A method for resourceful disposal of waste wind turbine blades

Abstract

The application relates to a method for resourceful treatment of waste wind turbine blades, and relates to the technical field of solid waste resourceful treatment. In order to solve the problem of low resource utilization rate of wind turbine blades, the method comprises blade crushing, screening and washing. The wind turbine blade fragments are put into a hydrothermal liquefaction reactor, water is added at a mass ratio of the fragments to the water of 1:5-1:20, the temperature in the hydrothermal liquefaction reactor is gradually increased to a subcritical temperature, the pressure is increased to the saturated steam pressure at the temperature, the temperature and pressure state is maintained for 20-40 minutes, and the mixture is stirred during the period; the temperature of the mixture in the hydrothermal liquefaction reactor is slowly increased to a supercritical temperature, the pressure is increased to the pressure value in the supercritical state, the temperature and pressure state is maintained for 30-60 minutes; the product is cooled and separated and recovered, the temperature of the mixture in the hydrothermal liquefaction reactor is gradually reduced to a discharge temperature, and the gaseous phase, the liquid phase and the solid phase products after cooling are collected respectively; and fiber reinforced concrete is prepared. The application has the effects of harmless treatment and resource utilization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid waste resource disposal, in particular to a method for resource disposal of waste wind turbine blades. BACKGROUND

[0002] Wind power generation is an important part of new energy power generation. As of the end of 2021, China's wind power installed capacity reached 30015 million kilowatts, and wind power accounted for about 13% of the total installed capacity of the country's power supply and about 7.5% of the total electricity consumption. Generally, the service life of a wind turbine is 20-25 years, and as wind power continues to popularize, the amount of waste wind turbines will also show an explosive growth.

[0003] The wind turbine blade is an important component of the wind turbine generator set, and the main body is composed of composite materials, including thermosetting / thermoplastic resin, fiber material (including glass fiber, carbon fiber, etc.), filling material (light wood, foam, etc.), and some adhesive materials. In addition to the high recycling value of fiber materials, other materials also have certain resource recycling value. However, due to the special structure and material of the wind turbine blade, it is difficult to separate and individually recycle each material. Traditionally, the disposal of waste wind turbine blades, including stacking, landfilling, incineration, etc., does not meet the needs of environmental protection and resource utilization, and is destined to be eliminated.

[0004] In recent years, resource utilization methods have been proposed, mainly including pyrolysis, chemical degradation, cement kiln co-processing, etc. Among them, pyrolysis can promote the thermal cracking of organic components by heating to separate glass fibers from the blade, but because the pyrolysis requires a high temperature, it is easy to cause the melting and adhesion of glass fibers, and the oxidation of carbon fibers, making it difficult to guarantee the quality and quantity of recycled fiber materials; chemical degradation uses organic solvents to dissolve resins to precipitate fiber materials, which is good for preserving fibers, but the use of organic solvents is large, and the separation process is complex, and may cause secondary pollution; In recent years, a method of co-processing waste wind turbine blades in a cement kiln has emerged, which can replace fossil fuels with combustible components as fuel and non-combustible components rich in silicon as cement raw materials, achieving low-cost resource utilization of waste wind turbine blades.

[0005] The method in the prior art destroys the most valuable fiber material in the wind turbine blade, and the overall process has low economic value, so it needs to be improved. SUMMARY

[0006] In order to solve the problem of low resource utilization rate of wind turbine blades, the present application provides a method for resource disposal of waste wind turbine blades.

[0007] The method for resourceful disposal of waste wind turbine blades provided by the application adopts the following technical scheme:

[0008] A method for resourceful disposal of waste wind turbine blades, characterized in that it comprises the following steps:

[0009] S1, crushing and cleaning, crushing the wind turbine blades into pieces, screening and cleaning for use;

[0010] S2, subcritical hydrothermal liquefaction, putting the wind turbine blade pieces into a hydrothermal liquefaction reactor, adding water in a mass ratio of 1:5-1:20 of the pieces to water, sealing the hydrothermal liquefaction reactor, gradually increasing the temperature in the hydrothermal liquefaction reactor to a subcritical temperature T1, and the pressure to the saturated vapor pressure P1 at this temperature, maintaining this temperature and pressure state for 20-40 min, and stirring the mixture in the hydrothermal liquefaction reactor during this period to promote sufficient reaction;

[0011] S3, supercritical hydrothermal liquefaction, slowly increasing the temperature of the mixture in the hydrothermal liquefaction reactor to a supercritical temperature T2, increasing the pressure in the hydrothermal liquefaction reactor to a pressure value P2 in the supercritical state, maintaining this temperature and pressure state for 30-60 min, and stirring the mixture in the hydrothermal liquefaction reactor during this period to promote sufficient reaction;

[0012] S4, cooling and separating and recovering the products, gradually reducing the temperature of the mixture in the hydrothermal liquefaction reactor to a discharge temperature T3, opening the gas outlet of the hydrothermal liquefaction reactor, and collecting the cooled gas phase, liquid phase and solid phase products respectively, the obtained gas phase product is rich in combustible components and can be used as fuel gas after collection; the liquid phase product is divided into oil phase and water phase, the oil phase product is bio-oil and can be used as liquid fuel or chemical raw material, and the water phase product can be recycled into the hydrothermal liquefaction reactor;

[0013] S5, preparing fiber reinforced concrete, after washing and drying the obtained solid phase product, screening out fiber products rich in glass fiber, carbon fiber, etc., trimming to make reinforcing fibers for concrete, grinding the remaining solid phase product as fine aggregate for concrete, mixing the reinforcing fibers for concrete into the premixed concrete slurry in a ratio of 1:25-1:100, adding coarse and fine aggregates in proportion, and fully stirring to obtain fiber reinforced concrete with improved tensile strength and toughness.

[0014] By adopting the technical scheme, the breaking operation in step 1 makes the fiber material in the fan blade meet the requirement of the length of the fiber to the concrete, and promotes the fan blade material to better perform the hydrothermal liquefaction reaction; in step 2, the biomass components in the fan blade fragments perform the hydrothermal liquefaction reaction, and since the hydrothermal liquefaction reaction of the biomass has a certain promoting effect on the resin material, part of the resin material also performs the hydrothermal liquefaction reaction in this stage; in step 3, the resin material performs the hydrothermal liquefaction reaction, and the fiber materials such as glass fiber and carbon fiber do not substantially react under the condition and the performance is not substantially damaged, reducing the influence on the structure and mechanical properties of the fiber; in step 4, the cooling and separation recover the gas phase product rich in combustible components such as low-carbon alkanes, olefins, hydrogen, carbon monoxide and the like, and the oil phase in the liquid phase product is bio-oil which can be used as a fuel for the hydrothermal liquefaction reactor, and the water phase in the liquid phase product can be put into the hydrothermal liquefaction reactor for recycling, so that the process realizes energy self-sufficiency, reduces the energy consumption and emission of the process, and at the same time, no other consumables except water are needed, and the used water can be reused, the material disposal cost is low, and resources are saved; in step 5, the solid phase product is prepared into concrete after screening, and through the above method, various fiber materials including glass fiber and carbon fiber can be extracted from the waste fan blade and effectively reused, and other materials contained in the fan blade can be completely harmless and resourceful, without generating secondary pollutants and secondary waste, and at the same time, all chemical reactions are completed in a unified hydrothermal liquefaction reactor, the equipment investment is small, and the land occupation is small.

[0015] Further, the diameter of the fan blade fragments after breaking in step S1 is 1.0-10.0 cm.

[0016] By adopting the technical scheme, the size of the fan blade to be broken is further limited, so that the fiber material in the fan blade meets the requirement of the length of the fiber to the concrete, and the hydrothermal liquefaction reaction of the fan blade material is better.

[0017] Further, in step 2, the subcritical temperature T1 is 325±25℃, the corresponding P1 is 8.5-16.5 MPa, and the heating rate is not greater than 10.0℃ / min.

[0018] By adopting the technical scheme, the temperature and pressure, heating time and rate are controlled, so that the hydrothermal liquefaction of the biomass material such as light wood can be realized, and the structure and performance of the glass fiber and carbon fiber material are not damaged. Since the reactants are immersed in water, oxygen is isolated, and the possibility of oxidation of the carbon fiber material by contacting oxygen is avoided.

[0019] Further, the supercritical temperature T2 in step 3 is in the range of 400±25℃, the corresponding P2 is in the range of 25.0±1.0MPa, and the heating rate is not greater than 5.0℃ / min.

[0020] By using the above technical solution, the selection of temperature and pressure, heating time and rate can realize hydrothermal liquefaction of organic materials such as resin, and can also ensure that the structure and performance of glass fiber and carbon fiber materials are not damaged. Since the reactants are immersed in water, oxygen is isolated, and the possibility of carbon fiber material contacting oxygen oxidation is avoided.

[0021] Further, the discharge temperature T3 in step 4 is in the range of 95±5℃.

[0022] Further, the fuel gas and bio-oil collected in step 4 can be used to heat the hydrothermal liquefaction reactor in steps 2 and 3, and does not have to rely on external heat sources.

[0023] By using the above technical solution, recycling can realize energy self-sufficiency, and does not have to rely on external heat sources.

[0024] Further, the low-alkali cement should be preferably used in the concrete slurry in step 5.

[0025] By using the above technical solution, low-alkali cement should be preferably used in the concrete slurry to avoid corrosion of the glass fiber component by alkali.

[0026] Further, the method can also be used for the resource disposal of other solid waste resources rich in glass fiber, carbon fiber and other fiber materials.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. The present application can extract various fiber materials including glass fiber and carbon fiber from waste wind turbine blades and effectively recycle them, and can completely harmlessly and resourcefully utilize other materials contained in the wind turbine blades without producing secondary pollutants and secondary waste;

[0029] 2. The present application has little effect on the structure and mechanical properties of the fiber while recycling the valuable fiber materials such as glass fiber and carbon fiber in the wind turbine blades;

[0030] 3. The fuel gas and bio-oil recovered by the present application can be used as fuel to heat the hydrothermal liquefaction reactor, so that the process realizes energy self-sufficiency, reduces energy consumption and emissions, and does not need other consumables except water, and the used water can be reused, and the material cost of disposal is low;

[0031] 4. In this invention, all chemical reactions for the treatment of wind turbine blades are completed in a unified hydrothermal liquefaction reactor, requiring less equipment investment and a smaller footprint. Attached Figure Description

[0032] Figure 1 This is a flowchart of a method for resource-based disposal of waste wind turbine blades according to an embodiment of this application.

[0033] Explanation of reference numerals in the attached figures: 1. Wind turbine blade; 2. Fragment of wind turbine blade; 3. Water; 4. Liquid phase product; 5. Reclaimed water; 6. Bio-oil; 7. Gas phase product; 8. Solid phase product; 9. Fiber product; 10. Reinforcing fiber for concrete; 11. Residual solid phase product; 12. Fine aggregate; 13. Concrete slurry; 14. Coarse aggregate; 15. Fiber-reinforced concrete. Detailed Implementation

[0034] To illustrate in detail the technical solutions adopted by the present invention to achieve the intended technical objectives, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Furthermore, the technical means or technical features in the embodiments of the present invention can be replaced without creative effort. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0035] like Figure 1 As shown, the present invention provides a method for the resource-based disposal of waste wind turbine blades, characterized by comprising the following steps:

[0036] S1. Crushing and washing: Crush the fan blades 1 into fan blade fragments 2 with a diameter of 1.0-10.0cm, sieve and wash them for later use;

[0037] S2. Subcritical hydrothermal liquefaction: Add fan blade fragments 2 to the hydrothermal liquefaction reactor. Add water 3 at a mass ratio of fan blade fragments 2 to water 3 of 1:5-1:20. Seal the hydrothermal liquefaction reactor and gradually raise the temperature in the hydrothermal liquefaction reactor to the subcritical temperature T1. The subcritical temperature T1 ranges from 325±25℃. Raise the pressure to the saturated vapor pressure P1 at this temperature. The saturated vapor pressure P1 ranges from 8.5-16.5MPa. Maintain this temperature and pressure for 20-40 minutes, and stir the mixture in the hydrothermal liquefaction reactor during this period. The heating rate should not exceed 10.0℃ / min to promote a complete reaction.

[0038] S3, supercritical hydrothermal liquefaction, slowly increase the temperature of the mixture in the hydrothermal liquefaction reactor to a supercritical temperature T2, the supercritical temperature T2 is in the range of 400±25℃, the pressure in the hydrothermal liquefaction reactor is increased to a supercritical state pressure value P2, the supercritical state pressure value P2 is in the range of 25.0±1.0MPa, the temperature and pressure are maintained for 30-60min, and the mixture in the hydrothermal liquefaction reactor is stirred during this period, the heating rate is not greater than 5.0℃ / min, to promote sufficient reaction;

[0039] S4, cooling and separating and recovering the product, gradually reducing the temperature of the mixture in the hydrothermal liquefaction reactor to a discharge temperature T3, the discharge temperature T3 is in the range of 95±5℃, opening the gas outlet of the hydrothermal liquefaction reactor, and collecting the cooled gas phase product 7, liquid phase product 4 and solid phase product 8 respectively, the obtained gas phase product 7 is rich in combustible components and can be used as fuel gas after collection, the gas phase product 7 is rich in combustible components such as low-carbon alkanes, alkenes, hydrogen and carbon monoxide; the liquid phase product 4 is divided into an oil phase and an aqueous phase, wherein the oil phase product is bio-oil 6 and can be used as liquid fuel or chemical raw material, the gas phase product 7 and the oil phase in the liquid phase product 4 can be used as fuel for the hydrothermal liquefaction reactor, and the aqueous phase in the liquid phase product 4 is recycled water 5 which can be put into the hydrothermal liquefaction reactor for recycling;

[0040] S5, preparing fiber reinforced concrete 15, after the obtained solid phase product 8 is washed and dried, the fiber product 9 rich in glass fiber and carbon fiber is sieved out, trimmed to form reinforced fiber 10 for concrete, the remaining solid phase product 11 is ground to be used as fine aggregate 12 for concrete, the reinforced fiber 10 for concrete is mixed into the premixed concrete slurry 13 in a proportion of 1:25-1:100, coarse aggregate 14 and fine aggregate 12 are added in proportion, and after being fully stirred and uniformly mixed, the tensile strength and toughness of the concrete can be improved to obtain fiber reinforced concrete 15.

[0041] The application will be further described below through specific examples.

[0042] Example 1:

[0043] A method for resource disposal of waste wind turbine blades, comprising the following steps:

[0044] S1, crushing the wind turbine blade 1 into wind turbine blade fragments 2 with a diameter of 1.0-10.0cm, sieving and washing for use;

[0045] S2, put the fan blade pieces 2 into the hydrothermal liquefaction reactor, add water 3 according to the mass ratio of 1:15 of the fan blade pieces 2 to water 3, close the hydrothermal liquefaction reactor, gradually increase the temperature in the hydrothermal liquefaction reactor to 325℃ at a heating rate of 8.0℃ / min, the pressure rises to 12.05MPa, keep the temperature and pressure for 30min, and continuously stir the mixture in the hydrothermal liquefaction reactor during this period;

[0046] S3, increase the temperature of the mixture in the hydrothermal liquefaction reactor to 400℃ at a heating rate of 4.0℃ / min, the pressure in the reactor rises to 25.0MPa, keep the temperature and pressure for 45min, and continuously stir the mixture in the hydrothermal liquefaction reactor during this period;

[0047] S4, decrease the temperature of the mixture in the hydrothermal liquefaction reactor to 95℃ at a cooling rate of 10.0℃ / min, open the gas outlet of the hydrothermal liquefaction reactor, collect the cooled gas phase product 7, liquid phase product 4 and solid phase product 8 respectively, and separate the bio-oil 6 and recycled water 5 from the liquid phase product 4 by standing and layering, the recycled water 5 in the liquid phase product 4 can be put into the hydrothermal liquefaction reactor for recycling;

[0048] S5, after washing and drying the obtained solid phase product 8, screen the fiber product 9 rich in glass fibers and carbon fibers, trim to make reinforced fibers 10 for concrete, grind the remaining solid phase product 11 as fine aggregate 12 for concrete, mix the reinforced fibers 10 for concrete into the premixed concrete slurry 13 according to a ratio of 1:75, add coarse aggregate 14 and fine aggregate 12 according to the ratio, fully stir and mix to obtain fiber reinforced concrete 15.

[0049] The collected gas phase product 7 and bio-oil 6 are used as fuel to heat the hydrothermal liquefaction reactor in steps 2 and 3.

[0050] As can be seen from the above embodiment, the method of the present application can extract various fiber materials including glass fibers and carbon fibers from the waste fan blades 1 and effectively recycle them, and completely harmlessly and resourcefully utilize other materials contained in the fan blades 1, without producing secondary pollutants and secondary waste.

[0051] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the technical solution of the present application, can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, but as long as it does not depart from the technical solution of the present application, and is within the spirit and principle of the present application, any simple modification, equivalent replacement and improvement of the above embodiments are still within the protection scope of the present application.

Claims

1. A method of resourceful disposal of a decommissioned wind turbine blade, characterized in that, The method comprises the following steps: S1, crushing and cleaning, crushing the fan blades into pieces, screening and cleaning for use; S2, subcritical hydrothermal liquefaction, putting the fan blade pieces into a hydrothermal liquefaction reactor, adding water in a proportion of 1:5-1:20 of the mass of the pieces to water, sealing the hydrothermal liquefaction reactor, gradually increasing the temperature in the hydrothermal liquefaction reactor to a subcritical temperature T1, and the pressure to the saturated steam pressure P1 at the temperature, maintaining the temperature and pressure for 20-40 min, and stirring the mixture in the hydrothermal liquefaction reactor during this period to promote sufficient reaction; in step 2, the subcritical temperature T1 is in the range of 325±25℃, and the corresponding P1 is in the range of 8.5-16.5MPa, and the heating rate is not greater than 10.0℃ / min; S3, supercritical hydrothermal liquefaction, slowly increasing the temperature of the mixture in the hydrothermal liquefaction reactor to a supercritical temperature T2, and increasing the pressure in the hydrothermal liquefaction reactor to a pressure value P2 in the supercritical state, maintaining the temperature and pressure for 30-60 min, and stirring the mixture in the hydrothermal liquefaction reactor during this period to promote sufficient reaction; in step 3, the supercritical temperature T2 is in the range of 400±25℃, and the corresponding P2 is in the range of 25.0±1.0MPa, and the heating rate is not greater than 5.0℃ / min; S4, cooling and separating and recovering the products, gradually reducing the temperature of the mixture in the hydrothermal liquefaction reactor to a discharge temperature T3, opening the gas outlet of the hydrothermal liquefaction reactor, and collecting the cooled gas phase, liquid phase and solid phase products respectively, the obtained gas phase product is rich in combustible components and is collected as fuel gas; The liquid phase product is divided into an oil phase and a water phase, the oil phase product is bio-oil and is used as liquid fuel or chemical raw material, and the water phase product is put into the hydrothermal liquefaction reactor for recycling; the fuel gas and bio-oil collected in step 4 are used to heat the hydrothermal liquefaction reactor in steps 2 and 3, and external heat sources are not needed; S5, preparing fiber reinforced concrete, after the obtained solid phase product is cleaned and dried, the fiber product rich in glass fiber and carbon fiber is screened out, the fiber product is trimmed to be a reinforcing fiber for concrete, the remaining solid phase product is ground to be a fine aggregate for concrete, the reinforcing fiber for concrete is mixed into a premixed concrete slurry in a proportion of 1:25-1:100, coarse and fine aggregates are added in proportion, and after being fully stirred and mixed, the tensile strength and toughness of the concrete are improved, and fiber reinforced concrete is obtained; low-alkali cement should be used in the concrete slurry in step 5.

2. A method of recycling a waste wind turbine blade according to claim 1, characterized in that: The fan blades crushed in step S1 are in the form of pieces with a diameter of 1.0-10.0cm.

3. A method of recycling a waste wind turbine blade according to claim 1, characterized in that: The discharge temperature T3 in step 4 is in the range of 95±5℃.

4. A method of recycling a waste wind turbine blade according to claim 1, characterized in that: The method can also be used for the resource disposal of other solid waste resources rich in glass fiber, carbon fiber and other fiber materials.

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