Device and method for thermally converting and recycling glass fiber of waste wind turbine blades

Abstract

The present invention discloses a device and method for thermally converting and recycling glass fibers from waste wind turbine blades, which relates to the technical field of organic solid waste pyrolysis. It solves the technical problems of non - continuous feeding, high energy consumption and product application degradation in existing thermal recovery solutions. The key points of its technical solution are that the pyrolysis unit uses a feed hopper and a screw auger to achieve the thermal decomposition of waste wind turbine blades under continuous feeding, generating pyrolysis oil - gas and pyrolysis solids; the residual carbon oxidation unit further completely oxidizes the residual carbon in the pyrolysis solids to obtain inorganic solids, and collects and separates them through a pneumatic separator to recover clean glass fibers; the oil - collecting and gas - washing unit and the inorganic solid collection unit recover the waste heat of the products to reduce the energy consumption of the device, thereby realizing the complete separation of the resin matrix and glass fibers of waste wind turbine blades and recovering glass fibers, reducing the energy consumption of waste wind turbine blade thermal recovery, reducing secondary pollution and improving the product quality.

Description

Technical Field

[0001] The present application relates to the technical field of pyrolysis of organic solid waste, and particularly relates to a device and method for thermally converting and recycling fiberglass from waste wind turbine blades. Background Art

[0002] After more than a decade of rapid development, clean and renewable wind power generation technology has become one of the most mature power generation technologies in China. The installation of a 1 MW wind turbine requires approximately 9.6 tons of wind turbine blade materials, and the lifespan of wind turbine blades is about 20 - 25 years. This means that a large number of waste wind turbine blades will be generated in China in the next 5 - 10 years, posing dual challenges to environmental protection and resource utilization.

[0003] Waste wind turbine blades are mainly thermosetting composites composed of organic resin matrix and inorganic fiberglass. There are significant differences in the properties of the resin matrix and fiberglass. Therefore, existing composite material treatment and recycling solutions such as mechanical crushing, landfilling, and incineration all have problems such as complex processes, resource waste, and secondary pollution. The pyrolysis method converts the resin matrix into pyrolysis gas, pyrolysis oil, and residual carbon, separating them from the fiberglass for separate utilization according to their characteristics. This method also has the advantages of complete engineering facilities, mature technology, and industrialization, and is an effective way for the recycling and resource utilization of waste wind turbine blades. However, further exploration and improvement are still needed in aspects such as process optimization, energy consumption reduction, pollution reduction, and product resource utilization. Summary of the Invention

[0004] The present application provides a device and method for thermally converting and recycling fiberglass from waste wind turbine blades, and its technical objective is to solve the technical problems of non - continuous feeding, high energy consumption, and product application degradation in existing thermal recovery solutions.

[0005] The above - mentioned technical objective of the present application is achieved through the following technical solutions:

[0006] A device for thermally converting and recycling fiberglass from waste wind turbine blades includes a pyrolysis unit, a residual carbon oxidation unit, an oil collection and gas washing unit, an inorganic solid collection unit, and a wind power separator;

[0007] The pyrolysis unit includes a feed hopper, an inert gas inlet, a pyrolysis oil - gas outlet, and a pyrolysis solid outlet;

[0008] The residual carbon oxidation unit includes an oxidation gas inlet, a flue gas outlet, an inorganic solid outlet, and a pyrolysis solid inlet;

[0009] The oil collection and gas washing unit includes an oil collection cold trap, a heat exchanger, and a gas washing chamber, and both the oil collection cold trap and the heat exchanger are connected to the gas washing chamber;

[0010] The inorganic solid collection unit includes an air inlet, an air outlet, an inorganic solid inlet, a discharge port, and a storage tank;

[0011] The inert gas inlet is connected to the heat exchanger, the pyrolysis oil and gas outlet is connected to the oil collection cold trap, and the pyrolysis solid outlet is connected to the pyrolysis solid inlet of the carbon residue oxidation unit;

[0012] The oxidation gas inlet is connected to the gas outlet of the inorganic solid collection unit, the flue gas outlet is connected to the heat exchanger, the inorganic solid outlet is connected to the inorganic solid inlet of the inorganic solid collection unit, and the discharge outlet is connected to the storage tank;

[0013] The inorganic solid collected in the storage tank is fed into the air classifier.

[0014] Further, the oil collection cold trap includes a pyrolysis oil and gas inlet and a pyrolysis gas outlet. The pyrolysis oil and gas inlet is connected to the pyrolysis oil and gas outlet of the pyrolysis unit, the pyrolysis gas outlet is connected to the scrubbing chamber, and the pyrolysis oil is condensed in the cold trap;

[0015] The heat exchanger includes a first inlet, a flue gas inlet, an inert gas outlet and a first outlet. The first inlet is used for introducing inert gas. The flue gas inlet is connected to the flue gas outlet of the carbon residue oxidation unit, the inert gas outlet is connected to the inert gas inlet of the pyrolysis unit, and the first outlet is connected to the scrubbing chamber.

[0016] Further, a screw auger that rotates clockwise continuously driven by a motor is provided in each of the pyrolysis unit, the carbon residue oxidation unit and the inorganic solid collection unit.

[0017] Further, the pyrolysis solid outlet is connected to the pyrolysis solid inlet of the carbon residue oxidation unit through a flange; the inorganic solid outlet is connected to the inorganic solid inlet of the inorganic solid collection unit through a flange; an electric valve is provided at the bottom of the feed hopper, and the electric valve remains open during the pyrolysis process of the waste fan blade to continuously feed the pyrolysis unit.

[0018] Further, the oil collection cold trap includes at least two cold traps containing organic solvents connected in series; the scrubbing chamber includes at least three deoiling, denitrification and de-bromination units connected in series.

[0019] Further, the inorganic solid collection unit includes an inner cylinder and an outer cylinder sleeved outside the inner cylinder. The inorganic solid inlet and the discharge outlet are both provided on the inner cylinder, and the air inlet and the gas outlet are both provided on the outer cylinder;

[0020] A method for thermally converting and recycling fiberglass of waste fan blades includes:

[0021] Before pyrolysis, the waste fan blade is cut into fan blade particles, the surface impurities of the fan blade particles are washed away with deionized water, and after air drying, they are fed into the feed hopper;

[0022] When the temperature of the pyrolysis unit rises to the target temperature, the electric valve is opened to continuously feed materials into the pyrolysis unit for rapid pyrolysis, obtaining pyrolysis solids and pyrolysis oil and gas; the pyrolysis oil and gas are sent to the oil collection cold trap, the pyrolysis oil is condensed in the oil collection cold trap, and the pyrolysis gas escapes to the scrubbing chamber and is discharged after reaching the standard;

[0023] The pyrolysis solids are sent to the carbon residue oxidation unit by a screw auger driven by a motor and undergo an oxidation reaction in an oxidizing atmosphere. The carbon residue in the pyrolysis solids is completely oxidized to generate flue gas and separated from the inorganic solids; the flue gas is sent to the scrubbing chamber for treatment and discharged after reaching the standard after heat exchange with inert gas through a heat exchanger;

[0024] The inorganic solids are sent to the inorganic solid collection unit by a screw auger driven by a motor, heat-exchanged with the oxidizing gas, and collected by a storage tank. After pyrolysis, they are sent to the air classifier for sorting to recover clean recycled glass fibers; among them, the inorganic solids include glass fibers and inorganic ash.

[0025] Further, the fan blade particles are square particles with a side length of 0.5 - 1.5 cm, the temperature of the blast drying is 25 - 50 °C, and the drying time is 5 - 6 h.

[0026] Further, the atmosphere of the rapid pyrolysis is an inert atmosphere, the target temperature is 400 - 600 °C, and the residence time is 15 - 30 min.

[0027] Further, the target temperature of the oxidation reaction is 300 - 500 °C, and the residence time is 60 - 120 min.

[0028] The beneficial effects of this application are as follows:

[0029] (1) This application uses a screw auger to push materials and regulate the reaction parameters (atmosphere, temperature, time) of the rapid pyrolysis oxidation process, realizing the complete separation of the resin matrix and glass fibers of waste fan blades under continuous feeding conditions, and recovering clean glass fibers. The set reaction parameters can be used as basic data for optimizing the waste fan blade heat recovery process in combination with existing industrial facilities.

[0030] (2) This application completely decomposes the resin matrix of the fan blade through low-temperature pyrolysis and oxidation. The rapid pyrolysis temperature is 400 - 600 °C, and the oxidation reaction temperature is 300 °C - 500 °C, reducing the energy consumption compared with traditional high-temperature pyrolysis (≥850 °C), reducing the damage to glass fibers at high temperature, and enhancing the value of the recovered glass fibers.

[0031] (3) This application uses inorganic solids to preheat the oxidizing gas and the flue gas to preheat the inert gas, realizing waste heat recovery to reduce the energy consumption of the device; a scrubbing chamber is set to treat the gas to reach the standard before discharging to reduce secondary pollution.

[0032] (4)The device of the present application is small in size and simple in structure, and can be used as a mobile device to address the difficulty of transporting large-sized waste wind turbine blades, thereby reducing the raw material transportation cost. Description of the Drawings

[0033] Figure 1 is a schematic diagram of the device described in the present application;

[0034] Figure 2 is a schematic diagram of the pyrolysis solid at 400 °C in the rapid pyrolysis of the embodiment of the present application;

[0035] Figure 3 is a schematic diagram of the inorganic solid at 400 °C in the oxidation reaction of the embodiment of the present application;

[0036] In the figure: 1 - pyrolysis unit; 2 - residual carbon oxidation unit; 3 - oil collection and gas washing unit; 4 - inorganic solid collection unit; 5 - air classifier; 6 - feed hopper; 7 - inert gas inlet; 8 - pyrolysis oil and gas outlet; 9 - pyrolysis solid outlet; 10 - oxidation gas inlet; 11 - flue gas outlet; 12 - inorganic solid outlet; 13 - oil collection cold trap; 14 - heat exchanger; 15 - gas washing chamber; 16 - motor; 17 - electric valve; 18 - storage tank; 19 - air inlet; 20 - air outlet; 21 - pyrolysis solid inlet; 22 - inorganic solid inlet; 23 - discharge port; 24 - pyrolysis oil and gas inlet; 25 - flue gas inlet; 26 - inert gas outlet; 27 - inner cylinder; 28 - outer cylinder; 29 - screw auger. Detailed Embodiments

[0037] The technical solution of the present application will be described in detail below with reference to the accompanying drawings.

[0038] As Figure 1 shown, the device for thermally converting and recycling fiberglass from waste wind turbine blades described in the present application includes a pyrolysis unit 1, a residual carbon oxidation unit 2, an oil collection and gas washing unit 3, an inorganic solid collection unit 4, and an air classifier 5.

[0039] The pyrolysis unit 1 pyrolyzes waste wind turbine blades in an inert atmosphere. Its structure includes a feed hopper 6, an inert gas inlet 7, a pyrolysis oil and gas outlet 8, and a pyrolysis solid outlet 9. Among them, the pyrolysis solid outlet 9 is connected to the pyrolysis solid inlet 21 of the residual carbon oxidation unit 2 through a flange, the pyrolysis oil and gas outlet 8 is connected to the pyrolysis oil and gas inlet 24 of the oil collection cold trap 13, and the inert gas inlet 7 is connected to the inert gas outlet 26 of the heat exchanger 14. Among them, an electric valve 17 is provided at the bottom of the feed hopper 6, and the electric valve 17 remains open during the pyrolysis process of the waste wind turbine blades to continuously feed the pyrolysis unit 1. The inert atmosphere includes, but is not limited to, one or a combination of nitrogen, argon, and helium. Nitrogen is selected in this embodiment.

[0040] The carbon residue oxidation unit 2 completely oxidizes the carbon residue in the pyrolysis solid under an oxidizing atmosphere to generate flue gas to obtain clean glass fiber, and its structure includes an oxidizing gas inlet 10, a flue gas outlet 11, an inorganic solid outlet 12 and a pyrolysis solid inlet 21. The oxidizing atmosphere includes but is not limited to air or oxygen, and air is selected in this embodiment. The oxidizing gas inlet 10 is connected to the gas outlet 20 of the inorganic solid collection unit 4; the flue gas outlet 11 is connected to the flue gas inlet 25 of the heat exchanger 14; and the inorganic solid outlet 12 is connected to the inorganic solid inlet 22 of the inorganic solid collection unit 4.

[0041] The oil collecting and gas washing unit 3 is used to collect pyrolysis oil, recover waste heat and perform gas washing to achieve emission standards. Its structure includes an oil collecting condenser 13 connected to the pyrolysis oil and gas outlet 8, a heat exchanger 14 connected to the flue gas outlet 11, and a gas washing chamber 15.

[0042] The oil collecting cooling hydrazine 13 comprises a pyrolysis oil and gas inlet 24 and a pyrolysis gas outlet. The pyrolysis oil and gas inlet 24 is connected to the pyrolysis oil and gas outlet 8 of the pyrolysis unit 1. The pyrolysis gas outlet is connected to the gas washing chamber 15. The pyrolysis oil is condensed in the cooling hydrazine.

[0043] The heat exchanger 14 includes a first inlet, a flue gas inlet 25, an inert gas outlet 26 and a first outlet. The first inlet is used to introduce inert gas. The flue gas inlet 25 is connected to the flue gas outlet 11 of the residual carbon oxidation unit 2. The inert gas outlet 26 is connected to the inert gas inlet 7 of the pyrolysis unit 1. The first outlet is connected to the scrubbing chamber 15.

[0044] Among them, the oil collecting condenser 13 uses cooling water to condense the pyrolysis oil and absorbs the pyrolysis oil with an organic solvent, and its structure includes at least two condensers filled with organic solvents in series; the heat exchanger 14 uses flue gas to preheat the inert gas, and the preheated inert gas is sent to the pyrolysis unit 1 to maintain a stable inert atmosphere; the scrubbing chamber 15 is used to treat the pyrolysis gas and flue gas to meet the emission standards, and its structure includes at least three de-oiling, denitrification and debromination units in series. The organic solvent includes but is not limited to anhydrous ethanol or methanol, and anhydrous ethanol is selected in this embodiment; the de-oiling agent includes but is not limited to anhydrous ethanol, the denitrification agent includes but is not limited to ammonia water or urea solution, and the debromination agent includes but is not limited to sodium hydroxide solution. In this embodiment, anhydrous ethanol, 5wt.% ammonia water, and 5wt.% sodium hydroxide solution are selected in sequence.

[0045] The inorganic solid collection unit 4 is used to collect inorganic solids and preheat the oxidizing gas, and send the preheated oxidizing gas into the residual carbon oxidation unit 2 to maintain a stable oxidizing atmosphere. The inorganic solid collection unit 4 includes an inner cylinder 27 and an outer cylinder 28 sleeved on the outside of the inner cylinder 27. The inorganic solid inlet 22 and the discharge port 23 are both arranged on the inner cylinder 27; the air inlet 19 and the air outlet 20 are both arranged on the outer cylinder 28. The inner cylinder 27 flows through the inorganic solids remaining after pyrolysis and oxidation of the waste fan blades. A flow channel for the oxidizing gas is formed between the inner cylinder 27 and the outer cylinder 28. The oxidizing gas is introduced from the air inlet 19, and after the inorganic solids are preheated, it is sent out from the air outlet 20 to the oxidizing gas inlet 10. The inorganic solids and the oxidizing gas flow in countercurrent; the inorganic solids are collected by the storage tank 18, and after the pyrolysis is completed, they are sent to the wind classifier 5 for sorting to obtain clean regenerated glass fibers.

[0046] The inorganic solid collecting unit 4 includes an air inlet 19 , an air outlet 20 , an inorganic solid inlet 22 and an inorganic solid outlet 12 ; the discharge port 23 is connected to the inlet of the storage tank 18 , and the outlet of the storage tank 18 is connected to the inlet of the wind classifier 5 .

[0047] The pyrolysis unit 1 , the residual carbon oxidation unit 2 and the inorganic solid collection unit 4 are all provided with a spiral auger 29 which is driven by a motor 16 and rotates continuously clockwise. The residence time of the material in the unit is controlled by adjusting the rotation speed of the motor 16 .

[0048] A method for thermal conversion and recovery of glass fiber from waste fan blades in the present embodiment includes the following steps: before pyrolysis, the waste fan blades are cut into square fan blade particles with a side length of 0.5 to 1.5 cm, impurities on the surface of the particles are washed with deionized water and dried with air at a drying temperature of 30°C and a drying time of 6 hours, and then the fan blade particles are fed into the feed hopper 6. When the temperature of the pyrolysis unit 1 rises to the target temperature, the electric valve 17 is opened, and the material is continuously fed into the pyrolysis unit 1 for rapid pyrolysis to obtain pyrolysis solids, pyrolysis oil, and pyrolysis gas. The pyrolysis oil and pyrolysis are fed into the oil collecting condenser 13, where the pyrolysis oil is condensed, and the pyrolysis gas escapes into the scrubbing chamber 15 and is scrubbed with anhydrous ethanol, 5wt.% ammonia water, and 5wt.% sodium hydroxide solution in turn, and then discharged after meeting the standards. In the present embodiment, the target temperature for rapid pyrolysis is 400°C, and the residence time is 30 min, and the following is obtained: Figure 2 Pyrolyzed solid shown.

[0049] The pyrolysis solid is sent to the residual carbon oxidation unit 2 by the spiral auger 29 driven by the motor 16 to undergo oxidation reaction in the air atmosphere. The residual carbon in the pyrolysis solid is completely oxidized to generate flue gas and separated from the inorganic solid; the flue gas is sent to the scrubbing chamber 15 for treatment and discharge after meeting the standards after heat exchange with the inert gas in the heat exchanger 14. In this embodiment, the oxidation target temperature is 400°C, the residence time is 30 min, and the following is obtained: Figure 3 Inorganic solids shown.

[0050] The inorganic solids are sent to the inorganic solid collection unit 4 by the spiral auger 29 driven by the motor 16, and then collected by the storage tank 18 after heat exchange with the oxidizing gas. The collected inorganic solids mainly include glass fibers and inorganic ash. After the pyrolysis is completed, the inorganic solids are sent to the wind classifier 5 for sorting and recovery of clean recycled glass fibers.

[0051] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above specific embodiments. The above specific embodiments and the description in the specification are only for further illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of the present invention to be protected is defined by the claims and their equivalents.

Claims

1. An apparatus for thermally converting and recycling fiberglass from waste wind turbine blades, characterized in that, It includes a pyrolysis unit (1), a residual carbon oxidation unit (2), an oil collection and gas washing unit (3), an inorganic solid collection unit (4), and a wind separator (5); The pyrolysis unit (1) includes a feed hopper (6), an inert gas inlet (7), a pyrolysis oil and gas outlet (8), and a pyrolysis solid outlet (9); The residual carbon oxidation unit (2) includes an oxidation gas inlet (10), a flue gas outlet (11), an inorganic solid outlet (12), and a pyrolysis solid inlet (21); The oil collection and gas washing unit (3) includes an oil collection cold trap (13), a heat exchanger (14), and a gas washing chamber (15). The oil collection cold trap (13) and the heat exchanger (14) are both connected to the gas washing chamber (15); The inorganic solid collection unit (4) includes an air inlet (19), an air outlet (20), an inorganic solid inlet (22), a discharge port (23), and a storage tank (18); The inert gas inlet (7) is connected to the heat exchanger (14), the pyrolysis oil and gas outlet (8) is connected to the oil collection cold trap (13), and the pyrolysis solid outlet (9) is connected to the pyrolysis solid inlet (21) of the residual carbon oxidation unit (2); The oxidation gas inlet (10) is connected to the air outlet (20) of the inorganic solid collection unit (4), the flue gas outlet (11) is connected to the heat exchanger (14), the inorganic solid outlet (12) is connected to the inorganic solid inlet (22) of the inorganic solid collection unit (4), and the discharge port (23) is connected to the storage tank (18); The inorganic solid collected in the storage tank (18) is sent to the wind separator (5); In the pyrolysis unit (1), the residual carbon oxidation unit (2), and the inorganic solid collection unit (4), there is a spiral auger (29) that is driven by a motor (16) and rotates clockwise continuously; The inorganic solid collection unit (4) includes an inner cylinder (27) and an outer cylinder (28) sleeved outside the inner cylinder (27). The inorganic solid inlet (22) and the discharge port (23) are both arranged on the inner cylinder (27), and the air inlet (19) and the air outlet (20) are both arranged on the outer cylinder (28).

2. The device according to claim 1, characterized in that, The oil collection cold trap (13) includes a pyrolysis oil and gas inlet (24) and a pyrolysis gas outlet. The pyrolysis oil and gas inlet (24) is connected to the pyrolysis oil and gas outlet (8) of the pyrolysis unit (1), the pyrolysis gas outlet is connected to the gas washing chamber (15), and the pyrolysis oil condenses in the cold trap; The heat exchanger (14) includes a first inlet, a flue gas inlet (25), an inert gas outlet (26), and a first outlet. The first inlet is used to introduce inert gas. The flue gas inlet (25) is connected to the flue gas outlet (11) of the residual carbon oxidation unit (2), the inert gas outlet (26) is connected to the inert gas inlet (7) of the pyrolysis unit (1), and the first outlet is connected to the gas washing chamber (15).

3. The device according to claim 1, characterized in that, The pyrolysis solid outlet (9) is flange-connected to the pyrolysis solid inlet (21) of the char oxidation unit (2); the inorganic solid outlet (12) is flange-connected to the inorganic solid inlet (22) of the inorganic solid collection unit (4); an electric valve (17) is provided at the bottom of the feed hopper (6), and the electric valve (17) remains open during the pyrolysis process of the waste fan blade to continuously feed materials into the pyrolysis unit (1).

4. The device according to claim 1, characterized in that, The oil collection cold trap (13) includes at least two cold traps filled with organic solvents connected in series; the gas washing chamber (15) includes at least three deoiling, denitrification, and de-bromination units connected in series.

5. A method for thermally converting and recycling fiberglass from waste wind turbine blades, which is realized by the device for thermally converting and recycling fiberglass from waste wind turbine blades according to any one of claims 1-4, characterized in that, Including: Before pyrolysis, the waste fan blade is cut into fan blade particles, the surface impurities of the fan blade particles are washed away with deionized water, and after air drying, they are sent into the feed hopper (6); When the temperature of the pyrolysis unit (1) rises to the target temperature, the electric valve (17) is opened to continuously feed materials into the pyrolysis unit (1) for rapid pyrolysis to obtain pyrolysis solids and pyrolysis oil and gas; the pyrolysis oil and gas are sent into the oil collection cold trap (13), the pyrolysis oil is condensed in the oil collection cold trap (13), and the pyrolysis gas escapes to the gas washing chamber (15) and is discharged after being treated to meet the standards; The pyrolysis solids are sent into the char oxidation unit (2) by a screw auger (29) driven by a motor (16) and undergo an oxidation reaction in an oxidizing atmosphere. The char in the pyrolysis solids is completely oxidized to generate flue gas and separated from the inorganic solids; the flue gas is sent into the gas washing chamber (15) after heat exchange with inert gas in the heat exchanger (14) and is discharged after being treated to meet the standards; The inorganic solids are sent into the inorganic solid collection unit (4) by a screw auger driven by a motor (16), heat-exchanged with the oxidation gas, and collected by the storage tank (18), and after the pyrolysis is completed, they are sent into the air classifier (5) for separation to recover clean recycled glass fiber; among them, the inorganic solids include glass fiber and inorganic ash.

6. The method according to claim 5, wherein The fan blade particles are square particles with a side length of 0.5 - 1.5 cm, the temperature of the air drying is 25 - 50 °C, and the drying time is 5 - 6 h.

7. The method according to claim 5, wherein The atmosphere of the rapid pyrolysis is an inert atmosphere, the target temperature is 400 - 600 °C, and the residence time is 15 - 30 min.

8. The method according to claim 5, characterized in that, The target temperature of the oxidation reaction is 300 - 500 °C, and the residence time is 60 - 120 min.

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