A method for hydrogenation of waste tires

Abstract

The application provides a method for hydrogenation of waste tires, comprising the following steps: S1, mixing waste tire particles, liquid oil and catalyst in an oil slurry stirring tank to obtain oil slurry; S2, then mixing pressurized oil slurry and heated hydrogen into a boiling bed reactor to react to obtain reaction products; S3, separating the reaction products of step S2 into hot high separation gas and hot high separation oil; S4, reducing the pressure of the hot high separation oil of step S3 into a hot low separation tank to obtain hot low separation tank low oil, and then feeding the hot low separation tank low oil into a supercritical extraction device to separate liquid oil and carbon black, wherein part of the liquid oil is fed into step S6; S5, processing the hot high separation gas of step S3; S6, feeding another part of the liquid oil in step S4 into a fixed bed hydrogenation refining and cracking device to react, and then feeding the reaction products into a product fractionating column to separate diesel and naphtha. The method can improve the yield of hydrogenation products, such as carbon black, naphtha and diesel.

Description

Technical Field

[0001] This invention relates to the field of oil refining and chemical technology, and more specifically, to a method for hydrogenating waste tires. Background Technology

[0002] With the continuous development of the automotive transportation industry, the amount of waste tires generated has increased dramatically. Due to their corrosion resistance and difficulty in decomposing under natural conditions, waste tires have become a "black pollution" problem of concern both in my country and globally. How to achieve "reduction, harmlessness, greening, resource utilization, reuse, and recycling" of waste tires is a major issue that urgently needs to be addressed in the rubber industry. Currently, the main processing technologies for waste tires include pyrolysis, catalytic pyrolysis, microwave pyrolysis, and retreading. However, pyrolysis technology suffers from low effective product yields, poor product properties, and difficulties in subsequent processing, while also exhibiting high gas yields, which is unfavorable for economic accounting.

[0003] The prior art disclosed in CN202310796016 is a method for hydrogenating waste tire pyrolysis oil, comprising the following steps: (1) in the presence of hydrogen, the waste tire pyrolysis oil raw material is subjected to a gas-phase desulfurization reaction in a first hydrogenation reactor to obtain a gas-phase desulfurization reaction product; (2) the gas-phase desulfurization reaction product is subjected to gas-liquid separation to obtain a gas phase component and a liquid phase component; (3) the liquid phase component is pressurized and mixed with hydrogen, and then subjected to a liquid-phase dearomatic reaction in a second hydrogenation reactor to obtain a liquid-phase dearomatic reaction product; the N content in the waste tire pyrolysis oil raw material is 3000-10000 μg / g. The raw material involved in this prior art is mainly waste tire pyrolysis oil, which limits the processing raw materials, and the process cannot produce carbon black, naphtha, diesel oil and other components.

[0004] Prior art, CN202310849576, discloses a method for preparing lubricating oil, comprising the following steps: a raw material containing waste rubber is placed in a sealed container under a hydrogen atmosphere and brought into contact with a catalyst to undergo a catalytic cracking reaction, yielding a product containing lubricating oil; the catalyst includes a support, an acidic component, and an active component supported on the surface of the support; the active component is selected from at least one of ruthenium, rhodium, platinum, palladium, iridium, and nickel; the acidic component is selected from at least one of silicotungstic acid, ammonium metatungstate, phosphotungstic acid, and tungstic acid. The reaction mechanism of this prior art is catalytic cracking, with a relatively high gas yield but a relatively low liquid yield.

[0005] To address the above problems, the inventors conducted extensive experimental research on hydrogenation technology for waste tires and proposed a method for hydrogenating waste tires. This method is used to produce carbon black, naphtha, and diesel fuel from waste tires and can improve the yield of these products. Summary of the Invention

[0006] In view of this, the present invention aims to propose a method for hydrogenation of waste tires. This addresses the problems of existing methods involving low yields, poor product properties, and difficult subsequent processing due to pyrolysis technology, while also highlighting the high gas yields that are uneconomical.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A method for hydrogenating waste tires includes the following steps:

[0009] S1. Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of a certain size. The waste tire particles, liquid oil, and catalyst are mixed in an oil slurry mixing tank (1) to obtain an oil slurry.

[0010] S2. The catalyst is loaded into the fluidized bed reactor (5), and the oil slurry from step S1 is pressurized in the booster pump (2) and the hydrogen gas passed through the hydrogen heater (4) is heated. The pressurized oil slurry and the heated hydrogen gas are then mixed and fed into the fluidized bed reactor (5) to react and obtain the reaction product.

[0011] S3. The reaction products of step S2 are separated into hot high-pressure gas and hot high-pressure oil in a hot high-pressure separator (6).

[0012] S4. The hot high-grade oil from step S3 is depressurized and transferred to the hot low-grade oil tank (9) to obtain the low-grade oil in the hot low-grade oil tank. The low-grade oil in the hot low-grade oil tank is then transferred to the supercritical extraction device (3) to separate liquid oil and carbon black. Part of the separated liquid oil is returned to step S1 to participate in the reaction, and the other part of the liquid oil is transferred to step S6.

[0013] S5. After the hot high-pressure gas from step S3 is cooled by the air cooler (7), it enters the cold high-pressure separator (10) to separate the cold high-pressure gas, cold high-pressure oil and sulfur-containing wastewater. The cold high-pressure gas enters the circulating hydrogen buffer tank (14) for buffering and then enters the circulating hydrogen compressor (12) for pressurization. The pressurized circulating hydrogen is mixed with high-purity hydrogen and enters the hydrogen heater (4). The cold high-pressure oil and sulfur-containing wastewater enter the cold low-pressure separator (11) to separate the sulfur-containing dry gas, sulfur-containing wastewater and cold low-pressure oil.

[0014] S6. Another portion of the liquid oil from step S4 is fed into a fixed-bed hydrorefining cracking unit (17) for reaction, and the reaction products are fed into a product fractionation tower to separate diesel and naphtha.

[0015] The method of this invention can produce carbon black, naphtha, and diesel oil, and can improve the yield of carbon black, naphtha, and diesel oil produced by hydrogenation. It avoids the problems of low effective product yield, poor properties, and difficult subsequent processing of traditional cracking technology, as well as high gas yield, which is not conducive to economic accounting.

[0016] Furthermore, in step S4, the supercritical extraction solvent used in the supercritical extraction device is one or a mixture of propane, n-butane, isobutane, and pentane.

[0017] Furthermore, in step S4, the supercritical extraction solvent used in the supercritical extraction device is a mixture of n-butane and isobutane, wherein the weight ratio of n-butane to isobutane is 1~3:1.

[0018] By limiting the composition of the supercritical extraction solvent in the supercritical extraction device, the separation effect of liquid oil and carbon black can be improved, and the yield of carbon black can be increased.

[0019] Further, in step S4, the weight ratio of the supercritical extraction solvent to the hot low-temperature oil is 3~5:1.

[0020] This setting limits the ratio of supercritical extraction solvent to oil in the hot low-temperature separation tank, which can improve the separation effect of liquid oil and carbon black and increase the yield of carbon black.

[0021] Further, in step S1, the weight ratio of the waste tire particles to the liquid oil is 1:0.8 to 2.

[0022] Furthermore, in step S1, the size of the waste tire particles is <2000μm.

[0023] Furthermore, in step S2, the weight ratio of the catalyst to the waste tire particles is 1~2:1.

[0024] Furthermore, in steps S1 and S2, the catalyst is either a microspherical catalyst or a homogeneous catalyst.

[0025] Furthermore, in step S2, the reaction conditions are specifically: reaction temperature 250–450°C, reaction pressure 3–20 MPa, and hydrogen-to-oil volume ratio 350–1500.

[0026] Furthermore, the carbon black produced in step S4 accounts for 25-50 wt% of the weight of the waste tire particles in step S1.

[0027] Compared with existing technologies, the method for hydrogenation of waste tires described in this invention has the following advantages:

[0028] 1) The method of the present invention can produce carbon black, naphtha and diesel, and can improve the yield of carbon black, naphtha and diesel produced by hydrogenation, avoiding the problems of low effective product yield, poor properties and difficult subsequent processing of traditional cracking technology, and high gas yield, which is not conducive to economic accounting.

[0029] 2) This invention uses a fluidized bed reactor and a supported microsphere catalyst. This catalyst can be regenerated and reused, which greatly reduces the cost of using the catalyst. By setting up a catalyst loading and unloading tank, the catalyst can be loaded and unloaded online, ensuring that the catalyst activity in the fluidized bed reactor remains stable, thereby ensuring the long-term stable operation of the device.

[0030] 3) This invention directly converts waste tires into oil products through fluidized bed hydrogenation, which can provide high-quality feedstock for subsequent fixed bed hydrorefining and cracking. It avoids the high content of chlorine and unsaturated hydrocarbons in waste tire oil produced by conventional pyrolysis, which are detrimental to the long-term stable operation of the fixed bed, and ensures the long-term stable operation of the subsequent fixed bed hydrogenation unit. Attached Figure Description

[0031] Figure 1 This is a flowchart of a method for hydrogenating waste tires according to the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1-Slurry mixing tank; 2-Slurry booster pump; 3-Supercritical extraction unit; 4-Hydrogen heater; 5-Boiled bed reactor; 6-Hot high-pressure separator; 7-Air cooler; 8-Catalyst loading and unloading tank; 9-Hot low-pressure separator; 10-Cold high-pressure separator; 11-Cold low-pressure separator; 12-Circulating hydrogen compressor; 13-New hydrogen compressor; 14-Circulating hydrogen buffer tank; 15-Fracturing tower; 16-Heat exchanger; 17-Fixed bed hydrorefining cracking unit. Detailed Implementation

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, this invention proposes a method for hydrogenation of waste tires, comprising the following steps:

[0036] S1. Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of a certain size. The waste tire particles, liquid oil, and catalyst are mixed in oil slurry mixing tank 1 to obtain oil slurry.

[0037] S2. The catalyst is loaded into the fluidized bed reactor 5. Then the oil slurry from step S1 is pressurized in the booster pump 2 and the hydrogen that has passed through the hydrogen heater 4 is heated. Then the pressurized oil slurry and the heated hydrogen are mixed and fed into the fluidized bed reactor to react and obtain the reaction product.

[0038] S3. The reaction products of step S2 are separated into hot high-pressure gas and hot high-pressure oil in hot high-pressure separator 6.

[0039] S4. The hot high-grade oil from step S3 is depressurized and transferred to the hot low-grade oil tank 9 to obtain the hot low-grade oil tank. The hot low-grade oil tank is then transferred to the supercritical extraction device 3 to separate liquid oil and carbon black. Part of the separated liquid oil is returned to step S1 to participate in the reaction, while the other part of the liquid oil enters step S6.

[0040] S5. After the hot high-pressure gas from step S3 is cooled by air cooler 7, it enters cold high-pressure separator 10 to separate cold high-pressure gas, cold high-pressure oil, and sulfur-containing wastewater. The cold high-pressure gas enters circulating hydrogen buffer tank 14 for buffering and then enters circulating hydrogen compressor 12 for pressurization. The pressurized circulating hydrogen is mixed with high-purity hydrogen and enters hydrogen heater. The cold high-pressure oil and sulfur-containing wastewater enter cold low-pressure separator 11 to separate sulfur-containing dry gas, sulfur-containing wastewater, and cold low-pressure oil.

[0041] S6. Another portion of the liquid oil from step S4 is fed into the fixed-bed hydrorefining cracking unit 17 for reaction, and the reaction products are fed into the product fractionation tower to separate diesel and naphtha.

[0042] Specifically, in step S1, the liquid oil is one or more of the following: circulating solvent oil, externally supplemented pyrolysis tire oil, and catalytic slurry.

[0043] Specifically, in step S1, the weight ratio of the waste tire particles to the liquid oil is 1:0.8 to 2.

[0044] Specifically, in step S1, the size of the waste tire particles is <2000μm.

[0045] Specifically, in steps S1 and S2, the catalyst is either a microspherical catalyst or a homogeneous catalyst.

[0046] Specifically, when the catalyst is a microsphere catalyst, the microsphere catalyst is supported, the active metal is one or more metals selected from Ni, Co, Mo and W, the particle size of the microsphere catalyst is 0.2~1.2 mm, more preferably, the particle size of the microsphere catalyst is 0.6~1.0 mm.

[0047] Specifically, when the catalyst is a homogeneous catalyst, the catalyst is a water-soluble catalyst or an oil-soluble catalyst made up of one or more metals selected from Ni, Co, Mo and W.

[0048] Specifically, in step S1, the amount of catalyst added is 50 to 1000 ppmw of the mass of waste tire particles, preferably 200 to 500 ppmw.

[0049] Specifically, in step S2, the weight ratio of the catalyst to waste tire particles is 1~2:1.

[0050] Specifically, in step S2, the reaction conditions are: reaction temperature 250–450°C, reaction pressure 3–20 MPa, and hydrogen-to-oil volume ratio 350–1500. Preferably, the reaction temperature is 360–410°C, the reaction pressure is 8–16 MPa, and the hydrogen-to-oil volume ratio is 600–1200.

[0051] Specifically, in step S2, the fluidized bed reactor is one or more fluidized bed reactors connected in series.

[0052] Specifically, in step S2, an intermittently operated catalyst loading / unloading tank 8 is installed at the bottom of the fluidized bed reactor 5. The catalyst loading / unloading tank 8 is equipped with a solid-liquid separator to separate the degraded catalyst from the liquid oil. This arrangement effectively ensures the stability of the catalyst activity in the fluidized bed reactor.

[0053] Specifically, the pressure of the pressurized slurry is 10~14 MPa, and the heating temperature is 200~300℃.

[0054] Specifically, in step S4, the solvent used in the supercritical extraction device is one or a mixture of propane, n-butane, isobutane, and pentane.

[0055] Specifically, in step S4, the solvent used in the supercritical extraction device is a mixture of n-butane and isobutane, wherein the weight ratio of n-butane to isobutane is 1~3:1.

[0056] Specifically, in step S4, the weight ratio of the supercritical extraction solvent to the hot low-temperature oil is 3~5:1.

[0057] Specifically, the carbon black produced in step S4 accounts for 25 to 50 wt% of the waste tires produced in step S1, preferably 30 to 40 wt%.

[0058] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0059] Example 1

[0060] This embodiment provides a method for hydrogenation of waste tires, including the following steps:

[0061] (1) Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of 1000 micrometers. The waste tire particles, recycled solvent oil, and homogeneous catalyst are mixed in oil slurry mixing tank 1 to obtain oil slurry. The weight ratio of waste tire particles to recycled solvent oil is 1:1, and the amount of homogeneous catalyst added is 0.5% of the mass of waste tire particles.

[0062] (2) A microsphere-type nickel-molybdenum catalyst is loaded into the fluidized bed reactor 5. The diameter of the spheres is 0.4~1.5mm and the nickel + molybdenum metal content is 5%~30%. Then, the oil slurry from step S1 is pressurized in the booster pump 2 to 12.0MPag. The hydrogen gas passed through the hydrogen heater 4 is heated to 410°C. Then, the pressurized oil slurry and the heated hydrogen gas are mixed. The temperature after mixing is 300~340°C. The mixture is introduced into the fluidized bed reactor 5 to react and obtain the reaction product. The reaction temperature is 400°C, the reaction pressure is 12.0MPag, the hydrogen-to-oil volume ratio is 600, and the weight ratio of the catalyst to the waste tire particles is 1:1.

[0063] (3) The reaction products of step (2) are separated into hot high-pressure gas and hot high-pressure oil in a hot high-pressure separator. The operating temperature and pressure of the hot high-pressure separator are the same as those of the fluidized bed reactor.

[0064] (4) The hot high-pressure oil from step (3) is depressurized and enters the hot low-pressure tank to obtain the hot low-pressure tank low-pressure oil. The process parameters are: pressure 5.0 MPaG, temperature 400℃. The gas phase is discharged from the top of the hot low-pressure separator 9. Specifically, gas-liquid separation is carried out through heat exchanger 16. After the liquid enters the cold low-pressure tank, it enters the fixed bed hydrorefining cracking unit. After the gas enters the cold low-pressure tank, sulfur-containing dry gas is discharged. The liquid phase is discharged from the bottom. The hot low-pressure tank low-pressure oil is entered into the supercritical extraction device 3. The supercritical extraction solvent used in the supercritical extraction device is a mixture of n-butane and isobutane. The ratio of n-butane to isobutane is 2:1 (weight ratio), and the ratio of supercritical extraction solvent to hot low-pressure tank low-pressure oil is 4:1 (weight ratio). The circulating solvent oil and carbon black are separated. The liquid temperature is 140~160℃ and the liquid pressure is 0.3~1.0 MPaG. Part of the separated circulating solvent oil continues to return to step (1) to participate in the reaction, and the other part of the circulating solvent oil enters step (6).

[0065] (5) After the hot high-pressure gas from step (3) is cooled to 50°C by an air cooler, it enters a cold high-pressure separator to separate cold high-pressure gas, cold high-pressure oil and sulfur-containing wastewater. The process parameters are: pressure 11.0 MPaG, temperature 50°C. The cold high-pressure gas enters a circulating hydrogen buffer tank for buffering and then enters a circulating hydrogen compressor for pressurization to 15.0 MPag. The pressurized circulating hydrogen is mixed with high-purity hydrogen at a pressure of 15.0 MPag and enters a hydrogen heater. The cold high-pressure oil and sulfur-containing wastewater enter a cold low-pressure separator to separate sulfur-containing dry gas, sulfur-containing wastewater and cold low-pressure oil.

[0066] S6. Another portion of the circulating solvent oil from step (4) is fed into a fixed-bed hydrorefining cracking unit for reaction, and the reaction products are fed into a product fractionation tower to separate diesel and naphtha.

[0067] Example 2

[0068] This embodiment provides a method for hydrogenation of waste tires, including the following steps:

[0069] (1) Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of 1000 micrometers. The waste tire particles, waste tire oil, circulating solvent oil, and homogeneous catalyst are mixed in oil slurry mixing tank 1 to obtain oil slurry. The weight ratio of waste tire particles to waste tire oil + circulating solvent oil is 1.5:1, and the weight ratio of waste tire oil to circulating solvent oil is 3:2. The amount of homogeneous catalyst added is 0.5% of the mass of waste tire particles.

[0070] (2) A microsphere-type nickel-molybdenum catalyst is loaded into the fluidized bed reactor 5. The diameter of the spheres is 0.2~1.2 mm and the cobalt + molybdenum metal content is 5%~30%. Then, the oil slurry from step S1 is pressurized in the booster pump 2 to 16.0 MPa. The hydrogen gas passed through the hydrogen heater 4 is heated to 400°C. Then, the pressurized oil slurry and the heated hydrogen gas are mixed. The temperature after mixing is 280~320°C. The mixture is introduced into the fluidized bed reactor 5 to react and obtain the reaction product. The reaction temperature is 400°C, the reaction pressure is 16.0 MPa, the hydrogen-to-oil volume ratio is 600, and the weight ratio of the microsphere-type nickel-molybdenum catalyst to the waste tire particles is 1:1.

[0071] (3) The reaction products of step (2) are separated into hot high-pressure gas and hot high-pressure oil in the hot high-pressure separator 6; the operating temperature and pressure of the hot high-pressure separator are the same as those of the fluidized bed reactor.

[0072] (4) The hot high-pressure oil from step (3) is depressurized and enters the hot low-pressure tank 9 to obtain the hot low-pressure tank low oil. The process parameters are: pressure 5.0 MPaG, temperature 400℃. The gas phase is discharged from the top of the hot low-pressure separator and the liquid phase is discharged from the bottom. The hot low-pressure tank low oil is entered into the supercritical extraction device 3. The supercritical extraction solvent is a mixture of n-butane and isobutane. The ratio of n-butane to isobutane is 2:1 (weight ratio), and the ratio of supercritical extraction solvent to hot low-pressure tank low oil is 4:1 (weight ratio). The circulating solvent oil and carbon black are separated. The liquid temperature is 140~160℃ and the liquid pressure is 0.3~1.0 MPaG. Part of the separated circulating solvent oil continues to be returned to step (1) to participate in the reaction, and the other part of the circulating solvent oil enters step (6).

[0073] (5) After the hot high-pressure gas from step (3) is cooled to 50°C by an air cooler, it enters a cold high-pressure separator to separate cold high-pressure gas, cold high-pressure oil and sulfur-containing wastewater. The process parameters are: pressure 11.0 MPaG, temperature 50°C. The cold high-pressure gas enters a circulating hydrogen buffer tank for buffering and then enters a circulating hydrogen compressor for pressurization to 15.0 MPag. The pressurized circulating hydrogen is mixed with high-purity hydrogen at a pressure of 15.0 MPag and enters a hydrogen heater. The cold high-pressure oil and sulfur-containing wastewater enter a cold low-pressure separator to separate sulfur-containing dry gas, sulfur-containing wastewater and cold low-pressure oil.

[0074] S6. Another portion of the circulating solvent oil from step (4) is fed into a fixed-bed hydrorefining cracking unit for reaction, and the reaction products are fed into a product fractionation tower to separate diesel and naphtha.

[0075] Example 3

[0076] This embodiment provides a method for hydrogenation of waste tires, including the following steps:

[0077] (1) Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of 1000 micrometers. The waste tire particles, recycled solvent oil, and homogeneous catalyst are mixed in oil slurry mixing tank 1 to obtain oil slurry. The weight ratio of waste tire particles to recycled solvent oil is 1:1, and the amount of homogeneous catalyst added is 0.5% of the mass of waste tire particles.

[0078] (2) A microsphere-type nickel-molybdenum catalyst is loaded into the fluidized bed reactor 5. The diameter of the spheres is 0.3~1.1 mm and the content of cobalt + nickel + molybdenum metal is 5%~30%. Then, the oil slurry from step S1 is pressurized in the booster pump 2 to 15.0 MPa. The hydrogen gas passed through the hydrogen heater 4 is heated to 430°C. Then, the pressurized oil slurry and the heated hydrogen gas are mixed. The temperature after mixing is 270~320°C. The mixture is introduced into the fluidized bed reactor 5 to react and obtain the reaction product. The reaction temperature is 400°C, the reaction pressure is 15.0 MPa, the hydrogen-to-oil volume ratio is 600, and the weight ratio of the catalyst to the waste tire particles is 1:1.

[0079] (3) The reaction products of step (2) are separated into hot high-pressure gas and hot high-pressure oil in a hot high-pressure separator; the operating temperature and pressure of the hot high-pressure separator are the same as those of the fluidized bed reactor.

[0080] (4) The hot high-pressure oil from step (3) is depressurized and enters the hot low-pressure tank to obtain the hot low-pressure tank low-pressure oil. The process parameters are: pressure 5.0 MPaG, temperature 400℃. The gas phase is discharged from the top of the hot low-pressure separator and the liquid phase is discharged from the bottom. The hot low-pressure tank low-pressure oil is entered into the supercritical extraction device. The supercritical extraction solvent is a mixture of n-butane and isobutane. The ratio of n-butane to isobutane is 2:1 (weight ratio), and the ratio of supercritical extraction solvent to hot low-pressure tank low-pressure oil is 4:1 (weight ratio). The circulating solvent oil and carbon black are separated. The liquid temperature is 140~160℃ and the liquid pressure is 0.3~1.0 MPaG. Part of the separated circulating solvent oil continues to be returned to step (1) to participate in the reaction, and the other part of the circulating solvent oil enters step (6).

[0081] (5) After the hot high-pressure gas from step (3) is cooled to 50°C by an air cooler, it enters a cold high-pressure separator to separate cold high-pressure gas, cold high-pressure oil and sulfur-containing wastewater. The process parameters are: pressure 11.0 MPaG, temperature 50°C. The cold high-pressure gas enters a circulating hydrogen buffer tank for buffering and then enters a circulating hydrogen compressor for pressurization to 17.0 MPag. The pressurized circulating hydrogen is mixed with high-purity hydrogen at a pressure of 17.0 MPag and enters a hydrogen heater. The cold high-pressure oil and sulfur-containing wastewater enter a cold low-pressure separator to separate sulfur-containing dry gas, sulfur-containing wastewater and cold low-pressure oil.

[0082] S6. Another portion of the circulating solvent oil from step (4) is fed into a fixed-bed hydrorefining cracking unit for reaction, and the reaction products are fed into a product fractionation tower to separate diesel and naphtha.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that in step (4), only n-butane is used as the supercritical extraction solvent, wherein the weight ratio of the supercritical extraction solvent to the hot low-temperature oil is 6:1.

[0085] To demonstrate the effectiveness of the hydrogenation and upgrading of waste tires as described in this invention, experimental measurements were conducted on the above-mentioned Examples 1, 2, 3, and Comparative Example 1.

[0086] Carbon black yield = (mass of carbon black / mass of waste tire pellets) × 100%;

[0087] Effective oil yield = (mass of naphtha + diesel) / mass of waste tire particles × 100%.

[0088] The experimental results of the examples are shown in Table 1.

[0089] Table 1 Results of hydrogenation of waste tires in the example

[0090]

[0091] As can be seen from Examples 1-3 and Comparative Example 1, the carbon black yield and effective product yield obtained by the method of the present invention are effectively improved.

[0092] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for hydrogenating waste tires, characterized in that, Includes the following steps: S1. Waste tires are sequentially processed by drawing steel wire, cutting, and grinding into waste tire particles of a certain size. The waste tire particles, liquid oil, and catalyst are mixed in an oil slurry mixing tank (1) to obtain an oil slurry. S2. The catalyst is loaded into the fluidized bed reactor (5), and the oil slurry from step S1 is pressurized in the booster pump (2) and the hydrogen gas passed through the hydrogen heater (4) is heated. The pressurized oil slurry and the heated hydrogen gas are then mixed and fed into the fluidized bed reactor (5) to react and obtain the reaction product. S3. The reaction products of step S2 are separated into hot high-pressure gas and hot high-pressure oil in a hot high-pressure separator (6). S4. The hot high-grade oil from step S3 is depressurized and transferred to the hot low-grade oil tank (9) to obtain the bottom oil of the hot low-grade oil tank. The bottom oil of the hot low-grade oil tank is then transferred to the supercritical extraction device (3) to separate liquid oil and carbon black. Part of the separated liquid oil is returned to step S1 to participate in the reaction, and the other part of the liquid oil is transferred to step S6. S5. After the hot high-pressure gas from step S3 is cooled by the air cooler (7), it enters the cold high-pressure separator (10) to separate the cold high-pressure gas, cold high-pressure oil and sulfur-containing wastewater. The cold high-pressure gas enters the circulating hydrogen buffer tank (14) for buffering and then enters the circulating hydrogen compressor (12) for pressurization. The pressurized circulating hydrogen is mixed with high-purity hydrogen and enters the hydrogen heater (4). The cold high-pressure oil and sulfur-containing wastewater enter the cold low-pressure separator (11) to separate the sulfur-containing dry gas, sulfur-containing wastewater and cold low-pressure oil. S6, another portion of the liquid oil in step S4 and the cold low-fraction oil in step S5 enter the fixed bed hydrorefining cracking unit (17) for reaction, and the reaction products enter the product fractionation tower to separate diesel and naphtha; In step S4, the supercritical extraction solvent used in the supercritical extraction device is a mixture of n-butane and isobutane, wherein the weight ratio of n-butane to isobutane is 2:

1. The carbon black produced in step S4 accounts for 25-50 wt% of the weight of the waste tire particles in step S1.

2. The method according to claim 1, characterized in that, In step S4, the weight ratio of the supercritical extraction solvent to the bottom oil of the hot low-temperature extraction tank is 3~5:

1.

3. The method according to claim 1, characterized in that, In step S1, the weight ratio of the waste tire particles to the liquid oil is 1:0.8 to 2.

4. The method according to claim 1, characterized in that, In step S1, the size of the waste tire particles is <2000μm.

5. The method according to claim 1, characterized in that, In step S2, the weight ratio of the catalyst to the waste tire particles is 1~2:

1.

6. The method according to claim 1, characterized in that, In step S1, the catalyst is a homogeneous catalyst; in step S2, the catalyst packed in the fluidized bed reactor (5) is a microsphere supported catalyst.

7. The method according to claim 1, characterized in that, In step S2, the specific reaction conditions are: reaction temperature 250-450℃, reaction pressure 3-20MPa, and hydrogen-to-oil volume ratio 350-1500.

Images