A method for resource utilization of retired wind turbine blades

Abstract

The present invention relates to a resource utilization method for retired wind turbine blades. The retired wind turbine blades are disassembled to recover metal parts in the retired wind turbine blades, and recycled products are produced through processing and combination processes; the scraps are ground through a crushing ball milling process to produce composite material powder, which is dispersed in an organic solvent and an alkaline catalyst, and separated from the resin-containing organic solution and glass fiber after being treated through a fluidized separation process; the glass fiber is subjected to pressure filtration treatment and heat exchange drying with an inert gas from the fluidized separation to obtain glass fiber; the resin-containing organic solution is separated by fluidization, and the resin and organic solvent are further separated in a solvent separation process. The present invention realizes the recycling and reuse of all retired wind turbine blades, not only realizing the production of recycled products by using retired wind turbine blades, but also realizing the recycling of resin and glass fiber products from the retired wind turbine blade scraps generated during the production process.

Description

Technical Field

[0001] The present invention relates to a resource utilization method, and in particular to a resource utilization method for retired wind turbine blades. Background Art

[0002] The main components of retired wind turbine blades are fiber-reinforced materials and plastic polymers (i.e. thermosetting and thermoplastic polymer-based composite materials), which account for more than 90% of the weight of the entire wind turbine blade. Among them, the fiber-reinforced materials are usually E-glass fiber, S-glass fiber or carbon fiber, etc., and the plastic polymer can be polyester, polyurethane, vinyl, epoxy resin, adhesive, etc.

[0003] At present, common treatment methods for retired wind turbine blades include direct landfill, reuse, mechanical recycling, incineration energy recovery, pyrolysis, cement manufacturing, etc.

[0004] (1) Direct burial

[0005] Direct landfill is the simplest way to directly deal with wind turbine blades. Currently, the amount of direct landfill accounts for 60-75% of the total amount of waste wind turbine blades.

[0006] (2) Reuse

[0007] For discarded wind turbine blades, if large plate-shaped or tubular pieces can be cut out, they can be reused in small containers, protective houses, etc., while the scraps of wind turbine blades after reuse are buried or otherwise disposed of.

[0008] (3) Mechanical recycling

[0009] Mechanical recycling is a method of secondary utilization of pre-processed wind turbine blades as raw materials. There are two methods of mechanical recycling: one is to decompose or grind the wind turbine blades into fine powder; the other is to crush the wind turbine blades. The short fibers and matrix powder obtained by these two methods are used as reinforcement materials or filling materials respectively.

[0010] (4) Incineration energy recovery

[0011] Incineration energy recovery method refers to the use of controlled incineration method to incinerate wind turbine blades and recover energy. The characteristics of this method are: first, the incineration recovery energy can be converted into usable heat or electricity; second, the incineration process produces less smoke and dust, and the pollutant emissions can reach or approach zero emission standards.

[0012] (5) Pyrolysis

[0013] The pyrolysis method is a method for heat treatment of wind turbine blades under oxygen-deficient conditions. Its working principle is to heat and decompose the plastic polymer matrix (such as polyester, epoxy resin, adhesive, etc.), sandwich materials (such as PVC, PET, cork, bamboo, etc.) and coating (mainly surface polyurethane coating) of the wind turbine blade at a relatively low temperature, and under this temperature reaction condition, it will not cause chemical reactions in the fiber reinforcement materials (such as glass fiber or carbon fiber, etc.) and metal parts of the wind turbine blade. Therefore, this method is also called a combination of chemical recovery and material recycling methods. During the pyrolysis treatment, the plastic polymer, sandwich materials and coatings are mainly decomposed into pyrolysis gas under the action of heat, while the fiber reinforcement materials, metal parts, etc. can be further recycled. Compared with the aforementioned mechanical recycling method, the advantage of the pyrolysis method is that the fiber reinforcement materials (such as glass fiber or carbon fiber, etc.) can maintain the maximum length and retain high strength during the pyrolysis process.

[0014] (6) Cement manufacturing method

[0015] Cement manufacturing is another application of the combination of energy recovery and mechanical recovery. When processing wind turbine blades, the main purpose of dismantling is to remove non-technical metal debris such as discarded blade metal parts; then, according to the requirements of cement manufacturing, the waste is gradually cut and shredded into 10-15mm particles and blocks, and then transported to the factory to mix with other cement raw materials, and then sent or blown into the kiln for combustion. The heat energy generated by the combustion of its organic components can continue to be used, while the inorganic components undergo chemical reactions to become cement raw materials. The gases released by wind turbine blades during the combustion process release extremely small amounts of dioxins and other toxic gases due to long-term decomposition in high-temperature kilns. There is basically no secondary pollution during the treatment, and it will not cause harm to the environment.

[0016] Therefore, the direct landfill method for treating wind turbine blades not only requires a large amount of land resources, but the non-degradable wind turbine blade composite materials will also have an adverse impact on the surrounding soil and groundwater environment; the reuse method uses physical methods to treat wind turbine blades and reuse some raw materials, but the unused scraps still pose environmental problems through landfill; the mechanical recycling method is to completely crush the pre-treated wind turbine blades into short fibers and matrix powders of a certain particle size, which are used as reinforcement materials or filling materials respectively. However, although short fibers and composite particles of different lengths can be recovered by applying this method to wind turbine blades, long fibers cannot be obtained due to severe damage to the fibers during the recycling process, which greatly reduces the value of the recycled materials; the economic feasibility of the incineration energy recovery method to treat wind turbine blades is still poor, and the disposal of ashes by landfill and other methods requires the occupation of land and incurs costs; the pyrolysis method recovers fibers in the form of ash and the plastic polymer matrix in the form of hydrocarbons, but the single pyrolysis method to treat wind turbine blades is not yet mature and has certain economic feasibility. It can be considered to be combined with other physical recycling methods to make up for the shortcomings; although the cement manufacturing method to treat wind turbine blades is very promising in terms of cost-effectiveness, efficiency and environmental protection, it also loses the opportunity to recycle and reuse high value-added fiber reinforcement materials in wind turbine blades. Summary of the invention

[0017] The purpose of the present invention is to address the problems existing in the above-mentioned common treatment methods for retired wind turbine blades, and to propose a new method for resource utilization of retired wind turbine blades, so as to achieve almost complete resource recycling of retired wind turbine blades. In addition to producing recycled products that can be used in ecology, gardening, landscape, cultural tourism and other fields, the resin and glass fiber in the scraps generated by the production of recycled products are also recycled and reused.

[0018] To achieve the above object, the present invention provides a method for resource utilization of retired wind turbine blades, the resource utilization method comprising the following steps:

[0019] A. Retired wind turbine blades are disassembled to recover metal parts from them. After the metal parts are disassembled, the retired wind turbine blades are processed and combined to produce recycled products.

[0020] B. Grind the scraps generated in the production and recycling process through a crushing ball milling process to produce composite material powder;

[0021] C. dispersing the composite material powder in an organic solvent and an alkaline catalyst, and separating the resin-containing organic solution and the glass fiber after a fluidized separation process; wherein the fluidized separation process comprises: heating by an external heat source, and passing a fluidized inert gas through the composite material powder;

[0022] D. The glass fiber treated by filter pressing is heat-exchanged and dried with the inert gas from fluidized separation to obtain the glass fiber, and the inert gas after drying and heat-exchanging is returned to the fluidized separation process through the inert blasting process;

[0023] E. Fluidized separation of the resin-containing organic solution: The resin and the organic solvent are further separated in the solvent separation process, and the organic solvent is recycled to the fluidized separation process.

[0024] Preferably, in step A, the recycled product is produced by processing and combining different parts of retired wind turbine blades.

[0025] Preferably, the steps of producing the recycled product include:

[0026] (1) Cut the entire retired wind turbine blade along the axis and arrange them in a row to serve as a gentle slope structure support for windbreak and sand fixation;

[0027] (2) Utilization of the middle part (02) of retired wind turbine blades: the middle part (02) of retired wind turbine blades is cut off as the main structure suitable for making petal seats and fish swimming seats, supplemented by wind turbine blade plates as seat surface materials;

[0028] (3) Utilization of the retired wind turbine blade root (01), cutting off the circular section of the retired wind turbine blade root (01) as the main structure of a store, coffee shop, etc.;

[0029] (4) The retired wind turbine blade tip (03) is used to cut off the thin end of the retired wind turbine blade tip (03) to point to the direction of a road sign or the like.

[0030] Preferably, the inert gas is nitrogen or argon.

[0031] Preferably, the fluidized separation process is carried out in a suspended fluidized device, which comprises a closed fluidized bed (04), in which a plurality of fluidized inert gas inlet pipelines (05) and a plurality of fluidized inert gas dispersion pipes (06) are respectively arranged in the vertical direction and the horizontal direction.

[0032] Preferably, the spacing between the fluidized inert gas inlet pipeline (05) and the fluidized inert gas dispersion pipe (06) in the horizontal and vertical directions is controlled to be 50-80 mm, and the fluidized inert gas dispersion pipe (06) closest to the bottom of the fluidized bed (04) in the vertical direction is 30-50 mm away from the bottom of the fluidized bed (04); the aperture of the fluidized inert gas dispersion pipe (06) is 1.0-1.2 mm, and the speed of the inert gas outflowing from the small hole is controlled to be 30-40 m·s -1 The gas velocity in the fluidized bed (04) is controlled at 1.0 to 2.0 m·s -1 .

[0033] Preferably, the organic solvent is an organic alcohol, and the alkaline catalyst is an alkali metal compound, wherein the mass ratio of the organic solvent to the alkaline catalyst is 30:1 to 50:1.

[0034] Preferably, in the fluidized separation process, the reaction time of the organic solvent and the alkaline catalyst on the composite material powder in the suspension fluidized device is 3 to 8 hours, and the suspension fluidized device uses an intermittent method to treat the composite material powder. After the fluidized bed (04) is cooled to room temperature in each batch, the resin-containing organic solution and the glass fiber are separated.

[0035] Preferably, during the fluidized separation process, the external heat source is heated in two stages, the operating temperature of the upper space (I) of the fluidized bed (04) is controlled at 150-180°C, and the operating temperature of the lower space (II) of the fluidized bed (04) is controlled at 200-300°C. The inert gas with a temperature of 140-160°C coming out of the fluidized bed (04) is used to preheat and dry the glass fibers treated in the filter press process. After the drying process, the inert gas with a temperature of 80-110°C is recycled to the fluidized separation process through a blowing process.

[0036] Preferably, in step E, the solvent separation process includes treating the resin-containing organic solution separated in the fluidized separation process by a closed rotary evaporation method; the solvent separation process uses an external heat source to heat the resin-containing organic solution until only the resin remains, and the operating temperature is controlled at 200°C to 300°C. The aqueous organic solvent is recovered by rotary evaporation and then reused in the fluidized separation process to continue to participate in the reaction with the composite material powder.

[0037] Based on the above technical solution, the advantages of the present invention are:

[0038] The resource utilization method of retired wind turbine blades of the present invention realizes the recycling and reuse of all retired wind turbine blades. Not only the retired wind turbine blades are used to realize the production of recycled products, but also the retired wind turbine blade scraps generated in the production process are recycled to realize the recycling of resin and glass fiber products. In particular, the recycling rates of resin and glass fiber of retired wind turbine blade scraps can reach more than 99.5%, which has extremely strong economic value.

[0039] 1) The present invention proposes a novel process for resource utilization of retired wind turbine blades, which realizes almost complete resource recycling of retired wind turbine blades. In addition to producing recyclable products that can be used in the fields of ecology, gardening, landscape, culture and tourism, the resin and glass fiber in the scraps generated by the production of recycled products are also recycled and reused.

[0040] 2) The present invention proposes a "fluidized separation + solvent separation" method for recycling scraps of retired wind turbine blades, which achieves efficient recovery of resin and glass fiber from scraps of retired wind turbine blades.

[0041] 3) The suspension fluidization device of the present invention adopts closed + double-stage temperature control operation, and the organic alcohols and alkaline catalysts react with the composite material powder under the action of inert gas flow to achieve efficient separation of resin-containing organic solvents and glass fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0043] Figure 1 A step diagram of the resource utilization method for retired wind turbine blades;

[0044] Figure 2 The process flow chart of the resource utilization method of retired wind turbine blades;

[0045] Figure 3 This is a schematic diagram of the various parts of the retired wind turbine blade;

[0046] Figure 4 It is a side view schematic diagram of a suspension fluidization device;

[0047] Figure 5 It is a top view schematic diagram of the suspension fluidization device. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments.

[0049] The present invention provides a method for resource utilization of retired wind turbine blades, such as Figure 1 to Figure 5 As shown, a preferred embodiment of the present invention is shown. Figure 1 As shown, the resource utilization method includes the following steps:

[0050] A. Retired wind turbine blades are disassembled to recover metal parts from them. After the metal parts are disassembled, the retired wind turbine blades are processed and combined to produce recycled products.

[0051] B. Grind the scraps generated in the production and recycling process through a crushing ball milling process to produce composite material powder;

[0052] C. dispersing the composite material powder in an organic solvent and an alkaline catalyst, and separating the resin-containing organic solution and the glass fiber after a fluidized separation process; wherein the fluidized separation process comprises: heating by an external heat source, and passing a fluidized inert gas through the composite material powder;

[0053] D. The glass fiber treated by filter pressing is heat-exchanged and dried with the inert gas from fluidized separation to obtain the glass fiber, and the inert gas after drying and heat-exchanging is returned to the fluidized separation process through the inert blasting process;

[0054] E. Fluidized separation of the resin-containing organic solution: The resin and the organic solvent are further separated in the solvent separation process, and the organic solvent is recycled to the fluidized separation process.

[0055] The process flow of the resource utilization method of retired wind turbine blades of the present invention mainly includes a disassembly process, a processing and assembly process, a crushing and ball milling process, a fluidized separation process, a filter press process, a drying process, a solvent separation process and an inert blast process, etc. Figure 2 shown.

[0056] Specifically, retired wind turbine blades first undergo a disassembly process to recover metal parts (such as lightning protection, connection systems, etc.) in the retired wind turbine blades. The retired wind turbine blades with disassembled metal parts are used to produce recycled products in the processing and assembly process, and the scraps produced in the process of producing recycled products enter the crushing and ball milling process for grinding to produce composite material powder. The composite material powder is dispersed in an organic solvent and an alkaline catalyst, and the resin-containing organic solution and glass fiber are separated in the fluidized separation process. The separated glass fiber containing the organic solution returns the resin-containing organic solvent to the fluidized separated resin-containing organic solution through a filter press process. The fluidized separation process is heated by an external heat source (generally hot flue gas), and the composite material powder is separated from the resin and glass fiber in the organic solvent by fluidizing inert gas (generally nitrogen or argon). The glass fiber treated in the filter press process is dried by heat exchange with the inert gas from the fluidized separation process to obtain a glass fiber product. The inert gas after heat exchange in the drying process is returned to the fluidized separation process through the inert blowing process. The resin-containing organic solution obtained by fluidized separation is further separated into resin and organic solvent in the solvent separation process. The organic solvent can be reused in the fluidized separation process.

[0057] Preferably, in step A, the recycled product is produced by processing and assembling different parts of the retired wind turbine blades. The retired wind turbine blades are disassembled and then processed and assembled to produce the recycled product. The recycled product can be processed and assembled by processing different parts of the retired wind turbine blades. Preferably, Figure 3 As shown, the steps to produce recycled products include:

[0058] (1) Cut the entire retired wind turbine blade along the axis and arrange them in a row to serve as a gentle slope structure support for windbreak and sand fixation;

[0059] (2) Utilization of the middle part (02) of retired wind turbine blades: the middle part (02) of retired wind turbine blades is cut off as the main structure suitable for making petal seats and fish swimming seats, supplemented by wind turbine blade plates as seat surface materials;

[0060] (3) Utilization of the retired wind turbine blade root (01), cutting off the circular section of the retired wind turbine blade root (01) as the main structure of a store, coffee shop, etc.;

[0061] (4) The retired wind turbine blade tip (03) is used to cut off the thin end of the retired wind turbine blade tip (03) to point to the direction of a road sign or the like.

[0062] The crushing and ball milling process uses a crusher and a ball mill to crush and ball mill the scraps of retired wind turbine blades into composite material powders with a particle size of less than 1.5 mm; the fluidized separation process mainly disperses the composite material powders with a particle size of less than 1.5 mm produced by the crushing and ball milling process in a suspended fluidized device filled with an organic solvent and an alkaline catalyst.

[0063] like Figure 4 , Figure 5 As shown, the fluidized separation process is carried out in a suspended fluidized device, and the suspended fluidized device includes a closed fluidized bed (04), and a plurality of fluidized inert gas inlet pipelines (05) and a plurality of fluidized inert gas dispersion pipes (06) are respectively provided in the vertical direction and the horizontal direction in the fluidized bed (04). The suspended fluidized device adopts a closed device, and an external heat source (electric heating or hot flue gas) is used to heat the device. The suspended fluidized device adopts a closed device, mainly considering that the organic solution is not easy to volatilize within the operating temperature range. The suspended fluidized device is provided with a fluidized inert gas inlet pipeline 05, and a fluidized inert gas dispersion pipe 06 is provided in the device, and an inert gas outlet hole with an opening downward is arranged on the dispersion pipe, and the purpose of the downward setting direction is to prevent the composite material powder from entering the small hole during the start-up, shutdown or operation of the fluidized separation to affect the fluidized separation effect.

[0064] Preferably, the spacing between the fluidized inert gas inlet pipeline (05) and the fluidized inert gas dispersion pipe (06) in the horizontal and vertical directions is controlled to be 50-80 mm, and the fluidized inert gas dispersion pipe (06) closest to the bottom of the fluidized bed (04) in the vertical direction is 30-50 mm away from the bottom of the fluidized bed (04); the aperture of the fluidized inert gas dispersion pipe (06) is 1.0-1.2 mm, and the speed of the inert gas outflowing from the small hole is controlled to be 30-40 m·s -1 The gas velocity in the fluidized bed (04) is controlled at 1.0 to 2.0 m·s -1 .

[0065] While the inert gas causes the solution to flow, the composite material powder in the device also undergoes an extraction fluidization reaction with the solution (organic solvent and alkaline catalyst) to separate the resin-containing organic solution and the glass fiber. Figure 5 shown.

[0066] The fluidized separation process uses organic solvents and alkaline catalysts to react and separate the composite material powder. Among them, the organic solvent is usually alcohol, such as ethylene glycol, ethanol, propanol, butanol, etc., and the alkaline catalyst is usually alkali metal compounds, such as sodium hydroxide, sodium carbonate, sodium hydroxide, potassium carbonate, etc. Among them, the mass ratio of organic solvent to alkaline catalyst is generally 30:1 to 50:1.

[0067] In the fluidized separation process, the reaction time of the organic solvent and the alkaline catalyst on the composite material powder in the suspension fluidized device is controlled to be 3 to 8 hours to ensure that the resin contained in the composite material powder and the glass fiber are completely separated. The suspension fluidized device used in the fluidized separation process uses an intermittent method to treat the composite material powder. After each batch of treatment, the resin-containing organic solution and the glass fiber are separated after the device is cooled to room temperature.

[0068] Preferably, during the fluidized separation process, the external heat source is heated in two stages, and the operating temperature of the upper space (I) of the fluidized bed (04) is controlled at 150-180°C to prevent the inert gas from being recycled to the inert gas blowing process and carrying organic matter such as alcohols, thereby affecting the recovery rate of the organic solvent. The operating temperature of the lower space (II) of the fluidized bed (04) is controlled at 200°C-300°C to ensure that the composite material powder and the organic solvent are fully separated from the resin and the glass fiber under the action of the alkaline catalyst. The inert gas at a temperature of 140-160°C coming out of the fluidized bed (04) is preheated and dried for the glass fiber treated in the filter press process to improve the waste heat utilization efficiency of the entire process. After the drying process, the inert gas at a temperature of 80-110°C is continuously recycled to the fluidized separation process through the blowing process.

[0069] Furthermore, the filter press process mainly uses a closed filter press to process the glass fibers separated in the fluidized separation process, and the resin-containing organic solvent collected by the filter press process is returned to the solvent separation process for processing, thereby maximizing the recovery rate of the resin and organic solvent in the process. The glass fibers separated in the filter press process are collected and used after the drying process.

[0070] The solvent separation process mainly uses a closed rotary evaporation method to process the resin-containing organic solution separated by the fluidized separation process. The solvent separation process also uses an external heat source (electric heating or hot flue gas method) to heat the resin-containing organic solution until the resin is left. The operating temperature is controlled at 200°C to 300°C. The water-containing organic solvent (mainly alcohols) is recovered by rotary evaporation and reused in the fluidized separation process to continue to participate in the reaction with the composite material powder. The remaining product of the rotary evaporation treatment is mainly the recovered epoxy resin. The recovered epoxy resin can be subsequently produced by adding organic carboxylic acids (such as maleic acid or fumaric acid, etc.) to produce regenerated resin.

[0071] The resource utilization method of retired wind turbine blades of the present invention realizes the recycling and reuse of all retired wind turbine blades. Not only the retired wind turbine blades are used to realize the production of recycled products, but also the retired wind turbine blade scraps generated in the production process are recycled to realize the recycling of resin and glass fiber products. In particular, the recycling rates of resin and glass fiber of retired wind turbine blade scraps can reach more than 99.5%, which has extremely strong economic value.

[0072] The method for resource utilization of retired wind turbine blades of the present invention realizes the recycling and reuse of all retired wind turbine blades in the process flow. It not only realizes the production of recycled products of retired wind turbine blades that can be applied to ecology, gardening, landscape, cultural tourism and other fields, but also realizes the recovery of resin and glass fiber products of retired wind turbine blade scraps generated in the production process of recycled products. It explores a new way for the resource utilization of retired wind turbine blades and helps the wind power industry achieve green and sustainable development.

[0073] Implementation Case 1

[0074] After the 100kW retired wind turbine blades (about 20m long, 2.8 tons) are disassembled to recycle the metal parts (such as lightning protection, connection system, etc.) in the retired wind turbine blades, the root of the retired wind turbine blades with a length of about 2.5m is processed into the main structure of the hot-selling beverage store for the scenic area, the middle part of the blade is processed into a petal seat for people to rest outside the hot-selling beverage store, and the tip part is processed into a signpost for the hot-selling beverage store. The above-mentioned recycled products of retired wind turbine blades recycle more than 85% of the mass of the entire retired blades. The scraps of retired wind turbine blades with a mass ratio of 15% produced by the combined processing are ground into composite material powder particles of about 1.2mm in the ball mill and fluidized and separated in a suspended fluidized device.

[0075] The suspended fluidized device is a closed device, using electric heating. The operating temperature is controlled by two-stage heating. The operating temperature in the upper space (I) is controlled at about 160°C, and the operating temperature in the lower space (II) is controlled at about 260°C. Three layers of fluidized inert gas dispersion pipes are arranged in the horizontal and vertical directions of the device. The aperture of the dispersion pipe is 1.0mm, and the gas velocity of the small hole is controlled at about 35m·s -1 The gas velocity in the device is controlled at about 1.5m·s-1, the distance between adjacent inert gas dispersion pipes is controlled at 65mm, and the inert gas dispersion pipe closest to the bottom of the suspension fluidization device in the vertical direction is 40mm from the bottom of the suspension fluidization device. The suspension fluidization device uses ethylene glycol and sodium hydroxide as the fluidized separation solution for treating composite material powders, and the mass ratio is controlled at 35:1. The reaction time of the above solution and composite material powder in the suspension fluidization device is controlled at 4.0h.

[0076] The inert gas with a temperature of about 150°C from the fluidized separation process can be used to preheat and dry the glass fiber treated in the filter press process. After the drying process, the inert gas with a temperature of about 90°C is recycled to the fluidized separation process through the blast process. The resin-containing organic solution is separated and treated in a closed rotary evaporator, using electric heating, and the operating temperature is controlled at 260°C.

[0077] After the above-mentioned treatment of retired wind turbine blade scraps, the recovery rates of resin and glass fiber in the scraps can reach 99.7% and 99.6% respectively.

[0078] Implementation Case 2

[0079] After the 600kW retired wind turbine blades (about 50m long, 10 tons) were disassembled to recover the metal parts (such as lightning protection, connection system, etc.) in the retired wind turbine blades, the root of the retired wind turbine blades with a length of about 3.0m was processed into the main structure of the park newsstand, the middle part of the blade was processed into the main structure of the sun-sensing seat for people to rest in the park, and the tip part was processed into the park's road sign. The above-mentioned recycled products of retired wind turbine blades recycled more than 88% of the mass of the entire retired blades. The scraps of retired wind turbine blades with a mass ratio of 12% produced by the combined processing were ground into composite material powder particles of about 1.0mm in a ball mill and fluidized and separated in a suspended fluidized device.

[0080] The suspended fluidized device is a closed device, using hot flue gas inter-wall heating. The operating temperature is controlled by two-stage heating. The operating temperature in the upper space (I) is controlled at about 155°C, and the operating temperature in the lower space (II) is controlled at about 240°C. Four layers of fluidized inert gas dispersion pipes are arranged in the horizontal and vertical directions of the device. The aperture of the dispersion pipe is 1.0 mm, and the gas velocity of the small hole is controlled at about 32 m·s -1The gas velocity in the device is controlled at about 1.2m·s-1, the distance between adjacent inert gas dispersion pipes is controlled at 60mm, and the inert gas dispersion pipe closest to the bottom of the suspension fluidization device in the vertical direction is 35mm from the bottom of the suspension fluidization device. The suspension fluidization device uses propanol and potassium carbonate as the fluidized separation solution for treating composite material powders, and the mass ratio is controlled at 30:1. The reaction time of the above solution and composite material powder in the suspension fluidization device is controlled at 6.0h.

[0081] The inert gas with a temperature of about 160°C from the fluidized separation process can be used to preheat and dry the glass fiber treated in the filter press process. After the drying process, the inert gas with a temperature of about 100°C is recycled to the fluidized separation process through the blast process. The resin-containing organic solution is separated and treated in a closed rotary evaporator, using electric heating, and the operating temperature is controlled at 240°C.

[0082] After the above-mentioned treatment of retired wind turbine blade scraps, the recovery rates of resin and glass fiber in the scraps can reach 99.6% and 99.5% respectively.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A method for resource utilization of retired wind turbine blades, characterized in that: The resource utilization method comprises the following steps: A. Retired wind turbine blades are disassembled to recover metal parts from them. After the metal parts are disassembled, the retired wind turbine blades are processed and combined to produce recycled products. B. Grind the scraps generated in the production and recycling process through a crushing ball milling process to produce composite material powder; C. dispersing the composite material powder in an organic solvent and an alkaline catalyst, and separating the resin-containing organic solution and the glass fiber after a fluidized separation process; wherein the fluidized separation process comprises: heating by an external heat source, and passing a fluidized inert gas through the composite material powder; the organic solvent is an organic alcohol, and the alkaline catalyst is an alkali metal compound, wherein the mass ratio of the organic solvent to the alkaline catalyst is 30:1 to 50:1; D. The glass fiber treated by filter pressing is heat-exchanged and dried with the inert gas from fluidized separation to obtain the glass fiber, and the inert gas after drying and heat-exchanging is returned to the fluidized separation process through the inert blasting process; E. Fluidized separation of resin-containing organic solution: In the solvent separation process, the resin and the organic solvent are further separated, and the organic solvent is recycled to the fluidized separation process; wherein, the solvent separation process includes treating the resin-containing organic solution separated in the fluidized separation process by a closed rotary evaporation method; the solvent separation process uses an external heat source to heat the resin-containing organic solution until only the resin remains, and the operating temperature is controlled at 200°C to 300°C. The water-containing organic solvent is recovered by rotary evaporation and then recycled to the fluidized separation process to continue to participate in the reaction with the composite material powder.

2. The resource utilization method according to claim 1, characterized in that: In step A, the recycled products are processed and combined by different parts of retired wind turbine blades.

3. The resource utilization method according to claim 2, characterized in that: The steps to produce recycled products include: (1) Cut the entire retired wind turbine blade along the axis and arrange them in a row to serve as a gentle slope structure support for windbreak and sand fixation; (2) Utilization of the middle part (02) of retired wind turbine blades: the middle part (02) of retired wind turbine blades is cut off as the main structure suitable for making petal seats and fish swimming seats, supplemented by wind turbine blade plates as seat surface materials; (3) Utilization of the retired wind turbine blade root (01), cutting off the circular section of the retired wind turbine blade root (01) as the main structure of a store, coffee shop, etc.; (4) The retired wind turbine blade tip (03) is used to cut off the thin end of the retired wind turbine blade tip (03) to point to the direction of a road sign or the like.

4. The resource utilization method according to claim 1, characterized in that: The inert gas is nitrogen or argon.

5. The resource utilization method according to claim 1, characterized in that: The fluidized separation process is carried out in a suspended fluidized device, which comprises a closed fluidized bed (04), in which a plurality of fluidized inert gas inlet pipelines (05) and a plurality of fluidized inert gas dispersion pipes (06) are respectively arranged in the vertical direction and the horizontal direction.

6. The resource utilization method according to claim 5, characterized in that: The spacing between the fluidized inert gas inlet pipeline (05) and the fluidized inert gas dispersion pipe (06) in the horizontal and vertical directions is controlled to be 50 to 80 mm, and the height of the fluidized inert gas dispersion pipe (06) closest to the bottom of the fluidized bed (04) in the vertical direction is 30 to 50 mm from the bottom of the fluidized bed (04); the aperture of the fluidized inert gas dispersion pipe (06) is 1.0 to 1.2 mm, and the speed of the inert gas flowing out of the small hole is controlled to be 30 to 40 m·s -1 The gas velocity in the fluidized bed (04) is controlled at 1.0 to 2.0 m·s -1 .

7. The resource utilization method according to claim 5 or 6, characterized in that: In the fluidized separation process, the reaction time of the organic solvent and the alkaline catalyst on the composite material powder in the suspension fluidized device is 3 to 8 hours. The suspension fluidized device uses an intermittent method to treat the composite material powder. After the fluidized bed (04) is cooled to room temperature in each batch, the resin-containing organic solution and the glass fiber are separated.

8. The resource utilization method according to claim 7, characterized in that: During the fluidized separation process, the external heat source is heated in two stages. The operating temperature of the upper space (I) of the fluidized bed (04) is controlled at 150-180°C, and the operating temperature of the lower space (II) of the fluidized bed (04) is controlled at 200-300°C. The inert gas with a temperature of 140-160°C coming out of the fluidized bed (04) is used to preheat and dry the glass fibers treated in the filter press process. After the drying process, the inert gas with a temperature of 80-110°C is recycled to the fluidized separation process through the blowing process.

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