A method of recycling at least a portion of a textile material comprising polyester fibers, and a system intended therefore

Abstract

The present invention describes a method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the method comprising - preheating a reaction liquid comprising at least methanol in a charging unit; - loading a reactor unit with a textile material comprising polyester fibers and at least one other type of fibers; - charging the reactor unit with the preheated reaction liquid from the charging unit and with catalyst; - performing a depolymerization step, said depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile to the catalyst and methanol, to perform a methanolysis depolymerization reaction of the polyester fibers in the textile material, leaving at least a portion of said other type of fibers in a fiber state; - withdrawing a liquid solution comprising depolymerized polyester and methanol from the reactor unit; and - withdrawing from the reactor unit a fiber material comprising said other type of fibers.

Description

[0001] A METHOD OF RECYCLING AT LEAST A PORTION OF A TEXTILE MATERIAL COMPRISING POLYESTER FIBERS, AND A SYSTEM INTENDED THEREFORE

[0002] Field of the invention

[0003] The present invention relates to a method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers.

[0004] Technical Background

[0005] Methods and systems for recycling at least a portion of a textile material comprising polyester fibers have been described. For instance, in WO 2018 / 150028 there is disclosed a method for recycling polyester from a polyester textile, wherein said method comprises the steps of providing said polyester textile soaked in a mixture comprising a solvent and a catalyst; providing and maintaining a temperature of said mixture comprising said polyester textile within a range of 80-240 °C during depolymerization of polyester in said polyester textile; wherein, in said step of providing said polyester textile soaked in said mixture, said catalyst of said mixture comprises calcium oxide. Moreover, in WO 2020 / 035590 there is disclosed a similar process as in WO 2018 / 150028, however in this case a catalyst comprising calcium hydroxide is used.

[0006] One aim of the present invention is to provide an optimal method and system for obtaining depolymerized polyester fibers from textile materials.

[0007] Summary of the invention

[0008] The purpose above is achieved by a method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the method comprising a method of recycling at least a portion of a textile material comprising polyester fibers, the method comprising

[0009] - preheating a reaction liquid comprising at least methanol in a charging unit;

[0010] - loading a reactor unit with a textile material comprising polyester fibers and at least one other type of fibers; - charging the reactor unit with the preheated reaction liquid from the charging unit and with catalyst;

[0011] - performing a depolymerization step, said depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile to the catalyst and methanol, to perform a methanolysis depolymerization reaction of the polyester fibers in the textile material, leaving at least a portion of said other type of fibers in a fiber state;

[0012] - withdrawing a liquid solution comprising depolymerized polyester and methanol from the reactor unit; and

[0013] - withdrawing from the reactor unit a fiber material comprising said other type of fibers.

[0014] By preheating methanol or the catalyst and methanol, it is possible to accelerate the dissolution of catalyst, e.g. CaO, in the methanol and thus generate methoxide ions. This shortens the time needed to complete the depolymerization, and thus shorten the cycle time for the batch operation taking place in the reactor.

[0015] The function / mechanism of the CaO-MgO mineral based ’’catalyst” is believed to be based on the fact that the CaO in the catalyst first reacts with methanol and forms calcium methoxide (Ca(OCH3)2). Then, Ca(OCH3)2, which is slightly soluble in methanol, triggers the depolymerization reaction, i.e. the methoxide group attacks bonds in the PET and the depolymerization start.

[0016] Brief description of the drawings

[0017] In Fig. 1 there is shown a schematic view of the steps involved in at least one embodiment of the method according to the present invention.

[0018] In Fig. 2 there is shown a schematic block view of a system according to the present invention.

[0019] In Fig. 3 there is shown one depolymerization reactor unit possible to use in a system according to the present invention.

[0020] In Fig. 4 there is shown a charging unit, according to an embodiment, arranged for providing a pre-heated suspension of methanol and catalyst to be supplied to a depolymerization reactor unit. In Fig. 5 there is shown a system for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers according to an embodiment.

[0021] In Fig. 6 there is shown a perforated, rotatable drum, according to an embodiment, for use in the present system, as well as in performing the present method.

[0022] Embodiments of the invention

[0023] Below there are provided some embodiments of the present invention.

[0024] According to one embodiment, the reaction liquid comprises a suspension of methanol and the catalyst. As should be understood from above, the method according to the present invention may involve preheating a suspension of catalyst and methanol or mixing preheated methanol with catalyst. In the first case, also cold methanol may be used when admixing methanol and catalyst.

[0025] According to yet another embodiment, the charging unit comprises a deagglomeration vessel, wherein methanol is mixed with the catalyst in the deagglomeration vessel to form a suspension. A de-agglomeration vessel according to the present invention provides a good dispersion of the catalyst in the methanol.

[0026] For de-agglomeration, also having an agitation unit may be of relevance. Therefore, according to one embodiment, the charging vessel is provided with an agitation unit. Thus, the de-agglomeration vessel may be provided with an agitation unit. It may be an advantage to have a stirrer / agitation unit to get a homogeneous suspension of the catalyst in the methanol. According to one embodiment, the charging unit, such as the agitation unit, is arranged with a high-shear mixer as an agitation unit. Such a high-shear mixer ensures the provision of high shear forces, which is relevant for de-agglomeration. It should be noted that different types of agitation units are possible. According to one embodiment, the charging unit, such as the agitation unit, is arranged with a de-agglomeration agitation unit. An example is an agitator adapted for dispersing powders in liquid (e.g. like dispersing paint powder).

[0027] According to another embodiment, the charging unit further comprises a storage vessel such that the suspension may be forwarded from the de-agglomeration vessel to the storage vessel. Preferably, the suspension is diluted in the storage vessel by addition of further methanol. The storage vessel may also be provided with an agitation unit, such as a paddle-based agitation unit, arranged for agitation of the entire volume of the storage vessel.

[0028] According to another embodiment, the preheated reaction liquid, preferably a suspension of methanol and the catalyst, is preheated to a temperature in the interval of 50 to 240°C, preferably in the interval of 70 to 200°C, more preferably in the interval of 80 to 180°C, most preferably in the interval of 140 to 175°C. According to yet another embodiment, the preheated reaction liquid, preferably the suspension of methanol and the catalyst, is preheated to a temperature in the interval of 100 to 180°C, more preferably in the interval of 140 to 175°C, during a time of at least 15 minutes, preferably 30 minutes. Given that the boiling point of methanol is about 65°C at atmospheric pressure, the pre-heating is typically performed at super-atmospheric pressure.

[0029] It should be noted that the method according to the present invention may be performed by preheating methanol and then mixing the preheated methanol with the catalyst, or by preheating a suspension of the catalyst and methanol. Moreover, the method according to the present invention may involve different types of combinations of preheating temperatures and times, as noted above, together with suitable reaction times and temperatures in the depolymerization reaction unit (see further details below).

[0030] As should be understood form the above, the charging unit is suitably separate from the reactor unit. According to one embodiment, the charging unit has a smaller volume than the reactor unit. Different alternatives of charging units and agitation configurations are possible according to the present invention. For instance, a charging unit with only a high-shear mixer. Another example is a charging unit having multiple agitation units, suitably with different purposes, e.g. a high-shear mixer / deagglomeration agitation unit in a small volume of the bottom of the charging unit for deagglomeration purposes, and a paddle-type agitation unit or the like arranged for agitation of the entire volume of the charging unit. Methanol may then be added in the top of such a charging unit configuration. According to one embodiment, the reaction liquid, preferably a suspension of methanol and the catalyst, is held, during at least a portion of the step of preheating the reaction liquid in a charging unit, at at least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably the pressure is less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably the pressure is, at least during a portion of the preheating step, in the range of 10 to 25 bar absolute pressure. The pressure depends on the temperature and the vapor pressure of the solvent at that specific temperature. Based on the solvent used and a set temperature, the pressure is obtained from the pressure-temperature dependency of that solvent.

[0031] Moreover, according to one embodiment, preheated reaction liquid from said charging unit and catalyst is supplied to more than one reactor unit, such as to at least two, or more preferably to at least three, separate reactor units.

[0032] Furthermore, according to one embodiment, the preheating is performed under an inert atmosphere in the charging unit, preferably under a N2 environment. As known to the skilled person, N2 (nitrogen) is essentially inert. Alternatively, other inert gases, such as noble gases (e.g. argon) may be used.

[0033] According to yet another embodiment, the method comprises

[0034] - a mixing step comprising bringing the textile material into contact with a suspension comprising the catalyst and methanol in a rotatable drum of the reactor unit, the rotatable drum being arranged for rotating around an axis (A), preferably said axis (A) having an angle to the horizontal plane being less than 45°. The drum is rotated during at least one of said mixing step and said depolymerization step to make the textile material tumble around inside thereof in contact with the catalyst and methanol. By using a rotating drum, a tumbling procedure is obtained where it is ensured that the textile material comprising polyester fibers and at least one other type of fibers is brought into contact with a suspension comprising a catalyst and methanol by being rotated in the rotatable drum of the reactor unit. This rotating procedure is advantageous when mixing the different components and is as such employed during the mixing step and / or the depolymerization step. This is also why the method involves rotation of the drum during at least one of said mixing step and said depolymerization step, and the rotation is preferably employed during at least a portion of both steps. This method provides an efficient manner of separating polyester, which is depolymerized under the action of the catalyst and methanol to form a solution of depolymerized polyester, from other fibers, such as cellulose fibers, e.g. cotton fibers, that are kept in a fiber state, i.e. in a solid state. Furthermore, rotation of the drum is also preferred during one or more subsequent suggested rinsing steps, which is further discussed below. Moreover, as the rotation should be performed for the fibers being brought into contact with the suspension a regular rotation around a more or less horizontal axis is preferred. Also, a rotation with a somewhat tilted plane and angle is possible according to the present invention. Therefore, according to the present invention, when a rotatable drum is being used, then the rotatable drum is arranged for rotating around an axis having an angle to the horizontal plane being less than 45°. It should however be noted that an angle to the horizontal plane below 25°, such as below 10° or even close to or being 0° is preferred according to the present invention. It should be noted that the rotatable drum inside of a housing of the pressure vessel preferably is a perforated drum. This is preferable as it simplifies the separation of the methanolmonomer solution and the textile remaining in the rotatable drum after reaction, draining and spin drying. By using a perforated drum, the other fiber may remain within the drum, whereas a solution / dispersion comprising depolymerized polyester may be separated therefrom via the perforations.

[0035] Moreover, according to one embodiment of the present invention, the temperature in the reactor unit is provided, during at least a portion of the depolymerization step, in a range of 100 to 200°C, preferably in a range of 110 to 180°C, more preferably in a range of 120 to 170°C, most preferably in a range of 140 to 170°C. A temperature below 200°C is preferred to perform depolymerization of polyester in the presence of some fiber materials, e.g. cotton, that are sensitive to high temperatures. Moreover, methanol performs most optimal at temperatures lower than 200°C. Moreover, at temperatures below 100°C the yield of depolymerized polyester is too low. Given that the boiling point of methanol is about 65°C at atmospheric pressure, the depolymerization is typically performed at super-atmospheric pressure.

[0036] According to one embodiment, the pressure in the reactor unit is held, during at least a portion of the depolymerization step, at at least 5 bar, preferably at least 10 bar absolute pressure, preferably the pressure is less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably the pressure is, at least during a portion of the depolymerization step, in the range of 10-25 bar absolute pressure. Further, the reactor unit preferably comprises a rotatable drum provided with perforations, preferably perforations at least on a mantle surface of the rotatable drum.

[0037] Different types of fiber materials may be used according to the present invention. According to one embodiment of the present invention, said at least one other fiber type of the textile material comprises a cellulose based fiber. Preferably, the cellulose based fiber is at least one of natural cellulose fibers such as cotton, and linen, and man-made cellulose fibers, such as viscose, lyocell, rayon, and / or modal fibers. More preferably, said at least one other fiber type comprises at least cotton fibers.

[0038] According to yet another embodiment, said textile material comprises at least 30 wt. %, preferably at least 40 wt. %, more preferably at least 50 wt. %, cellulose based fibers. The textile material may comprise at least 30 wt. %, preferably at least 40 wt.%, more preferably at least 50 wt.%, cotton fiber. Further, the textile material may comprise at least 30 wt. %, preferably at least 40 wt. %, more preferably at least 60 wt.%, of polycotton textile material.

[0039] Moreover, the catalyst used according to the present invention may be of different type. According to one embodiment, the catalyst comprises Ca. Preferably, the catalyst comprises at least one of CaO, CaO-MgO, and Ca(OH)2. Different Ca-sources are possible to use according to the present invention, where one example is dolomite, e.g. a Ca / Mg / O source derived from CaMg(CO3)2. As recognized by the skilled person, dolomite is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally represented as CaMg(CO3)2. According to an embodiment, the catalyst comprises dolomite.

[0040] According to yet another embodiment, the specific surface area of the catalyst is at least 5 m2 / g, preferably at least 10 m2 / g, more preferably at least 15 m2 / g, most preferably at least 20 m2 / g. The specific surface area of the catalyst may be determined by using the BET (Brunauer-Emmett-Teller) method. According to an embodiment, specific surface area of the catalyst is determined according to an applicable standard, such as according to ASTM D3663-20 or ISO 9277:2022. Furthermore, according to one embodiment, the catalyst is added at a concentration of 0.05-0.5 m2per gram of textile, preferably at a concentration of 0.08- 0.4 m2per gram of textile. Thus, the specific surface area of the catalyst rather than the weight thereof, may be decisive in dosing the catalyst.

[0041] Moreover, and in line with having an inert atmosphere in the charging vessel, according to one embodiment, the methanolysis depolymerization reaction is performed under an inert atmosphere in the reactor unit, preferably under a N2 environment. The inert environment may prevent unwanted reactions, such as oxidation and hydrolysis.

[0042] Furthermore, according to yet another embodiment, the method comprises performing one or more rinsing steps. Preferably, the one or more rinsing steps is performed in additional methanol charged to the reactor unit. More preferably, heated methanol is used in the rinsing step(s). More preferably, the method comprises multiple rinsing steps after having withdrawn a liquid solution comprising depolymerized polyester and methanol from the reactor unit to dissolve remaining depolymerized polyester in the reactor unit. Preferably, a rotatable drum according to the present invention is being rotated during at least a portion of the rinsing step. According to yet another embodiment of the present invention, the method may comprise multiple rinsing steps.

[0043] Furthermore, according to yet another embodiment, the method comprises drying the fiber material remaining after said depolymerization step for providing a dry fiber material substantially free from methanol, and optionally drawing off remaining methanol from the reactor unit. The step of drying may be performed before withdrawing a fiber material comprising said other type of fibers from the reactor unit. Preferably, the step of drying is performed by using low pressure, e.g. vacuum, applied to the reactor unit.

[0044] According to one embodiment, the method comprises at least one rinsing step according to above, preferably being performed in methanol being charged to the reactor unit. Preferably the reactor unit is a rotatable drum being rotated during at least a portion of the rinsing step. More preferably the method comprises multiple rinsing steps. According to another embodiment, said at least one rinsing step comprises a spin-drying rotation principle for separating methanol and depolymerized polyester from the fiber material. By using a perforated drum, the methanol and the depolymerized polyester may be separated from the remining fiber material by rotating the perforated drum.

[0045] Moreover, according to one embodiment, the fiber material remaining in the reactor unit, preferably the reactor unit being a rotatable drum, after depolymerization of the polyester is dried by applying a vacuum to the reactor unit to evaporate methanol. Also, during such a drying procedure, it is preferable to keep the rotatable drum in rotation to facilitate evaporation of methanol. Moreover, it is preferable to evaporate and remove methanol before withdrawing any fiber material from the drum.

[0046] According to another embodiment of the present invention, the catalyst and methanol solution is discharged through an outlet with a particle filter after the depolymerization step, draining and / or rinsing step. This may be performed to filter off catalyst particles. This may preferably be performed for further use of the catalyst particles. The catalyst used may be filtered off and then follow a waste stream, reusage is another possibility. According to this embodiment, residues and used catalyst or unused catalyst particles are filtered off. DMT (dimethyl terephthalate, i.e. depolymerized polyester resulting from methanolysis of the polyester), being dissolved in the methanol, however is passed through the filter for the next step in the process. Furthermore, residues of catalysts are washed away from the treated textile material later on in the process.

[0047] Furthermore, according to one embodiment, depolymerized polyester (e.g. DMT) being produced is concentrated, cooled, and crystallized after said step of withdrawing from the reactor unit a liquid solution comprising depolymerized polyester, to enable separation of the DMT and recirculation and reuse of the methanol to the reactor unit. Preferably the DMT is cooled and crystallized in a separate crystallization reactor unit.

[0048] Moreover, according to yet another embodiment of the present invention, methanol is recovered via at least one evaporation step or via a distillation step after being discharged from the reactor unit, preferably as part of a loop after methanol is separated from depolymerized polyester and any remaining catalyst. After a final spin drying, the reactor may be coupled to vacuum to evaporate any remaining methanol from the remaining textile while rotating the textile. Since the reactor still is warm, i.e. has a temperature of at least 80°C, this means that the textile in the reactor is dried in a process step resulting in the textile in the reactor being tumble dried.

[0049] According to one embodiment, the reactor unit is in a closed state when being charged with the suspension comprising a catalyst and methanol.

[0050] Furthermore, according to one embodiment, the method involves:

[0051] - withdrawing a liquid solution comprising depolymerized polyester and methanol from the reactor unit,

[0052] - drying the fiber material remaining for providing a dry fiber material substantially free from methanol, and drawing off remaining methanol from the reactor unit, such as via vacuum to a methanol recovery system; and

[0053] - withdrawing from the reactor unit a fiber material comprising said other type of fibers, preferably the reactor unit is in an open state in relation to the surrounding when withdrawing the fiber material comprising said other type of fibers.

[0054] Moreover, according to yet another embodiment, the withdrawn liquid solution comprising depolymerized polyester (e.g. DMT) and methanol is processed by at least filtration, preferably first crystallization and then filtration, for separation of methanol from depolymerized polyester.

[0055] Furthermore, according to one embodiment, separated methanol is recirculated and reused for being mixed with a stream of suspension comprising a catalyst and methanol intended to be charged into the reactor unit, optionally a waste stream is separated off before the methanol is recirculated and reused.

[0056] According to one embodiment, the depolymerized polyester separated from methanol is dried before being retained as DMT (dimethyl terephthalate, i.e. depolymerized polyester resulting from methanolysis of the polyester).

[0057] The present invention also provides a system, such as a textile recycling system, for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the system being arranged for conducting a depolymerization reaction, preferably a methanolysis depolymerization reaction, of polyester fibers and leaving the other type of fibers comprised in the textile material in a fiber state, said system comprising

[0058] - a charging unit;

[0059] - a depolymerization reactor unit, said depolymerization reactor unit being a pressure vessel adapted to withstand a temperature of at least 80°C, preferably adapted to withstand a pressure of at least 5 bar, more preferably at least 10 bar; wherein the charging unit is arranged for supplying a preheated reaction liquid and a catalyst, preferably a suspension of methanol and catalyst, to the depolymerization reactor unit.

[0060] According to one embodiment, the charging unit is arranged as a unit separate from the depolymerization reactor unit.

[0061] According to one embodiment, the charging unit comprises a de-agglomeration vessel. The de-agglomeration vessel is arranged for mixing methanol with the catalyst to form a suspension. Moreover, according to yet another embodiment, the charging unit further comprises a storage vessel. The storage vessel is connected with the deagglomeration vessel to enable for the suspension to be forwarded from the deagglomeration vessel to the storage vessel. Preferably, the suspension may be diluted in the storage vessel by addition of further methanol.

[0062] In line with what has been described above, according to yet another embodiment, the charging unit is provided with an agitation unit. According to one embodiment, the charging unit is arranged with a high-shear mixer as an agitation unit. Furthermore, according to yet another embodiment, the charging unit is arranged with a de-agglomeration agitation unit. The charging unit may also comprise multiple agitation units, such as a high-shear mixer / a de-agglomeration agitation unit combined with another type, such as a paddle-based agitation unit.

[0063] Furthermore, the system according to the present invention is preferably based on using vacuum, as means for charging the reactor unit. The system according to the present invention may also instead be based on incorporating a pump for charging, however this has the disadvantage of ensuring ATEX classification of certain equipment as methanol is considered a flammable solvent. In line with the above, according to one embodiment, the system is connected to overpressure and / or vacuum to enable for transportation of methanol, catalyst and / or suspension of methanol and catalyst by use of over-pressure or vacuum.

[0064] According to yet another embodiment, the charging unit is arranged to ensure that the preheated reaction liquid, preferably a suspension of methanol and the catalyst, may be preheated to a temperature in the interval of 50 to 240°C, preferably in the interval of 70 to 200°C, more preferably in the interval of 80 to 180°C, most preferably in the interval of 140 to 175°C. According to one embodiment, the charging unit is arranged to ensure that the preheated reaction liquid, preferably a suspension of methanol and the catalyst, may be preheated to a temperature in the interval of 100 to 180°C, more preferably in the interval of 140 to 175°C, during a time of at least 15 minutes, preferably at least 30 minutes.

[0065] Furthermore, according to one embodiment, the charging unit has a smaller volume than the depolymerization reactor unit.

[0066] Moreover, according to one embodiment, the charging unit is arranged to withstand at least 5 bar absolute pressure, more preferably at least 10 bar, so that preheated reaction liquid and a catalyst, preferably a suspension of methanol and catalyst may be held, during at least a portion of the preheating step, at at least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably at a pressure being less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably at a pressure being, at least during a portion of the preheating step, in the range of 10 to 25 bar absolute pressure.

[0067] According to one embodiment, the charging unit comprises heating means. The heating capability may be provided in different ways. Examples are charging unit having a jacked heated with oil or another medium, steam, electricity or in fact with heating coils inside of the charging unit.

[0068] According to yet another embodiment, the system comprises more than one depolymerization reactor unit enabling for preheated reaction liquid from said charging unit and catalyst being supplied to said more than one depolymerization reactor unit, such as at least two, or more preferably at least three, separate depolymerization reactor units. As mentioned, according to one embodiment, the charging unit is connected to an inert source so that the charging unit is arranged for a preheating step under an inert atmosphere, preferably the source for the inert atmosphere is a N2 source.

[0069] Moreover, according to yet another embodiment, the system comprises a depolymerization reactor unit comprising a rotatable drum. The rotatable drum is arranged for rotating around an axis. Preferably said axis having an angle to the horizontal plane being less than 45°, preferably the angle to the horizontal plane of the axis during rotation of the rotatable drum is less than 25°, preferably in a range of from O to 10°.

[0070] According to yet another embodiment, the reactor unit is a rotatable drum which is perforated to enable separation of methanol-monomer solution (e.g. a solution of DMT in methanol) and remaining textile after depolymerization reaction and potential subsequent steps. The rotatable drum is arranged inside a housing of the reactor unit. The housing is arranged to maintain a desired pressure in the reactor unit and collect solutions discharged via perforations of the perforated rotatable drum. Preferably the rotatable drum, typically being cylindric, is provided with perforations in its mantle portion and / or at least one of its side portions (corresponding to the basis of a cylinder). More preferably the rotatable drum is provided with perforations in its mantle portion and at least one of its side portions. Still more preferably, the rotatable drum comprises perforations in its mantle portions and both of its side portions. The perforations mentioned above are preferred to enable separation of methanol-monomer solution from the remaining textile after depolymerization reaction and / or after any potential subsequent steps, such as rinsing. The size and form of the perforations is thus adapted to retain the textile in the drum.

[0071] According to another embodiment of the present invention, said depolymerization reactor unit comprises heating means. Preferably such heating means are arranged at the inside of a housing of the depolymerization reactor unit. Still more preferably, the heating means is arranged at least partly in a space between the housing of the depolymerization reactor unit and a mantle of the depolymerization reactor unit, the depolymerization reactor unit preferably comprising a rotatable drum. By including heating means, it becomes easier to hold a desired process temperature during the depolymerization reactions. Preferably such heating means is arranged at the inside of a housing of the reactor unit. Still more preferably said heating means is arranged at least partly in a space between the housing of the reactor unit and a mantle of the rotatable drum. The heating means of the system according to the present invention are adapted to heat to at least 80°C, preferably to at least 100°C, more preferably to at least 120°C, more preferably to at least 140°C, most preferably at least 170°C, or even up to at least 200°C. Furthermore, heating of the reactor may be performed by using different types of fluids in a mantle, such as oil.

[0072] Moreover, also cooling means may be of relevance to incorporate. Such cooling means may be included in a mechanical gasket of the reactor unit.

[0073] Furthermore, according to yet another embodiment, the depolymerization reactor unit is connected to an outlet with a particle filter. In the particle filter, any catalyst particles still being present may be filtered off along with any solid textile fragments and other particles, such as particulate pigments.

[0074] Moreover, according to another embodiment, the system also comprises a crystallization reactor unit being connected to the depolymerization reactor unit. Preferably, the system also comprises a recirculation loop for recirculation of a solvent from the crystallization reactor unit to the depolymerization reactor unit, preferably via at least a distillation unit or an evaporator unit or a combination thereof. In a preferred embodiment, the recirculation loop may go via at least an evaporator unit or via a distillation unit or a combination thereof.

[0075] According to yet another embodiment, the system is arranged for rotating a reactor unit in the form of a rotatable drum, typically a perforated drum, in a spin drying mode. This may be done for separating solutions comprising methanol and depolymerized polyester from the fiber material subsequent to a depolymerization step, and / or for separating methanol from the fiber material in a rinsing step. The rotatable drum may be arranged for maintaining the fiber material inside the rotatable drum during such spin drying and for allowing solutions to be released from the drum via perforations and be collected in a housing of the reactor unit and subsequently withdrawn via a discharge outlet. Moreover, according to another embodiment, the system comprises a vacuum arrangement for applying a vacuum to the depolymerization reactor unit for drying a fiber material retained in the depolymerization reactor unit, preferably comprising a rotatable drum, by evaporation of methanol.

[0076] Other aspects of the present invention

[0077] The present invention is also directed to some further aspects. According to one aspect of the present invention there is provided a method for achieving at least one of: i) recycling polyester and ii) recovering cellulose fibers from a textile comprising polyester and cellulose fibers, wherein said method comprises the steps of:

[0078] - providing said textile soaked in a suspension comprising methanol and a catalyst in a reactor;

[0079] - providing and maintaining a temperature of said suspension comprising said textile within a range of 80 to 240°C during depolymerization of polyester in said textile, said depolymerization being performed by methanolysis; and

[0080] - recycling polyester and / or recovering cellulose fibers after said depolymerization, wherein, in said step of providing said textile soaked in said mixture, said catalyst of said suspension comprises calcium oxide or calcium hydroxide, or a combination thereof; wherein the specific surface area of the catalyst is at least 5 m2 / g and wherein the suspension comprising methanol and a catalyst comprises 0.2 to 10 wt.% catalyst.

[0081] According to one embodiment for this aspect of the present invention, the reactor is arranged without a rotating drum. According to another, the reactor is provided with a stationary inner wall and an agitator. Moreover, according to yet another embodiment for this aspect of the present invention, the reactor is chosen among plug flow reactors and continuous reactors, such as a continuous stirred tank reactor (CSTR), preferably the reactor is a plug flow reactor.

[0082] The presence of calcium is a key property of the catalyst to be used according to the present invention. Furthermore, also other parameters are of relevance. One such parameter is specific surface area of the catalyst mentioned herein above. A high specific surface area may be obtained by providing comparatively small catalyst particles. As an example, grinding may be used to ensure an intended maximum size. Total catalyst surface area is usually measured by using the BET (Brunauer-Emmett- Teller) method, such as in accordance with an applicable standard, e.g. ASTM D3663- 20 or ISO 9277:2022. According to one embodiment of the present invention, the total surface area of the catalyst is at least 10 m2 / g, more preferably at least 15 m2 / g, most preferably at least 20 m2 / g. According to another embodiment, the catalyst comprises Ca. Preferably, the catalyst comprises at least one of CaO, CaO-MgO and Ca(OH)2, more preferably CaO-MgO. Furthermore, according to yet another embodiment, the catalyst is added at a concentration of 0.05 to 0.5 m2per gram of textile, preferably at a concentration of 0.08 to 0.4 m2per gram of textile. According to a further embodiment of the present invention, the catalyst is added at a concentration of 0.05 to 0.5 m2 / g of textile, preferably at a concentration of 0.08 to 0.4 m2 / g of textile. Examples are 0.05 m2of catalyst per gram of textile, or 0.15 m2of catalyst per gram of textile, or 0.3 m2of catalyst per gram of textile. Preferably, the relation between textile, in kilograms, and methanol, in liters, in the reactor during depolymerization is at least 4 liters methanol per 1 kg of textile, i.e. the relation of methanol in liters to textile in kg is at least 4: 1, more preferably at least 5: 1, still more preferably at least 7: 1. This has been shown to provide for an efficient process. Preferably the relation of methanol (liters) to textile (kg) is less than 15: 1, more preferably less than 12: 1, still more preferably less than 10: 1.

[0083] According to another aspect of the present invention, there is provided a method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the method comprising:

[0084] - loading a reactor unit with a textile material comprising polyester fibers and at least one other type of fibers;

[0085] - providing the reactor unit in a closed state in relation to the surrounding;

[0086] - charging the reactor unit with a suspension comprising a catalyst and methanol;

[0087] - performing a depolymerization step, said depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile to the catalyst and methanol, to perform a methanolysis depolymerization reaction of the polyester fibers in the textile material, leaving said other type of fibers in a fiber state;

[0088] - discharging a liquid solution comprising depolymerized polyester and methanol from the reactor unit;

[0089] - performing one or more rinsing steps, preferably performing one or more rinsing steps in heated methanol being charged to the reactor unit, more preferably the method comprises multiple rinsing steps;

[0090] - drying the fiber material remaining for providing a dry fiber material substantially free from methanol, and drawing off remaining methanol from the reactor unit and recirculating the methanol;

[0091] - providing the reactor unit in an open state in relation to the surrounding; and

[0092] - discharging the fiber material from the reactor unit.

[0093] Also here, to use inert atmosphere in the reactor unit is preferred. Furthermore, a charging unit may be included as explained above. Also for such a unit, inert atmosphere is preferred.

[0094] Moreover, according to one embodiment for this aspect of the present invention, depolymerized polyester (e.g. DMT) being produced is concentrated, cooled and crystallized after said step of withdrawing from the reactor unit a liquid solution comprising depolymerized polyester, and optionally after any rinsing step, to enable separation of the DMT and recirculation and reuse of the methanol to the reactor unit, preferably the DMT is cooled and crystallized in a separate crystallization reactor unit. Moreover, methanol may be recovered via at least one evaporation step or via distillation.

[0095] Furthermore, in line with this aspect of the present invention, according to one embodiment, the withdrawn liquid solution comprising depolymerized polyester and methanol is processed by at least filtration, preferably first crystallization and then filtration, for separation of methanol from depolymerized polyester. According to one embodiment, separated methanol is recirculated and reused for being mixed with a stream of suspension comprising a catalyst and methanol intended to be charged into the reactor unit, optionally a waste stream is separated off before the methanol is recirculated and reused. Moreover, according to yet another embodiment, the depolymerized polyester separated from methanol is dried before being retained as DMT.

[0096] Other embodiments linked to this aspect of the present invention include that the drum is rotated during at least one of said mixing step and said depolymerization step to make the textile material tumble around inside thereof in contact with the catalyst and methanol. Furthermore, multiple rinsing steps may be used. Moreover, according to one embodiment the rinsing step comprises a spin-drying rotation principle for separating methanol and depolymerized polyester from the fiber material.

[0097] According to yet another embodiment, the present invention is directed to a system for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the system being arranged for conducting a methanolysis depolymerization reaction of polyester fibers and leaving the other type of fibers comprised in the textile material in a fiber state. The recycling system comprises a depolymerization reactor unit comprising a rotatable drum, wherein the system also comprises a crystallization reactor unit being connected to the depolymerization reactor unit. Preferably, the system also comprises a recirculation loop for recirculation of a solvent from the crystallization reactor unit to the depolymerization reactor unit, preferably via at least an evaporator unit or via a distillation unit or a combination thereof, more preferably the system also comprises a charging unit. As one example, a thin film evaporator may be included in the system according to the present invention. To recover and recycle methanol for reusing the same is of course of interest in a system according to the present invention.

[0098] As mentioned above, preferably said depolymerization reactor unit may be a pressure vessel adapted to withstand a temperature of at least 80°C, preferably adapted to withstand a pressure of at least 5 bar, more preferably at least 10 bar. Moreover, the charging vessel may have features as mentioned above. Furthermore, according to one embodiment, said depolymerization reactor unit is a rotatable drum.

[0099] It should be noted that the embodiments and starting scopes for different objects according to the present invention, mentioned above, may be combined with other embodiments mentioned above to define even further embodiments of the present invention. Detailed description of the drawings

[0100] In Fig. 1 there is shown a schematic view of the steps involved in at least one embodiment of the method according to the present invention.

[0101] The method according to the present invention comprises loading a reactor unit with a textile material comprising polyester fibers and at least one other type of fibers (e.g. cotton) and charging the reactor unit with preheated suspension comprising a catalyst and methanol from a preheated charging vessel. The methanolysis depolymerization reaction is performed in a rector at a temperature of at least 80°C. Separation of methanol and depolymerized polyester (DMT) from the least one other type of fibers, e.g. cotton fibers, is performed via centrifugation. According to this embodiment, one or multiple rinsing steps, typically employing methanol, are performed, and recirculation of the rinsing liquid is used. The drying is performed, suitably with vacuum. Then, the unloading is performed by withdrawing a fiber material, in this case comprising cotton, from the reactor unit.

[0102] From the separation step of the centrifugation, separated methanol, comprising depolymerized polyester (DMT), is sent to crystallization of DMT dissolved in the methanol. Then filtration is performed and the permeate, comprising methanol possible to reuse, is recirculated to an inflow of methanol to the preheated charging vessel. Moreover, the remaining DMT is obtained after drying.

[0103] Moreover, in Fig. 2 there is shown a schematic block view of a system according to the present invention. In the broadest aspect of the present invention, the system 200 comprises a charging unit 250, intended to be preheated when containing a suspension comprising a catalyst and methanol, and a depolymerization reactor unit 210. The depolymerization reactor unit 210 is a pressure vessel adapted to withstand a temperature of at least 80°C and preferably adapted to withstand a pressure of at least 5 bar. Suitable other units of a system 200 are mentioned above in different embodiments of the present invention. In this embodiment, the charging unit 250 comprises a high- shear mixer 254’, as a de-agglomeration agitation unit 254. Furthermore, as depicted, the depolymerization reactor unit 210 has a larger volume than the charging unit 250. Moreover, it should be noted that the charging unit 250 may be connected to several depolymerization reactor units 210.

[0104] In Fig. 3 there is shown one reactor unit 210 possible to include in a system 200 according to the present invention. In this case, the reactor unit 210 comprises a rotatable drum 220 having an axis A, as mentioned said axis A preferably having an angle to the horizontal plane being less than 45°. Moreover, in this case, the rotatable drum 220 comprises paddles 225. Moreover, the reactor unit 210 comprises heating means 230.

[0105] In Fig. 4 there is shown a schematic view of one embodiment of a charging unit 250 according to the present invention. The charging unit 250 comprises a deagglomeration vessel 252, in which methanol is mixed with the catalyst to form a suspension. The de-agglomeration vessel 252 is thus arranged for mixing methanol with the catalyst to form a suspension and therefore provided with an agitation unit 254. The agitation unit 254 may be a high-shear mixer 254’ as shown in Fig. 2. As seen in Fig. 4, the charging unit 250 may have multiple agitation units 254” and 254’”, suitably with different purposes, e.g. a high-shear mixer / de-agglomeration agitation unit 254’” arranged in a small volume of the bottom of the de-agglomeration vessel 252 for deagglomeration purposes, and a paddle-type agitation unit 254” or the like arranged for agitation of the entire volume of the de-agglomeration vessel 252. Further, the charging unit 250 comprises a storage vessel 253. The storage vessel 253 is connected with the de-agglomeration vessel 252 to enable for the suspension of methanol and catalyst to be forwarded from the de-agglomeration vessel 252 to the storage vessel 253. The storage vessel 253 is be provided with a paddle-based agitation unit 257 arranged for agitation of the entire volume of the storage vessel 253. Furthermore, the charging unit 250 comprises heating means 255.

[0106] In Fig. 5 there is shown a schematic view of one embodiment of a 200 system according to the present invention. There are several parts of Fig. 5, which equal those in Fig. 3. Hence, focus on the description related to Fig. 5 will be on the additional parts of the system 200. The system 200 further comprises a charging unit 250, such as the one in Fig. 4, for charging the depolymerization reactor unit 210 with pre-heated methanol and catalyst. The charging unit 250 is used for supplying preheated methanol and a catalyst to the depolymerization reactor unit 210. The rotatable drum 220 may be provided with lids (not shown) for charging to the drum with the textile material that is to be treated according to the method, and for withdrawing from the drum 220 the fiber material, e.g. said at least one other type of fibers, remaining after the depolymerization, and any rinsing. The depolymerization reactor unit 210 further comprises an outlet 240 with a particle filter 260. The particle filter 260 may be used to separate and filtrate particles from liquid withdrawn from the depolymerization reactor unit 220, such as spent catalyst and particles still in the suspension. The system 200 also comprises a crystallization reactor unit 270. The crystallization reactor unit 270 is connected to the depolymerization reactor unit 210. Further, the textile recycling system also comprises a recirculation loop 280. The recirculation loop 280 is used for recirculation of methanol from the crystallization reactor unit 270 to the depolymerization reactor unit 210.

[0107] Moreover, the system comprises 200 at least a distillation unit 291 or an evaporator unit 290 or a combination thereof. The recirculation loop 280 recirculates the methanol via at least the distillation unit 291 or the evaporator unit 290, or the combination thereof.

[0108] In Fig. 6 there is shown a schematic view of one embodiment of a rotatable rum 220 for use in the present system. The rotatable drum 220 is perforated with perforations 245. The perforations 245 enables separation of methanol-monomer solution from the remaining textile after depolymerization reaction and potential subsequent steps, e.g. rinsing.

Claims

CLAIMS1. A method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the method comprising- preheating a reaction liquid comprising at least methanol in a charging unit;- loading a reactor unit with a textile material comprising polyester fibers and at least one other type of fibers;- charging the reactor unit with the preheated reaction liquid from the charging unit and with catalyst;- performing a depolymerization step, said depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile to the catalyst and methanol, to perform a methanolysis depolymerization reaction of the polyester fibers in the textile material, leaving at least a portion of said other type of fibers in a fiber state;- withdrawing a liquid solution comprising depolymerized polyester and methanol from the reactor unit; and- withdrawing from the reactor unit a fiber material comprising said other type of fibers.

2. The method according to claim 1, wherein the reaction liquid comprises a suspension of methanol and the catalyst.

3. The method according to claim 1 or 2, wherein the charging unit comprises a de-agglomeration vessel, wherein methanol is mixed with the catalyst in the deagglomeration vessel to form a suspension.

4. The method according to claim 3, wherein the charging unit further comprises a storage vessel, and wherein the suspension is forwarded from the deagglomeration vessel to the storage vessel, preferably the suspension being diluted in the storage vessel by addition of further methanol.

5. The method according to any of claims 1 to 4, wherein the charging unit is arranged with an agitation unit.

6. The method according to claim 5, wherein the charging unit is arranged with a high-shear mixer as the agitation unit; and / or with a paddle-type agitation unit.

7. The method according to any of claims 1 to 6, wherein the charging unit is arranged with a de-agglomeration agitation unit; and / or with a paddle-type agitation unit.

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

9. The method according to any of the preceding claims, wherein the preheated reaction liquid, preferably a suspension of methanol and the catalyst, is preheated to a temperature in the interval of 100 to 180°C, more preferably in the interval of 140to 175°C, during a time of at least 15 minutes, preferably 30 minutes.

10. The method according to any of the preceding claims, wherein the charging unit is separate from the reactor unit.

11. The method according to any of the preceding claims, wherein the charging unit has a smaller volume than the reactor unit.

12. The method according to any of the preceding claims, wherein the reaction liquid, preferably a suspension of methanol and the catalyst, is held, during at least a portion of the step of preheating the reaction liquid, in the charging unit at a pressure ofat least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably the pressure is less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably the pressure is, at least during a portion of the preheating step, in the range of 10 to 25 bar absolute pressure.

13. The method according to any one of the preceding claims, wherein the preheated reaction liquid from said charging unit and the catalyst is supplied to more than one reactor unit, such as to at least two, or more preferably to at least three, separate reactor units.

14. The method according to any of the preceding claims, wherein the preheating is performed under an inert atmosphere in the charging unit, preferably under a N2 environment.

15. The method according to any of the preceding claims, wherein the method comprises- a mixing step comprising bringing the textile material into contact with a suspension comprising the catalyst and methanol in a rotatable drum of the reactor unit, preferably the rotatable drum being arranged for rotating around an axis (A), said axis (A) having an angle to the horizontal plane being less than 45°; wherein the drum is rotated during at least one of said mixing step and said depolymerization step to make the textile material tumble around inside thereof in contact with the catalyst and methanol, optionally the rotatable drum perforated.

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

17. The method according to any of the preceding claims, wherein the pressure in the reactor unit is held, during at least a portion of the depolymerization step, at a pressure of at least 5 bar, preferably at least 10 bar absolute pressure, preferably the pressure is less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably the pressure is, at least during a portion of the depolymerization step, in the range of 10 to 25 bar absolute pressure, and / or wherein the reactor unit preferably comprises a rotatable drum provided with perforations, preferably said perforations being arranged at least on a mantle surface of the rotatable drum.

18. The method according to any of the preceding claims, wherein said at least one other fiber type of the textile material comprises a cellulose based fiber, preferably the cellulose based fiber is at least one of natural cellulose fibers such as cotton, and linen, and man-made cellulose fibers, such as viscose, lyocell, rayon, and modal, more preferably said at least one other fiber type comprises at least cotton.

19. The method according to any of the preceding claims, wherein said textile material comprises at least 30 wt. %, preferably at least 40 wt. %, more preferably at least 50 wt. %, cellulose based fibers, and / or wherein said textile material comprises at least 30 wt. %, preferably at least 40 wt.%, more preferably at least 50 wt.%, cotton fibers, and / or wherein the textile material comprises at least 30 wt. %, preferably at least 40 wt. %, more preferably at least 60 wt.%, of poly cotton textile material.

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

21. The method according to any of the preceding claims, wherein the specific surface area of the catalyst is at least 5 m2 / g, preferably at least 10 m2 / g, more preferably at least 15 m2 / g, most preferably at least 20 m2 / g.

22. The method according to any of the preceding claims, wherein the catalyst is added at a concentration of 0.05 to 0.5 m2per gram of textile, preferably at a concentration of 0.08 to 0.4 m2per gram of textile.

23. The method according to any of the preceding claims, wherein the relation between textile, in kilograms, and methanol, in liters, in the reactor during the depolymerization is at least 4 liters methanol per 1 kg of textile (4: 1), preferably at least 5: 1, more preferably at least 7: 1.

24. The method according to any of the preceding claims, wherein the methanolysis depolymerization reaction is performed under an inert atmosphere in the reactor unit, preferably under a N2 environment.

25. The method according to any of the preceding claims, wherein the method further comprises performing one or more rinsing steps, preferably performing one or more rinsing steps in additional methanol charged to the reactor unit, more preferably in heated methanol, more preferably the method comprises multiple rinsing steps after withdrawing a liquid solution comprising depolymerized polyester and methanol from the reactor unit to dissolve remaining depolymerized polyester in the reactor unit.

26. The method according to any of the preceding claims, wherein the method comprises drying the fiber material remaining after said depolymerization step for providing a dry fiber material substantially free from methanol, and optionally drawing off remaining methanol from the reactor unit, said step of drying being performed before withdrawing from the reactor unit a fiber material comprising said other type of fibers, preferably said step of drying is performed by using vacuum.

27. The method according to any of the preceding claims, wherein the other type of fibers remaining after said depolymerization step is dried by spin drying in a perforated rotatable drum of the reactor unit; preferably the reactor, after the spin drying, being coupled to vacuum to evaporate any remaining methanol from the othertype of fibers while rotating the other type of fibers in the rotatable drum, the reactor unit still being warm in coupling the reactor unit to vacuum.

28. A system (200) for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the system (200) being arranged for conducting a depolymerization reaction, preferably a methanolysis depolymerization reaction, of polyester fibers and leaving a the other type of fibers comprised in the textile material in a fiber state, said system (200) comprising- a charging unit (250);- a depolymerization reactor unit (210), said depolymerization reactor unit (210) being a pressure vessel adapted to withstand a temperature of at least 80°C, preferably adapted to withstand a pressure of at least 5 bar, more preferably at least 10 bar; wherein the charging unit (250) is arranged for supplying a preheated reaction liquid and a catalyst, preferably a suspension of methanol and catalyst, to the depolymerization reactor unit (210).

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

30. The system (200) according to claim 28 or 29, wherein the charging unit (250) comprises a de-agglomeration vessel (252), wherein the de-agglomeration vessel (252) is arranged for mixing methanol with the catalyst to form the suspension.

31. The system (200) according to any of claims 28 to 30, wherein the charging unit (250) further comprises a storage vessel (253), wherein the storage vessel (253) is connected with the de-agglomeration vessel (252) to enable for the suspension to be forwarded from the de-agglomeration vessel (252) to the storage vessel (253), preferably the suspension being diluted in the storage vessel (253) by addition of further methanol.

32. The system (200) according to any of claims 28 to 31, wherein the charging unit (250) is provided with an agitation unit (254).

33. The system (200) according to claim 32, wherein the charging unit (250) is arranged with a high-shear mixer (254’) as the agitation unit (254); and / or with a paddle-type agitation unit (254”).

34. The system (200) according to any of claims 28 to 33, wherein the charging unit (250) is arranged with a de-agglomeration agitation unit (254’”); and / or with a paddle-type agitation unit (254”).

35. The system (200) according to any of claims 28 to 34, wherein the system (200) is connected to overpressure and / or vacuum to enable for transportation of methanol, catalyst and / or suspension of methanol and catalyst by use of over-pressure or vacuum.

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

37. The system (200) according to any of claims 28 to 36, wherein the charging unit (250) is arranged to ensure that the preheated reaction liquid, preferably a suspension of methanol and the catalyst, is preheated to a temperature in the interval of 100 to 180°C, more preferably in the interval of 140 to 175°C, during a time of at least 15 minutes, preferably 30 minutes.

38. The system (200) according to any of claims 28 to 37, wherein the charging unit (250) has a smaller volume than the depolymerization reactor unit (210).

39. The system (200) according to any of claims 28 to 38, wherein the charging unit (250) is arranged to withstand at least 5 bar absolute pressure, more preferably at least 10 bar absolute pressure, so that preheated reaction liquid and a catalyst, preferably a suspension of methanol and catalyst, may be held, during at least a portion of the preheating step, at at least 5 bar absolute pressure, preferably at least 10 bar absolute pressure, preferably at a pressure being less than 40 bar absolute pressure, such as less than 30 bar absolute pressure, still more preferably at a pressure being, at least during a portion of the preheating step, in the range of 10 to 25 bar absolute pressure.

40. The system (200) according to any of claims 28 to 39, wherein the charging unit (250) comprises heating means (255).

41. The system (200) according to any of claims 28 to 40, wherein the system (200) comprises more than one depolymerization reactor unit (210) enabling for preheated reaction liquid from said charging unit (250) and catalyst being supplied to said more than one depolymerization reactor unit (210), such as at least two, or more preferably at least three, separate depolymerization reactor units (210).

42. The system (200) according to any of claims 28 to 41, wherein the charging unit (250) is connected to an inert source so that the charging unit (250) is arranged for a preheating step under an inert atmosphere, preferably the inert source is a N2 source.

43. The system (200) according to any of claims 28 to 42, wherein the system (200) comprises a depolymerization reactor unit (210) comprising a rotatable drum (220), preferably the rotatable drum (220) being arranged for rotating around an axis (A), said axis (A) having an angle to the horizontal plane being less than 45°, preferably the angle to the horizontal plane of the axis (A) during rotation of the rotatable drum (220) is less than 25°, preferably in a range of from 0 to 10°.

44. The system (200) according to claim 43, wherein the rotatable drum (220) is perforated.

44. A method for achieving at least one of: i) recycling polyester and ii) recovering cellulose fibers, from a textile comprising polyester and cellulose fibers, wherein said method comprises the steps of:- providing said textile soaked in a suspension comprising methanol and a catalyst in a reactor;- providing and maintaining a temperature of said suspension comprising said textile within a range of 80 to 240°C during depolymerization of polyester in said textile, said depolymerization being performed by methanolysis; and- recycling polyester and / or recovering cellulose fibers after said depolymerization, wherein, in said step of providing said textile soaked in said mixture, said catalyst of said suspension comprises calcium oxide or calcium hydroxide, or a combination thereof; wherein the specific surface area of the catalyst is at least 5 m2 / g and wherein the suspension comprising methanol and a catalyst comprises 0.2 to 10 wt.% catalyst.

45. A method of recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the method comprising- loading a reactor unit with the textile material comprising polyester fibers and at least one other type of fibers;- providing the reactor unit in a closed state in relation to the surrounding;- charging the reactor unit with a suspension comprising a catalyst and methanol;- performing a depolymerization step, said depolymerization step comprising providing a temperature of at least 80°C in the reactor unit and exposing the textile to the catalyst and methanol, to perform a methanolysis depolymerization reaction of the polyester fibers in the textile material, leaving said other type of fibers in a fiber state;- discharging a liquid solution comprising depolymerized polyester and methanol from the reactor unit;- performing one or more rinsing steps, preferably performing one or more rinsing steps in heated methanol being charged to the reactor unit, more preferably the method comprises multiple rinsing steps;- drying the fiber material remaining for providing a dry fiber material substantially free from methanol, and drawing off remaining methanol from the reactor unit and recirculating the methanol;- providing the reactor unit in an open state in relation to the surrounding; and- discharging the fiber material from the reactor unit.

46. A system (200) for recycling at least a portion of a textile material comprising polyester fibers and at least one other type of fibers, the system (200) being arranged for conducting a methanolysis depolymerization reaction of polyester fibers and leaving the at least one other type of fibers comprised in the textile material in a fiber state, the recycling system comprising a depolymerization reactor unit (210) comprising a rotatable drum (220), wherein the system (200) also comprises a crystallization reactor unit (270) being connected to the depolymerization reactor unit (210), preferably also comprising a recirculation loop (280) for recirculation of a solvent from the crystallization reactor (270) unit to the depolymerization reactor unit (210), preferably via at least an evaporator unit (290) or via a distillation unit (291) or a combination thereof, more preferably the system also comprises a charging unit (250).

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