Method for recycling at least a portion of a textile material comprising polyester fibers, and system for the method

Abstract

This invention describes a method for recovering at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the method comprising: - preheating a reaction liquid comprising at least methanol in a feeding unit; - loading the textile material comprising polyester fibers and at least one other type of fiber into a reactor unit; - injecting the preheated reaction liquid and catalyst from the feeding unit into the reactor unit; - performing a depolymerization step, the depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile material to the catalyst and methanol to perform a methanol depolymerization reaction on the polyester fibers in the textile material while keeping at least a portion of the other type of fiber in a fibrous state; - recovering a liquid solution comprising depolymerized polyester and methanol from the reactor unit; and - recovering fibrous material comprising the other type of fiber from the reactor unit.

Description

Technical Field

[0001] The present invention relates to a method for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber. Background Technology

[0002] This document describes methods and systems for recovering at least a portion of textile materials containing polyester fibers. For example, WO2018 / 150028 discloses a method for recovering polyester from polyester textiles, wherein the method includes the steps of: providing the polyester textiles immersed in a mixture comprising a solvent and a catalyst; during the depolymerization of the polyester in the polyester textiles, heating the mixture containing the polyester textiles and maintaining its temperature in the range of 80-240°C; wherein, in the step of immersing the polyester textiles in the mixture, the catalyst of the mixture comprises calcium oxide. Furthermore, WO2020 / 035590 discloses a process similar to WO2018 / 150028, but in this case using a catalyst comprising calcium hydroxide.

[0003] One of the objectives of this invention is to provide an optimal method and system for obtaining depolymerized polyester fibers from textile materials. Summary of the Invention

[0004] The above objective is achieved by a method for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the method comprising: - Preheat the reaction solution containing at least methanol in the charging unit; - A textile material containing polyester fibers and at least one other type of fiber is loaded into the reactor unit; - Inject the preheated reaction liquid and catalyst from the feed unit into the reactor unit; - Perform a depolymerization step, which includes providing a temperature of at least 80°C in a reactor unit and exposing the textile material to a catalyst and methanol to perform a methanol depolymerization reaction on the polyester fibers in the textile material, while keeping at least a portion of the other types of fibers in a fibrous state. - Recover a liquid solution containing depolymerized polyester and methanol from the reactor unit; as well as - Recover fibrous materials containing the other types of fibers from the reactor unit.

[0005] Preheating methanol or a mixture of catalyst and methanol can accelerate the dissolution of the catalyst (e.g., CaO) in methanol, thereby generating methoxide ions. This reduces the time required to complete depolymerization, and consequently shortens the cycle time for batch operations in the reactor.

[0006] It is believed that the function / mechanism of the CaO-MgO mineral-based "catalyst" is as follows: the CaO in the catalyst first reacts with methanol to form methoxy calcium (Ca(OCH3)2). Subsequently, the slightly soluble Ca(OCH3)2 in methanol triggers a depolymerization reaction, that is, the methoxy group attacks the chemical bonds in PET, thereby initiating depolymerization. Attached Figure Description

[0007] Figure 1 A schematic diagram illustrating the steps involved in at least one embodiment of the method of the present invention is shown.

[0008] Figure 2 A schematic block diagram view of the system of the present invention is shown.

[0009] Figure 3 A depolymerization reactor unit that can be used in the system of the present invention is shown.

[0010] Figure 4 A feeding unit according to an embodiment is shown, which is used to supply preheated methanol and catalyst suspension to a depolymerization reactor unit.

[0011] Figure 5 A system for recycling at least a portion of textile material consisting of polyester fibers and at least one other type of fiber, according to an embodiment, is shown.

[0012] Figure 6 A perforated rotatable roller according to an embodiment is shown, which is used in this system and for implementing this method. Detailed Implementation

[0013] Several embodiments of the present invention are provided below.

[0014] According to one embodiment, the reaction solution comprises a suspension of methanol and a catalyst. As described above, the method of the present invention may involve preheating the suspension of catalyst and methanol, or mixing preheated methanol with the catalyst. In the first case, cold methanol may also be used when mixing methanol with the catalyst.

[0015] According to another embodiment, the feeding unit includes a de-agglomeration vessel, in which methanol and the catalyst are mixed to form a suspension. The de-agglomeration vessel according to the invention allows for good dispersion of the catalyst in methanol.

[0016] For depolymerization, equipping the tank with an agitation unit can also be of great significance. Therefore, according to one embodiment, the feed tank is equipped with an agitation unit. Thus, the depolymerization tank can be equipped with an agitation unit. Equipping the tank with an agitator / agitation unit to form a homogeneous suspension of the catalyst in methanol can be advantageous. According to one embodiment, the feed unit (e.g., the agitation unit) is configured with a high-shear mixer as the agitation unit. Such a high-shear mixer ensures the provision of high shear forces, which are crucial for depolymerization. It should be noted that different types of agitation units can also be used. According to one embodiment, the feed unit (e.g., the agitation unit) is equipped with a depolymerization agitation unit. An example is an agitator suitable for dispersing powder in a liquid (e.g., an agitator similar to that used for dispersing coating powder).

[0017] According to another embodiment, the feeding unit further includes a storage vessel, through which the suspension can be conveyed from the depolymerization tank to the storage vessel. Preferably, the suspension is diluted in the storage vessel by adding more methanol. The storage vessel may also be equipped with a stirring unit, such as a paddle-type stirring unit, for stirring the entire volume of the storage vessel.

[0018] According to another embodiment, the preheated reaction solution, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 50-240°C, preferably 70-200°C, more preferably 80-180°C, and most preferably 140-175°C. According to another embodiment, the preheated reaction solution, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 100-180°C, more preferably 140-175°C, for at least 15 minutes, preferably 30 minutes. Since the boiling point of methanol at atmospheric pressure is approximately 65°C, preheating is typically carried out under conditions above atmospheric pressure.

[0019] It should be noted that the method of the present invention can be implemented by preheating methanol and then mixing the preheated methanol with the catalyst, or by preheating a suspension of the catalyst and methanol. Furthermore, as mentioned above, the method of the present invention can involve various combinations of preheating temperature and time, in conjunction with appropriate reaction time and temperature in the depolymerization reaction unit (see below for details).

[0020] As can be seen from the above, the feed unit and reactor unit are appropriately separated. According to one embodiment, the volume of the feed unit is smaller than that of the reactor unit. According to the invention, different alternatives to the feed unit and stirring configurations can be employed. For example, a feed unit equipped only with a high-shear mixer. Another example is a feed unit with multiple stirring units, which typically have different purposes; for example, a high-shear mixer / depolymerization stirring unit for depolymerization is provided in a small volume region at the bottom of the feed unit, and a paddle-type stirring unit or similar device is provided within the feed unit to stir the entire feed unit volume. Methanol can then be added at the top of this feed unit configuration.

[0021] According to one embodiment, in at least a portion of the step of preheating the reaction liquid in the feeding device, the reaction liquid (preferably a suspension of methanol and catalyst) is maintained at an absolute pressure of at least 5 bar, preferably at least 10 bar, more preferably less than 40 bar, for example less than 30 bar, and more preferably, the pressure is in the range of 10-25 bar absolute pressure for at least a portion of the time during the depolymerization step. The pressure depends on the temperature and the vapor pressure of the solvent at that particular temperature. Depending on the solvent used and the set temperature, the pressure value can be obtained from the pressure-temperature curve of the solvent.

[0022] Furthermore, according to one embodiment, the preheated reaction liquid and catalyst from the feed unit are conveyed to multiple reactor units, such as at least two, or more preferably at least three separate reactor units.

[0023] Furthermore, according to one embodiment, preheating is carried out within the feeding unit under an inert atmosphere, preferably in an N2 environment. As those skilled in the art know, N2 (nitrogen) is essentially inert. Alternatively, other inert gases, such as noble gases (e.g., argon), may also be used.

[0024] According to yet another embodiment, the method includes - A mixing step, which includes contacting a textile material with a suspension containing a catalyst and methanol in a rotatable drum of the reactor unit, preferably the rotatable drum being arranged to rotate about an axis (A) at an angle of less than 45° to the horizontal plane. During at least one of the mixing and depolymerization steps, the drum is rotated to tumble the textile material inside and bring it into contact with the catalyst and methanol. By using a rotating drum, a tumbling process is achieved that ensures that the textile material, composed of polyester fibers and at least one other fiber, comes into contact with the suspension containing the catalyst and methanol as it rotates within the rotatable drum of the reactor unit. This rotation process is advantageous when mixing different components and is therefore applied in the mixing and / or depolymerization steps. This is also why the method requires drum rotation in at least one of the mixing and depolymerization steps, and this rotation operation is preferably performed for at least a portion of the time in both steps.

[0025] This method provides an efficient way to separate polyester, which has been depolymerized by a catalyst and methanol to form a depolymerized polyester solution, from other fibers that remain in a fibrous state (i.e., solid state), such as cellulose fibers, for example, cotton fibers. Furthermore, in one or more subsequent rinsing steps, drum rotation is also preferred, as will be discussed further below. Moreover, since the rotation should be performed while the fibers are in contact with the suspension, it is preferable to rotate regularly about a generally horizontal axis. Additionally, according to the invention, rotation with both a slightly inclined plane and angle can also be performed. Therefore, according to the invention, when a rotatable drum is used, it is arranged to rotate about an axis with an angle of less than 45° to the horizontal plane. However, it should be noted that according to the invention, an angle of less than 25°, for example less than 10°, or even close to or equal to 0° to the horizontal plane, is more preferred. It should also be noted that the rotatable drum within the pressure vessel shell is preferably a perforated drum. This is because it simplifies the separation process of the methanol-monomer solution from the textiles remaining in the rotatable drum after the reaction, drainage, and centrifugal drying. By using a perforated roller, other fibers can remain inside the roller, while the solution / dispersion containing depolymerized polyester can be separated from it through the holes.

[0026] Furthermore, according to one embodiment of the invention, during at least a portion of the depolymerization step, the temperature within the reactor unit is maintained in the range of 100-200°C, preferably in the range of 110-180°C, more preferably in the range of 120-170°C, and most preferably in the range of 140-170°C. In the presence of certain high-temperature sensitive fibrous materials (e.g., cotton), the temperature is preferably below 200°C when performing polyester depolymerization. Furthermore, methanol performs best at temperatures below 200°C. Moreover, at temperatures below 100°C, the yield of depolymerized polyester is too low. Given that the boiling point of methanol at atmospheric pressure is approximately 65°C, depolymerization is typically carried out at pressures above atmospheric pressure.

[0027] According to one embodiment, during at least a portion of the depolymerization step, the pressure within the reactor unit is maintained at an absolute pressure of at least 5 bar, preferably at least 10 bar, more preferably less than 40 bar, for example less than 30 bar, and more preferably, the pressure is in the range of 10-25 bar absolute pressure during at least a portion of the depolymerization step. Furthermore, the reactor unit preferably includes a perforated rotatable drum, preferably with the perforations at least arranged on the mantle surface of the rotatable drum.

[0028] According to the present invention, different types of fiber materials can be used. According to one embodiment of the present invention, at least one other type of fiber in the textile material includes cellulose-based fibers. Preferably, the cellulose-based fiber is at least one of natural cellulose fibers and man-made cellulose fibers, such as cotton and flax, and such as viscose, lyocell, rayon, and / or modal fibers. More preferably, the at least one other type of fiber includes at least cotton fibers.

[0029] According to another embodiment, the textile material comprises at least 30% by weight, preferably at least 40% by weight, and more preferably at least 50% by weight of cellulose-based fibers. The textile material comprises at least 30% by weight, preferably at least 40% by weight, and more preferably at least 50% by weight of cotton fibers. Further, the textile material may comprise at least 30% by weight, preferably at least 40% by weight, and more preferably at least 50% by weight of polyester cotton textile material.

[0030] Furthermore, the catalyst used according to the invention can be of different types. According to one embodiment, the catalyst comprises Ca. Preferably, the catalyst comprises at least one of CaO, CaO-MgO, and Ca(OH)₂. According to the invention, different Ca sources can be used, one example being dolomite, such as a Ca / Mg / O source derived from CaMg(CO₃)₂. As known to those skilled in the art, dolomite is an anhydrous carbonate mineral composed of calcium and magnesium carbonate, with the ideal chemical formula CaMg(CO₃)₂. According to one embodiment, the catalyst comprises dolomite.

[0031] According to another embodiment, the catalyst has a specific surface area of ​​at least 5 m². 2 / g, preferably at least 10m 2 / g, more preferably at least 15m 2 / g, preferably at least 20m 2 / g. The specific surface area of ​​the catalyst can be determined by the BET (Brunauer-Emmett-Teller) method. According to one embodiment, the specific surface area of ​​the catalyst is determined according to applicable standards, such as ASTM D3663-20 or ISO 9277:2022.

[0032] Furthermore, according to one embodiment, the catalyst is at a concentration of 0.05-0.5 m per gram of textile. 2 The preferred concentration for addition is 0.08-0.4 mg / gram of textile. 2 Therefore, in determining the amount of catalyst to be added, the specific surface area of ​​the catalyst, rather than its weight, may play a decisive role.

[0033] Furthermore, to maintain an inert atmosphere within the charging container, according to one embodiment, the methanol depolymerization reaction is carried out under an inert atmosphere within the reactor unit, preferably in a N2 environment. This inert environment prevents unintended reactions such as oxidation and hydrolysis.

[0034] Furthermore, according to another embodiment, the method further includes performing one or more rinsing steps, preferably performing one or more rinsing steps by further adding methanol to the reactor unit. More preferably, heated methanol is used in the rinsing steps. More preferably, the method includes performing multiple rinsing steps after recovering a liquid solution containing depolymerized polyester and methanol from the reactor unit to dissolve residual depolymerized polyester in the reactor unit. Preferably, the rotatable drum of the present invention is rotating for at least a portion of the rinsing steps. According to yet another embodiment of the present invention, the method may include multiple rinsing steps.

[0035] Furthermore, according to another embodiment, the method includes drying the remaining fibrous material after the depolymerization step to obtain a substantially methanol-free dry fibrous material, and optionally discharging the remaining methanol from the reactor unit. The drying step can be performed before removing the fibrous material containing the other types of fibers from the reactor unit. Preferably, the drying step is performed by applying a low pressure (e.g., vacuum) to the reactor unit.

[0036] According to one embodiment, the method includes at least one rinsing step as described above, which is preferably carried out in methanol injected into a reactor unit. Preferably, the reactor unit is a rotatable drum that rotates for at least a portion of the rinsing step. More preferably, the method includes multiple rinsing steps.

[0037] According to another embodiment, the at least one rinsing step employs a centrifugal dehydration principle to separate methanol and depolymerized polyester from the fibrous material. By using a perforated roller, the methanol and depolymerized polyester can be separated from the remaining fibrous material by rotating the roller.

[0038] Furthermore, according to one embodiment, after the polyester depolymerization, the fibrous material remaining in the reactor unit (preferably a rotatable drum) is dried by applying a vacuum to the reactor unit to evaporate methanol. Moreover, during this drying process, it is preferable to keep the drum continuously rotating to promote methanol evaporation. Additionally, it is preferable to evaporate and remove the methanol before removing any fibrous material from the drum.

[0039] According to another embodiment of the invention, after the depolymerization step, drainage, and / or rinsing step, the catalyst and methanol solution are discharged through an outlet equipped with a particulate filter. This operation aims to filter out the catalyst particles. Preferably, this operation is for further utilization of the catalyst particles. The catalyst used can be filtered out and disposed of with the waste stream; reuse is also another possibility. According to this embodiment, residues, as well as used catalyst or unused catalyst particles, are filtered out. However, DMT (dimethyl terephthalate, i.e., depolymerized polyester produced by methanol depolymerization of polyester) dissolved in methanol is filtered and proceeds to the next step of the process. Furthermore, in a later stage of the process, catalyst residues on the treated textile material are rinsed away.

[0040] Furthermore, according to one embodiment, after the step of withdrawing the liquid solution containing the depolymerized polyester from the reactor unit, the resulting depolymerized polyester (e.g., DMT) is concentrated, cooled, and crystallized to separate the DMT, and the methanol is returned to the reactor unit for recycling. Preferably, the DMT is cooled and crystallized in a separate crystallization reactor unit.

[0041] Furthermore, according to another embodiment of the invention, methanol, after being discharged from the reactor unit, is recovered through at least one evaporation step or through a distillation step, preferably as part of a recycling process after methanol is separated from the depolymerized polyester and any residual catalyst. After final centrifugal drying, the reactor can be connected to a vacuum system to evaporate any remaining methanol in the textile while rotating it. Since the reactor remains at a high temperature, i.e., at least 80°C, this means that the textile inside the reactor is dried in this process step, thus subjecting the textile inside the reactor to drum drying.

[0042] According to one embodiment, the reactor unit is in a closed state when a suspension containing a catalyst and methanol is fed.

[0043] Furthermore, according to one embodiment, the method includes: - Recover a liquid solution containing depolymerized polyester and methanol from the reactor unit. - The remaining fiber material is dried to provide a dry fiber material that is essentially free of methanol, and the remaining methanol in the reactor unit is discharged, for example, by conveying it to a methanol recovery system via vacuum. as well as - Recover fibrous materials containing the other types of fibers from the reactor unit, preferably, the reactor unit is in an open state relative to the surrounding environment when recovering fibrous materials containing the other types of fibers.

[0044] In addition, according to another embodiment, the recovery liquid containing depolymerized polyester (e.g., DMT) and methanol is subjected to at least filtration treatment, preferably crystallization before filtration, in order to separate methanol from depolymerized polyester.

[0045] Furthermore, according to one embodiment, the separated methanol is recycled and mixed with a suspension stream containing the catalyst and methanol, which is intended to be injected into the reactor unit; alternatively, a waste stream is separated before the methanol is recycled.

[0046] According to one embodiment, the depolymerized polyester separated from methanol needs to be dried before it can be retained as DMT (dimethyl terephthalate, i.e., depolymerized polyester produced by methanol depolymerization of polyester).

[0047] The present invention also provides a system (e.g., a textile recycling system) for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber; the system is used to depolymerize the polyester fibers (preferably by methanol depolymerization) while maintaining the other types of fibers contained in the textile material in a fibrous state; the system includes - Feeding unit; - A depolymerization reactor unit, wherein the depolymerization reactor unit is a pressure vessel, suitable for withstanding a temperature of at least 80°C, preferably suitable for withstanding a pressure of at least 5 bar, more preferably at least 10 bar; The feeding unit is used to supply preheated reaction liquid and catalyst to the depolymerization reactor unit, preferably a suspension of methanol and catalyst.

[0048] According to one embodiment, the feeding unit is configured as a separate unit from the depolymerization reactor unit.

[0049] According to one embodiment, the feeding unit includes a depolymerization tank. The depolymerization tank is used to mix methanol with the catalyst to form a suspension. Furthermore, according to yet another embodiment, the feeding unit also includes a storage tank. The storage tank is connected to the depolymerization tank to transfer the suspension from the depolymerization tank to the storage tank. Preferably, the suspension can be diluted by adding more methanol to the storage tank.

[0050] Based on the above description, according to another embodiment, the feeding unit is equipped with a stirring unit. According to one embodiment, the feeding unit is configured with a high-shear mixer as the stirring unit. Furthermore, according to yet another embodiment, the feeding unit is configured with a depolymerization stirring unit. The feeding unit may also include multiple stirring units, such as a combination of a high-shear mixer / depolymerization stirring unit and another type of stirring unit (such as a paddle-type stirring unit).

[0051] Furthermore, the system of the present invention is preferably based on using vacuum as a means of filling the reactor unit. The system of the present invention can also be based on integrating a pump for feeding, but this approach has a drawback: since methanol is considered a flammable solvent, certain equipment must be ensured to meet ATEX classification requirements. Based on the foregoing, according to one embodiment, the system is connected to an overpressure and / or vacuum system to utilize overpressure or vacuum to transport methanol, catalyst, and / or a suspension of methanol and catalyst.

[0052] According to another embodiment, the feeding unit is configured to ensure that the preheated reaction liquid, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 50-240°C, preferably 70-200°C, more preferably 80-180°C, and most preferably 140-175°C. According to another embodiment, the feeding unit is configured to ensure that the preheated reaction liquid, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 100-180°C, more preferably 140-175°C, for at least 15 minutes, preferably 30 minutes.

[0053] Furthermore, according to one embodiment, the volume of the feeding unit is smaller than that of the depolymerization reactor unit.

[0054] Furthermore, according to one embodiment, the feed unit is configured to withstand an absolute pressure of at least 5 bar, more preferably at least 10 bar, so that during at least a portion of the preheating step, the reaction liquid, preferably a suspension of methanol and catalyst, is held in the feed unit at a pressure of at least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably less than 40 bar absolute pressure, for example less than 30 bar absolute pressure, and more preferably, the pressure is in the range of 10-25 bar absolute pressure for at least a portion of the preheating step.

[0055] According to one embodiment, the feeding unit includes heating means. Heating capacity can be provided in various ways. For example, the feeding unit may have a jacket heated by oil or other media, steam, electricity, or may actually have a heating coil inside the feeding unit.

[0056] According to another embodiment, the system includes multiple depolymerization reactor units, such that preheated reaction liquid and catalyst from the feed unit can be delivered to the multiple depolymerization reactor units, for example at least two, or more preferably at least three independent depolymerization reactor units.

[0057] As mentioned above, according to one embodiment, the feeding unit is connected to an inert gas source, so that the feeding unit can perform a preheating step in an inert atmosphere. Preferably, the inert atmosphere source is an N2 source.

[0058] Furthermore, according to another embodiment, the system includes a depolymerization reactor unit consisting of a rotatable drum. The rotatable drum is configured to rotate about an axis. Preferably, the angle between the axis and the horizontal plane is less than 45°; more preferably, the angle between the axis and the horizontal plane is less than 25° during the rotation of the rotatable drum; most preferably, the angle is in the range of 0-10°.

[0059] According to another embodiment, the reactor unit is a rotatable drum with perforations to separate the methanol-monomer solution (e.g., a methanol solution of DMT) from the remaining textiles after the depolymerization reaction and any subsequent possible steps. The rotatable drum is housed inside the reactor unit's housing. The housing serves to maintain the required pressure within the reactor unit and collect the solution draining through the perforations in the rotatable drum. Preferably, the rotatable drum (typically cylindrical) has perforations in its cylindrical portion and / or at least one side portion (corresponding to the bottom surface of the cylinder). More preferably, the rotatable drum has perforations in its cylindrical portion and at least one side portion. More preferably, the rotatable drum has perforations in both its cylindrical portion and both sidewall portions. The perforations are designed to allow the methanol-monomer solution to separate from the remaining textiles after the depolymerization reaction and / or any potential subsequent steps (such as rinsing). Therefore, the size and shape of the perforations are adjusted to retain the textiles within the drum.

[0060] According to another embodiment of the invention, the depolymerization reactor unit includes a heating device. Preferably, the heating device is arranged inside the shell of the depolymerization reactor unit. More preferably, the heating device is at least partially disposed in the space between the shell of the depolymerization reactor unit and the jacket of the depolymerization reactor unit, which preferably includes a rotatable drum. By providing a heating device, it is easier to maintain the required process temperature during the depolymerization reaction. Preferably, the heating device is disposed inside the shell of the reactor unit. More preferably, the heating device is at least partially disposed in the space between the shell of the reactor unit and the outer jacket of the rotatable drum. The heating device of the system according to the invention is suitable for heating the temperature to at least 80°C, preferably at least 100°C, more preferably at least 120°C, even more preferably at least 140°C, most preferably at least 170°C, and even up to at least 200°C. Furthermore, the reactor can be heated by using different types of fluids (e.g., oil) in the jacket.

[0061] In addition, an integrated cooling system may be required. Such a cooling system can be housed within the mechanical seal of the reactor unit.

[0062] Furthermore, according to another embodiment, the depolymerization reactor unit is connected to an outlet equipped with a particulate filter. In the particulate filter, any residual catalyst particles can be filtered out along with any solid textile debris and other particles (e.g., particulate pigments).

[0063] Furthermore, according to another embodiment, the system further includes a crystallization reactor unit connected to the depolymerization reactor unit. Preferably, the system also includes a recirculation loop for recycling the solvent from the crystallization reactor unit back to the depolymerization reactor unit, preferably via at least one distillation unit or an evaporator unit, or a combination of both. In a preferred embodiment, the recirculation loop may be via at least one evaporator unit, a distillation unit, or a combination of both.

[0064] According to another embodiment, the system is configured to rotate a reactor unit in the form of a rotatable drum, typically a perforated drum, in a centrifugal drying mode. This operation can be used to separate a solution containing methanol and depolymerized polyester from the fibrous material after a depolymerization step, and / or to separate methanol from the fibrous material during a rinsing step. The rotatable drum can be designed to retain the fibrous material within the drum during the aforementioned centrifugal drying process and allow the solution to be released from the drum through the perforations, collected in the shell of the reactor unit, and subsequently discharged via a discharge port.

[0065] In addition, according to another embodiment, the system includes a vacuum arrangement for applying a vacuum to the depolymerization reactor unit to dry the fibrous material retained in the depolymerization reactor unit (preferably including a rotatable drum) by methanol evaporation.

[0066] Other aspects of the invention The present invention also relates to some further aspects. According to one aspect of the invention, a method is provided for achieving at least one of the following: i) recycling polyester, and ii) regenerating cellulose fibers from textiles comprising polyester and cellulose fibers, wherein the method comprises the following steps: - The textiles, which are soaked in a suspension including methanol and a catalyst, are placed in a reactor; - During the depolymerization of the polyester in the textile, the temperature of the suspension containing the textile is maintained in the range of 80-240°C, and the depolymerization is carried out by methanol depolymerization; and - After the depolymerization, polyester and / or regenerated cellulose fibers are recovered, wherein, in the step of placing the textiles soaked in the mixture into the reactor, the catalyst in the suspension comprises calcium oxide or calcium hydroxide, or a combination thereof; The catalyst has a specific surface area of ​​at least 5 m². 2 / g, and the suspension containing methanol and catalyst contains 0.2-10% by weight of catalyst.

[0067] According to one embodiment of this aspect of the invention, the reactor does not have a rotating drum. According to another embodiment, the reactor has a fixed inner wall and an agitator. Furthermore, according to yet another embodiment of this aspect of the invention, the reactor is selected from plug flow reactors and continuous reactors, such as continuous stirred tank reactors (CSTRs), preferably plug flow reactors.

[0068] The presence of calcium is a key characteristic of the catalyst used according to the present invention. In addition, other parameters are also important. One such parameter is the catalyst specific surface area, as mentioned above. A higher specific surface area can be obtained by providing relatively small catalyst particles. For example, a grinding process can be used to ensure that the desired maximum particle size is achieved. The total specific surface area of ​​the catalyst is typically determined using the BET (Brunauer-Emmett-Teller) method, for example according to applicable standards such as ASTM D3663-20 or ISO 9277:2022. According to one embodiment of the present invention, the total specific surface area of ​​the catalyst is at least 10 m². 2 / g, more preferably at least 15 m 2 / g, preferably at least 20 m 2 / g. According to another embodiment, the catalyst comprises Ca. Preferably, the catalyst comprises one or more of CaO, CaO-MgO, and Ca(OH)2, more preferably CaO-MgO. Furthermore, according to another embodiment, the catalyst is present at a concentration of 0.05-0.5 m per gram of textile. 2 The preferred concentration for addition is 0.08-0.4 mg / gram of textile. 2 According to a further embodiment of the present invention, the catalyst is applied at a concentration of 0.05-0.5 mg / gram of textile. 2 The preferred concentration for addition is 0.08-0.4 mg / gram of textile. 2 For example, adding 0.05 mg per gram of textiles. 2 The catalyst, or 0.15 mg per gram of textiles. 2 The catalyst, or 0.3 mg per gram of textiles. 2The catalyst. Preferably, during the depolymerization process, the ratio of textiles (in kilograms) to methanol (in liters) in the reactor is at least 4 liters of methanol per kilogram of textiles, that is, the ratio of methanol (in liters) to textiles (in kilograms) is at least 4:1, preferably at least 5:1, and more preferably at least 7:1. Practice has shown that this ratio ensures efficient process operation. Preferably, the ratio of methanol (in liters) to textiles (in kilograms) is less than 15:1, more preferably less than 12:1, and even more preferably less than 10:1.

[0069] According to another aspect of the invention, a method is provided for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the method comprising... - A textile material containing polyester fibers and at least one other type of fiber is loaded into the reactor unit; - To keep the reactor unit in a closed state, isolated from the surrounding environment; - Add a suspension containing catalyst and methanol to the reactor unit; - Perform a depolymerization step, which includes providing a temperature of at least 80°C within a reactor unit and exposing the textile to a catalyst and methanol to perform a methanol depolymerization reaction on the polyester fibers in the textile material, while keeping the other types of fibers in a fibrous state. - The liquid solution containing the depolymerized polyester and methanol is discharged from the reactor unit; - Perform one or more flushing steps, preferably in heated methanol injected into the reactor unit, more preferably, the method includes multiple flushing steps; - Dry the remaining fiber material to obtain a dry fiber material that is essentially free of methanol, and recover the remaining methanol from the reactor unit and recycle it. - To keep the reactor unit in an open state relative to the surrounding environment; and - Discharge the fibrous material from the reactor unit.

[0070] Here, it is also preferable to use an inert atmosphere in the reactor unit. Furthermore, a feed unit as described above may be included. For such units, it is also preferable to use an inert atmosphere.

[0071] Furthermore, according to one embodiment of this aspect of the invention, after the step of removing the liquid solution containing the depolymerized polyester from the reactor unit, and optionally after any rinsing step, the depolymerized polyester being produced (e.g., DMT) is concentrated, cooled, and crystallized to separate the DMT and return the methanol to the reactor unit for reuse; preferably, the DMT is cooled and crystallized in a separate crystallization reactor unit. Additionally, the methanol can be recovered via at least one evaporation step or by distillation.

[0072] Furthermore, according to this aspect of the invention, in one embodiment, the extract liquid solution comprising depolymerized polyester and methanol is at least filtered, preferably crystallized before filtration, to separate methanol from the depolymerized polyester. In one embodiment, the separated methanol is recycled and reused, and mixed with a suspension stream comprising the catalyst and methanol, intended for injection into the reactor unit; optionally, a waste stream is separated before methanol recycling and reuse. Furthermore, in another embodiment, the depolymerized polyester separated from methanol is dried before being retained as DMT.

[0073] Other embodiments related to this aspect of the invention include rotating a drum during at least one of the mixing and depolymerization steps to tumble the textile material inside and bring it into contact with the catalyst and methanol. Furthermore, multiple rinsing steps may be employed. Additionally, according to one embodiment, the rinsing step employs a centrifugal dehydration principle to separate the methanol and the depolymerized polyester from the fibrous material.

[0074] According to another embodiment, the present invention relates to a system for recovering at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the system being configured to perform a methanol depolymerization reaction on the polyester fibers and retain the at least one other type of fiber contained in the textile material in a fibrous state. The recovery system includes a depolymerization reactor unit comprising a rotatable drum, wherein the system further includes a crystallization reactor unit connected to the depolymerization reactor unit. Preferably, the system further includes a recirculation loop for recycling solvent from the crystallization reactor unit to the depolymerization reactor unit, preferably through at least an evaporator unit or through a distillation unit or a combination thereof, more preferably, the system further includes a feed unit. For example, a thin-film evaporator may be included in the system according to the invention. In the system according to the invention, the recovery and recycling of methanol for its reuse is of course of great significance.

[0075] As described above, the depolymerization reactor unit is preferably a pressure vessel capable of withstanding a temperature of at least 80°C, more preferably capable of withstanding a pressure of at least 5 bar, and more preferably at least 10 bar. Furthermore, the feed container may have the above-described characteristics. Additionally, according to one embodiment, the depolymerization reactor unit is a rotatable drum.

[0076] It should be noted that the above-described embodiments and starting scopes of the present invention for different objects can be combined with the other embodiments described above to define more embodiments of the present invention.

[0077] Detailed description of the attached diagram Figure 1 A schematic diagram illustrating the steps involved in at least one embodiment of the method of the present invention is shown.

[0078] The method of the present invention includes: loading a textile material comprising polyester fibers and at least one other type of fiber (e.g., cotton) into a reactor unit, and injecting a preheated suspension comprising a catalyst and methanol into the reactor unit from a preheated charging vessel. A methanol depolymerization reaction is carried out in a reactor at a temperature of at least 80°C. Methanol and the depolymerized polyester (DMT) are separated from at least one other type of fiber (e.g., cotton fibers) by centrifugation. According to this embodiment, one or more rinsing steps (typically using methanol) are performed, and the rinsing solution is recycled. Drying is then performed, preferably under vacuum conditions. Discharge is then completed by removing the fibrous material (cotton fibers in this example) from the reactor unit.

[0079] The methanol solution containing depolymerized polyester (DMT) obtained from the centrifugation step is fed into a methanol crystallization process containing dissolved DMT. It is then filtered, and the filtrate, containing reusable methanol, is refluxed to the preheated feed tank inlet. Furthermore, the remaining DMT is obtained after drying.

[0080] also, Figure 2 A schematic block diagram view of a system according to the invention is shown. In the broadest aspect of the invention, system 200 includes a feeding unit 250 (which requires preheating when containing a suspension comprising a catalyst and methanol) and a depolymerization reactor unit 210. The depolymerization reactor unit 210 is a pressure vessel capable of withstanding a temperature of at least 80°C and preferably a pressure of at least 5 bar. Other suitable units in system 200 have been mentioned in the various embodiments of the invention described above. In this embodiment, the feeding unit 250 includes a high-shear mixer 254' as a depolymerization stirring unit 254. Furthermore, as shown, the volume of the depolymerization reactor unit 210 is larger than that of the feeding unit 250. Additionally, it should be noted that the feeding unit 250 may be connected to multiple depolymerization reactor units 210.

[0081] Figure 3 A reactor unit 210 that may be included in a system 200 according to the invention is shown. In this case, the reactor unit 210 includes a rotatable drum 220 having a shaft A, which, as previously described, preferably has an angle of less than 45° with the horizontal plane. Furthermore, in this case, the rotatable drum 220 includes blades 225. Additionally, the reactor unit 210 also includes a heating device 230.

[0082] Figure 4 A schematic diagram of an embodiment of a feeding unit 250 according to the present invention is shown. The feeding unit 250 includes a depolymerization tank 252, in which methanol is mixed with a catalyst to form a suspension. Therefore, the depolymerization tank 252 is used to mix methanol with the catalyst to form a suspension, and is equipped with a stirring unit 254 for this purpose. The stirring unit 254 may be as follows: Figure 2 The high-shear mixer 254' is shown. Figure 4 As shown, the feeding unit 250 may be equipped with multiple stirring units 254'' and 254''', each with different functions. For example, a high-shear mixer / depolymerization stirring unit 254''' located in a small volume area at the bottom of the depolymerization tank 252 may be used for depolymerization; and a paddle-type stirring unit 254'' or similar device may be installed throughout the entire volume of the depolymerization tank 252 for stirring. Furthermore, the feeding unit 250 includes a storage tank 253. The storage tank 253 is connected to the depolymerization tank 252 to transport a suspension of methanol and catalyst from the depolymerization tank 252 to the storage tank 253. The storage tank 253 is equipped with a paddle-type stirring unit 257 for stirring the entire volume of the storage tank 253. Additionally, the feeding unit 250 also includes a heating device 255.

[0083] Figure 5 A schematic diagram of one embodiment of the 200 system involved in the present invention is shown. Figure 5 Several components and Figure 3 The components are the same. Therefore, regarding Figure 5 The description focuses on the new components of system 200. System 200 further includes a feeding unit 250 (e.g., Figure 4As shown in the diagram, a feed unit 250 is used to add preheated methanol and catalyst to the depolymerization reactor unit 210. A rotatable drum 220 may be fitted with a cover (not shown) for loading textile material to be treated according to the method into the drum and removing residual fiber material, such as at least one other type of fiber, after depolymerization and any rinsing steps, from the drum 220. The depolymerization reactor unit 210 also includes an outlet 240 with a particulate filter 260. The particulate filter 260 is used to separate and filter particles, such as spent catalyst and particles still suspended in the liquid, from the recovered liquid from the depolymerization reactor unit 220. The system 200 also includes a crystallization reactor unit 270. The crystallization reactor unit 270 is connected to the depolymerization reactor unit 210. Furthermore, the textile recycling system includes a recirculation loop 280. The recirculation loop 280 is used to recycle methanol from the crystallization reactor unit 270 back to the depolymerization reactor unit 210. In addition, the system includes at least one distillation unit 291 or evaporator unit 290, or a combination of both. The recirculation loop 280 recycles methanol through at least one distillation unit 291 or evaporator unit 290, or a combination of both.

[0084] Figure 6 A schematic diagram of one embodiment of the rotatable roller 220 used in this system is shown. The rotatable roller 220 is provided with perforations 245. The perforations 245 enable the separation of the methanol-monomer solution from the remaining textiles after the depolymerization reaction and possible subsequent steps (e.g., rinsing).

Claims

1. A method for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the method comprising: - Preheat the reaction solution containing at least methanol in the feeding unit; - A textile material containing polyester fibers and at least one other type of fiber is loaded into the reactor unit; - Inject the preheated reaction liquid and catalyst from the feed unit into the reactor unit; - Perform a depolymerization step, which includes providing a temperature of at least 80°C in a reactor unit and exposing the textile material to a catalyst and methanol to perform a methanol depolymerization reaction on the polyester fibers in the textile material, while keeping at least a portion of the other types of fibers in a fibrous state. - Recover a liquid solution containing depolymerized polyester and methanol from the reactor unit; and - Recover fibrous materials containing the other types of fibers from the reactor unit.

2. The method of claim 1, wherein, The reaction solution consists of a suspension of methanol and catalyst.

3. The method of claim 1 or 2, wherein, The feeding unit includes a depolymerization tank in which methanol is mixed with the catalyst to form a suspension.

4. The method of claim 3, wherein, The feeding unit also includes a storage tank, and the suspension is transported from the depolymerization tank to the storage tank. Preferably, the suspension is diluted in the storage tank by adding more methanol.

5. The method according to any one of claims 1-4, wherein, The feeding unit is equipped with a mixing unit.

6. The method according to claim 5, wherein, The feeding unit is equipped with a high-shear mixer as a stirring unit; and / or is equipped with a paddle-type stirring unit.

7. The method according to any one of claims 1-6, wherein, The feeding unit is equipped with a depolymerization stirring unit; and / or a paddle-type stirring unit.

8. The method of any one of claims 1-7, wherein, The preheated reaction solution, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 50-240°C, more preferably in the range of 70-200°C, more preferably in the range of 80-180°C, and most preferably in the range of 140-175°C.

9. The method of any preceding claim, wherein, The preheated reaction solution, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 100-180°C, more preferably 140-175°C, for at least 15 minutes, preferably 30 minutes.

10. The method of any preceding claim, wherein, The feeding unit and the reactor unit are separate.

11. The method of any preceding claim, wherein, The volume of the feeding unit is smaller than that of the reactor unit.

12. The method of any preceding claim, wherein, During at least a portion of the reaction liquid preheating step, the reaction liquid, preferably a suspension of methanol and catalyst, is held in the feed unit at a pressure of at least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably less than 40 bar absolute pressure, for example less than 30 bar absolute pressure, and more preferably, the pressure is in the range of 10-25 bar absolute pressure for at least a portion of the preheating step.

13. The method of any preceding claim, wherein, The preheated reaction liquid and catalyst from the feed unit are conveyed to one or more reactor units, such as at least two, or more preferably at least three separate reactor units.

14. The method of any preceding claim, wherein, Preheating is carried out in an inert atmosphere within the feeding unit, preferably in an N2 environment.

15. The method of any preceding claim, wherein, The method includes - A mixing step, which includes contacting a textile material with a suspension containing a catalyst and methanol in a rotatable drum of a reactor unit, preferably the rotatable drum being arranged to rotate about an axis (A) at an angle of less than 45° to the horizontal plane; wherein, during at least one of the mixing step and the depolymerization step, the drum is rotated to tumble the textile material inside and contact it with the catalyst and methanol, optionally the rotatable drum being perforated.

16. The method according to any one of the preceding claims, wherein, During at least a portion of the depolymerization step, the temperature within the reactor unit is maintained in the range of 100-200°C, preferably in the range of 110-180°C, more preferably in the range of 120-170°C, and most preferably in the range of 140-170°C.

17. The method of any preceding claim, wherein, During at least a portion of the depolymerization step, the pressure within the reactor unit is maintained at an absolute pressure of at least 5 bar, preferably at least 10 bar, preferably less than 40 bar, for example less than 30 bar, more preferably, the pressure is in the range of 10-25 bar absolute pressure during at least a portion of the depolymerization step, and / or wherein the reactor unit preferably includes a rotatable drum with perforations, preferably the perforations being arranged at least on the surface of the drum wall.

18. The method of any preceding claim, wherein, At least one other type of fiber in the textile material includes cellulose-based fibers, preferably at least one of natural cellulose fibers and man-made cellulose fibers, such as cotton and flax, and such as viscose, lyocell, rayon, and modal, and more preferably, at least one other type of fiber includes cotton.

19. The method of any preceding claim, wherein, The textile material comprises at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of cellulose-based fibers, and / or the textile material comprises at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of cotton fibers, and / or the textile material comprises at least 30% by weight, preferably at least 40% by weight, more preferably at least 50% by weight of polyester cotton textile material.

20. The method of any preceding claim, wherein, The catalyst contains Ca, and preferably the catalyst contains at least one of CaO, CaO-MgO and Ca(OH)2.

21. The method of any preceding claim, wherein, The catalyst has a specific surface area of ​​at least 5 m². 2 / g, preferably at least 10m 2 / g, more preferably at least 15m 2 / g, preferably at least 20m 2 / g.

22. The method of any preceding claim, wherein, The catalyst was applied at a concentration of 0.05-0.5 mg / gram of textiles. 2 The preferred concentration for addition is 0.08-0.4 mg / gram of textile. 2 .

23. The method of any preceding claim, wherein, During the depolymerization process, the ratio of textiles in kilograms to methanol in liters in the reactor is at least 4 liters of methanol per kilogram of textiles (4:1), preferably at least 5:1, and more preferably at least 7:

1.

24. The method of any preceding claim, wherein, The methanol depolymerization reaction is carried out in an inert atmosphere within the reactor unit, preferably in an N2 environment.

25. The method of any preceding claim, wherein, The method further includes performing one or more rinsing steps, preferably performing one or more rinsing steps by further adding methanol to the reactor unit, more preferably performing them in heated methanol, and more preferably, the method includes performing multiple rinsing steps after recovering the liquid solution containing depolymerized polyester and methanol from the reactor unit to dissolve the residual depolymerized polyester in the reactor unit.

26. The method of any preceding claim, wherein, The method includes drying the remaining fibrous material after the depolymerization step to obtain a dry fibrous material that is substantially free of methanol, and optionally discharging the remaining methanol from the reactor unit. The drying step is performed before recovering the fibrous material containing the other types of fibers from the reactor unit. Preferably, the drying step is performed using a vacuum.

27. The method of any preceding claim, wherein, The remaining fibers after the depolymerization step are dried by centrifugal drying in a perforated rotatable drum of the reactor unit; preferably, after centrifugal drying, the reactor is connected to a vacuum system to evaporate any remaining methanol from the fibers while they are rotating in the rotatable drum, and the reactor unit is still warm when it is connected to the vacuum system.

28. A system (200) for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the system (200) being configured to depolymerize the polyester fibers, preferably with methanol, and to retain the other type of fiber contained in the textile material in a fibrous state, said system (200) comprising - Feeding unit (250); - Depolymerization reactor unit (210), said depolymerization reactor unit (210) is a pressure vessel, suitable for withstanding a temperature of at least 80°C, preferably suitable for withstanding a pressure of at least 5 bar, more preferably at least 10 bar; wherein The feed unit (250) is used to supply preheated reaction liquid and catalyst, preferably a suspension of methanol and catalyst, to the depolymerization reactor unit (210).

29. The system (200) according to claim 28, wherein the feeding unit (250) is provided as a unit separate from the depolymerization reactor unit (210).

30. The system (200) according to claim 28 or 29, wherein the feed unit (250) includes a depolymerization tank (252) for mixing methanol with a catalyst to form a suspension.

31. The system (200) according to any one of claims 28-30, wherein the feeding unit (250) further includes a storage tank (253) connected to the depolymerization tank (252) for conveying the suspension from the depolymerization tank (252) to the storage tank (253), preferably by adding more methanol to the storage tank (253) to dilute the suspension.

32. The system (200) according to any one of claims 28-31, wherein, The feeding unit (250) is equipped with a stirring unit (254).

33. The system (200) according to claim 32, wherein the feeding unit (250) is configured with a high-shear mixer (254') as a stirring unit (254); and / or is configured with a paddle-type stirring unit (254'').

34. The system (200) according to any one of claims 28-33, wherein the feeding unit (250) is configured with a depolymerization stirring unit (254'''); and / or is configured with a paddle stirring unit (254'').

35. The system (200) according to any one of claims 28-34, wherein, The system (200) is connected to an overpressure and / or vacuum environment to deliver methanol, catalyst and / or a suspension of methanol and catalyst using overpressure or vacuum.

36. The system (200) according to any of claims 28-35, wherein, The feed unit (250) is configured to ensure that the preheated reaction liquid, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 50-240°C, preferably 70-200°C, more preferably 80-180°C, and most preferably 140-175°C.

37. The system (200) according to any one of claims 28-36, wherein the feed unit (250) is configured to ensure that the preheated reaction liquid, preferably a suspension of methanol and catalyst, is preheated to a temperature range of 100-180°C, more preferably 140-175°C, for at least 15 minutes, preferably 30 minutes.

38. The system (200) according to any one of claims 28-37, wherein, The volume of the feeding unit (250) is smaller than that of the depolymerization reactor unit (210).

39. The system (200) according to any one of claims 28-38, wherein the feed unit (250) is configured to withstand an absolute pressure of at least 5 bar, more preferably at least 10 bar, so that during at least a portion of the preheating step, the reaction liquid, preferably a suspension of methanol and catalyst, is held in the feed unit at a pressure of at least 5 bar, preferably at least 10 bar, preferably less than 40 bar, for example less than 30 bar, and more preferably, the pressure is in the range of 10-25 bar for at least a portion of the preheating step.

40. The system (200) according to any of claims 28-39, wherein, The feeding unit (250) includes a heating device (255).

41. The system (200) according to any of claims 28-40, wherein, The system (200) includes one or more depolymerization reactor units (210) such that preheated reaction liquid and catalyst from the feed unit (250) can be delivered to the one or more depolymerization reactor units (210), for example at least two, or more preferably at least three separate depolymerization reactor units (210).

42. The system (200) according to any one of claims 28-41, wherein the feeding unit (250) is connected to an inert gas source, such that the feeding unit (250) can perform a preheating step in an inert atmosphere, preferably, the inert gas source is an N2 source.

43. The system (200) according to any one of claims 28-42, wherein, The system (200) includes a depolymerization reactor unit (210) comprising a rotatable drum (220), preferably configured to rotate about an axis (A) at an angle of less than 45° to the horizontal plane, preferably, during the rotation of the rotatable drum (220), the angle between the axis (A) and the horizontal plane is less than 25°, preferably in the range of 0-10°. The system (200) according to claim 43, wherein the rotatable roller (220) is perforated.

44. A method for at least one of i) recovering a polyester, and ii) regenerating cellulosic fibers from a textile comprising a polyester and cellulosic fibers, wherein, The method includes the following steps: - The textiles, which are soaked in a suspension including methanol and a catalyst, are placed in a reactor; - During the depolymerization of the polyester in the textile, the temperature of the suspension containing the textile is maintained in the range of 80-240°C, and the depolymerization is carried out by methanol depolymerization; and - After the depolymerization, polyester and / or regenerated cellulose fibers are recovered, wherein, in the step of placing the textiles soaked in the mixture into the reactor, the catalyst in the suspension comprises calcium oxide or calcium hydroxide, or a combination thereof; wherein the catalyst has a specific surface area of at least 5 m 2 / g and the suspension comprises 0.2 to 10 wt.-% of the catalyst.

45. A method for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the method comprising: - A textile material containing polyester fibers and at least one other type of fiber is loaded into the reactor unit; - To keep the reactor unit in a closed state, isolated from the surrounding environment; - Add a suspension containing catalyst and methanol to the reactor unit; - Perform a depolymerization step, which includes providing a temperature of at least 80°C within a reactor unit and exposing the textile to a catalyst and methanol to perform a methanol depolymerization reaction on the polyester fibers in the textile material, while keeping the other types of fibers in a fibrous state. - The liquid solution containing the depolymerized polyester and methanol is discharged from the reactor unit; - Perform one or more flushing steps, preferably in heated methanol injected into the reactor unit, more preferably, the method includes multiple flushing steps; - Dry the remaining fiber material to obtain a dry fiber material that is essentially free of methanol, and recover the remaining methanol from the reactor unit and recycle it. - To keep the reactor unit in an open state relative to the surrounding environment; and - Discharge the fibrous material from the reactor unit.

46. ​​A system (200) for recovering at least a portion of a textile material comprising polyester fibers and at least one other type of fiber, the system (200) being configured to perform a methanol depolymerization reaction on the polyester fibers and retain at least one other type of fiber contained in the textile material in a fibrous state, the recovery system comprising a depolymerization reactor unit (210) comprising a rotatable drum (220), wherein the system (200) further comprises a crystallization reactor unit (270) connected to the depolymerization reactor unit (210), preferably further comprising a recirculation loop (280) for recycling solvent from the crystallization reactor unit (270) to the depolymerization reactor unit (210), preferably at least through an evaporator unit (290) or through a distillation unit (291) or a combination thereof, More preferably, the system also includes a feeding unit (250).

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