Waste tire circulating fluidized bed pyrolysis method and system

Abstract

The invention provides a waste tire circulating fluidized bed pyrolysis method and system.The method comprises the steps that broken raw materials are taken and enter a fluidized bed pyrolysis furnace, and large-particle carbon black, small-particle carbon black and mixed gas are obtained; the large-particle carbon black and the small-particle carbon black are used as heat carriers for circulation; carrying out gas-liquid separation treatment on the mixed gas to obtain an oil-water mixture and pyrolysis gas, and carrying out oil-water separation treatment on the oil-water mixture to obtain pyrolysis oil and circulating water; pyrolysis oil is processed to obtain an oil product, pyrolysis gas is subjected to high-temperature treatment to obtain first hot flue gas, one part of the first hot flue gas serves as hot carrier gas to be circulated, the other part of the first hot flue gas enters a waste heat boiler to obtain second hot flue gas and a steam product, and the second hot flue gas is purified to obtain purified flue gas. According to the method, solid and gas double circulation is adopted, and high gasification efficiency and low energy consumption are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of waste tire liquefaction treatment, and in particular to a waste tire circulating fluidized bed pyrolysis method and system. Background Art

[0002] With the increasing number of waste tires, the resource utilization of waste tires has also received a lot of attention and research. Among them, the Chinese invention patent application number is: CN209685694U discloses a waste tire fluidized bed rapid liquefaction and carbon black gasification integrated system. Among them, the upper end outlet of the fluidized bed reactor in the patent is connected to the primary cyclone separator and the secondary cyclone separator respectively, and the separated heat carrier and carbon black enter the heat carrier receiving tank and the carbon black receiving tank respectively. In particular, the solid heat carrier does not participate in the pyrolysis reaction, but only provides reaction heat as a heat carrier. Since the solid heat carrier itself needs to be heated to reach the reaction temperature, it will absorb more heat from the system, thereby consuming more energy when pyrolyzing the same mass of waste tires. Moreover, there is only solid circulation in the patent, but no gas circulation, the gas generated by pyrolysis is not fully utilized, the system efficiency is low, and it is not economical.

[0003] Based on this, in the face of technical problems in the prior art of waste tire pyrolysis systems, such as high energy consumption, low system efficiency, or high economic cost, there is an urgent need to provide a new type of waste tire circulating fluidized bed pyrolysis method and system to improve the above problems. Summary of the invention

[0004] The main purpose of the present invention is to provide a waste tire circulating fluidized bed pyrolysis method and system to solve the technical problems of high energy consumption, low system efficiency or high economic cost in the waste tire pyrolysis system in the prior art.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a waste tire circulating fluidized bed pyrolysis method is provided, which comprises the following steps: taking waste tires and subjecting them to wire drawing, crushing and screening treatment in sequence to obtain crushed raw materials with an average particle size of 10 to 30 mm; taking the crushed raw materials into a fluidized bed pyrolysis furnace through a feeding device for pyrolysis treatment to obtain large-particle carbon black, small-particle carbon black and a mixed gas, wherein the mixed gas comprises large-molecular volatiles and small-molecular non-condensable gases; wherein a portion of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through a returning device, and another portion of the large-particle carbon black is used as a pyrolysis solid phase product and enters a pyrolysis carbon cooling device to obtain a large-particle carbon black product; the large-molecular volatiles, small-molecular non-condensable gases and small-particle carbon black enter a cyclone separator for cyclone separation treatment to obtain small-particle carbon black and a mixed gas; wherein a portion of the small-particle carbon black As a solid heat carrier, it enters the fluidized bed pyrolysis furnace through the return device, and a part of the small particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a small particle carbon black product; the mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas, and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain a first hot flue gas, a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain a second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas; wherein the waste tires include passenger car tires, motorcycle tires, truck tires and other types of tires.

[0006] Furthermore, the temperature in the fluidized bed pyrolysis furnace is 450-600° C., and the pressure is normal pressure.

[0007] Furthermore, the temperature of the mixed gas is 30-80°C.

[0008] Furthermore, the temperature of the first hot flue gas is 900-1100°C.

[0009] Furthermore, large-particle carbon black is used as a solid heat carrier, wherein a portion of the large-particle carbon black enters the circulating fluidized bed pyrolysis furnace as a solid heat carrier, and a portion of the large-particle carbon black accounts for 20-40% of the total output of large-particle carbon black, and another portion of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product, and another portion of the large-particle carbon black accounts for 60-80% of the total output of large-particle carbon black.

[0010] Furthermore, the particle size of the large particle carbon black is 10 to 20 mm.

[0011] Furthermore, the particle size of the small particle carbon black is 3 to 5 mm.

[0012] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a waste tire circulating fluidized bed pyrolysis system is provided. Using the above-mentioned method, the system comprises: a wire drawing, crushing and screening device, a feeding device, a fluidized bed pyrolysis furnace, a cyclone separator, a pyrolytic carbon cooling device, a gas-liquid separation device, an oil-water separation device, a tar hydrogenation device, a gas boiler and a waste heat boiler; wherein the waste tire raw material enters at the inlet of the wire drawing, crushing and screening device, the outlet of the wire drawing, crushing and screening device is connected to the inlet of the feeding device, the outlet of the feeding device is connected to the inlet of the fluidized bed pyrolysis furnace, the outlet of the fluidized bed pyrolysis furnace is respectively connected to the inlet of the feeding device, the inlet of the cyclone separator and the inlet of the pyrolytic carbon cooling device, the outlet of the cyclone separator is respectively connected to the inlet of the gas-liquid separation device and the inlet of the pyrolytic carbon cooling device, the outlet of the gas-liquid separation device is respectively connected to the inlet of the oil-water separation device and the inlet of the gas boiler, the outlet of the oil-water separation device is connected to the inlet of the tar hydrogenation device, and the outlet of the gas boiler is respectively connected to the inlet of the fluidized bed pyrolysis furnace and the inlet of the waste heat boiler.

[0013] Furthermore, the system also includes: a silo, a material return device and a flue gas purification device.

[0014] Furthermore, the inlet of the silo is connected to the outlet of the wire drawing crushing and screening device, the outlet of the silo is connected to the inlet of the feeding device, and the outlet of the waste heat boiler is connected to the inlet of the flue gas purification device.

[0015] The waste tire circulating fluidized bed pyrolysis method provided by the present invention uses a gas and solid dual circulating fluidized bed continuous reactor. On the one hand, the solid heat carrier and the first hot flue gas generated by the combustion of the pyrolysis gas fully pyrolyze the tire, and the energy and reaction are carried out in stages, and the pyrolysis products are separated in time to prevent blockage and coking. On the other hand, the circulation of the pyrolysis products (including solids and gases) in the system is used as a heat source and fuel to provide heat and fuel for the pyrolysis reaction, and the materials entering the system and the intermediate products in the reaction and the heat energy they carry are recycled, which can further save energy and reduce emissions. The system has a higher gasification efficiency, lower pyrolysis energy consumption, and is more energy-saving. It can also complete the co-production of three phases: solid (charcoal), liquid (oil), and gas (steam), so that the waste tires are more fully utilized as resources, and the pyrolysis system is coupled with a tar hydrogenation device to process the pyrolysis oil to produce a lighter oil with better quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. In the drawings:

[0017] Figure 1 A flow chart showing a waste tire circulating fluidized bed pyrolysis method according to one embodiment of the present invention; and

[0018] Figure 2 A flow chart of a waste tire circulating fluidized bed pyrolysis system according to one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0020] According to what is described in the background technology part of the present invention, there are technical problems in the waste tire pyrolysis system in the prior art, such as high energy consumption, low system efficiency, or high economic cost. The present invention provides a waste tire circulating fluidized bed pyrolysis method, which includes the following steps: taking waste tires and subjecting them to wire drawing, crushing and screening in sequence to obtain crushed raw materials with an average particle size of 10 to 30 mm; taking the crushed raw materials into a fluidized bed pyrolysis furnace through a feeding device for pyrolysis treatment to obtain large-particle carbon black, small-particle carbon black and a mixed gas, wherein the mixed gas includes large-molecular volatiles and small-molecular non-condensable gases; wherein a portion of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through a return device, and another portion of the large-particle carbon black is used as a pyrolysis solid phase product and enters a pyrolysis carbon cooling device to obtain a large-particle carbon black product; the large-molecular volatiles, small-molecular non-condensable gases and small-particle carbon black enter a cyclone separator for cyclone separation treatment to obtain small-particle carbon black and a mixed gas; wherein a portion of the small-particle carbon black is used as a solid heat carrier and passes through a return device to enter the fluidized bed pyrolysis furnace ... passes through a pyrolysis carbon The return device enters the fluidized bed pyrolysis furnace, and a part of the small-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a small-particle carbon black product; the mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas, and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain a first hot flue gas, a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain a second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas; wherein the waste tires include passenger car tires, motorcycle tires, truck tires and other types of tires.

[0021] Compared with the waste tire pyrolysis method in the prior art, the traditional pyrolysis method only has solid circulation but no gas circulation, so that the gas generated by pyrolysis is not fully utilized, the system efficiency is low, and it is not economical. The technical solution of the solid and gas dual-circulation fluidized bed adopted in the present invention, the heat carrier of the solid circulation is the large particle carbon black produced by the incomplete pyrolysis of the tire, which is passed into the furnace again to burn and release heat to provide the temperature conditions required for the pyrolysis of the waste tires newly entering the system, which is more energy-saving and further improves the gasification efficiency. The heat carrier of the gas circulation is the high-temperature hot flue gas generated by burning the pyrolysis gas as fuel in the gas boiler. There is no need to consume additional gas as fuel input into the system, reducing the system operation cost.

[0022] Specifically, Figure 1 The flowchart of the waste tire circulating fluidized bed pyrolysis method shown in the figure, the waste tires are sequentially subjected to wire drawing, crushing and screening treatment to obtain crushed raw materials with an average particle size of 10 to 30 mm; then, the crushed raw materials enter the fluidized bed pyrolysis furnace for pyrolysis treatment to obtain large-particle carbon black, small-particle carbon black and a mixed gas; a portion of the large-particle carbon black enters the fluidized bed pyrolysis furnace through a return device as a solid heat carrier, and another portion of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product; large-molecular volatiles, small-molecular non-condensable gases and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and a mixed gas; wherein, a portion of the small-particle carbon black enters the fluidized bed pyrolysis furnace through a return device as a solid heat carrier In the fluidized bed pyrolysis furnace, a portion of small-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a small-particle carbon black product; the mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas, and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain a first hot flue gas, a portion of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another portion of the first hot flue gas enters the waste heat boiler to obtain a second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas.

[0023] In order to further improve the pyrolysis efficiency and ensure sufficient pyrolysis to produce high-quality pyrolysis products, the temperature in the fluidized bed pyrolysis furnace is 450-600°C and the pressure is atmospheric pressure. The large particles of carbon black produced by pyrolysis are discharged from the bottom of the fluidized bed and then enter the return device. As a solid heat carrier, it reduces the temperature difference between the fluidized bed pyrolysis furnace and the reaction temperature, making it easier to reach the reaction temperature and making the reaction more complete.

[0024] In a preferred embodiment, the temperature of the pyrolysis gas is 30-80°C, and the pyrolysis gas enters the gas boiler and burns to form hot flue gas. More preferably, the temperature of the first hot flue gas is 900-1100°C, and is passed into the fluidized bed pyrolysis furnace as a heat carrier for gas circulation, providing sufficient heat source for the fluidized bed pyrolysis furnace.

[0025] In order to further promote solid circulation, improve production efficiency and save energy consumption, large-particle carbon black is preferably used as a solid heat carrier, wherein a portion of the large-particle carbon black entering the circulating fluidized bed pyrolysis furnace as a solid heat carrier accounts for 20-40% of the total output of large-particle carbon black, and another portion of the large-particle carbon black entering the pyrolysis carbon cooling device as a pyrolysis solid phase product accounts for 60-80% of the total output of large-particle carbon black. Reduce the heat input from the outside required by the system. It is more preferred that the particle size of large-particle carbon black is 10-20 mm, and the particle size of small-particle carbon black is 3-5 mm.

[0026] On the other hand, the present invention also provides a waste tire circulating fluidized bed pyrolysis system. Using the above method, the system includes: a wire drawing, crushing and screening device, a feeding device, a fluidized bed pyrolysis furnace, a cyclone separator, a pyrolytic carbon cooling device, a gas-liquid separation device, an oil-water separation device, a tar hydrogenation device, a gas boiler and a waste heat boiler; wherein the waste tire raw material enters at the inlet of the wire drawing, crushing and screening device, the outlet of the wire drawing, crushing and screening device is connected to the inlet of the feeding device, the outlet of the feeding device is connected to the inlet of the fluidized bed pyrolysis furnace, the outlet of the fluidized bed pyrolysis furnace is respectively connected to the inlet of the feeding device, the inlet of the cyclone separator and the inlet of the pyrolytic carbon cooling device, the outlet of the cyclone separator is respectively connected to the inlet of the gas-liquid separation device and the inlet of the pyrolytic carbon cooling device, the outlet of the gas-liquid separation device is respectively connected to the inlet of the oil-water separation device and the inlet of the gas boiler, the outlet of the oil-water separation device is connected to the inlet of the tar hydrogenation device, and the outlet of the gas boiler is respectively connected to the inlet of the fluidized bed pyrolysis furnace and the inlet of the waste heat boiler.

[0027] Specifically, the device diagram of the system is shown in the attached Figure 2As shown, the waste tires enter the wire drawing, crushing and screening machine in sequence, and the waste tires are subjected to wire drawing, crushing and screening treatments, so that the steel wires in the tires are completely separated from the rubber, and the steel wires are separated from the rubber particles by a magnetic separator, and the raw materials can be processed to an average particle size of 10 to 30 mm. The crushed raw materials enter the feeding device through the silo and enter the fluidized bed pyrolysis furnace for pyrolysis treatment to obtain large-particle carbon black, small-particle carbon black and a mixed gas, wherein the mixed gas includes large-molecular volatiles and small-molecular non-condensable gases; wherein a portion of the large-particle carbon black enters the fluidized bed pyrolysis furnace through the returning device as a solid heat carrier, and another portion of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product; the large-molecular volatiles, small-molecular non-condensable gases and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and a mixed gas; wherein a portion of the small-particle carbon black enters the fluidized bed pyrolysis furnace through the returning device as a solid heat carrier, and a portion of the small-particle carbon black enters the pyrolysis solid phase product The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas, and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain a first hot flue gas, a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain a second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas; wherein the waste tires include passenger car tires, motorcycle tires, truck tires and other types of tires.

[0028] In a preferred embodiment, the system further comprises: a silo, a material return device and a flue gas purification device. More preferably, the inlet of the silo is connected to the outlet of the wire drawing crushing and screening device, the outlet of the silo is connected to the inlet of the feeding device, and the outlet of the waste heat boiler is respectively connected to the inlet of the flue gas purification device.

[0029] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0030] Example 1

[0031] Take the waste tires and put them into the wire drawing, crushing and screening machine in turn. The waste tires are subjected to wire drawing, crushing and screening treatment, so that the steel wire in the tire is completely separated from the rubber, and the steel wire is separated from the rubber particles by a magnetic separator. The raw materials can be processed to an average particle size of 15mm. The waste tires are passenger car tires. The crushed raw materials enter the silo, and then enter the fluidized bed pyrolysis furnace through the feeding device for pyrolysis treatment. The temperature in the fluidized bed pyrolysis furnace is 580℃, and the pressure is normal pressure. Large-particle carbon black (particle size is 10mm), small-particle carbon black (particle size is 3mm), large-molecular volatile matter, small-molecular non-condensable gas and. Among them, the heat source in the pyrolysis process is provided by the first hot flue gas in the gas circulation. A part of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through the return device, and another part of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product, wherein a part of the large-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and the large-particle carbon black accounts for 30% of the total output of large-particle carbon black, and another part of the large-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device, and the large-particle carbon black accounts for 70% of the total output of large-particle carbon black. The large molecular volatile matter, small molecular non-condensable gas and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and mixed gas, wherein a part of the small-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and a part of the small-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device to obtain a small-particle carbon black product. The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas (temperature is 80°C). The oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain the first hot flue gas (temperature is 950°C), a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain the second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas.

[0032] Example 2

[0033] Take the waste tires and put them into the wire drawing, crushing and screening machine in turn. The waste tires are subjected to wire drawing, crushing and screening treatment, so that the steel wire in the tire is completely separated from the rubber, and the steel wire is separated from the rubber particles by a magnetic separator. The raw materials can be processed to an average particle size of 15mm. The waste tires are passenger car tires. The crushed raw materials enter the silo, and then enter the fluidized bed pyrolysis furnace through the feeding device for pyrolysis treatment. The temperature in the fluidized bed pyrolysis furnace is 630℃, and the pressure is normal pressure. Large-particle carbon black (particle size is 10mm), small-particle carbon black (particle size is 3mm), large-molecular volatile matter, small-molecular non-condensable gas and. Among them, the heat source in the pyrolysis process is provided by the first hot flue gas in the gas circulation. A part of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through the return device, and another part of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product, wherein a part of the large-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and the large-particle carbon black accounts for 25% of the total output of large-particle carbon black, and another part of the large-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device, and the large-particle carbon black accounts for 75% of the total output of large-particle carbon black. The large molecular volatile matter, small molecular non-condensable gas and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and mixed gas; wherein a part of the small-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and a part of the small-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device to obtain a small-particle carbon black product. The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas (temperature is 80°C). The oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain the first hot flue gas (temperature is 950°C), a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain the second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas.

[0034] Example 3

[0035] Take the waste tires and put them into the wire drawing, crushing and screening machine in turn. The waste tires are subjected to wire drawing, crushing and screening treatment, so that the steel wire in the tire is completely separated from the rubber, and the steel wire is separated from the rubber particles by a magnetic separator. The raw materials can be processed to an average particle size of 15mm. The waste tires are passenger car tires. The crushed raw materials enter the silo, and then enter the fluidized bed pyrolysis furnace through the feeding device for pyrolysis treatment. The temperature in the fluidized bed pyrolysis furnace is 530℃, and the pressure is normal pressure. Large-particle carbon black (particle size is 10mm), small-particle carbon black (particle size is 3mm), large-molecular volatile matter, small-molecular non-condensable gas and. Among them, the heat source in the pyrolysis process is provided by the first hot flue gas in the gas circulation. A part of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through the return device, and another part of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product, wherein a part of the large-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, accounting for 35% of the total output of large-particle carbon black, and another part of the large-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device, accounting for 65% of the total output of large-particle carbon black. The large molecular volatile matter, small molecular non-condensable gas and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and mixed gas; wherein a part of the small-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and a part of the small-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device to obtain a small-particle carbon black product. The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas (temperature is 80°C). The oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high-temperature treatment to obtain the first hot flue gas (temperature is 950°C), a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain the second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas.

[0036] Comparative Example 1

[0037] Take the waste tires and put them into the wire drawing, crushing and screening machine in turn. The waste tires are subjected to wire drawing, crushing and screening treatment, so that the steel wire in the tire is completely separated from the rubber, and the steel wire is separated from the rubber particles by a magnetic separator. The raw materials can be processed to an average particle size of 15mm. The waste tires are passenger car tires. The crushed raw materials enter the silo, and then enter the fluidized bed pyrolysis furnace through the feeding device for pyrolysis treatment. The temperature in the fluidized bed pyrolysis furnace is 570℃, and the pressure is normal pressure. Large-particle carbon black (particle size is 10mm), small-particle carbon black (particle size is 3mm), large-molecular volatile matter, small-molecular non-condensable gas and. Among them, the heat source in the pyrolysis process is provided by the first hot flue gas in the gas circulation. A part of the large-particle carbon black is used as a solid heat carrier and enters the fluidized bed pyrolysis furnace through the return device, and another part of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a large-particle carbon black product, wherein a part of the large-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and the large-particle carbon black accounts for 32% of the total output of large-particle carbon black, and another part of the large-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device, and the large-particle carbon black accounts for 68% of the total output of large-particle carbon black. The large molecular volatile matter, small molecular non-condensable gas and small-particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small-particle carbon black and mixed gas; wherein a part of the small-particle carbon black as a solid heat carrier enters the fluidized bed pyrolysis furnace through the return device, and a part of the small-particle carbon black as a pyrolysis solid phase product enters the pyrolysis carbon cooling device to obtain a small-particle carbon black product. The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas (temperature is 80°C). The oil-water mixture is separated by oil and water in the oil-water separation device to obtain pyrolysis oil and circulating water. The pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas is not subjected to subsequent high-temperature treatment operations. The gas phase hot flue gas is not further recycled, resulting in high energy consumption and low system efficiency.

[0038] Comparative Example 2

[0039] Take the waste tires and put them into the wire drawing, crushing and screening machine in turn. The waste tires are subjected to wire drawing, crushing and screening treatment, so that the steel wire in the tire is completely separated from the rubber, and the steel wire and the rubber particles are separated by a magnetic separator. The raw materials can be processed to an average particle size of 15mm. The waste tires are passenger car tires. The crushed raw materials enter the silo, and then enter the fluidized bed pyrolysis furnace through the feeding device for pyrolysis treatment. The temperature in the fluidized bed pyrolysis furnace is 610℃, and the pressure is normal pressure. Large-particle carbon black (particle size is 10mm), small-particle carbon black (particle size is 3mm), large-molecular volatile matter, small-molecular non-condensable gas and. Among them, the heat source in the pyrolysis process is provided by the first hot flue gas in the gas circulation. The macromolecular volatile matter, small molecular non-condensable gas and small particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small particle carbon black and mixed gas; wherein, a part of the small particle carbon black enters the fluidized bed pyrolysis furnace through the return device as a solid heat carrier, and a part of the small particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain a small particle carbon black product. The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas (temperature is 80°C), and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; the pyrolysis gas enters the gas boiler for high temperature treatment to obtain the first hot flue gas (temperature is 950°C), a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain the second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas. Among them, the large particle carbon black does not provide heat as a heat carrier, resulting in high energy consumption and low efficiency of the system.

[0040] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0041] The waste tire circulating fluidized bed pyrolysis method provided by the present invention uses a gas and solid dual circulating fluidized bed continuous reactor. On the one hand, the solid heat carrier and the first hot flue gas generated by the combustion of the pyrolysis gas fully pyrolyze the tire, and the energy and reaction are carried out in stages, and the pyrolysis products are separated in time to prevent blockage and coking. On the other hand, the circulation of the pyrolysis products (including solids and gases) in the system is used as a heat source and fuel to provide heat and fuel for the pyrolysis reaction, and the materials entering the system and the intermediate products in the reaction and the heat energy they carry are recycled, which can further save energy and reduce emissions. The system has a higher gasification efficiency, lower pyrolysis energy consumption, and is more energy-saving. It can also complete the co-production of three phases: solid (charcoal), liquid (oil), and gas (steam), so that the waste tires are more fully utilized as resources, and the pyrolysis system is coupled with a tar hydrogenation device to process the pyrolysis oil to produce a better quality light oil.

[0042] Although this specification includes many specific implementation details, these should not be interpreted as limiting the scope of any invention or the scope of protection claimed, but are mainly used to describe the features of the specific embodiments of specific inventions. Certain features described in multiple embodiments in this specification may also be implemented in combination in a single embodiment. On the other hand, the various features described in a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination. In addition, although features may work in certain combinations as described above and even initially claim protection, one or more features from the claimed combination may be removed from the combination in some cases, and the claimed combination may point to a sub-combination or a variation of a sub-combination.

[0043] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the particular order or sequential order shown to achieve the desired results. In some implementations, multitasking and parallel processing may be advantageous.

[0044] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0045] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A circulating fluidized bed pyrolysis method for waste tires, characterized in that: The method comprises the following steps: Take the waste tires and perform wire drawing, crushing and screening in sequence to obtain crushed raw materials with an average particle size of 10 to 30 mm; The crushed raw material is fed into a fluidized bed pyrolysis furnace through a feeding device for pyrolysis treatment to obtain large carbon black particles, small carbon black particles and a mixed gas, wherein the mixed gas includes large molecular volatiles and small molecular non-condensable gases; Part of the large-particle carbon black enters the fluidized bed pyrolysis furnace as a solid heat carrier, and another part of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain the large-particle carbon black product; The macromolecular volatile matter, the small molecular non-condensable gas and the small particle carbon black enter the cyclone separator for cyclone separation treatment to obtain small particle carbon black and mixed gas; wherein a part of the small particle carbon black enters the fluidized bed pyrolysis furnace as a solid heat carrier, and a part of the small particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product to obtain the small particle carbon black product; The mixed gas enters the gas-liquid separation device for gas-liquid separation treatment to obtain an oil-water mixture and pyrolysis gas, and the oil-water mixture is subjected to oil-water separation treatment by the oil-water separation device to obtain pyrolysis oil and circulating water, wherein the pyrolysis oil is processed by the tar hydrogenation device to obtain oil products, and the circulating water enters the gas-liquid separation device; The pyrolysis gas enters the gas boiler for high-temperature treatment to obtain the first hot flue gas, a part of the first hot flue gas enters the fluidized bed pyrolysis furnace as a hot carrier gas, and another part of the first hot flue gas enters the waste heat boiler to obtain the second hot flue gas and steam products, wherein the second hot flue gas is purified by the flue gas purification device to obtain purified flue gas; wherein, The waste tires include passenger car tires, motorcycle tires, truck tires and other types of tires.

2. The waste tire circulating fluidized bed pyrolysis method according to claim 1, characterized in that: The temperature in the fluidized bed pyrolysis furnace is 450-600° C., and the pressure is normal pressure.

3. The waste tire circulating fluidized bed pyrolysis method according to claim 1, characterized in that: The temperature of the pyrolysis gas is 30-80°C.

4. The waste tire circulating fluidized bed pyrolysis method according to claim 1, characterized in that: The temperature of the first hot flue gas is 900-1100°C.

5. The method for pyrolysis of waste tires in a circulating fluidized bed according to claim 1, characterized in that: The large-particle carbon black is used as a solid heat carrier, wherein a portion of the large-particle carbon black enters the fluidized bed pyrolysis furnace through a return device as a solid heat carrier, and the portion of the large-particle carbon black accounts for 20-40% of the total output of the large-particle carbon black, and another portion of the large-particle carbon black enters the pyrolysis carbon cooling device as a pyrolysis solid phase product, and the other portion of the large-particle carbon black accounts for 60-80% of the total output of the large-particle carbon black.

6. The circulating fluidized bed pyrolysis method of waste tires according to claim 1, characterized in that: The particle size of the large particle carbon black is 10 to 20 mm.

7. The circulating fluidized bed pyrolysis method of waste tires according to claim 1, characterized in that: The particle size of the small particle carbon black is 3 to 5 mm.

8. A waste tire circulating fluidized bed pyrolysis system according to any one of claims 1 to 7, characterized in that: Using the method described in any one of claims 1 to 7, the system comprises: a wire drawing, crushing and screening device, a feeding device, a fluidized bed pyrolysis furnace, a cyclone separator, a pyrolytic carbon cooling device, a gas-liquid separation device, an oil-water separation device, a tar hydrogenation device, a gas boiler and a waste heat boiler; wherein the waste tire raw material enters at the inlet of the wire drawing, crushing and screening device, the outlet of the wire drawing, crushing and screening device is connected to the inlet of the feeding device, the outlet of the feeding device is connected to the inlet of the fluidized bed pyrolysis furnace, the outlet of the fluidized bed pyrolysis furnace is respectively connected to the inlet of the feeding device, the inlet of the cyclone separator and the inlet of the pyrolytic carbon cooling device, the outlet of the cyclone separator is respectively connected to the inlet of the gas-liquid separation device and the inlet of the pyrolytic carbon cooling device, the outlet of the gas-liquid separation device is respectively connected to the inlet of the oil-water separation device and the inlet of the gas boiler, the outlet of the oil-water separation device is connected to the inlet of the tar hydrogenation device, and the outlet of the gas boiler is respectively connected to the inlet of the fluidized bed pyrolysis furnace and the inlet of the waste heat boiler.

9. The waste tire circulating fluidized bed pyrolysis system according to claim 8, characterized in that: The system also includes: a material bin, a material return device and a fume purification device.

10. The waste tire circulating fluidized bed pyrolysis system according to claim 9, characterized in that: The inlet of the silo is connected to the outlet of the wire drawing crushing and screening device, the outlet of the silo is connected to the inlet of the feeding device, and the outlet of the waste heat boiler is respectively connected to the inlet of the flue gas purification device.

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