A wind turbine waste blade recycling system and method

Abstract

This invention discloses a wind turbine waste blade recycling system and method. The recycling method includes the following steps: cutting the waste blades after removing metal components into blocks; pyrolyzing and carbonizing the cut waste blade blocks in an oxygen-containing atmosphere to obtain reinforcing fibers coated with pyrolyzed carbon; oxidizing the glass fibers coated with pyrolyzed carbon in an oxidizing atmosphere to recover the glass fibers; recovering tar components from the pyrolyzed carbonization tail gas after cooling; using a portion of the cooled pyrolyzed carbonization tail gas directly as the oxidizing atmosphere for the oxidation reaction, and using the other portion as the oxidizing atmosphere after heat exchange with the oxidizing tail gas produced by the oxidation reaction; subjecting the oxidizing tail gas after heat exchange to SCR denitrification treatment; and decarbonizing the denitrification tail gas at room temperature using ammonia method to recover ammonium carbonate. The decarbonized tail gas is then directly discharged as clean gas. This invention's recycling method effectively reduces the energy consumption of related technologies, recovers high-quality fibers, and is low-carbon and environmentally friendly, with broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of solid waste recycling technology. Specifically, this invention relates to a wind turbine waste blade recycling system and method. Background Technology

[0002] Wind turbine blades are a type of high-value-added industrial solid waste generated during the "clean" renewable energy process of wind power generation. Currently, the main method for disposing of these blades is landfilling, which presents numerous pollution problems and seriously impacts the ecological environment. Pyrolysis is a novel method for recycling resin-based composite materials. It typically involves converting the composite matrix resin into gases such as carbon dioxide and a small amount of pyrolytic carbon under specific atmosphere and high temperature (≥850℃) to recover the high-value-added reinforcing fibers, thus achieving resource utilization. Since the main material of wind turbine blades is glass fiber reinforced epoxy resin composite material, this method can be used for wind turbine blade recycling, offering advantages such as ease of scalability and broad application prospects. However, pyrolysis is energy-intensive, produces low-quality recycled fibers, and generates primarily carbon dioxide in the exhaust gas, making it a high-energy-consuming, low-quality, and high-carbon-emission technology. Therefore, developing a low-energy-consuming, high-quality fiber recycling and low-carbon-emission technology is of great significance for the recycling of wind turbine blades. Summary of the Invention

[0003] This invention aims to at least partially address one of the technical problems in related technologies. To this end, embodiments of this invention provide a wind turbine waste blade recycling system and method. The recycling system and method of this invention effectively reduce energy consumption in related technologies, produce high-quality recycled fibers, and are low-carbon and environmentally friendly, showing broad application prospects in the field of wind turbine waste blade recycling.

[0004] One embodiment of the present invention provides a method for recycling waste blades of wind turbine generators, comprising the following steps:

[0005] (1) Cut the waste blades after removing the metal components into blocks;

[0006] (2) The waste leaves cut into blocks are pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 300℃~320℃ for 1h~2h to obtain glass fibers wrapped in pyrolyzed carbon.

[0007] (3) The glass fiber wrapped in pyrolytic carbon is oxidized in an oxidizing atmosphere at a temperature of 400℃~420℃ for 1h~2h, and the glass fiber is recovered.

[0008] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. Part of the cooled pyrolysis carbonization tail gas is directly used as the oxidizing atmosphere in step (3), and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0009] (5) The oxidized tail gas after heat exchange in step (4) is subjected to SCR denitrification treatment;

[0010] (6) The denitrification tail gas from step (5) is decarbonized by ammonia at room temperature to recover ammonium carbonate. The tail gas after decarbonization is clean gas and is directly discharged into the air.

[0011] This invention, through the regulation of pyrolysis conditions, divides the traditional pyrolysis process into two units: carbonization and oxidation. Compared to traditional pyrolysis processes, it minimizes the reaction temperature during the recovery process, thereby reducing energy consumption in leaf recovery and improving the quality of the recovered fibers. Furthermore, this invention recovers ammonium carbonate through processes such as cooling and recovering tar from the pyrolysis and carbonization tail gas, low-temperature SCR denitrification, and ammonia decarbonization. The tar can be used as fuel, and the ammonium carbonate can be used as fertilizer. The final exhaust gas is fully purified. This invention's recovery system and method are clean and environmentally friendly, fully realizing resource utilization and possessing broad application prospects.

[0012] In some embodiments, the dimensions of the waste leaves cut into blocks are: length ≤ 10cm, width ≤ 10cm.

[0013] In some embodiments, the oxygen-containing atmosphere in step (2) consists of nitrogen and air, with an oxygen content of 5% to 8%.

[0014] In some embodiments, the pyrolysis carbonization tail gas is cooled to 150–200°C.

[0015] In some embodiments, the cooling of the pyrolysis carbonization exhaust gas is carried out in a cold trap, which includes a hollow cavity and a jacket fitted outside the hollow cavity. The pyrolysis carbonization exhaust gas enters the bottom of the hollow cavity through an inlet pipe and is discharged through an outlet pipe located at the top inside the hollow cavity. Coolant air flows through the jacket, and the coolant air is supplied by a fan. The temperature of the pyrolysis carbonization exhaust gas at the outlet of the cold trap is adjusted by controlling the flow ratio of the coolant air to the pyrolysis carbonization exhaust gas.

[0016] In some embodiments, the outlet temperature of the oxidized tail gas after heat exchange is 205–235°C.

[0017] In some embodiments, the ammonia-nitrogen molar ratio of the SCR denitrification treatment is 0.8 to 1.0.

[0018] In some embodiments, the catalyst for the SCR denitrification treatment is RuO2-MnO2-CeO2 / TiO2; the active components and their mass percentages are: ruthenium oxide: 1% to 5%; manganese oxide: 15% to 20%; cerium oxide: 10% to 20%; and the support is anatase nano-titanium dioxide.

[0019] In some embodiments, RuO2-MnO2-CeO2 / TiO2 is prepared by a method comprising the following steps: equimolar conversion of metal elements according to the content of each active component in the catalyst is performed to calculate the corresponding amounts of precursors ruthenium chloride, manganese acetate, and cerium nitrate. These are weighed and dissolved in water to prepare an impregnation solution. Then, honeycomb cordierite is impregnated with the impregnation solution in equal volumes, followed by drying and calcination to obtain the SCR denitration catalyst RuO2-MnO2-CeO2 / TiO2.

[0020] In some embodiments, in the preparation of RuO2-MnO2-CeO2 / TiO2, the drying temperature is 60℃~70℃, the drying time is 4h~6h, the calcination temperature is 550℃~600℃, and the calcination time is 3h~4h.

[0021] In some embodiments, the ammonia decarbonization process uses ammonia water as the decarbonization absorbent, with a liquid-to-gas ratio of 2 L / m³. 3 ~4L / m 3 .

[0022] Another aspect of this invention provides a wind turbine waste blade recycling system, comprising: a pyrolysis carbonization furnace, wherein the pyrolysis carbonization furnace is used for pyrolysis carbonization of waste blades cut into blocks in an oxygen-containing atmosphere;

[0023] A cold trap, used for cooling the pyrolysis and carbonization tail gas of the pyrolysis and carbonization furnace;

[0024] An oxidation furnace, wherein the oxidation furnace is used for oxidizing the pyrolysis and carbonization products of the pyrolysis and carbonization furnace;

[0025] A heat exchanger is used for heat exchange between the pyrolysis carbonization tail gas cooled by the cold trap and the oxidation tail gas of the oxidation furnace.

[0026] An SCR reactor is used for the denitrification treatment of the oxidized tail gas after heat exchange in a heat exchanger.

[0027] A decarbonization absorption tower is used for ammonia-based decarbonization of the denitrification tail gas after denitrification treatment by an SCR reactor.

[0028] In some embodiments, the cold trap includes a hollow cavity and a jacket fitted around the outside of the hollow cavity. Coolant air flows through the jacket. The hollow cavity is provided with a removable sealing cover. The sealing cover is provided with an inlet pipe and an outlet pipe. One end of the inlet pipe is connected to the tail gas outlet of the pyrolysis carbonization furnace through a pipeline, and the other end extends to the bottom of the hollow cavity. One end of the outlet pipe is located at the upper part of the hollow cavity, and the other end extends out of the sealing cover and splits into a first branch and a second branch. The first branch is directly connected to the gas inlet of the oxidation furnace, and the second branch is connected to a heat exchanger. After heat exchange in the heat exchanger, it is then connected to the gas inlet of the oxidation furnace.

[0029] In some embodiments, the heat exchanger is a tubular heat exchanger.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) By controlling the pyrolysis conditions, the present invention divides the traditional pyrolysis process into two units: carbonization and oxidation. Compared with the traditional pyrolysis process, the reaction temperature of the recycling process is reduced to the greatest extent, thereby reducing the energy consumption of leaf recycling and improving the quality of recycled fibers.

[0032] (2) This invention recovers ammonium carbonate by cooling and recovering tar from pyrolysis carbonization tail gas, low-temperature SCR denitrification and ammonia decarbonization, etc. Tar can be used as fuel, ammonium carbonate can be used as fertilizer, and the gas discharged in the end is fully purified. The recovery system and method of this invention are clean and environmentally friendly, and fully realize resource utilization, and have broad application prospects.

[0033] (3) The outlet gas temperature of the oxidation (furnace) of the present invention is higher than the inlet gas temperature. The heat of the gas is recovered by the heat exchanger and used to heat the inlet gas of the oxidation (furnace), thereby realizing the recovery and utilization of waste heat and effectively reducing the energy consumption of waste leaf recycling.

[0034] (4) This invention achieves efficient removal of nitrogen oxides from oxidizing tail gas through an innovatively designed low-temperature denitrification catalyst. The denitrification process does not require additional heating and has low energy consumption. Attached Figure Description

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0036] Figure 1 This is a schematic diagram of a wind turbine waste blade recycling system according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the cold trap structure according to an embodiment of the present invention.

[0038] Figure label:

[0039] 1 is a pyrolysis carbonization furnace, 2 is a cold trap, 3 is an oxidation furnace, 4 is a heat exchanger, 5 is an SCR reactor, 6 is a decarbonization absorption tower, and 7 is a blower.

[0040] 201 is a hollow cavity, and 202 is a jacket. Detailed Implementation

[0041] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0042] Unless otherwise specified, the raw materials and equipment used in the embodiments of this invention can be obtained commercially or prepared or processed by known methods.

[0043] One embodiment of the present invention provides a method for recycling waste blades of wind turbine generators, comprising the following steps:

[0044] (1) Cut the waste blades after removing the metal components into blocks;

[0045] (2) The waste leaves cut into blocks are pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 300℃~320℃ for 1h~2h to obtain glass fibers wrapped in pyrolyzed carbon.

[0046] (3) The glass fiber wrapped in pyrolytic carbon is oxidized in an oxidizing atmosphere at a temperature of 400℃~420℃ for 1h~2h, and the glass fiber is recovered.

[0047] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. Part of the cooled pyrolysis carbonization tail gas is directly used as the oxidizing atmosphere in step (3), and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0048] (5) The oxidized tail gas after heat exchange in step (4) is subjected to SCR denitrification treatment;

[0049] (6) The denitrification tail gas from step (5) is decarbonized by ammonia at room temperature to recover ammonium carbonate. The tail gas after decarbonization is clean gas and is directly discharged into the air.

[0050] Non-limiting examples include: the temperature for pyrolysis carbonization can be 300℃, 305℃, 310℃, 315℃, 320℃, etc., and the time can be 1h, 1.2h, 1.5h, 1.8h, 2h, etc. The temperature for oxidation reaction can be 400℃, 405℃, 410℃, 415℃, 420℃, etc., and the time can be 1h, 1.2h, 1.5h, 1.8h, 2h, etc.

[0051] This invention divides the traditional pyrolysis process into two units, carbonization and oxidation, by controlling the pyrolysis conditions. Compared with the traditional pyrolysis process, it minimizes the reaction temperature of the recycling process, thereby reducing the energy consumption of leaf recycling and improving the quality of recycled fibers.

[0052] In some embodiments, the oxygen-containing atmosphere in step (2) consists of nitrogen and air, with an oxygen content of 5% to 8%. Non-limiting examples include: the oxygen content of the oxygen-containing atmosphere can be 5%, 5.5%, 6%, 7%, 8%, etc.

[0053] In some embodiments, the dimensions of the waste leaves cut into blocks are: length ≤ 10cm, width ≤ 10cm. Non-limiting examples include: the dimensions can be cut into, for example, length × width = 10cm × 10cm, 8cm × 8cm, 8cm × 6cm, 6cm × 4cm, 6cm × 4cm, etc.

[0054] As a specific example, the dimensions of a discarded wind turbine blade are length × width = 10cm × 10cm, and the total gas flow rate of the oxygen-containing atmosphere can be 13L / min to 16L / min; preferably, the total gas flow rate is 15L / min. Non-limiting examples include: total gas flow rates of 13L / min, 14L / min, 14.5L / min, 15L / min, 16L / min, etc.

[0055] In some embodiments, the pyrolysis carbonization tail gas is cooled to 150°C to 200°C. Non-limiting examples include: the pyrolysis carbonization tail gas is cooled to 150°C, 160°C, 170°C, 185°C, 200°C, etc.

[0056] In some embodiments, the cooling of the pyrolysis carbonization tail gas is carried out in a cold trap, which includes a hollow cavity and a jacket fitted outside the hollow cavity. The pyrolysis carbonization tail gas enters the bottom of the hollow cavity through an inlet pipe and is discharged through an outlet pipe located at the top inside the hollow cavity. Coolant air flows inside the jacket, and the coolant air is supplied by a fan. The temperature of the pyrolysis carbonization tail gas at the outlet of the cold trap is adjusted by controlling the flow ratio of coolant air to pyrolysis carbonization tail gas.

[0057] In some embodiments, to avoid the oxidizing tail gas temperature being too low after heat exchange, which would affect subsequent denitrification treatment, the outlet temperature of the oxidizing tail gas after heat exchange is 205–235°C. Non-limiting examples include: the outlet temperature of the oxidizing tail gas after heat exchange can be 205°C, 210°C, 220°C, 230°C, 235°C, etc. The outlet temperature of the oxidizing tail gas is adjusted by controlling the flow ratio of the pyrolysis carbonization tail gas and the oxidizing tail gas participating in the heat exchange.

[0058] In some embodiments, the ammonia-to-nitrogen molar ratio in the SCR denitrification treatment is 0.8 to 1.0. Non-limiting examples include: the ammonia-to-nitrogen molar ratio can be 0.8, 0.85, 0.9, 0.95, 1.0, etc.

[0059] In some embodiments, the catalyst for SCR denitrification is RuO2-MnO2-CeO2 / TiO2; the active components and their mass percentages are: ruthenium oxide: 1% to 5%; manganese oxide: 15% to 20%; cerium oxide: 10% to 20%; and the support is anatase nano-titanium dioxide.

[0060] Non-limiting examples include: ruthenium oxide can be 1%, 2%, 3%, 4%, 5% by mass, etc.; manganese oxide can be 15%, 16%, 17.5%, 18%, 20% by mass, etc.; and cerium oxide can be 10%, 12%, 14%, 16%, 20% by mass, etc.

[0061] The low-temperature denitrification catalyst of this invention achieves efficient removal of nitrogen oxides from oxidizing exhaust gas, and the denitrification process does not require additional heating and has low energy consumption.

[0062] In some embodiments, the RuO2-MnO2-CeO2 / TiO2 catalyst is prepared by a method comprising the following steps: equimolar conversion of the metal elements according to the content of each active component in the catalyst, calculating the corresponding amounts of precursors ruthenium chloride, manganese acetate, and cerium nitrate, weighing them, dissolving them in water to prepare an impregnation solution, then impregnating the honeycomb cordierite with the impregnation solution (equal volume), and then drying and calcining to obtain the SCR denitration catalyst.

[0063] In some embodiments, in the preparation of the RuO2-MnO2-CeO2 / TiO2 catalyst, the drying temperature is 60℃~70℃, the drying time is 4h~6h, the calcination temperature is 550℃~600℃, and the calcination time is 3h~4h.

[0064] Non-limiting examples include: drying temperatures of 60℃, 62℃, 65℃, 68℃, 70℃, etc., and drying times of 4h, 4.5h, 5h, 5.5h, 6h, etc.; and calcination temperatures of 550℃, 560℃, 580℃, 590℃, 600℃, etc., and calcination times of 3h, 3.2h, 3.5h, 3.8h, 4h, etc.

[0065] In some embodiments, the ammonia decarbonization process uses ammonia water as the decarbonization absorbent, with a liquid-to-gas ratio of 2 L / m³. 3 ~4L / m 3 Non-limiting examples include: a liquid-to-gas ratio of 2 L / m³. 3 2.5L / m 3 3L / m3 3.5L / m 3 4L / m 3 wait.

[0066] Another aspect of the present invention provides a wind turbine waste blade recycling system, such as... Figure 1 As shown, it includes:

[0067] Pyrolysis carbonization furnace 1 is used for the pyrolysis carbonization of waste leaves cut into blocks in an oxygen-containing atmosphere.

[0068] Cold trap 2 is used to cool the pyrolysis and carbonization tail gas of the pyrolysis carbonization furnace.

[0069] Oxidation furnace 3 is used for the oxidation of the pyrolysis and carbonization products of pyrolysis and carbonization furnace 1.

[0070] Heat exchanger 4 is used for heat exchange between the pyrolysis carbonization tail gas cooled by the cold trap 2 and the oxidation tail gas of the oxidation furnace 3.

[0071] SCR reactor 5 is used for denitrification treatment of the oxidized tail gas after heat exchange in heat exchanger 4.

[0072] Decarbonization absorption tower 6 is used for ammonia-based decarbonization of the denitrification tail gas after denitrification treatment by SCR reactor 5.

[0073] In some embodiments, the cold trap 2 (such as...) Figure 2 (As shown) includes a hollow cavity 201 and a jacket 202 fitted outside the hollow cavity 201. Coolant air flows inside the jacket 202. The hollow cavity 201 is provided with a removable sealing cover. The sealing cover is provided with an inlet pipe and an outlet pipe. One end of the inlet pipe is connected to the tail gas outlet of the pyrolysis carbonization furnace 1 through a pipeline, and the other end extends to the bottom of the hollow cavity 201. One end of the outlet pipe is located at the upper part of the hollow cavity 201, and the other end extends out of the sealing cover and is divided into a first branch and a second branch. The first branch is directly connected to the gas inlet of the oxidizer 3, and the second branch is connected to the heat exchanger 4. After heat exchange in the heat exchanger 4, it is then connected to the gas inlet of the oxidizer 3.

[0074] In some embodiments, heat exchanger 4 is a tubular heat exchanger.

[0075] In this embodiment of the invention, the working process of the waste blade recycling system is as follows: After removing the metal components, the waste blades are cut into blocks and pyrolyzed in a pyrolysis carbonization furnace 1 to obtain glass fibers coated with pyrolysis carbon. The pyrolysis carbonization exhaust gas (mainly CO2, NO...) xThe pyrolysis carbonization tail gas (containing polycyclic aromatic hydrocarbons, also known as tar) enters cold trap 2 to recover the tar component (which can be used as fuel). Part of the tail gas from the outlet of cold trap 2 directly enters oxidizer 3, while the other part exchanges heat with the high-temperature oxidizing tail gas from the outlet of oxidizer 3 through heat exchanger 4 before entering oxidizer 3. Glass fibers wrapped in pyrolysis carbon are transferred into oxidizer 3, where they are oxidized to carbon dioxide at a certain temperature to obtain pure glass fibers. The oxidizing tail gas in oxidizer 3 is cooled to an appropriate temperature through heat exchanger 4 and then enters SCR reactor 5 for denitrification. The denitrified tail gas then enters decarbonization absorption tower 6 (spray tower) for ammonia decarbonization at room temperature to recover ammonium carbonate (which can be used as fertilizer). The decarbonized tail gas is then discharged directly into the atmosphere as clean gas.

[0076] In cold trap 2, the pyrolysis carbonization tail gas enters from the bottom and exits from the top in the hollow cavity 201. Coolant air (room temperature air) is supplied by a fan and flows through jacket 202. The temperature of the pyrolysis carbonization tail gas at the outlet of cold trap 2 is adjusted by controlling the flow ratio of coolant air to pyrolysis carbonization tail gas. The reaction in oxidizer 3 is exothermic. The outlet gas temperature of oxidizer 3 is higher than its inlet gas temperature. The heat is recovered by heat exchanger 4 and used to heat the inlet gas of oxidizer 3, realizing the recovery and utilization of waste heat.

[0077] The following are non-limiting embodiments of the present invention. In Examples 1-5, the catalyst for SCR denitration is RuO2-MnO2-CeO2 / TiO2; the active components and their mass percentages are: ruthenium oxide: 1%; manganese oxide: 20%; and cerium oxide: 10%; the support is anatase nano-titanium dioxide. The preparation method includes the following steps: 1.56 g of ruthenium trichloride, 39.77 g of manganese acetate, and 18.96 g of cerium nitrate are weighed and dissolved in 75 ml of water to form an impregnation solution. 100 g of honeycomb cordierite (Jiangxi Kexing, model: 200 mesh) is weighed and placed into the impregnation solution for impregnation. After impregnation, the cordierite support is removed, dried at 60°C for 6 h, and then calcined at 550°C for 4 h to obtain a honeycomb SCR denitration catalyst (RuO2-MnO2-CeO2 / TiO2).

[0078] The recycling effect in Examples 1-5 of this invention was evaluated using the resin residue rate and strength retention rate of the recycled fibers.

[0079] The resin content in the recovered fibers was analyzed using a Mettler Toledo pyrolysis gravimetric analyzer. The lower the resin content, the more complete the resin degradation in the leaves.

[0080] The tensile strength of the fiber was determined using an LLY-06E tensile testing machine. The ratio of the tensile strength to that of the original fiber represents the strength retention rate of the recycled fiber. The higher the retention rate, the less impact the degradation process has on the recycled fiber.

[0081] The NO content in the raw and clean exhaust gases was tested using a flue gas analyzer (Testo 350). x Based on the CO2 concentration, calculate the denitrification efficiency and decarbonization rate.

[0082] Example 1

[0083] A method for recycling waste blades from wind turbines includes the following steps:

[0084] (1) Cut the waste blades after removing the metal components into blocks (length × width = 10cm × 10cm);

[0085] (2) The waste leaves cut into blocks were pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 305℃ for 1.9h to obtain glass fibers wrapped in pyrolyzed carbon; the oxygen-containing gas consisted of nitrogen and air with an oxygen content of 5.2%; the total gas flow rate was 15.5L / min.

[0086] (3) The glass fiber wrapped in pyrolytic carbon was oxidized in an oxidizing atmosphere at a temperature of 408°C for 1.9 hours, and the fiber was recovered. The purity of the recovered fiber was 94.8%, and the fiber strength retention rate was 93.5%.

[0087] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. The pyrolysis carbonization tail gas is cooled by heat exchange with room temperature air. The cooled pyrolysis carbonization tail gas (cooled down to 187°C) is used as the oxidizing atmosphere in step (3) in part, and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0088] (5) The oxidized tail gas after heat exchange in step (4) (temperature 230℃) is subjected to SCR denitrification treatment, with an ammonia-nitrogen molar ratio of 0.95 and a denitrification efficiency of 96.1%.

[0089] (6) The denitrification tail gas from step (5) was decarbonized using ammonia at room temperature, achieving a decarbonization rate of 97.4%. Ammonia water was used as the decarbonization absorbent in the ammonia decarbonization process, with a liquid-to-gas ratio of 3.5 L / m³. 3 After decarbonization, the exhaust gas is clean gas and is directly discharged into the air.

[0090] Example 2

[0091] A method for recycling waste blades from wind turbines includes the following steps:

[0092] (1) Cut the waste blades after removing the metal components into blocks (length × width = 10cm × 10cm);

[0093] (2) The waste leaves cut into blocks were pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 310℃ for 1.6h to obtain glass fibers wrapped in pyrolyzed carbon; the oxygen-containing gas consisted of nitrogen and air with an oxygen content of 6.5%; the total gas flow rate was 14.4L / min.

[0094] (3) The glass fiber wrapped in pyrolytic carbon was oxidized in an oxidizing atmosphere at a temperature of 415°C for 1.6 hours, and the fiber was recovered. The purity of the recovered fiber was 95.3%, and the fiber strength retention rate was 93.8%.

[0095] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. The pyrolysis carbonization tail gas is cooled by heat exchange with room temperature air. The cooled pyrolysis carbonization tail gas (cooled down to 180°C) is used as the oxidizing atmosphere in step (3) in part, and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0096] (5) The oxidized tail gas after heat exchange in step (4) (temperature 224℃) is subjected to SCR denitrification treatment, with an ammonia-nitrogen molar ratio of 0.86 and a denitrification efficiency of 95.7%.

[0097] (6) The denitrification tail gas from step (5) was decarbonized using ammonia at room temperature, achieving a decarbonization rate of 95.6%. Ammonia water was used as the decarbonization absorbent in the ammonia decarbonization process, with a liquid-to-gas ratio of 2.3 L / m³. 3 After decarbonization, the exhaust gas is clean gas and is directly discharged into the air.

[0098] Example 3

[0099] A method for recycling waste blades from wind turbines includes the following steps:

[0100] (1) Cut the waste blades after removing the metal components into blocks (length × width = 10cm × 10cm);

[0101] (2) The waste leaves cut into blocks were pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 320℃ for 2 hours to obtain glass fibers wrapped in pyrolyzed carbon; the oxygen-containing gas consisted of nitrogen and air, with an oxygen content of 7.1%; the total gas flow rate was 14 L / min.

[0102] (3) The glass fiber wrapped in pyrolytic carbon was oxidized in an oxidizing atmosphere at a temperature of 405℃ for 2 hours, and the fiber was recovered. The purity of the recovered fiber was 93.6%, and the fiber strength retention rate was 94.8%.

[0103] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. The pyrolysis carbonization tail gas is cooled by heat exchange with room temperature air. The cooled pyrolysis carbonization tail gas (cooled down to 170°C) is used as the oxidizing atmosphere in step (3) in part and as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0104] (5) The oxidized tail gas after heat exchange in step (4) (temperature 215℃) is subjected to SCR denitrification treatment, with an ammonia-nitrogen molar ratio of 0.84 and a denitrification efficiency of 95.1%.

[0105] (6) The denitrification tail gas from step (5) was decarbonized using ammonia at room temperature, achieving a decarbonization rate of 95.1%. Ammonia water was used as the decarbonization absorbent in the ammonia decarbonization process, with a liquid-to-gas ratio of 2.2 L / m³. 3 After decarbonization, the exhaust gas is clean gas and is directly discharged into the air.

[0106] Example 4

[0107] A method for recycling waste blades from wind turbines includes the following steps:

[0108] (1) Cut the waste blades after removing the metal components into blocks (length × width = 10cm × 10cm);

[0109] (2) The waste leaves cut into blocks were pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 313℃ for 1.4h to obtain glass fibers wrapped in pyrolyzed carbon; the oxygen-containing gas consisted of nitrogen and air with an oxygen content of 7.8%; the total gas flow rate was 13.1L / min.

[0110] (3) The glass fiber wrapped in pyrolytic carbon was oxidized in an oxidizing atmosphere at a temperature of 416°C for 1.4 hours, and the fiber was recovered. The purity of the recovered fiber was 94.4%, and the fiber strength retention rate was 92.9%.

[0111] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. The pyrolysis carbonization tail gas is cooled by heat exchange with room temperature air. The cooled pyrolysis carbonization tail gas (cooled down to 155°C) is used as the oxidizing atmosphere in step (3) in part and as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0112] (5) The oxidized tail gas (temperature 210℃) after heat exchange in step (4) is subjected to SCR denitrification treatment, with an ammonia-nitrogen molar ratio of 0.81 and a denitrification efficiency of 94.7%.

[0113] (6) The denitrification tail gas from step (5) was decarbonized using ammonia at room temperature, achieving a decarbonization rate of 94.8%. Ammonia water was used as the decarbonization absorbent in the ammonia decarbonization process, with a liquid-to-gas ratio of 2 L / m³. 3After decarbonization, the exhaust gas is clean gas and is directly discharged into the air.

[0114] Example 5

[0115] A method for recycling waste blades from wind turbines includes the following steps:

[0116] (1) Cut the waste blades after removing the metal components into blocks (length × width = 10cm × 10cm);

[0117] (2) The waste leaves cut into blocks were pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 317℃ for 1.2h to obtain glass fibers wrapped in pyrolyzed carbon; the oxygen-containing gas consisted of nitrogen and air with an oxygen content of 8%; the total gas flow rate was 14.5L / min.

[0118] (3) The glass fiber wrapped in pyrolytic carbon was oxidized in an oxidizing atmosphere at a temperature of 418°C for 1.2 hours. The fiber was then recovered. The purity of the recovered fiber was 94.9%, and the fiber strength retention rate was 92.7%.

[0119] (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. The pyrolysis carbonization tail gas is cooled by heat exchange with room temperature air. The cooled pyrolysis carbonization tail gas (cooled down to 190°C) is used as the oxidizing atmosphere in step (3) in part, and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3).

[0120] (5) The oxidized tail gas after heat exchange in step (4) (temperature 234℃) is subjected to SCR denitrification treatment, with an ammonia-nitrogen molar ratio of 0.89 and a denitrification efficiency of 98.4%.

[0121] (6) The denitrification tail gas from step (5) was decarbonized using ammonia at room temperature, achieving a decarbonization rate of 99.1%. Ammonia water was used as the decarbonization absorbent in the ammonia decarbonization process, with a liquid-to-gas ratio of 3.9 L / m³. 3 After decarbonization, the exhaust gas is clean gas and is directly discharged into the air.

[0122] As can be seen from Examples 1 to 5, the present invention divides the traditional pyrolysis process into two units, carbonization and oxidation, by controlling the pyrolysis conditions, thereby minimizing the reaction temperature of the recycling process, thus reducing the energy consumption of leaf recycling and achieving high quality recycled fibers (recycled fiber purity of over 93% and fiber strength retention rate of over 92%).

[0123] Furthermore, this invention recovers ammonium carbonate through processes such as cooling and recovering tar from pyrolysis carbonization tail gas, low-temperature SCR denitrification (denitrification efficiency of over 94%), and ammonia decarbonization (denitrification rate of over 94%). Tar can be used as fuel, and ammonium carbonate can be used as fertilizer. Moreover, the exhaust gas is fully purified. The recovery system and method of this invention are clean and environmentally friendly, and fully realize resource utilization, with broad application prospects.

[0124] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0125] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0126] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0127] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for recycling a waste blade of a wind power generator, characterized by, Includes the following steps: (1) Cut the waste blades after removing the metal components into blocks; (2) The waste leaves cut into blocks are pyrolyzed and carbonized in an oxygen-containing atmosphere at a temperature of 300℃~320℃ for 1h~2h to obtain glass fibers wrapped in pyrolyzed carbon. (3) The glass fiber wrapped in pyrolytic carbon is oxidized in an oxidizing atmosphere at a temperature of 400℃~420℃ for 1h~2h, and the glass fiber is recovered. (4) The pyrolysis carbonization tail gas in step (2) is cooled and the tar components are recovered. Part of the cooled pyrolysis carbonization tail gas is directly used as the oxidizing atmosphere in step (3), and the other part is used as the oxidizing atmosphere in step (3) after heat exchange with the oxidizing tail gas generated in step (3). (5) The oxidized tail gas after heat exchange in step (4) is subjected to SCR denitrification treatment; (6) The denitrification tail gas from step (5) is decarbonized by ammonia at room temperature to recover ammonium carbonate. The tail gas after decarbonization is clean gas and is directly discharged into the air.

2. A method of recovering waste blades of a wind power generator according to claim 1, characterized in that, The dimensions of the waste leaves cut into blocks are: length ≤ 10cm, width ≤ 10cm.

3. A method of recovering waste blades of a wind power generator according to claim 1, characterized in that, The oxygen-containing atmosphere in step (2) consists of nitrogen and air, with an oxygen content of 5% to 8%.

4. A method of recovering waste blades of a wind power generator according to claim 1, characterized in that, The pyrolysis carbonization tail gas is cooled to 150~200℃.

5. A method of recovering waste blades of a wind power generator according to claim 4, characterized in that, The cooling of the pyrolysis carbonization exhaust gas is carried out in a cold trap, which includes a hollow cavity and a jacket fitted outside the hollow cavity. The pyrolysis carbonization exhaust gas enters the bottom of the hollow cavity through an inlet pipe and is discharged through an outlet pipe located at the top inside the hollow cavity. Coolant air flows inside the jacket, and the coolant air is supplied by a fan. The temperature of the pyrolysis carbonization exhaust gas at the outlet of the cold trap is adjusted by controlling the flow ratio of the coolant air to the pyrolysis carbonization exhaust gas.

6. The method for recycling waste blades of a wind turbine according to claim 1, characterized in that, The outlet temperature of the oxidized tail gas after heat exchange is 205~235℃.

7. The method for recycling waste blades of a wind turbine according to claim 1, characterized in that, The ammonia-to-nitrogen molar ratio in the SCR denitrification treatment is 0.8~1.0; Furthermore, the catalyst for the SCR denitrification treatment is RuO2-MnO2-CeO2 / TiO2; the active components and their mass percentages are: ruthenium oxide: 1%~5%; manganese oxide: 15%~20%; cerium oxide: 10%~20%; and the support is anatase nano-titanium dioxide.

8. A method for recycling waste blades of a wind turbine according to claim 1, characterized in that, The ammonia decarbonization adopts ammonia water as a decarbonization absorbent, and the liquid-gas ratio is 2L / m 3 4L / m 3 .

9. A wind turbine waste blade recycling system, characterized in that, include: A pyrolysis carbonization furnace, used for pyrolysis carbonization of waste leaves cut into blocks in an oxygen-containing atmosphere; A cold trap, used for cooling the pyrolysis and carbonization tail gas of the pyrolysis and carbonization furnace; An oxidation furnace, wherein the oxidation furnace is used for oxidizing the pyrolysis and carbonization products of the pyrolysis and carbonization furnace; A heat exchanger is used for heat exchange between the pyrolysis carbonization tail gas, which has been partially cooled by the cold trap, and the oxidation tail gas of the oxidation furnace. SCR reactor, the SCR reactor is used for denitrification treatment of oxidized tail gas after heat exchange in a heat exchanger; A decarbonization absorption tower is used for ammonia-based decarbonization of the denitrification tail gas after denitrification treatment by an SCR reactor. The cold trap includes a hollow cavity and a jacket fitted outside the hollow cavity. Coolant air flows through the jacket. The hollow cavity is provided with a removable sealing cover, which has an inlet pipe and an outlet pipe. One end of the inlet pipe is connected to the tail gas outlet of the pyrolysis carbonization furnace through a pipeline, and the other end extends to the bottom of the hollow cavity. One end of the outlet pipe is located at the upper part of the hollow cavity, and the other end extends out of the sealing cover and splits into a first branch and a second branch. The first branch is directly connected to the gas inlet of the oxidation furnace, and the second branch is connected to a heat exchanger. After heat exchange in the heat exchanger, it is then connected to the gas inlet of the oxidation furnace.

Images