Wind turbine blade treatment

Abstract

A method of making a wind turbine blade for recovery. At least a portion of the wind turbine blade is subjected to a first chemical treatment. The first chemical treatment is selected to degrade the first binding material of the wind turbine blade portion to a substantially greater extent than the second binding material of the wind turbine blade portion. A portion of the wind turbine blade portion is separated from a remainder of the wind turbine blade portion after the first chemical treatment has sufficiently degraded the first binding material to release the portion from the remainder of the wind turbine blade portion and before the first chemical treatment has significantly degraded the second binding material. This separation of material by chemical treatment improves the ability of the blade to be recovered.

Description

Technical Field

[0001] The present invention relates to a method of preparing wind turbine blades for recycling. Background Art

[0002] Wind turbine blades are currently difficult to recycle effectively due to the strong bonds between the material types. Wind turbine blades typically include a variety of materials, such as glass fiber composites, carbon fiber composites, foam cores, and metal components (such as lightning protection system components, sensors, and electronics). Many of these different materials are bonded together by a resin system that is infused during blade manufacturing. However, blades can also include a variety of different bonding materials, such as adhesives and other resins used before or after this infusion step during blade manufacturing. Mechanical separation of these different material types is particularly difficult for wind turbine blades due to their design. Summary of the Invention

[0003] The present invention provides a method of preparing a wind turbine blade for recycling, the method comprising: subjecting at least a portion of the wind turbine blade portion to a first chemical treatment, wherein the first chemical treatment is selected to degrade a first bonding material of the wind turbine blade portion to a significantly greater extent than a second bonding material of the wind turbine blade portion; and separating the portion from the remainder of the wind turbine blade portion after the first chemical treatment has sufficiently degraded the first bonding material to release the portion from the remainder of the wind turbine blade portion and before the first chemical treatment has significantly degraded the second bonding material.

[0004] The present invention utilizes a chemical treatment to separate at least a portion of a wind turbine blade and utilizes different bonding materials of the wind turbine blade to positive advantage. In particular, the present invention utilizes the discovery that a selected chemical treatment can be used to significantly degrade a selected bonding material.

[0005] "Substantially degraded" here means that the bonding material is degraded to the extent that it can no longer fully perform its bonding function, so that the bonding parts can be easily separated by mechanical action.

[0006] The first chemical treatment utilizes specific chemicals under specific reaction conditions and for specific reaction times to significantly degrade the first binding material through interaction with the chemical compound. At the same time and under the same conditions as those with the same chemical treatment, the second binding material does not significantly degrade and therefore still performs a strong binding function such that the materials bound by the second binding material cannot be easily separated by mechanical action. However, it is not necessary to exclude that the second binding material can be significantly degraded by the same chemicals used in the first chemical treatment under different reaction conditions (e.g., different temperatures, pressures, concentrations and / or reaction times, or by adding reaction enhancing additives); nor is it necessary to exclude that the second binding material can be slightly degraded under the first chemical treatment.

[0007] A bonding material is any material used to bond another material or materials or components together. Examples of bonding materials may include thermoplastic or thermosetting polymers that may function as, for example, a resin or composite matrix, an adhesive, or a covering layer, such as a coating, bag, transition layer, or wrap, that may form, for example, a barrier layer and bond to another material or part.

[0008] The portion after the first chemical treatment can be separated from the rest of the wind turbine blade by mechanical action. For example, the portion can be separated by applying an external force (particularly a relatively low force) that is significantly lower than the bonding force of the first bonding material before the first chemical treatment. The external force can be provided by, for example, a lifting force using a tool, gravity, fluid flow, or the like.

[0009] Separation can provide a separated portion comprising one or more materials. In the case where the separated portion consists of a single material, then the material can be ready for immediate recycling into another product. In the case where the separated portion comprises more than one material, then the material can be further processed into a form in which it can be recycled into another product. In addition, in the case where the separated portion comprises more than one material but those materials are already in a form in which they can be recycled into another product, then further processing may not be required to achieve recycling goals. In addition, the separated portion may be considered non-recyclable, but the remainder of the wind turbine blade after separation of the portion may include one or more recyclable materials. The remainder of the wind turbine blade can undergo further processing to achieve one or more desired materials for recycling.

[0010] The first chemical treatment may be an acid treatment. The acid treatment may use formic acid or acetic acid. Alternatively, the first chemical treatment may use an organic solvent.

[0011] The first chemical treatment may dissolve the first bonding material into a solution or separate the first bonding material into particles having a size much smaller than that of the untreated first bonding material, thereby preventing the remainder of the wind turbine blade from decomposing. Alternatively, the first chemical treatment may degrade the first bonding material into a soft, ductile fluid or particle form, from which the remainder of the wind turbine blade can be easily mechanically separated.

[0012] The first bonding material may be a polymer, preferably a thermoset, preferably an epoxy resin.

[0013] The second bonding material may be a polymer, preferably a thermoplastic or thermosetting polymer.

[0014] After the first chemical treatment, the method may further include subjecting a portion of the wind turbine blade section including the second bonding material therein to a second treatment to degrade or remove the second bonding material.

[0015] The second treatment can be a second chemical treatment, wherein the second chemical treatment i) uses different chemicals than the first chemical treatment, or ii) uses the same chemicals as used in the first chemical treatment, but is used under different reaction conditions such that degradation of the second bonding material occurs at a different reaction rate than the first chemical treatment.

[0016] The second bonding material may be a thermoplastic polymer. In the case of using a thermoplastic polymer as the second bonding material, the second treatment may be a heat treatment. The heat treatment may be sufficient to soften or melt the second bonding material so that it can be removed.

[0017] The portion separated after the first chemical treatment may be one or more of a glass fiber portion, a carbon fiber portion, a foam core portion, or a metal portion.

[0018] The method may also include recovering (recovering) one or more materials from the separated portion for recycling into another product. Additionally or alternatively, one or more materials may be recovered from the remaining portion of the wind turbine blade for recycling or other purposes. For example, the first bonding material may be recovered in the form of a (semi-)degraded polymer or oligomer powder after the first chemical treatment.

[0019] The wind turbine blade portion may comprise a first fiber composite portion comprising first fibers in a matrix comprising a first binding material and a second fiber composite portion comprising second fibers in a matrix comprising a second binding material.

[0020] The first fibers may be glass fibers and the second fibers may be carbon fibers, or vice versa, or the first fibers and the second fibers may both be glass or may both be carbon.

[0021] The second bonding material may be the matrix material of the second fiber composite material part.

[0022] The second bonding material may be a covering layer on the matrix material of the second fiber composite material part.

[0023] The matrix material of the second fiber composite material part may be a third bonding material.

[0024] The method may further comprise a third treatment for partially degrading or removing the third bonding material from the second fibrous composite material.

[0025] The second fiber composite portion may comprise a stack of pultruded carbon fiber composite tapes, each tape having opposing major surfaces, and wherein the cover layer of the second bonding material covers i) at least the major surface of each tape, or ii) a majority of the exterior of the stack of tapes.

[0026] In one instance, the third bonding material is the same as the first bonding material, and the third treatment is the same as the first chemical treatment.

[0027] The second bonding material may have a relatively high barrier effect to the first chemical treatment compared to the barrier effect of the first bonding material to the first chemical treatment.

[0028] The method may further comprise mechanically dividing the wind turbine blade to produce wind turbine blade sections, for example prior to the first chemical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0030] Figure 1 A wind turbine is shown;

[0031] Figure 2 A wind turbine blade is shown to be divided into blade parts:

[0032] Figure 3 A first flow chart illustrating a process for preparing a wind turbine for recycling;

[0033] Figure 4 a second flow chart illustrating a process for preparing a wind turbine for recycling;

[0034] Figure 5 a third flow chart illustrating a process for preparing a wind turbine for recycling;

[0035] Figure 6 A chord-wise cross section of a typical wind turbine blade is shown;

[0036] Figure 7 Shown Figure 6 Detailed view of area B;

[0037] Figures 8 to 13 shows a process for preparing wind turbine blade sections for recycling; and

[0038] Figures 14 to 16 Shown is a process for preparing wind turbine blade sections for recycling. DETAILED DESCRIPTION

[0039] Figure 1 A wind turbine 10 is shown. The wind turbine 10 has a tower 12 and a nacelle 14 at the top of the tower 12. A wind turbine rotor 16 is connected to the nacelle 14 and is arranged to rotate relative to the nacelle 14. The wind turbine rotor 16 includes a hub 18 and a plurality of blades 20 extending from the hub 18.

[0040] Wind turbine blades 20 may be comprised of a variety of different materials. For example, a wind turbine blade may include a carbon fiber composite portion, a glass fiber composite portion, a foam core portion, a metal portion, and the like. These materials may all be bonded together within blade 20, making them difficult to disassemble. The bonding materials within blade 20 may include a variety of resins, adhesives, coatings, interlayers, and the like. While glass fiber, carbon fiber, metal, and many polymers are recyclable, the manner in which they are bonded within blade 20 may make it difficult to mechanically separate these materials so that they can be recycled into new products.

[0041] Thermosetting polymer binders are commonly found in wind turbine blades. For example, epoxy resin is commonly used as the potting fluid for the shells of many wind turbine blades. This potting fluid not only serves as a matrix material for the glass fiber layers to form a glass fiber composite when cured, but it can also be used to bond other components, such as metal foil (used in the blade's lightning strike protection system) and carbon fiber composites to the glass fiber composite. The internal shear webs within the blade 20 may also include a glass fiber composite with a thermosetting polymer matrix. This may be the same or a different thermosetting or other epoxy resin used as the potting fluid. The carbon fiber composite may include different matrix materials, and additional polymers may be used as adhesives, for example, to attach the shear webs to the shell or to attach the blade shell halves together. When designing the blade, each binding material will be selected to perform a specific function.

[0042] However, it has been found that some thermosetting polymer bonding materials can degrade through chemical reactions, reducing their bonding capacity. If the polymer degrades sufficiently, such as by removing some crosslinks and / or breaking apart, such as by swelling, the portions of the blade 20 bonded by the thermosetting polymer can be separated. It is recognized that not all bonding materials degrade at the same rate under the same conditions, so while a particular polymer or group of polymers may be degraded by a particular chemical treatment, other portions of the blade may remain bonded together by other bonding materials within the blade.

[0043] By including these different bonding materials, it is proposed to actively exploit this material difference in the processing of wind turbine blades to recycle one or more blade materials, and also to design the blades to achieve more optimized material separation at the end of their life. For example, different material parts of the blade can be coated with a bonding material that is resistant to chemical treatment by another bonding material of the blade, so that the discrete parts of the blade can be separated more easily, thereby ensuring that the resulting recycled products are better separated and have a higher value. For example, a mixture of carbon fiber and glass fiber has a much lower value than pure glass fiber and pure carbon fiber.

[0044] Figure 2 A wind turbine blade 20 having a span-wise longitudinal axis S is shown. Blades 20 can be over 100 meters long, which can make processes for separating blade material for recycling difficult, and therefore the blade may be initially segmented into a plurality of blade sections 21. This segmentation can be accomplished mechanically, for example by using a saw to create a plurality of generally chord-wise cuts in blade 20 to form a plurality of blade sections 21. Each of these blade sections 21 can be further cut along the longitudinal axis or the transverse axis. For example, the interior of a wind turbine blade may include a shear web, which may comprise a subset of the materials used throughout blade 20, and therefore, removal of discrete components such as the shear web may facilitate recycling. Additionally, certain materials, such as carbon fiber composite spar caps and metal foil lightning strike protection layers, may only be present in specific locations within blade 20, and therefore, cutting along or near the boundaries of these materials may further facilitate processing of the blade for recycling.

[0045] Once the blade 20 is cut into the blade portions 21 , the blade portions 21 may be processed depending on the material within the blade portion.

[0046] Figure 3A flow chart illustrating an exemplary method for preparing a wind turbine blade 20 for recycling is shown. After the initial step of mechanically segmenting the blade (which may include blade cutting) to produce a wind turbine blade portion 21 at step 300, the blade portion may be subjected to a first chemical treatment at step 302. At step 304, the first chemical treatment 302 is selected to degrade a first bonding material of the blade. The first chemical treatment is selected to degrade the first bonding material of the blade portion 21 to a significantly greater extent than the second bonding material. Degrading the first bonding material step 304 enables the first portion of the blade to be separated from the remainder of the blade, including the second bonding material at step 308, at step 306. The separation step 306 is initiated when the first chemical treatment at step 302 has sufficiently degraded the first bonding material to release the portion from the remainder of the wind turbine blade portion 21, but before the first chemical treatment has significantly degraded the second bonding material.

[0047] Once the first portion of the blade previously bonded by the first bonding material has been separated from the remainder of the blade at step 306, first blade material may be recovered from the first blade portion at step 310. Thereafter, the recovered first blade material may be forwarded to a recycling station for recycling at step 312.

[0048] The remaining portion of the blade with the second bonding material separated from the first blade portion at step 308 may not be further processed or may undergo a second process at step 314. The second process may degrade the second bonding material at step 316. After degrading the second bonding material, the second blade material may be recovered at step 318. The second blade material may then proceed to a recycling station for recycling at step 320.

[0049] It should be understood that the second treatment can be a second chemical treatment or a non-chemical treatment. For example, the second chemical treatment can use different chemicals than the first chemical treatment, or can use the same chemicals as used in the first chemical treatment but under different reaction conditions, or alternatively, can occur at a different reaction rate than the first chemical treatment. Examples of non-chemical treatments include, for example, heat treatment or mechanical separation. Heat treatment can be used to melt or deform the second bonding material, making it removable. Examples of mechanically separating the second bonding material can include unraveling or cleaving the second bonding material from the blade portion.

[0050] In one example, the blade portion 21 may include a first fiber composite portion comprising first fibers in a matrix comprising a first binding material and a second fiber composite portion comprising a second binding material. The first matrix material may be degraded so that the glass fibers may be removed for recycling and the carbon fiber composite portion may be separated from the glass fiber composite portion. At this stage, after the first chemical treatment, the second matrix material of the carbon fiber composite portion is substantially not degraded by the first chemical treatment. This is because the matrix material used as the first binding material is different from the matrix material used as the second binding material. This illustrates how different matrix materials for the carbon fiber composite portion and the glass fiber composite portion can be advantageously used to separate the carbon fiber composite portion, and also illustrates how, in the same process, the first binding material can be degraded to the extent that the glass fibers can be successfully removed from its matrix (which is the first binding material).

[0051] The matrix material of the fiberglass composite portion can include a polymer, such as a cured thermoset material, for example, an epoxy resin. The chemical composition of the chemical substances used in the first chemical treatment at step 302 will depend on the nature of the matrix material to be degraded by the first chemical treatment. For example, in the case where the first bonding material is an epoxy resin, an acid treatment can be used. The acid treatment can include, for example, acetic acid or formic acid. The acid can preferably have a pH below 4, and most preferably have a pH below 3. These acids can have a relatively low environmental impact and can generally effectively degrade certain thermosetting matrix materials, such as epoxy resins.

[0052] For example, the matrix material may include a The epoxy system, which https: / / www.abg-am.com / portfolio / chemistry / recyclamine-technology / F008?tab=1 (available on October 16, 2022), or as described in La Rosa, Angela & Blanco, Ignazio & Banatao, Diosdado & Pastine, Stefan & Anna&Cicala,Gianluca.(2018).Innovative ChemicalProcess for Recycling Thermosets Cured with by Converting Bio-Epoxy Composites in Reusable Thermoplastic—An LCA Study. Materials. 11.353.10.3390 / ma11030353 (hereinafter referred to as La Rosa et al.) as described in.

[0053] Acid treatment can be performed at or above ambient temperature. Higher temperatures can increase the reaction rate of chemical treatments. Lower temperatures will reduce energy requirements.

[0054] Alternatively, the acid treatment is an acetic acid solution, which is applied by placing the wind turbine section in a dilute (25%) acetic acid recovery bath at 70 degrees Celsius for one hour as described by La Rosa et al. Once the thermosetting matrix is ​​partially or completely degraded or dissolved, the first portion of the blade section and / or the remainder of the blade section can be physically separated, for example, by mechanical action. To recover the degraded particles or dissolved epoxy resin from the first chemical treatment liquid, the acidic recovery liquid of the first chemical treatment can be treated, for example, with sodium hydroxide base (NaOH) under suitable conditions to depolymerize the degraded binder material.

[0055] The second matrix material may also be an epoxy resin, but may have a different composition so that the second matrix material does not significantly degrade during the first chemical treatment. Alternatively, the second matrix material may be another polymer.

[0056] Figure 4 Another exemplary method of preparing a wind turbine blade for recycling is shown. The method begins with a blade segmentation step 400 (e.g., cutting), a first chemical treatment step 402, and degradation of a first bonding material 404, similar to steps 300, 302, and 304 described above. However, Figure 4 The method recognizes that upon degrading the first binding material in step 404, not only can the first blade portion be separated in step 406 and the remaining blade portion with the second binding material be separated in step 408 (similar to steps 306 and 308 described above), but additional materials can also be recovered from the blade for recycling or other purposes. For example, in addition to recovering blade material X from the separated first blade portion from step 406 at step 410, additional blade material Y can be recovered at step 422.

[0057] In one example, blade material X may be fiberglass 410 and blade material Y recovered at step 422 may be metal foil. Both materials X and Y may be recovered from the separated first blade portion 406 upon degradation of the first bonding material at step 404, which may be, for example, epoxy resin. Both blade material X recovered at step 410 and blade material Y recovered at step 422 may proceed to separate recycling streams at respective recycling stations 412 and 414. The remaining blade portion of the second bonding material separated at step 408 may be recovered as described above with respect to Figure 3 Proceed in the same manner as described.

[0058] Furthermore, by degrading the first bonding material in step 404, the first bonding material can also be recovered as a third blade material Z at step 426 after the first chemical treatment 402. For example, where the first bonding material is a thermosetting polymer and the first chemical treatment is an acid treatment, the acid treatment may sufficiently remove some crosslinks or otherwise degrade the thermosetting polymer chains such that the first blade portion and the remaining blade portion can be separated at steps 406 and 408, and the now degraded first bonding material can be recovered from the acid treatment at step 426. The degraded first bonding material recovered as material Z at step 426, through further chemical treatment or otherwise, can proceed to a further recycling station at step 428 as an uncured or partially cured thermosetting resin, which can then be used in the subsequent manufacture of another product.

[0059] Figure 5 Another exemplary method for preparing a wind turbine blade for recycling is illustrated. The method includes similar blade segmentation, a cutting step 500, a first chemical treatment step 502, and degradation of a first bonding material at step 504, similar to steps 302, 304, and 306 described above. The step of degrading the first bonding material 504 is different in the first blade portion, which is separated from the remaining blade portion 508 at step 506.

[0060] The first blade portion separated at step 506 is coated with a second bonding material. By coating the first blade portion with a second bonding material that is not significantly degraded by the first chemical treatment 502, the possibility of recovering dissimilar blade materials that may have been bonded by similar bonding materials that might otherwise have reacted unintentionally or undesirably with the first chemical treatment at step 502 is created. For example, wind turbine blade portion 21 may include a carbon fiber composite and a glass fiber composite using the same or similar polymer matrix materials. In such cases, it may be difficult to prevent the first chemical treatment at step 502 from degrading both matrices of the dissimilar fiber composites, which may make it more difficult to subsequently separate the two dissimilar fiber materials, such as glass fiber and carbon fiber.

[0061] To address this issue, the first blade portion (e.g., a carbon fiber composite portion) is covered with a second bonding material, such as a conventional epoxy matrix, that is different from the first bonding material. The second bonding material used as a covering can be, for example, a glass material or a thermoplastic polymer that does not substantially degrade under the first chemical treatment used to degrade the composite matrix material.

[0062] Afterwards, if Figure 5 As shown, the first blade portion separated at 506 may undergo a second treatment at step 510. At step 512, the second treatment may degrade or remove the second bonding material.

[0063] Once the covering of the second bonding material has been removed at step 512, the blade portion including the third bonding material can be separated at step 514. In one example, the blade portion including the third bonding material can be a fiber composite material, for example having the same or similar matrix material as the first bonding material that can be degraded by the first chemical treatment 502 at step 504. Alternatively, the third bonding material can be different from the first bonding material or the second bonding material. Once the blade portion including the third bonding material has been separated at step 514, it can undergo a third treatment at step 516. At step 518, the third treatment 516 can degrade or remove the third bonding material. At step 520, the degraded third bonding material can be recovered as blade material A. At step 522, blade material A can be forwarded to a recycling station for recycling.

[0064] The second bonding material removed at step 512 may be recovered at step 524 as a second blade material B. At step 526 , the blade material B may be recycled at a recycling station.

[0065] In one example, wind turbine blade portion 21 includes a first fiber composite portion and a second fiber composite portion. The first fiber composite portion may include glass fibers in a matrix comprising a first bonding material, and the second fiber composite portion may include carbon fibers. The second bonding material may be a cover layer on the matrix material of the second fiber composite portion. The matrix material may be a third bonding material. In one example, the first fiber composite portion is a glass fiber material having a thermosetting epoxy resin matrix, and the second fiber composite portion is a carbon fiber composite portion having a thermosetting resin matrix and covered with a thermoplastic polymer.

[0066] The carbon fiber composite part may comprise a stack of pultruded carbon fiber composite tapes, each tape having opposing major surfaces. The cover layer of the second bonding material may cover at least a major surface of each tape, or cover a substantial portion of the exterior of the stack of tapes.

[0067] The use of a second bonding material as a cover layer can be designed into the manufacturing process of a wind turbine blade to enable improved separation of the blade for recycling at the end of its life. The cover layer of the second bonding material can be compatible (e.g., adherent) with both the first bonding material and the third bonding material (e.g., the thermosetting resin matrix materials of the carbon fiber composite portion and the glass fiber composite portion). Aside from enabling improved separation of the blade materials at the end of their life, the cover layer of the second bonding material may not serve any useful structural purpose within the blade.

[0068] The second bonding material may have a relatively high barrier effect to the first chemical treatment compared to the barrier effect of the first bonding material to the first chemical treatment.

[0069] Figure 6 and Figure 7 A cross section of a wind turbine blade is illustrated, showing a chord-wise cross-section of one of the blade sections 21. Wind turbine blade 20 may include a first shell half 22 and a second shell half 24 connected at a leading edge 26 and a trailing edge 28. The blade section has a hollow interior 34 and a shear web 40 extending between the first and second shell halves 22, 24. Each shell half 22, 24 may have a sandwich construction including a fiber composite material 42 and a core material 44. The fiber composite material may include an inner fiber composite layer 45 and an outer fiber composite layer 46. The core material 44 is sandwiched between the inner and outer fiber composite layers 45, 46. A metal foil layer 48 may be disposed within the outer fiber composite layer. The core material 44 may terminate adjacent to the shear web 40 to form a stack of fiber composite layers for forming a spar cap 100. The spar cap 100 may be a stack of carbon fiber composite layers, particularly pultruded carbon fiber composite layers.

[0070] A process for recycling a wind turbine blade 20 having a structure similar to that described with respect to FIG. Figure 6 and Figure 7 The structure shown is the same as the structure shown.

[0071] exist Figure 8 In the embodiment of the present invention, the divided blade portion 21 including the first fiber composite material 42, the core material 44 and the second fiber composite material 100 is placed in a container 50 carrying a first liquid chemical 52. The first chemical 52 may be a chemical for a first chemical treatment for degrading the first matrix material 43 of the first fiber composite material 44. The wind turbine blade portion 21 may be immersed in the liquid chemical 52 or exposed to the liquid chemical, for example, by spraying.

[0072] After a period of time sufficient to allow the liquid chemical 52 to chemically react with the first bonding material 43 under certain reaction conditions and at certain reaction rates, the first bonding material 43 is sufficiently degraded to release the individual fibers 45 from the now degraded first bonding material 43a, and the core material 44 and the second fiber composite portion 100 are also detached from the first fiber composite 42 due to the degradation of the first bonding material 43. The detached portion after the first chemical treatment is as shown in FIG. Figure 9 shown.

[0073] exist Figure 10In the process, the second fiber composite material portion 100, which is substantially unaffected by the first chemical treatment, is separated from the remainder of the blade portion 21. The second fiber composite material portion 100 may be placed in a second container 54.

[0074] like Figure 11 As shown, the core material piece 44 can be removed from the container 50 and recovered in a separate recycling stream. Similarly, the first fibers 45 can be removed from the container and recovered in a separate recycling stream. The degraded first bonding material 43a can be completely dissolved in the first chemical 52, or can remain within the container 50 as a malleable / fluid or solid particulate material.

[0075] like Figure 12 As shown, the first chemical 52 may be drained from the container 50 to a third container 56 to leave behind the degraded first bonding material 43a, which may be recovered and possibly recycled in a separate recycling stream.

[0076] Returning to the second fiber composite material part 100 , Figure 13 The second fiber composite portion 54 is shown being processed in a container 52 containing a second chemical liquid 58. The second chemical liquid 58 may cause a second chemical treatment reaction to occur with a second bonding material 102, which may be a second matrix material of the second fibers 104 of the second fiber composite portion 100.

[0077] The second chemical 58 performs a second chemical reaction in the second vessel 54 to degrade the second bonding material 102, thereby separating the individual fiber layers and / or fibers of the second fiber layer 102. Once the second bonding material 102 is sufficiently degraded, the second fiber material 104 can be removed from the vessel 54 and recovered in a separate recovery stream.

[0078] Figures 14 to 16 A further example is shown, in which the blade portion 21 differs in that the second fiber composite material portion 100 is covered in a layer of a third bonding material 106. In all other respects, Figure 14 The blade portion 21 shown in FIG. Figure 8 Same as described. Figure 15 Shows the first chemical treatment Figure 14 of the blade portion 21, and again similar to Figure 9 , except that a covering layer of the third bonding material 106 remains on the second fiber composite material portion 100 and is substantially unaffected by the first chemical treatment.

[0079] Steering Figure 16, the processing of the first fiber composite material and the core block is as previously described and is not shown again for the sake of brevity. The second fiber composite material portion 100 covered in the third binding material 106 can be removed from the container 50 after the first chemical treatment and can be subjected to a second treatment to remove the covering third binding material 106 from the second fiber composite material portion 100. In one example, the covering layer of the third binding material is a thermoplastic material. In this example, the second fiber composite material portion 100 covered with the third binding material 106 is placed in the oven 56 and subjected to a heat treatment, resulting in the removal of the covering layer of thermoplastic material 106, which can be recycled in a separate recycling stream. The now uncovered second fiber composite material 100 can then be recycled, for example, in the same manner as previously referenced. Figure 13 The same manner as described is handled for recycling.

[0080] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method of preparing a wind turbine blade (20) for recycling, the method comprising: subjecting at least a portion (21) of the wind turbine blade to a first chemical treatment (302), wherein the first chemical treatment (302, 402, 502) is selected to degrade a first bonding material (43) of the wind turbine blade portion (21) to a significantly greater extent than a second bonding material (102) of the wind turbine blade portion (21); and After the first chemical treatment (302, 402, 502) has sufficiently degraded the first bonding material (43) to release a portion of the wind turbine blade portion from the remainder of the wind turbine blade portion and before the first chemical treatment has significantly degraded the second bonding material (102), separating the portion from the remainder of the wind turbine blade portion.

2. The method according to claim 1, wherein The first chemical treatment (302, 402, 502) is an acid treatment, and preferably, formic acid or acetic acid is used in the acid treatment.

3. The method according to claim 1 or claim 2, wherein: The first bonding material (43) is a polymer, preferably a thermosetting material, preferably an epoxy resin.

4. A method according to any preceding claim, wherein: The second bonding material (102) is a polymer, preferably a thermoplastic or thermosetting polymer.

5. The method according to any preceding claim, further comprising: After the first chemical treatment (304, 402, 502), the portion of the wind turbine blade section including the second bonding material is subjected to a second treatment (314, 510) to degrade or remove (316, 512) the second bonding material (102).

6. The method according to claim 5, wherein: The second treatment (314, 510) is a second chemical treatment, wherein the second chemical treatment i) uses different chemicals than the first chemical treatment, or ii) uses the same chemicals as used in the first chemical treatment but under different reaction conditions, so that degradation of the second bonding material (102) occurs at a different reaction rate than the first chemical treatment (304, 402, 502).

7. The method according to claim 5, wherein: The second bonding material (102) is a thermoplastic polymer and the second treatment is a heat treatment.

8. A method according to any preceding claim, wherein: The portion (306, 406) separated after the first chemical treatment (304, 402) is one or more of a glass fiber portion, a carbon fiber portion, a foam core portion, or a metal portion.

9. The method of claim 8, further comprising recovering (310, 410, 422) one or more materials from the separated portion for recycling into another product.

10. A method according to any preceding claim, wherein The wind turbine blade portion (21) comprises a first fiber composite portion and a second fiber composite portion, wherein the first fiber composite portion comprises first fibers in a matrix comprising the first bonding material and the second fiber composite portion comprises second fibers in a matrix comprising the second bonding material, preferably wherein the first fibers are glass fibers and the second fibers are carbon fibers.

11. The method according to claim 10, wherein: The second bonding material is the matrix material of the second fiber composite material portion.

12. The method according to claim 10, wherein: The second bonding material is a covering layer on the matrix material of the second fiber composite part, preferably, wherein the matrix material of the second fiber composite part is a third bonding material, and further preferably, wherein the method includes a third treatment (516) for degrading or removing the third bonding material (518) from the second fiber composite part.

13. The method according to claim 12, wherein: The second fiber composite portion comprises a stack of pultruded carbon fiber composite tapes, each tape having opposing major surfaces, and wherein the cover layer of the second bonding material covers i) at least a major surface of each tape, or ii) a majority of the exterior of the stack of tapes.

14. A method according to any preceding claim, wherein: The second bonding material (102) has a relatively high barrier effect on the first chemical treatment (302, 402, 502) compared to the barrier effect of the first bonding material (43) on the first chemical treatment (302, 402, 502).

15. The method according to any preceding claim, further comprising mechanically dividing (300) the wind turbine blade (20) to produce wind turbine blade sections (21).

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