. After being cooled by the primary cooler, the oil and gas enter the aftercooler. Process water enters the aftercooler to participate in the cooling. The process water discharged from the aftercooler is reused. At the same time, the aftercooler discharges oil, VOCs and wastewater respectively.

[0008] More details: A tire wastewater oil extraction and resource utilization system includes an adsorption tower, which is connected to a distillation furnace via a dewatering spiral, and the distillation furnace is connected to an aftercooler via a primary cooler; the primary cooler is connected to an oil pump via an oil-water separation system. The pyrolysis furnace is connected to the pressure conveying tank via the regeneration furnace, and the pressure conveying tank is connected to the adsorption tower; the regeneration furnace is connected to the ceramic fiber filter via the cyclone separator, the ceramic fiber filter is connected to the alkaline washing and deacidification tower via the RTO, and the alkaline washing and deacidification tower is connected to the induced draft fan.

[0009] Preferably, the process water enters the adsorption tower, the adsorption tower discharges compliant process water, and the adsorption tower is filled with activated carbon.

[0010] Preferably, the adsorption tower is connected to a dehydration spiral, which transports the adsorption-saturated activated carbon to the dehydration spiral. The dehydration spiral is connected to a dryer through a drying tower, and the saturated activated carbon after dehydration in the drying tower enters the dryer.

[0011] Preferably, the dry distillation furnace is connected to a primary cooler. The oil and gas produced by the dry distillation furnace enter the primary cooler, and the primary cooler discharges the exhaust steam. At the same time, electrical energy is connected to the primary cooler to provide operating power for the primary cooler.

[0012] Preferably, the primary cooler is connected to the aftercooler. The oil and gas are cooled by the primary cooler and then enter the aftercooler. The process water enters the aftercooler to participate in the cooling. The process water discharged from the aftercooler is reused. At the same time, the aftercooler discharges VOCs and wastewater respectively.

[0013] Preferably, the primary cooler is connected to an oil-water separation system, and the oil separated by the oil-water separation system is connected to an oil pump, which discharges and collects the oil.

[0014] Preferably, the pyrolysis furnace is connected to the regeneration furnace, and the remaining activated carbon after pyrolysis in the pyrolysis furnace enters the regeneration furnace; the regeneration furnace is connected to the cyclone separator, and the flue gas generated in the regeneration furnace enters the cyclone separator; the cyclone separator is connected to the ceramic fiber filter, and the flue gas after most of the dust is removed by the cyclone separator enters the ceramic fiber filter.

[0015] Preferably, the ceramic fiber filter is connected to the RTO, and the flue gas after denitrification and filtration by the ceramic fiber filter enters the RTO; the RTO is connected to the alkaline washing deacidification tower, and the flue gas after catalytic combustion in the RTO enters the alkaline washing deacidification tower, with alkaline solution entering the alkaline washing deacidification tower; the alkaline washing deacidification tower is connected to the induced draft fan, and the flue gas purified by the alkaline washing deacidification tower is discharged into the air by the induced draft fan.

[0016] Preferably, the regeneration furnace is connected to the pressure conveying tank, and the activated carbon regenerated in the regeneration furnace enters the pressure conveying tank; electrical energy is connected to the regeneration furnace, and urea solution is connected to the pipeline between the regeneration furnace and the pressure conveying tank; supplementary activated carbon and process water enter the pressure conveying tank respectively, and the pressure conveying tank is connected to the adsorption tower, and the pressure conveying tank supplements the adsorption tower with new carbon and regenerated carbon.

[0017] Preferably, the inclination angle of the regeneration furnace cylinder is 1~3° and the rotation speed is 1-3 rpm.

[0018] Preferably, the activated carbon includes activated carbon composite particles, and the preparation method of the activated carbon composite particles includes the following steps: The activated carbon is washed, dried at 110-120℃ for 4-8 hours, and then placed in a tube furnace for heat treatment at 300-400℃ for 1-2 hours to obtain pretreated activated carbon. Ba(OH)2·8H2O and anatase TiO2 nanopowder were dispersed in deionized water at a Ba:Ti molar ratio of 1.05-1.15:1. The concentration was adjusted, and the mixture was transferred to a hydrothermal reactor and reacted at 180-220℃ for 12-24 h. The reaction product was centrifuged, washed, dried, and then annealed in air at 650-750℃ for 2-4 h to obtain BaTiO3 nanoparticles. BaTiO3 nanoparticles were dispersed in anhydrous ethanol, and APTES was added. The mass of APTES was 3-8 wt% of the mass of BaTiO3. The mixture was stirred at 60-80℃ for 4-8 h. After the reaction was completed, the nanoparticles were separated by centrifugation, washed, and dried to obtain modified BaTiO3 nanoparticles. Modified BaTiO3 nanoparticles were dispersed in anhydrous ethanol, and TEOS (5-15 wt% of the mass of the modified BaTiO3 nanoparticles) was added. The pH was adjusted and the mixture was stirred until homogeneous to obtain a loading solution. Pretreated activated carbon was immersed in the loading solution and impregnated. After impregnation, the carbon was filtered, washed, dried, and then calcined at 350-450℃ for 2-4 hours under N2 atmosphere to obtain composite particles. The composite particles are spread between two parallel stainless steel plates. The plate assembly is placed in an oven and heated to 80-120℃. A DC electric field of 5-15kV / cm is applied and maintained for 30-60 minutes. Then, the electric field is removed after the plate is naturally cooled to room temperature while maintaining the electric field, thus obtaining activated carbon composite particles.

[0019] It should be noted that the specific principle of the preparation process of the above technical solution is as follows: Preparation of pretreated activated carbon: Oxygen-containing functional groups (-OH, -COOH) are introduced on the outer surface of activated carbon particles and the inner wall of shallow pores as anchoring sites for subsequent piezoelectric nanoparticles. At the same time, the oxidation depth is controlled to be limited to the outer layer of the particles within 50-150 μm, so as to maintain the original hydrophobicity and adsorption performance of the deep pores.

[0020] Preparation of modified BaTiO3 nanoparticles: The amino terminus of APTES can form chemical bonds with the oxygen-containing functional groups on the surface of activated carbon and the subsequent SiO2 bonding layer, while the siloxane terminus forms a protective layer on the surface of BaTiO3, enhancing the bonding force between BaTiO3 and activated carbon.

[0021] Preparation of composite particles: Due to the larger particle size (30-100 nm) of BaTiO3 nanoparticles compared to most mesopores and micropores of activated carbon, the nanoparticles, under ultrasonic agitation, can only enter the outer surface and shallow macropores of the particles. They are naturally sieved and blocked from deeper layers by the pore size, thus forming a gradient distribution with a denser outer layer and a sparser inner layer. During impregnation, TEOS undergoes in-situ hydrolysis and condensation under alkaline conditions, forming a SiO2 inorganic binder layer at the interface between BaTiO3 and activated carbon, firmly anchoring BaTiO3 to the activated carbon surface. Calcination fully solidifies the SiO2 binder layer.

[0022] Preparation of activated carbon composite particles: A DC electric field of 5-15 kV / cm is applied to the composite particles at a temperature of 100-140℃. BaTiO3 is near its Curie temperature, and the ferroelectric domains exhibit high mobility. Under the drive of the electric field, the free domains align and align along the direction of the electric field. Cooling to room temperature while maintaining the electric field preserves the orientation of the ferroelectric domains, endowing the BaTiO3 nanoparticles with macroscopic remanent polarization, thus exhibiting a piezoelectric response: when subjected to mechanical stress, polarization charges can be generated on the particle surface, forming a local electric field.

[0023] The activated carbon composite particles consist of a granular activated carbon carrier and piezoelectric nanoparticles loaded on the surface and shallow macropores of the granular activated carbon carrier. The piezoelectric nanoparticles are polarized tetragonal BaTiO3 nanoparticles with a particle size of 30-100 nm, and their loading is 5-15 wt% of the mass of the granular activated carbon carrier. The piezoelectric nanoparticles exhibit a gradient distribution on the granular activated carbon carrier, with a denser outer layer and a sparser inner layer. Specifically, the density of piezoelectric nanoparticles on the outer surface and in the shallow macropores (depth ≤ 100 μm) is greater than the density in the deeper mesopores and micropores. This concentrates the electric field enhancement effect on the outer surface region where oil droplets first contact the particles, while preserving the original adsorption performance of the deeper mesopores and micropores. A SiO2 inorganic binder layer, 1-5 nm thick, is provided between the piezoelectric nanoparticles and the granular activated carbon carrier to firmly anchor the piezoelectric nanoparticles to the activated carbon surface.

[0024] The beneficial effects of this invention are as follows: 1. This invention constructs a circulating system combining an adsorption tower, a dry distillation furnace, a regeneration furnace, and a tail gas purification unit, realizing the adsorption and enrichment of oily substances in tire wastewater by activated carbon, dry distillation for oil extraction, high-temperature regeneration, and recycling. The adsorption tower enhances the uniformity of contact between wastewater and activated carbon. The dry distillation furnace operates at a temperature of 180-250℃, a negative pressure of -0.02~-0.05MPa, and an oxygen content ≤3%, achieving efficient desorption of oily substances without combustion or coking, with an oil recovery rate ≥50%. The regeneration furnace uses a high-frequency electromagnetic heating rotary kiln with a cylinder inclination angle of 1-3° and a rotation speed of 1-3 rpm, ensuring precise temperature control and a ≥90% recovery rate of activated carbon adsorption performance after regeneration.

[0025] 2. The exhaust gas purification unit of this invention employs a cyclone separator, a ceramic fiber filter, an RTO (Regenerative Thermal Oxidizer), and an alkaline scrubbing desulfurization tower. The cyclone separator removes ≥90% of the dust and returns it to the dry distillation furnace for recycling. The ceramic fiber filter has a built-in denitrification catalyst, utilizing ammonia produced by the pyrolysis of urea at the outlet of the regeneration furnace for denitrification, eliminating the need for an additional ammonia supply system. The RTO is supplemented to 380-420℃ and the oxygen content is controlled at 3-8%, with catalytic combustion removing VOCs. The alkaline scrubbing desulfurization tower controls the pH of the circulating liquid to 7±0.2 online, effectively removing acidic gases such as SO2 and HCl. After four stages of purification, all pollutant indicators of the flue gas meet national emission standards.

[0026] 3. This invention recovers oily substances from tire wastewater as a resource, obtaining oily byproducts that can be reused as fuel oil or feedstock; the process water discharged from the aftercooler is heated and returned to the workshop for recycling; and some of the heat energy from the distillation furnace and regeneration furnace is recovered through heat exchange within the system. The entire system achieves the comprehensive goals of wastewater discharge meeting standards (oil content ≤ 5 mg / L), activated carbon recycling, and tail gas emission meeting standards, demonstrating good environmental and economic benefits.

[0027] 4. This invention improves the adsorption material: By loading polarized tetragonal BaTiO3 piezoelectric nanoparticles onto the surface and shallow macropores of a granular activated carbon carrier, this invention utilizes the mechanical stress generated by wastewater flow and particle collisions to excite the piezoelectric effect, thus generating a local microscopic electric field in situ in the water medium surrounding the particles. This electric field effectively weakens the negatively charged double layer on the surface of emulsified oil droplets, overcoming the electrostatic repulsion barrier between ordinary activated carbon and emulsified oil droplets, achieving both demulsification and adsorption simultaneously without the need for chemical demulsifiers.

[0028] In summary, this invention achieves a closed-loop operation of "adsorption-oil extraction-activation-reuse", combining the advantages of oil recovery, activated carbon regeneration, and clean emissions. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall system structure of the present invention; The following are labeled in the diagram: 1. Adsorption tower; 2. Dewatering spiral; 3. Pressure conveying tank; 4. Dry distillation furnace; 5. Primary cooler; 6. Aftercooler; 7. Regeneration furnace; 8. Cyclone separator; 9. Fiberglass filter; 10. RTO; 11. Alkali washing deacidification tower; 12. Exhaust fan; 13. Oil pump; 14. Oil-water separation system. Detailed Embodiments

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with embodiments and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Unless otherwise specified, the experimental methods used below are all conventional methods. Parts, equipment, materials, reagents, etc. used, unless otherwise specified, can all be obtained through commercial channels. The principles or mechanisms of parts or equipment that can be conventionally purchased through commercial channels are well-known, and general names have been given below, so no further details will be elaborated.

[0033] SNCR (Selective Non-Catalytic Reduction) is a denitrification technology, the principle of which is well-known to those skilled in the art and will not be elaborated further.

[0034] The meaning of ceramic fiber is ceramic fiber.

[0035] Embodiment 1 Refer to Figure 1 , the present invention provides a system for extracting oil and resource utilization from tire wastewater. The system includes an adsorption tower 1. Process water enters the adsorption tower 1, and the adsorption tower 1 discharges qualified process effluent.

[0036] The adsorption tower 1 is connected to a dewatering screw 2 for transporting the saturated activated carbon to the dewatering screw 2. The dewatering screw 2 is connected to a dry distillation furnace 4 through an external drying tower. The saturated activated carbon after dehydration in the drying tower enters the dry distillation furnace 4. The dry distillation furnace 4 is connected to a primary cooler 5, and the oil gas generated by dry distillation enters the primary cooler 5. The primary cooler 5 discharges exhausted steam, and at the same time, electric energy is connected to the primary cooler 5 to provide operating power for it.

[0037] The primary cooler 5 is connected to a secondary cooler 6. The oil gas enters the secondary cooler 6 after being cooled by the primary cooler 5. Process water enters the secondary cooler 6 to participate in the cooling. The secondary cooler 6 discharges the process water for recycling (for recycling), and at the same time, the secondary cooler 6 discharges VOC (volatile organic compounds) and sewage respectively. The sewage needs to be returned to the front-end wastewater treatment system. The front-end wastewater treatment system is located before the adsorption tower 1 and treats untreated tire wastewater and oil-containing sewage returned from the system interior. The wastewater treated by the front-end wastewater treatment system can enter the adsorption tower 1. The VOC discharged from the secondary cooler 6 is preferably incorporated into the subsequent tail gas purification unit for unified treatment; in other embodiments, it can also be connected to an independent VOC treatment device.

[0038] The primary cooler 5 is also connected to an oil-water separation system 14. The oil separated by the oil-water separation system 14 is connected to an oil pump, and the oil pump discharges and collects the oil. The oil-water separation system 14 can be an oil-water separator.

[0039] The dry distillation furnace 4 is also connected to the regeneration furnace 7, and the remaining activated carbon after dry distillation enters the regeneration furnace 7; the regeneration furnace 7 is connected to the cyclone separator 8, and the flue gas generated by the regeneration furnace 7 enters the cyclone separator 8; the cyclone separator 8 is connected to the ceramic fiber filter 9, and the flue gas after removing most of the dust enters the ceramic fiber filter 9.

[0040] The ceramic fiber filter 9 is connected to the RTO (Regenerative Thermal Oxidizer) 10. The flue gas after denitrification and filtration by the ceramic fiber filter 9 enters the RTO 10. The RTO 10 is connected to the alkaline washing and deacidification tower 11. The flue gas after catalytic combustion in the RTO 10 enters the alkaline washing and deacidification tower 11. The alkaline solution is introduced into the alkaline washing and deacidification tower 11 for deacidification. The alkaline washing and deacidification tower 11 is connected to the induced draft fan 12. The flue gas purified by the alkaline washing and deacidification tower 11 is discharged through the induced draft fan 12. The regeneration furnace 7 is also connected to the pressure conveying tank 3. The regenerated activated carbon enters the pressure conveying tank 3. Electricity is introduced into the regeneration furnace 7 for electric heating to provide heat for the regeneration reaction. Urea solution is introduced into the pipeline between the regeneration furnace 7 and the pressure conveying tank 3 for rapid cooling and denitrification. The supplementary activated carbon and process water enter the pressure conveying tank 3 respectively. The pressure conveying tank 3 is connected to the adsorption tower 1 to supplement the adsorption tower 1 with new carbon and regenerated carbon, realizing the recycling of activated carbon.

[0041] This invention provides a system for oil extraction and resource utilization from tire wastewater, comprising an adsorption oil extraction unit, a dry distillation oil extraction unit, an activated carbon regeneration unit, and a tail gas purification unit. The aforementioned equipment and components can be incorporated into different units. 1. Adsorption oil extraction unit: Tire wastewater is pumped into the bottom of adsorption tower 1 by a booster pump, flowing upwards and contacting the floating granular activated carbon in the tower countercurrently. The activated carbon efficiently adsorbs oily substances in the wastewater, and the effluent meets discharge standards. Saturated activated carbon at the bottom of adsorption tower 1 is intermittently discharged and sent to a low-temperature negative pressure dehydration device (water dewatering spiral 2, drying tower, and distillation furnace 4); the upper layer of activated carbon in the tower moves downwards, and new carbon is added simultaneously.

[0042] 2. Dry distillation and oil extraction unit: Saturated activated carbon is dehydrated via a dewatering spiral 2 and a drying tower before entering a dry distillation furnace 4 for dry distillation under limited oxygen, low temperature, and negative pressure conditions. Adsorbed oily substances desorb to form oil vapor, which, after condensation, enters an oil-water separation system 14 to obtain an oily byproduct (recovery rate ≥50%). Wastewater is returned to the front-end treatment system. The activated carbon after oil extraction enters a regeneration furnace 7.

[0043] 3. Activated carbon regeneration unit: After oil extraction, activated carbon enters from the kiln head of the rotary kiln (i.e., regeneration furnace 7), with a cylinder inclination angle of 1-3° and a rotation speed of 1-3 rpm. An internal lifting plate is installed. The cylinder is heated by high-frequency electromagnetic heating, transferring heat to the activated carbon. As the material moves towards the kiln tail, it comes into countercurrent contact with the high-temperature gas entering from the kiln tail, undergoing thermal decomposition and activation reactions sequentially. A dilute urea solution is injected into the discharge port for rapid cooling. The pyrolysis of urea produces ammonia gas, which participates in SNCR denitrification. The resulting superheated steam participates in the activation reaction, clearing the pores and restoring the adsorption performance of the activated carbon. After rapid cooling, the activated carbon enters the pressure conveying tank 3 for later use.

[0044] 4. Exhaust gas purification unit: Cyclone separator 8: Removes most of the dust from the exhaust gas at the rotary kiln outlet, and the dust is returned to the raw material hopper regeneration furnace 7.

[0045] Fiberglass filter 9: Further filters micro-dust, with a built-in denitrification catalyst, utilizing ammonia gas generated from urea cracking for deep denitrification.

[0046] RTO 10: Exhaust gas reheating, catalytic combustion of VOC components on the catalyst surface, and supplemental air to control oxygen content to 3-8%.

[0047] Alkali washing deacidification tower 11: The tail gas is first cooled by water spraying before entering the alkali washing deacidification tower 11. The circulating liquid maintains a pH of 7±0.2, and a demister is installed at the top of the tower.

[0048] Exhaust gas 12 and chimney: After purification, the exhaust gas is discharged into the chimney and vented after being controlled by frequency converter of exhaust fan 12.

[0049] Example 2 Based on Example 1, a more detailed explanation of the device connections and operating principles is provided. (Refer to...) Figure 1 , Figure 1 Not all equipment and parts of Example 2 are shown.

[0050] This invention provides a tire wastewater oil extraction and resource utilization system, which is divided into an adsorption oil extraction unit, a dry distillation oil extraction unit, an activated carbon regeneration unit, and a tail gas purification unit.

[0051] 1. Adsorption oil extraction unit: Reference Figure 1 The core equipment in this unit is adsorption tower 1, and the supporting equipment includes a booster pump, a pressure tank, and a screw conveyor. The connection relationship and operating principle of each piece of equipment are as follows: The process wastewater (tire wastewater) is piped into the inlet of a booster pump. The outlet of the booster pump is connected to the wastewater inlet at the bottom of adsorption tower 1 via a sealed pipe. The booster pump is frequency-controlled and can automatically adjust the flow rate according to the wastewater level in adsorption tower 1 to ensure a stable flow of wastewater into the tower. Adsorption tower 1 is filled with floating granular activated carbon (0.5-2mm particle size) to a height of 60%-80% of the tower height. The tire wastewater enters from the bottom of adsorption tower 1 and flows upward, contacting the activated carbon which moves downward in a countercurrent manner. Utilizing the adsorption properties of the activated carbon, the oily substances in the tire wastewater are efficiently adsorbed. The effluent that meets the standards after adsorption (oil content ≤5mg / L) is discharged from the outlet at the top of adsorption tower 1, either entering an external wastewater reuse system or being directly discharged. Figure 1 The process water output in the middle.

[0052] An intermittent discharge valve is installed at the bottom of the adsorption tower 1. When the activated carbon at the bottom reaches saturation, the discharge valve opens automatically, and the saturated activated carbon is transported to the dewatering screw 2 and the drying tower for dehydration treatment via a screw conveyor. At the same time, the unsaturated activated carbon in the upper layer of the adsorption tower 1 moves down automatically under gravity to fill the gap after the activated carbon is discharged from the bottom.

[0053] The pressure tank 3 is equipped with a replenishment activated carbon inlet and a process water inlet. After the activated carbon regenerated by the regeneration furnace 7 is cooled to room temperature by a cooling device, it is transported to the pressure tank 3 by a screw conveyor or chute. It is mixed with the replenished fresh activated carbon in the pressure tank 3. Process water is introduced into the pressure tank 3 as a transport carrier. The mixed carbon slurry is pumped through a pipeline into the fresh carbon replenishment port at the top of the adsorption tower 1 by a pressure pump, so as to realize the continuous replenishment and recycling of activated carbon and ensure the stable adsorption efficiency of the adsorption tower 1.

[0054] 2. Dry distillation and oil extraction unit The core equipment of this unit is the dry distillation furnace 4, and the supporting equipment includes the dewatering spiral 2, the primary cooler 5, the aftercooler 6, the oil pump 13, and the sealed feeding device (not shown in the figure). The connection relationship and operating principle of each piece of equipment are as follows: A screw conveyor from the adsorption and oil extraction unit transports saturated activated carbon to a dehydration screw 2, which is connected to a drying tower. This reduces the moisture content of the activated carbon to below 5%. The dehydrated activated carbon then enters the inlet of the dry distillation furnace 4 through a sealed feeding device (to prevent leakage of negative pressure within the furnace). The dry distillation furnace 4 operates under low-temperature negative pressure, with the operating temperature controlled between 180-250℃ and the negative pressure value between -0.02 and -0.05 MPa. An oxygen-limited environment (oxygen content ≤3%) is maintained inside the furnace. Under these conditions, oily substances adsorbed on the surface and within the pores of the activated carbon are efficiently desorbed to form oil vapor, achieving an oil extraction rate ≥50% and preventing the combustion of oily substances.

[0055] After a certain period of dry distillation in the dry distillation furnace 4, the oily substances adsorbed on the surface and in the pores of the activated carbon are desorbed to form oil gas. The oil gas is discharged from the oil gas outlet at the top of the dry distillation furnace 4 and enters the primary cooler 5 through the pipeline.

[0056] The primary cooler 5 cools the high-temperature oil and gas to 80-100℃, where most of the heavy oil components condense and precipitate. The condensate enters the oil-water separation system 14, where it undergoes gravity sedimentation separation. The separated oil is then fed into the oil pump 13, which discharges the oil and collects it in an external oil storage device, yielding an oil byproduct (recovery rate ≥50%). Furthermore, the primary cooler 5 is equipped with a cooling circulation assembly, powered by electricity.

[0057] The remaining light oil and gas, along with non-condensable gases (containing water vapor and a small amount of VOCs), after cooling in the primary cooler 5, enters the aftercooler 6 through pipelines. The aftercooler 6 uses process water as the cooling medium to further cool the gas to 20-30°C. The process water, after heat exchange, is heated and discharged from the aftercooler 6, returning to the workshop for process water reuse (circulation). This part corresponds to... Figure 1 Process water inlet and reuse path. Oily wastewater generated by condensation in aftercooler 6 is discharged separately and returned to the front-end wastewater treatment system through pipeline; non-condensable VOC gases are discharged from the top of aftercooler 6. The non-condensable VOC gases discharged from the top of aftercooler 6 are preferably incorporated into the tail gas purification unit and treated together with the flue gas generated by the dry distillation furnace 4 and regeneration furnace 7; in other embodiments, they can also be connected to an external VOC treatment system separately.

[0058] The flue gas generated during the operation of the dry distillation furnace 4 (containing a small amount of dust, VOCs, NOx, etc.) is discharged from the flue gas outlet of the dry distillation furnace 4 and combined with the regeneration flue gas generated by the regeneration furnace 7 through pipelines, and then enters the subsequent tail gas purification unit. The activated carbon remaining after dry distillation (with most of the oil removed) is discharged from the activated carbon outlet at the bottom of the dry distillation furnace 4 and conveyed by conveyor belt to the kiln head of the regeneration furnace 7 in the subsequent activated carbon regeneration unit for the next regeneration process.

[0059] 3. Activated carbon regeneration unit The core equipment of this unit is regeneration furnace 7, which is specifically configured as a rotary kiln equipped with high-frequency electromagnetic heating. Supporting equipment includes a urea solution storage tank, a cooling device, and a conveyor belt. The connection relationships and operating principles of each piece of equipment are as follows: The activated carbon after dry distillation is conveyed to the kiln inlet of regeneration furnace 7 (i.e., rotary kiln) via a conveyor belt. The rotary kiln cylinder has an inclination angle of 1~3° and a rotation speed of 1~3 rpm. Lifting plates are installed on the inner wall of the cylinder. When the rotary kiln is running, the lifting plates evenly lift the activated carbon, ensuring sufficient contact between the activated carbon and the high-temperature gas. A high-frequency electromagnetic heating device is installed around the outside of regeneration furnace 7. The heating power can be adjusted according to the activated carbon regeneration requirements. The rotary kiln cylinder is heated through electromagnetic induction, and the heat is conducted to the activated carbon inside, causing the activated carbon temperature to gradually increase.

[0060] Electrical energy is fed into the regeneration furnace 7 to provide power for the high-frequency electromagnetic heating device and to provide the heat required for the regeneration reaction and thermal decomposition of activated carbon.

[0061] High-temperature gas (800-900℃) is introduced through the gas inlet of the regeneration furnace 7. The gas source can be inert gas supplied from the outside or high-temperature flue gas recirculation gas generated by the regeneration furnace 7 itself.

[0062] High-temperature gas is introduced from the tail of the rotary kiln and comes into countercurrent contact with the activated carbon entering from the kiln head. As the activated carbon moves toward the kiln tail, two reactions occur in sequence: first, a thermal decomposition reaction, which removes residual oil and impurities from the surface of the activated carbon, causing the impurities to be converted into gas and discharged; second, an activation reaction, in which the rotary kiln is connected to an external gas source through a pipe at the kiln tail inlet corresponding to the activation section along the material travel direction, and high-temperature gas is introduced into the kiln to promote the activation reaction.

[0063] The high-temperature activated carbon (approximately 800-900℃) discharged from the kiln tail outlet is connected to a urea solution spraying device on the conveying pipeline leading from the outlet to the pressure tank 3. A urea solution storage tank is directly connected to this spraying device via a pipeline, allowing dilute urea solution to be sprayed onto the high-temperature activated carbon.

[0064] When dilute urea solution encounters high-temperature activated carbon, it vaporizes. The resulting superheated steam reacts with the activated carbon in a water-gas reaction (C + H₂O → CO + H₂), clearing and activating the pore structure of the activated carbon and restoring its adsorption performance. Simultaneously, the ammonia gas produced by urea pyrolysis is drawn out along with the dust gas generated during the high-temperature carbon discharge and the flue gas from the regeneration furnace, entering the subsequent tail gas purification unit. There, it participates in a selective catalytic reduction denitrification reaction on the catalyst surface of the ceramic fiber filter 9.

[0065] The vaporization of the dilute urea solution absorbs heat and simultaneously rapidly cools the activated carbon, quickly reducing its temperature from 800-900℃ to 200-250℃. The rapidly cooled activated carbon then continues along the conveying pipeline into the pressure tank 3 for later use, or undergoes further cooling before entering the pressure tank 3. The cooled activated carbon is then conveyed back to the pressure tank 3 via a screw conveyor to replenish the activated carbon consumed in the adsorption tower 1, achieving activated carbon recycling. The adsorption performance recovery rate of the regenerated activated carbon is ≥90%. The flue gas (containing dust, NOx, VOCs, etc.) generated during the operation of the regeneration furnace 7 is discharged from the flue gas outlet at the kiln tail, and is collected with the flue gas from the dry distillation furnace 4 through a pipeline before entering the tail gas purification unit.

[0066] 4. Exhaust gas purification unit The core equipment in this unit includes a cyclone separator 8, a ceramic fiber filter 9, an RTO 10, and an alkali washing and deacidification tower 11. Supporting equipment includes an induced draft fan 12, a chimney, a pH control device, and an alkali circulation system. The connections and operating principles of each piece of equipment are as follows: The flue gas generated by the dry distillation furnace 4 and the regeneration furnace 7 enters the inlet of the cyclone separator 8 through the collection pipe. The cyclone separator 8 uses centrifugal force to remove most of the dust in the flue gas (removal rate ≥90%). The removed dust is returned to the raw material hopper of the dry distillation furnace 4 through the pipe, mixed with new saturated activated carbon, and then reintroduced into the dry distillation furnace 4 to realize the recycling and reuse of dust.

[0067] After most of the dust has been removed, the flue gas enters the ceramic fiber filter 9 through a pipeline. The ceramic fiber filter 9 has a built-in denitrification catalyst, which can be a vanadium-titanium catalyst. At the same time, the ammonia gas generated by the pyrolysis of urea on the discharge pipeline of the regeneration furnace 7 undergoes a selective catalytic reduction denitrification reaction under the action of the catalyst, further removing NOx from the flue gas. Meanwhile, the filter tube of the ceramic fiber filter 9 performs fine filtration of the fine dust in the flue gas.

[0068] After denitrification, the flue gas enters the RTO 10 through a pipeline. The RTO 10 is equipped with a heat replenishment device, which is either electric or gas-fired, to heat the flue gas to 380-420℃. At the same time, air is supplied through an air replenishment pipeline to control the oxygen content in the flue gas to 3-8%. The flue gas undergoes a catalytic combustion reaction on the catalyst surface of the RTO 10 to remove VOC components from the flue gas and reduce the pollutant content of the flue gas.

[0069] The flue gas treated by RTO 10 enters the alkaline washing and deacidification tower 11 through a pipeline. The top of the alkaline washing and deacidification tower 11 is equipped with a rapid cooling spray section, where the flue gas is first cooled by water spray before entering the alkaline absorption section at the bottom of the tower to circulate and contact with the alkaline solution inside the tower 11. The alkaline solution can be a sodium hydroxide solution, which removes acidic components (such as SO2, HCl, etc.) from the flue gas. The alkaline solution circulation system uses an online pH monitoring device to control the pH of the circulating liquid to maintain it at 7±0.2, ensuring the deacidification effect. A demister is installed at the top of the alkaline washing and deacidification tower 11 to remove mist droplets from the flue gas, preventing the droplets from carrying alkaline solution into subsequent equipment.

[0070] The purified flue gas temperature is approximately 76℃, and all pollutant indicators meet national emission standards. The purified flue gas enters the induced draft fan 12 through a pipeline. The induced draft fan 12 is frequency-controlled and can automatically adjust its speed according to the flue gas flow rate, delivering the flue gas to the chimney for final emission in compliance with standards, i.e., flue gas venting.

[0071] It should be noted that in existing technologies, oily substances in tire wastewater typically coexist in three forms: dissolved, dispersed, and emulsified. Emulsified oil accounts for as much as 40%-60%, posing a significant challenge for adsorption treatment. The surface of emulsified oil droplets is coated with surfactants such as degradation products of vulcanization accelerators and fatty acid soaps, exhibiting a ZETA potential typically of -30 to -50 mV, resulting in a highly stable colloidal system. Ordinary activated carbon also carries a negative surface charge in water (ZETA potential -15 to -35 mV), creating electrostatic repulsion between it and the emulsified oil droplets. This hinders the oil droplets from approaching and adhering to the activated carbon surface, leading to slow adsorption kinetics and a low emulsified oil removal rate.

[0072] Therefore, the activated carbon is improved as follows: Example 3 Based on Examples 1 and 2, this example improves the activated carbon used in the system and provides a piezoelectrically enhanced adsorption activated carbon composite particle to replace the ordinary granular activated carbon filled in the adsorption tower 1 in Examples 1 and 2. This can improve the adsorption efficiency of the adsorption tower 1 for emulsified oil in tire wastewater and achieve demulsification and adsorption simultaneously without the need to add chemical demulsifiers.

[0073] The preparation method of piezoelectrically enhanced adsorption activated carbon composite particles includes the following specific steps: Prepare the ingredients: Activated carbon: Coconut shell granular activated carbon, particle size 0.5-2mm, specific surface area 800-1500m² 2 / g, with mesopores accounting for 30%-60% of the total pore volume.

[0074] Ba(OH)2·8H2O: Barium hydroxide (octahydrate).

[0075] Anatase TiO2 nanopowder: particle size 5-10nm.

[0076] γ-aminopropyltriethoxysilane: APTES.

[0077] Tetraethyl orthosilicate: TEOS.

[0078] Preparation using the above raw materials: Step 1: Select coconut shell granular activated carbon, wash it sequentially with deionized water and 0.5-2 mol / L dilute hydrochloric acid to remove ash and metallic impurities, and dry it at 110-120℃ for 4-8 hours. Place the dried activated carbon in a tube furnace and heat-treat it at 300-400℃ for 1-2 hours under a mixed atmosphere of Ar and O2 (O2 volume fraction 1%-5%) to obtain pretreated activated carbon.

[0079] Step 2: Using a hydrothermal method, Ba(OH)₂·8H₂O and anatase TiO₂ nanoparticles are dispersed in deionized water at a Ba:Ti molar ratio of 1.05-1.15:1. NaOH is added to adjust the concentration to 0.5-2 mol / L, and the mixture is transferred to a hydrothermal reactor and reacted at 180-220℃ for 12-24 h. The reaction product is centrifuged and washed, dried at 80℃ for 12 h, and then annealed at 650-750℃ in air for 2-4 h to increase the crystallinity and tetragonal phase content to ≥95%, yielding BaTiO₃ (barium titanate) nanoparticles.

[0080] Step 3: Disperse the BaTiO3 nanoparticles obtained in Step 2 in anhydrous ethanol with a concentration of 5-20 g / L, add APTES (3-8 wt% of BaTiO3), and stir the mixture at 60-80℃ for 4-8 h. After the reaction is complete, centrifuge the mixture, wash it three times with anhydrous ethanol, and vacuum dry it at 60℃ for 12 h to obtain surface-coupled modified BaTiO3 nanoparticles, i.e., modified BaTiO3 nanoparticles.

[0081] Step 4: Disperse the modified BaTiO3 nanoparticles in anhydrous ethanol with a concentration of 10-50 g / L, add TEOS (5-15 wt% of the modified BaTiO3 nanoparticles), and add a small amount of ammonia to adjust the pH to 9-10. Stir until homogeneous to obtain the loading solution. Immerse the pretreated activated carbon obtained in Step 1 into the loading solution under ultrasonic assistance. The ultrasonic frequency is 25-40 kHz, the power is 100-300 W, the temperature is 25-40℃, and the immersion time is 30-90 min. After immersion, filter and separate the nanoparticles. Wash with anhydrous ethanol 2-3 times to remove unbound nanoparticles, dry at 110-120℃ for 6-12 h, and then calcine at 350-450℃ for 2-4 h under N2 atmosphere to obtain composite particles.

[0082] Step 5: Spread the composite particles obtained in Step 4 evenly between two parallel stainless steel plates, with a particle layer thickness of 5-20 mm. Place the plate assembly in an oven and heat it to 80-120℃. Apply a DC electric field of 5-15 kV / cm and maintain it for 30-60 min. Then, under the condition of maintaining the electric field, allow it to cool naturally to room temperature and remove the electric field to obtain piezoelectric activated carbon composite particles (referred to as activated carbon composite particles).

[0083] The prepared piezoelectrically enhanced adsorption activated carbon composite particles have a BaTiO3 loading of 5-15 wt% and a specific surface area of ​​800-1300 m². 2 / g.

[0084] It should be noted that the principle or function of the above steps is as follows: Step 1: Introduce oxygen-containing functional groups (-OH, -COOH) on the outer surface of activated carbon particles and the inner wall of shallow pores as anchoring sites for subsequent piezoelectric nanoparticles. At the same time, control the oxidation depth to be limited to the outer layer of the particles within the range of 50-150μm to maintain the original hydrophobicity and adsorption performance of the deep pores.

[0085] Step 3: The amino terminus of APTES can form chemical bonds with the oxygen-containing functional groups on the surface of activated carbon and the subsequent SiO2 bonding layer, while the siloxane terminus forms a protective layer on the surface of BaTiO3, enhancing the bonding force between BaTiO3 and activated carbon.

[0086] Step 4: Because the particle size of BaTiO3 nanoparticles (30-100nm) is larger than the pore size of most mesopores and micropores of activated carbon, the nanoparticles can only enter the outer surface and shallow macropores under ultrasonic agitation. They are naturally sieved and blocked from the deeper layers by the pore size, thus forming a gradient distribution with a denser outer layer and a sparser inner layer. During the impregnation process, TEOS undergoes in-situ hydrolysis and condensation under alkaline conditions, forming a SiO2 inorganic binder layer at the interface between BaTiO3 and activated carbon, firmly anchoring BaTiO3 to the surface of activated carbon. Calcination fully solidifies the SiO2 binder layer.

[0087] Step 5: Apply a DC electric field of 5-15 kV / cm to the composite particles at a temperature of 100-140℃. BaTiO3 is near its Curie temperature, and the ferroelectric domains exhibit high mobility. Under the drive of the electric field, the free domains align and align along the direction of the electric field. Cooling to room temperature while maintaining the electric field preserves the orientation of the ferroelectric domains, endowing the BaTiO3 nanoparticles with macroscopic remanent polarization, thus exhibiting a piezoelectric response: when subjected to mechanical stress, polarization charges can be generated on the particle surface, forming a local electric field.

[0088] The piezoelectric-enhanced adsorption activated carbon composite particles provided in this embodiment include a granular activated carbon carrier and piezoelectric nanoparticles loaded on the surface and shallow macropores of the granular activated carbon carrier. The piezoelectric nanoparticles are polarized tetragonal BaTiO3 nanoparticles with a particle size of 30-100 nm and a loading amount of 5-15 wt% of the granular activated carbon carrier mass. The piezoelectric nanoparticles exhibit a gradient distribution on the granular activated carbon carrier, with a denser outer layer and a sparser inner layer. That is, the density of piezoelectric nanoparticles on the outer surface of the particles and in the shallow macropores (depth ≤ 100 μm) is greater than the density in the deep mesopores and micropores. This concentrates the electric field enhancement effect on the outer surface region of the particles where the oil droplets first contact, while preserving the original adsorption performance of the deep mesopores and micropores. A SiO2 inorganic bonding layer with a thickness of 1-5 nm is provided between the piezoelectric nanoparticles and the granular activated carbon carrier to firmly anchor the piezoelectric nanoparticles to the activated carbon surface.

[0089] Example 4 In this embodiment, the piezoelectrically enhanced activated carbon composite particles prepared in Example 3 are filled into the adsorption tower 1 described in Examples 1 and 2, replacing the original ordinary granular activated carbon. The filling height is 60%-80% of the tower height. A repolarization device needs to be installed on the conveying pipeline between the pressure tank 3 and the adsorption tower 1. The connection relationship and operating principle of the other equipment in the system are the same as in Examples 1 and 2. The following focuses on explaining the working principle of the activated carbon composite particles in the adsorption tower 1 and their synergistic relationship with other units in the system: Tire wastewater is pumped into adsorption tower 1 from the bottom by a booster pump and flows upward through the activated carbon composite particle bed. Adsorption tower 1 adopts an upflow expanded moving bed operation mode. When the wastewater flows upward, the activated carbon composite particle bed is in a moderately expanded state (expansion rate 10%-30%), and the particles frequently collide, rub, and tumble under the drive of the water flow. The hydraulic impact generated by the wastewater flow and the collision and compression between particles apply periodic mechanical stress to the BaTiO3 nanoparticles on the surface of the activated carbon composite particles. The BaTiO3 nanoparticles utilize the piezoelectric effect (positive piezoelectric effect) to convert mechanical energy into polarized charges on the particle surface, generating a local micro-electric field in the water medium around the particles.

[0090] This microscopic electric field plays three roles in the aqueous medium surrounding the activated carbon composite particles: First, it weakens the negative charge on the surface of the emulsified oil droplets, helping to reduce the absolute value of the zeta potential of the droplets, disrupting colloidal stability, and promoting destabilization and aggregation. Second, it generates a local positive potential region on the surface of the activated carbon composite particles, attracting the destabilized oil droplets to the activated carbon surface through electrostatic attraction, overcoming the original electrostatic repulsion barrier. Third, it enhances the polarization of oil molecules, increasing the van der Waals forces between oil molecules and the activated carbon surface, thus improving the adsorption driving force. Under the synergistic effect of these three roles, the emulsified oil droplets destabilize, adhere, and spread on the surface of the activated carbon composite particles, and the oil molecules subsequently enter the deep mesopores and micropores of the activated carbon for physical adsorption. The entire process requires no chemical demulsifiers or coagulants, achieving a self-driven demulsification-destabilization-adsorption process.

[0091] In the dry distillation oil extraction unit, the saturated activated carbon composite particles at the bottom of adsorption tower 1 are discharged through an intermittent discharge valve and then conveyed by a screw conveyor to the dehydration screw 2 and drying tower for dehydration to a moisture content of less than 5%. They then enter the dry distillation furnace 4 through a sealed feeding device. The operating conditions of the dry distillation furnace 4 are the same as in Examples 1 and 2 (operating temperature 180-250℃, negative pressure -0.02~-0.05MPa, oxygen-limited environment). Due to piezoelectric enhanced adsorption, emulsified oil droplets are effectively destabilized and then aggregated and adsorbed onto the activated carbon surface. Compared to direct adsorption in the emulsified state, the state of adsorbed oil substances within the activated carbon channels is more conducive to thermal desorption, reducing the resistance to oil molecule desorption from the channels during dry distillation. The oil and gas generated by thermal desorption are cooled by the primary cooler 5 and then enter the oil-water separation system 14 for separation and collection. The remaining gas after cooling by the primary cooler 5 enters the aftercooler 6 for further condensation. The oily wastewater discharged from the aftercooler 6 is returned to the front-end wastewater treatment system. Non-condensable VOC gases are incorporated into the combined flue gas pipeline and enter the tail gas purification unit. The connection relationship and operation mode of each device are the same as in Example 2.

[0092] In the activated carbon regeneration unit, the activated carbon composite particles after dry distillation are discharged from the bottom of the dry distillation furnace 4 and conveyed to the kiln head of the regeneration furnace 7 via a conveyor belt. The equipment structure and operating parameters of the regeneration furnace 7 are the same as in Examples 1 and 2. The activated carbon composite particles undergo thermal decomposition and activation reactions sequentially in the regeneration furnace 7, removing residual oil and impurities and restoring the pore structure and adsorption performance.

[0093] The BaTiO3 nanoparticles in the activated carbon composite particles remain chemically stable at regeneration temperatures of 800-900℃, and the SiO2 binder layer is heat-resistant. Therefore, the nanoparticles do not decompose or dissolve during regeneration, and their structure remains intact on the activated carbon surface. However, because the regeneration temperature far exceeds the Curie temperature of BaTiO3, the ferroelectric domains of the nanoparticles depolarize at high temperatures, and the piezoelectric activity temporarily disappears. This characteristic does not affect the regeneration process itself, as the regeneration process does not require piezoelectric activity. However, the regenerated activated carbon composite particles need to be repolarized to restore their piezoelectric activity before they can be used in adsorption tower 1.

[0094] The high-temperature activated carbon composite particles discharged from the kiln tail of regeneration furnace 7 are rapidly cooled by spraying with urea solution, reducing the temperature from 800-900℃ to 200-250℃. The ammonia gas generated from urea pyrolysis enters the tail gas purification unit to participate in the denitrification reaction, and the superheated steam generated participates in the activated carbon activation reaction. This process is exactly the same as in Examples 1 and 2. After rapid cooling, the activated carbon composite particles enter the pressure conveying tank 3.

[0095] A repolarization device is installed on the conveying pipeline between the pressure tank 3 and the adsorption tower 1. The repolarization device includes a repolarization tube section, with a stainless steel annular electrode surrounding the outer wall of the tube section. The annular electrode is connected to a high-voltage DC power supply with an output voltage of 5-20kV. An electric heating section is located upstream of the annular electrode to preheat the passing wet carbon slurry containing activated carbon composite particles to 80-120℃. As the activated carbon composite particles pass through the repolarization tube section with the carbon slurry, they undergo repolarization under the combined action of an electric field and temperature. The electric domains of the BaTiO3 nanoparticles realign along the direction of the electric field, restoring the piezoelectric response. The repolarized activated carbon composite particles are mixed with freshly added activated carbon composite particles in the pressure tank 3, and a pressure pump forces the mixed carbon slurry into the top of the adsorption tower 1, achieving the recycling of the activated carbon composite particles.

[0096] In the exhaust gas purification unit, the connection relationships and operating principles of each device are exactly the same as in Examples 1 and 2. The flue gas generated by the dry distillation furnace 4 and the regeneration furnace 7 is collected and then sequentially passed through the cyclone separator 8 to remove most of the dust, the ceramic fiber filter 9 for fine filtration and denitrification, the RTO 10 for catalytic combustion to remove VOCs, and the alkaline washing and deacidification tower 11 to remove acidic components. Finally, the purified flue gas is discharged into the chimney by the induced draft fan 12.

[0097] The performance of ordinary granular activated carbon and activated carbon composite granules is tested and compared below: Example 5 The preparation method of piezoelectrically enhanced adsorption activated carbon composite particles includes the following specific steps: Prepare the ingredients: Activated carbon: Coconut shell granular activated carbon, particle size 1.2mm, specific surface area 1100m² 2 / g, with mesopores accounting for 45% of the total pore volume.

[0098] Ba(OH)2·8H2O: Barium hydroxide (octahydrate).

[0099] Anatase TiO2 nanopowder: particle size 5-10nm.

[0100] γ-aminopropyltriethoxysilane: APTES.

[0101] Tetraethyl orthosilicate: TEOS.

[0102] Preparation using the above raw materials: Step 1: Select coconut shell granular activated carbon, wash it sequentially with deionized water and 1 mol / L dilute hydrochloric acid to remove ash and metallic impurities, and dry it at 110-120℃ for 4-8 hours. Place the dried activated carbon in a tube furnace and heat-treat it at 350℃ for 1.5 hours under a mixed atmosphere of Ar and O2 (O2 volume fraction 3%) to obtain pretreated activated carbon.

[0103] Step 2: Using a hydrothermal method, Ba(OH)₂·8H₂O and anatase TiO₂ nanoparticles were dispersed in deionized water at a Ba:Ti molar ratio of 1.1:1. NaOH was added to adjust the concentration to 1 mol / L, and the mixture was transferred to a hydrothermal reactor and reacted at 200℃ for 18 h. The reaction product was centrifuged and washed, dried at 80℃ for 12 h, and then annealed at 700℃ in air for 3 h to increase the tetragonal phase content to 97%, yielding BaTiO₃ nanoparticles.

[0104] Step 3: Disperse the BaTiO3 nanoparticles obtained in Step 2 in 10 g / L anhydrous ethanol, add APTES (5 wt% of BaTiO3 mass), and stir at 70 °C for 6 h. After the reaction is complete, centrifuge, wash three times with anhydrous ethanol, and vacuum dry at 60 °C for 12 h to obtain surface-coupled modified BaTiO3 nanoparticles, i.e., modified BaTiO3 nanoparticles.

[0105] Step 4: Disperse the modified BaTiO3 nanoparticles in 30 g / L anhydrous ethanol, add TEOS (10 wt% of the modified BaTiO3 nanoparticles), and adjust the pH to 9-10 with a small amount of ammonia. Stir until homogeneous to obtain the loading solution. Immerse the pretreated activated carbon obtained in Step 1 into the loading solution under ultrasonic assistance (30 kHz, 200 W, 30 °C, 60 min). After impregnation, filter and separate the nanoparticles, wash three times with anhydrous ethanol to remove unbound nanoparticles, dry at 110 °C for 8 h, and then calcine at 400 °C for 3 h under N2 atmosphere to obtain composite particles.

[0106] Step 5: Spread the composite particles obtained in Step 4 evenly between two parallel stainless steel plates, with a particle layer thickness of 10 mm. Place the plate assembly in an oven and heat it to 100-140℃. Apply a DC electric field of 10 kV / cm and maintain it for 45 min. Then, under the condition of maintaining the electric field, allow it to cool naturally to room temperature and remove the electric field to obtain piezoelectric active activated carbon composite particles (referred to as activated carbon composite particles).

[0107] The prepared piezoelectrically enhanced adsorption activated carbon composite particles have a BaTiO3 loading of 10 wt% and a specific surface area of ​​1050 m². 2 / g.

[0108] Comparative Example 1 Ordinary coconut shell granular activated carbon was selected as the control adsorbent material, with a particle size of 1.2 mm and a specific surface area of ​​1050 m². 2 / g, iodine value ≥900mg / g, ash content ≤5%, wash with deionized water and 0.5mol / L dilute hydrochloric acid in sequence before use, and dry at 110℃ for 8h before use.

[0109] Tire wastewater was collected and pretreated by a screen and equalization tank before being used as test water. The main water quality indicators of the test water are as follows: pH: 7.2-7.8; Initial total oil content: 215 mg / L; Emulsified oil concentration: 112 mg / L (52% of total oil content); Emulsified oil ZETA potential: -38mV; Temperature: 25℃; Electrical conductivity: 1.8 mS / cm.

[0110] Experimental apparatus: An adsorption column is used. The adsorption column is made of plexiglass with an inner diameter of 50 mm and an effective column height of 1000 mm. A constant temperature water bath sleeve is installed on the outer wall of the column. A peristaltic pump is equipped to control the inlet water flow rate, and sampling valves are installed at the inlet and outlet.

[0111] Experimental steps: Step 1: Fill the adsorption column with the activated carbon to be tested (activated carbon of Example 5 or Comparative Example 1), with a packing height of 800 mm and a packing volume of about 70% of the column volume.

[0112] Step 2: Pump the test wastewater into the adsorption column from the bottom and let it flow from bottom to top through the activated carbon bed. Control the empty bed contact time (EBCT) to be 30 min, the influent flow rate to be about 65 mL / min, and the temperature to be constant at 25℃.

[0113] Step 3: Continuously run until the effluent water quality is stable, that is, the relative deviation of the oil content in the effluent is ≤5% after three consecutive sampling tests, which is the standard for judging stability, and is recorded as the stable operation stage.

[0114] Step 4: During the stable operation phase, take a 50 mL sample from the outlet every 2 hours, for a total of 5 times. Use infrared spectrophotometry (HJ 637-2018) to determine: ① the total oil content of the effluent; ② the oil content (i.e., dissolved oil content) of the filtrate after filtration through a 0.45 μm microporous membrane. The difference between the total oil content and the dissolved oil content is used to calculate the emulsified oil concentration in the effluent. The average of the 5 measurements is taken as the final result.

[0115] Step 5: Calculate the emulsified oil removal rate: Emulsified oil removal rate (%) = [(Influent emulsified oil concentration - Effluent emulsified oil concentration) / Influent emulsified oil concentration] × 100% The experimental results showed that the emulsified oil removal rate in Example 5 was 91.3%, while the emulsified oil removal rate in Comparative Example 1 was 66.1%.

[0116] Analysis: Under the same operating conditions, the removal rate of emulsified oil by ordinary granular activated carbon in Comparative Example 1 was 66.1%, while the removal rate of emulsified oil by activated carbon composite granules in Example 5 was 91.3%, which was 25.2% higher than that of Comparative Example 1. These results indicate that the present invention, by loading polarized BaTiO3 piezoelectric nanoparticles onto the surface of activated carbon, utilizes the mechanical stress generated by wastewater flow and particle collisions within the adsorption tower to excite the piezoelectric effect, generating a local micro-electric field in the water medium surrounding the particles. This effectively promotes the destabilization and surface adhesion of emulsified oil droplets, thereby improving the removal efficiency of emulsified oil from tire wastewater by activated carbon.

[0117] Those skilled in the art should understand that the above embodiments are merely illustrative and the present invention is not limited thereto. Various modifications and variations can be made to the present invention without departing from the scope of the claims. Furthermore, it should be understood that regardless of whether a technical feature is disclosed in the specification, claims, drawings, or otherwise, even if it is described together with other features, it can still constitute an essential part of the present invention on its own. In all the drawings, the same reference numerals refer to the same components; therefore, if a component is mentioned only in one drawing or is not described in all drawings, the relevant description is equally applicable to other drawings in the specification where the component is not explicitly described.

Claims

1. A system for oil extraction and resource utilization from tire wastewater, characterized in that, The system includes an adsorption tower, which is connected to a distillation furnace via a dewatering spiral, and the distillation furnace is connected to an aftercooler via a primary cooler; the primary cooler is connected to an oil pump via an oil-water separation system. The distillation furnace is connected to the alkali washing and deacidification tower, and the alkali washing and deacidification tower is connected to the induced draft fan.

2. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, Process water enters the adsorption tower, and the adsorption tower discharges compliant process water. The adsorption tower is filled with activated carbon.

3. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The adsorption tower is connected to a dehydration spiral. The adsorption tower transports the adsorbed saturated activated carbon to the dehydration spiral. The dehydration spiral is connected to a dryer through a drying tower. The saturated activated carbon dehydrated in the drying tower enters the dryer.

4. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The pyrolysis furnace is connected to the primary cooler. The oil and gas produced by the pyrolysis furnace enter the primary cooler, and the primary cooler discharges the exhaust steam. At the same time, electrical energy is connected to the primary cooler to provide operating power for the primary cooler.

5. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The primary cooler is connected to the aftercooler. After being cooled by the primary cooler, the oil and gas enter the aftercooler. Process water enters the aftercooler to participate in the cooling. The process water discharged from the aftercooler is reused. At the same time, the aftercooler discharges oil, VOCs and wastewater respectively.

6. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The primary cooler is connected to the oil-water separation system. The oil separated by the oil-water separation system is connected to the oil pump, which discharges and collects the oil.

7. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The pyrolysis furnace is connected to the regeneration furnace, and the remaining activated carbon after pyrolysis enters the regeneration furnace; the regeneration furnace is connected to the cyclone separator, and the flue gas generated in the regeneration furnace enters the cyclone separator.

8. The tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The filtered flue gas enters the RTO; the RTO is connected to the alkaline washing and deacidification tower, and the flue gas after catalytic combustion in the RTO enters the alkaline washing and deacidification tower, with alkaline solution entering the alkaline washing and deacidification tower; the alkaline washing and deacidification tower is connected to the induced draft fan, and the flue gas purified by the alkaline washing and deacidification tower is discharged into the air by the induced draft fan.

9. A tire wastewater oil extraction and resource utilization system according to claim 1, characterized in that, The regeneration furnace is connected to the pressure conveying tank, and the regenerated activated carbon enters the pressure conveying tank; electricity is connected to the regeneration furnace, and urea solution is connected to the pipeline between the regeneration furnace and the pressure conveying tank; supplementary activated carbon and process water enter the pressure conveying tank respectively, and the pressure conveying tank is connected to the adsorption tower, and the pressure conveying tank replenishes the adsorption tower with new carbon and regenerated carbon.

10. A tire wastewater oil extraction and resource utilization system according to claim 7, characterized in that, The regeneration furnace cylinder has an inclination angle of 1~3° and a rotation speed of 1-3 rpm.

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