Method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments waste

Abstract

A method for the recycling of items comprising poly(ethylene terephthalate), particularly polyester garments, is realised so as in the first step, the raw material for recycling is comminuted and then cleaned In the second step, the raw material is introduced into a reactor and a mixture of esters of dicarboxylic acids is added to it in a amount of at least 100% m / m; then, the mixture is heated to a temperature in the range of 20 to 180°C under a pressure in the range of 0.5 bar to 1.5 bar and the mixture is stirred for 5 to 30 minutes with a rate of 3 to 8,000 rpm. In the third step, decolourisation of the raw material is carried out, wherein the reactor content is heated to a temperature of 20 to 200°C, and the mixture is stirred for 5 to 30 minutes with a rate of 3 do 8,000 rpm. The comminuted and decolourised raw material is rinsed in acetone until the decolourising solvent is removed. In the fourth step, glycolysis is carried out, wherein an excess of ethylene glycol is added to the reactor, in a amount of 20 to 500% of the stoichiometric value in relation to terephthalic acid monomer present in the solution, and an excess of a catalyst is added in a amount of 5 do 20% of the stoichiometric value in relation to terephthalic acid monomer present in the solution. The reaction is carried out for 5 to 60 minutes at a temperature not exceeding 160°C under atmospheric pressure. In the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein a reaction of sodium salt of terephthalic acid or potassium salt of terephthalic acid present in the mixture with glycol, with sulfuric(VI) acid having concentration of 20 to 96% is carried out. Sulfuric(VI) acid is being added to the mixture until it reaches a pH value in the range of 1 to 5. Next, the obtained solution is filtered and terephthalic acid is collected on the filter in the form of a precipitate. In the sixth step, the filtered solution is crystallised, and ethylene glycol and crystallised sodium sulfate(VI) or potassium sulfate(VI) are obtained.

Description

[0001] Method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments waste

[0002] The invention relates to a method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments waste, with the recovery of terephthalic acid and ethylene glycol from them.

[0003] Presently, a high amount of clothing products is manufactured, particularly garments. Some of them are subject to material recycling, as a result of which other products are manufactured from the same material. Waste not suitable for recycling is placed mostly in landfills, becoming a burden for the natural environment. Therefore, methods for recovery of raw materials and their re-use are sought after.

[0004] Patent description number PL239189B 1 discloses a method for recycling of PET waste with the recovery of terephthalic acid and ethylene glycol. In this method, PET waste is dissolved in hot ethylene glycol at a temperature of 195°C in the presence of a catalyst selected from either sodium or potassium hydroxide. The obtained glycolysate is dissolved in water yielding a solution, and then, insoluble particles of impurities present in the starting PET waste are separated by filtration. Next, the solution is acidified with an aqueous solution of a mineral acid, to achieve its concentration in the mixture in the range of 0.5% by wt. to 30% by wt., preferably in the range of 5% to 10% by wt. Acidic hydrolysis is carried out at a temperature between 60°C and the boiling temperature of the solution, preferably between 90°C and the boiling temperature of the solution. During the hydrolysis, terephthalic acid precipitates in the form of a white suspension. The so-obtained terephthalic acid is filtered and washed off with hot water until the neutralisation of the acidic reaction, and then dried. The filtrate obtained at separation of terephthalic acid is neutralised, concentrated by evaporation of water, the precipitated salts are separated, and then ethylene glycol is recovered, preferably by distillation under reduced pressure.

[0005] Patent description number EP3778744B 1 discloses a method for recycling of poly(ethylene terephthalate), wherein a partial PET depolymerisation is carried out to obtain PET oligomers, and also a repolymerisation of the partially depolymerised PET containing PET oligomers is carried out.

[0006] Patent description number EP320033B 1 discloses a method for depolymerisation of poly(ethylene terephthalate), wherein the polymer is mixed with a mixture of a non-polar solvent and a mixture of an alcohol with a hydroxide. The method is carried out without supplying external heat.

[0007] None of the solutions known in the art allows for obtaining pure terephthalic acid and ethylene glycol also from dyed items.

[0008] The goal of the invention is to develop a new method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, which allows for obtaining of high-purity terephthalic acid and ethylene glycol, also from dyed garments.

[0009] The method for recycling of items comprising poly(ethylene terephthalate) according to the invention, particularly polyester garments, wherein glycolysis of poly(ethylene terephthalate) with ethylene glycol is carried out using a catalyst, namely a hydroxide of alkaline metals, particularly sodium hydroxide or potassium hydroxide, and precipitation of terephthalic acid is carried out, is characterised by the first step, in which the raw material for recycling is comminuted and then purified, and next, in the second step, the raw material is placed in a reactor and a mixture of esters of dicarboxylic acids is added to it in an amount of at least 100% m / m, and then, the mixture is heated to a temperature from the range of 20 to 180°C under a pressure from the range of 0.5 bar do 1.5 bar and stirred for 5 to 30 minutes with a rotational speed of 3 to 8,000 rpm, and next, in the third step, decolourisation of the raw material is carried out, wherein the reactor content is heated to a temperature of 20 to 200°C and the mixture is stirred for 5 to 30 minutes with a rotational speed of 3 to 8,000 rpm, and then, the comminuted and decolourised raw material is rinsed in acetone until the decolourising solvent is removed, and next, in the fourth step, glycolysis is carried out, wherein an excess of ethylene glycol is added to the reactor, in an amount of 20 to 500% of the stoichiometric amount in relation to the terephthalic acid monomer present in the solution, and an excess of the catalyst is added in an amount of 5 to 20% of the stoichiometric amount in relation to terephthalic acid monomer present in the solution, wherein the reaction is carried out for 5 to 60 minutes at a temperature of at most 160°C under atmospheric pressure, and next, in the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein the sodium salt of terephthalic acid or potassium salt of terephthalic acid being in a mixture with glycol is reacted with sulfuric(VI) acid having concentration of 20 to 96%, and moreover, sulfuric(VI) acid is being added to the mixture until it reaches a pH value from the range of 1 to 5, and then, the obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and next, in the sixth step, the filtered solution is crystallised and ethylene glycol and crystallised sodium sulfate(VI) or potassium sulfate(VI) are obtained.

[0010] Preferably, in the first step, the raw material for recycling is comminuted mechanically, wherein the raw material for recycling is comminuted to a grain size of 1x1 mm to 70x70 mm, and moreover, if textile waste is used as the raw material for recycling, then in the first step, after the comminution, the waste is cleansed by dry-cleaning in tetrachloroethylene at a temperature of 10 to 60°C, and then dried at a temperature of 40 to 60°C.

[0011] Further advantages are accomplished if in the second step, the stirring is carried out using a mechanical stirrer and / or a sonicator, and as the mixture of esters of dicarboxylic acids, a mixture of dimethyl succinate, dimethyl adipate, and dimethyl glutarate is used, wherein the mixture of esters of dicarboxylic acids, dimethyl succinate is used in an amount of 5 to 60% by wt., dimethyl adipate is used in an amount of 5 to 80% by wt., while dimethyl glutarate is used in an amount of 30 to 90% by wt., and moreover, heating is carried out using microwaves and / or indirectly.

[0012] The new method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments, according to the invention, may be used for chemical recycling of textile waste, including garment waste comprising poly(ethylene terephthalate) (PET) as the main component, as well as those comprising additional components other than PET. Moreover, this new method for recycling may be used for the recycling of other PET waste, particularly containers or bottles. The raw material recycled using the method according to the invention may comprise impurities. The new method enables recovery of such compounds as high-purity terephthalic acid and ethylene glycol, also from dyed waste. Then, these compounds may be used as substrates for synthesis of new PET plastics, allowing for a reduction of volume of waste unsuitable for material recycling, as well as a reduction of volume of primary raw materials used for this purpose and produced from petroleum. Owing to the high purity of the obtained micromolecular compounds - terephthalic acid and ethylene glycol - used subsequently for syntheses of new polymers, the obtained polymers have the quality of primary plastics.

[0013] The subject of the invention is illustrated as embodiments and in the drawing, where Fig. 1 is aXH NMR spectrum for a reference sample of terephthalic acid, Fig. 2 is a13C NMR spectrum for a reference sample of terephthalic acid, Fig. 3 is a1H NMR spectrum for sample No. 1, Fig. 4 is a13C NMR spectrum for sample No. 1, Fig. 5 is a1H NMR spectrum for sample No. 2, Fig. 6 is a13C NMR spectrum for sample No. 2, Fig. 7 is a ’ H NMR spectrum for sample No. 3, Fig. 8 is a13C NMR spectrum for sample No. 3, and Fig. 9 is a ’ H NMR spectrum for sample No. 1 and spectrum for sample No. 1 with an addition of terephthalic acid.

[0014] In first embodiment, the method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, according to the invention, is realised so as to in the first step, the textile waste constituting the raw material for recycling is subject to mechanical comminution to the particle size of 50x50 mm. Next, the comminuted raw material is cleaned by dry-cleaning in tetrachloroethylene at a temperature of 40°C, and then dried at a temperature of 50°C. Subsequently, in the second step, defibration of the raw material is carried out, wherein it is placed in a reactor equipped with a mechanical stirrer and a solvent is added to it in an amount of 100% m / m, in the form of a mixture of esters of dicarboxylic acids, wherein 30% by wt. of dimethyl succinate, 30% by wt. of dimethyl adipate, and 40% by wt. of dimethyl glutarate are used. The mixture of the raw material and the solvent is heated to 120°C under atmospheric pressure while stirring using the mechanical stirrer with a rate of 2,500 rpm. The stirring is carried out for 15 minutes. Subsequently, in the third step, decolourisation of the textile fibres obtained in the second step is carried out. To this end, the reactor content is heated to a temperature of 160°C and the mixture is stirred using a mechanical stirrer with a rate of 3,000 rpm for 20 minutes. Then, the comminuted and decolourised raw material is rinsed in acetone until the decolourizing solvent is removed. Subsequently, in the fourth step, glycolysis of poly(ethylene terephthalate) (PET) is carried out, wherein an excess of ethylene glycol is added to the raw material comprised in the reactor, in an amount of 200% greater than the amount resulting from the stoichiometric amount in relation to terephthalic acid monomer in the solution. Additionally, an excess of sodium hydroxide is introduced into the reactor as a catalyst in an amount of 15% greater than the amount resulting from the stoichiometric amount in relation to terephthalic acid monomer in the solution. The reaction is carried out for 40 minutes at a temperature not exceeding 160°C under atmospheric pressure. In the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein to this end, sodium salt of terephthalic acid dissolved in glycol is introduced into the reactor and 50% sulfuric(VI) acid is being added to the mixture portionwise until the mixture reaches a pH of 4. The obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and the filtered solution contains sodium sulfate(VI) and ethylene glycol. In the sixth step, the solution obtained in the fifth step is crystallised, and ethylene glycol and crystallised sodium sulfate(VI) are obtained.

[0015] In second embodiment, the method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments, according to the invention, is realised so as to in the first step, the textile waste constituting the raw material for recycling is subject to mechanical comminution to the particle size of 1x1 mm. Next, the comminuted raw material is cleaned by dry-cleaning in tetrachloroethylene at a temperature of 10°C, and then dried at a temperature of 40°C. Subsequently, in the second step, defibration of the raw material is carried out, wherein it is placed in a reactor equipped with a sonicator and a mechanical stirrer, and solvent is added to it in an amount of 200% m / m (this is an embodiment example so a specific amount is cited), in the form of a mixture of esters of dicarboxylic acids, wherein 20% by wt. of dimethyl succinate, 50% by wt. of dimethyl adipate, and 30% by wt. of dimethyl glutarate are used. The mixture of the raw material and the solvent is heated to 60°C under a pressure of up to 0.5 bar while stirring using the sonicator and the mechanical stirrer with a rate of 3 rpm. The stirring is carried out for 30 minutes. Subsequently, in the third step, decolourisation of the textile fibres obtained in the second step is carried out. To this end, the reactor content is heated to a temperature of 20°C and the mixture is stirred using a sonicator and a mechanical stirrer with a rate of 10 rpm for 30 minutes. Then, the comminuted and decolourised raw material is rinsed in acetone until the decolourizing solvent is removed. Subsequently, in the fourth step, glycolysis of poly(ethylene terephthalate) (PET) is carried out, wherein an excess of ethylene glycol is added to the raw material comprised in the reactor, in an amount of 20% greater than the amount resulting from the stoichiometric amount in relation to terephthalic acid monomer in the solution. Additionally, an excess of potassium hydroxide is introduced into the reactor as a catalyst in an amount of 5% greater than the amount resulting from the stoichiometric amount in relation to terephthalic acid monomer in the solution. The reaction is carried out for 60 minutes at a temperature not exceeding 160°C under atmospheric pressure. In the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein to this end, a solution of potassium salt of terephthalic acid in glycol is introduced into the reactor and 20% sulfuric(VI) acid is added to the mixture until the mixture reaches a pH of 1. The obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and the filtered solution contains potassium sulfates(VI) and ethylene glycol. In the sixth step, the solution obtained in the fifth step is crystallised, and ethylene glycol and crystallised potassium sulfate(VI) are obtained.

[0016] In third embodiment, the method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments, according to the invention, is realised so as to in the first step, the textile waste constituting the raw material for recycling is subject to mechanical comminution to the particle size of 70x70 mm. Next, the comminuted raw material is cleaned by dry-cleaning in tetrachloroethylene at a temperature of 60°C and then dried at a temperature of 60°C. Subsequently, in the second step, defibration of the raw material is carried out, wherein it is placed in a reactor equipped with a sonicator and solvent is added to it in an amount of 500% m / m, in the form of a mixture of esters of dicarboxylic acids, wherein 60% by wt. of dimethyl succinate, 10% by wt. of dimethyl adipate, and 30% by wt. of dimethyl glutarate are used. The mixture of the raw material and the solvent stirred using the sonicator is heated with microwaves to a temperature of 180°C under a pressure 1.5 bar. The stirring is carried out for 5 minutes. Subsequently, in the third step, decolourisation of the textile fibres obtained in the second step is carried out. To this end, the reactor content is heated to a temperature of 200°C and the mixture is stirred using the sonicator for 5 minutes. Then, the comminuted and decolourised raw material is rinsed in acetone until the decolourizing solvent is removed. Subsequently, in the fourth step, glycolysis of poly(ethylene terephthalate) (PET) is carried out, wherein an excess of ethylene glycol is added to the raw material comprised in the reactor, in an amount of 300% greater than the amount resulting from the stoichiometric amount in relation to the terephthalic acid monomer in the solution. Additionally, an excess of potassium hydroxide is introduced into the reactor as a catalyst in an amount of 20% greater than the amount resulting from the stoichiometric amount in relation to the terephthalic acid monomer in the solution. The reaction is carried out for 5 minutes at a temperature not exceeding 160°C under atmospheric pressure. In the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein to this end, a solution of potassium salt of terephthalic acid in glycol is introduced into the reactor and 96% sulfuric(VI) acid is being added to the mixture portion-wise until the mixture reaches pH of 5. The obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and the filtered solution contains potassium sulfates(VI) and glycol. In the sixth step, the solution obtained in the fifth step is crystallised, and ethylene glycol and crystallised potassium sulfate(VI) are obtained.

[0017] In fourth embodiment, the method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments, according to the invention is carried out as in the third embodiment, but a mixture of 20% by wt. of dimethyl succinate, 10% by wt. of dimethyl adipate, and 70% by wt. of dimethyl glutarate is used as the solvent, and the solvent is used in an amount of 1000% m / m, and moreover, an excess of ethylene glycol is used in an amount of 500% greater than the amount resulting from the stoichiometric amount in relation to terephthalic acid monomer in the solution.

[0018] In fifth embodiment, the method for recycling of items comprising poly (ethylene terephthalate), particularly of polyester garments, according to the invention is carried out as in the second embodiment, but a mixture of 10% by wt. of dimethyl succinate, 80% by wt. of dimethyl adipate, and 10% by wt. of dimethyl glutarate is used as the solvent.

[0019] In sixth embodiment, the method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, according to the invention is carried out as in the first embodiment, but a mixture of 5% by wt. of dimethyl succinate, 5% by wt. of dimethyl adipate, and 90% by wt. of dimethyl glutarate is used as the solvent, and the solvent-raw material mixture is heated to a temperature of 20°C, and moreover, heating is carried out using both indirect heating and microwaves.

[0020] In seventh embodiment, the method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, according to the invention is carried out as in the third embodiment, but a mixture of 60% by wt. of dimethyl succinate, 10% by wt. of dimethyl adipate, and 40% by wt. of dimethyl glutarate is used as the solvent, and the heating is carried out using indirect heating.

[0021] In eighth embodiment, the method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, according to the invention is carried out so as to in the first step, containers made of poly(ethylene terephthalate) (PET) constituting the raw material for recycling, are subject to mechanical comminution to the particle size of 30x30 mm. Then, the comminuted raw material is cleaned by washing. Subsequently, in the second step, defibration of the raw material is carried out, wherein it is placed in a reactor equipped with a mechanical stirrer and solvent is added to it in an amount of 500% m / m, in the form of a mixture of esters of dicarboxylic acids, wherein 20% by wt. of dimethyl succinate, 15% by wt. of dimethyl adipate, and 65% by wt. of dimethyl glutarate are used. The mixture of the raw material and the solvent is heated to 120°C under atmospheric pressure while stirring using the mechanical stirrer with a rate of 100 rpm. The stirring is carried out for 25 minutes. Subsequently, in the third step, decolourisation of the raw material is carried out. To this end, the reactor content is heated to a temperature of 160°C and the mixture is stirred using a mechanical stirrer with a rate of 100 rpm for 30 minutes. Then, the comminuted and decolourised raw material is rinsed in acetone until the decolourizing solvent is removed. Subsequently, in the fourth step, glycolysis of poly(ethylene terephthalate) (PET) is carried out, wherein an excess of ethylene glycol is added to the raw material comprised in the reactor, in an amount of 100% greater than the amount resulting from the stoichiometric amount in relation to the terephthalic acid monomer in the solution. Additionally, an excess of sodium hydroxide is introduced into the reactor as a catalyst in an amount of 15% greater than the amount resulting from the stoichiometric amount in relation to the terephthalic acid monomer in the solution. The reaction is carried out for 40 minutes at a temperature not exceeding 160°C under atmospheric pressure. In the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein to this end, a solution of sodium salt of terephthalic acid in glycol is introduced into the reactor and 70% sulfuric(VI) acid is being added to the mixture portion-wise until the mixture reaches pH of 4. The obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and the filtered solution contains sodium sulfates(VI) and glycol. In the sixth step, the solution obtained in the fifth step is crystallised, and ethylene glycol and crystallised sodium sulfate(VI) are obtained.

[0022] Compounds obtained by the method according to the invention were analysed by NMR. To identify the components, one-dimensional experiments (XH NMR,13C NMR), as well as two-dimensional experiments COSY, ^-^C HSQC, and ^-^C HMBC) were carried out. All experiments were carried out using a Bruker Avance II Plus 16.4 T spectrometer. The basic frequency of the device was 700 MHz. For measurements, the sample was dissolved in deuterated DMSO. 12 mg of the sample was weighed and dissolved in 0.75 mF of DMSO-d6. The measurement temperature was 300 K.

[0023] To confirm the presence of terephthalic acid, the method of standard addition to the sample was used. Terephthalic acid was purchased from Sigma Aldrich. ’ H and13C NMR spectra for the reference sample are shown in Fig. 1 and Fig. 2.1H spectrum of terephthalic acid consists of two signals: first signal from protons of the aromatic system, with a chemical shift of 8.03 ppm (4H, s), and second signal from protons of hydroxy lie groups in the carboxylic acid, with a chemical shift of 13.26 ppm (2H, br s). The other signals in the spectrum originate from the solvent (DMSO-d6, 2.48 ppm) and water comprised in the solvent (3.33 ppm).13C spectrum of terephthalic acid consists of three signals: first signal from tertiary carbons in the aromatic ring, with a chemical shift of 129.4 ppm (CH), second signal from quaternary carbons in the aromatic ring, with a chemical shift of 134.4 ppm (Civ), and signal from carbonyl carbons, with a chemical shift of 166.6 ppm (COOH). The signal having a chemical shift of 39.51 ppm originates from the solvent - DMSO-d6. Analyses carried out for three samples, number 1, 2, and 3, proved the presence of terephthalic acid, which is confirmed by the spectra. Fig. 3 and Fig. 4 illustrate proton and carbon spectra, respectively, for sample No. 1, Fig. 5 and Fig. 6 illustrate proton and carbon spectra, respectively, for sample No. 2, while Fig. 7 and Fig. 8 illustrate proton and carbon spectra, respectively, for sample No. 3. In the case of sample No. 1, an addition of a standard solution of terephthalic acid in an amount of 10 |1L was used. As one can see in Fig. 9, an increase in the intensity of signals originating from the acid was observed, confirming that the recorded signals originate from the same compound. For the obtained samples, quantitative measurements were carried out to verify their percentages of terephthalic acid. The results of these analyses are presented in Table 1.

[0024] Table 1

Claims

Claims1. The method for recycling of items comprising poly(ethylene terephthalate), particularly of polyester garments, wherein glycolysis of poly(ethylene terephthalate) with ethylene glycol is carried out using a catalyst, namely a hydroxide of alkaline metals, particularly sodium hydroxide or potassium hydroxide, and precipitation of terephthalic acid is carried out, characterised in that in the first step, the raw material for recycling is comminuted and then purified and next, in the second step, the raw material is placed in a reactor and a mixture of esters of dicarboxylic acids is added to it in a amount of at least 100% m / m, and then, the mixture is heated to a temperature from the range of 20 to 180°C under a pressure from the range of 0.5 bar to 1.5 bar and stirred for 5 to 30 minutes with a rotational speed of 3 to 8,000 rpm, and next, in the third step, decolourisation of the raw material is carried out, wherein the reactor content is heated to a temperature of 20 to 200°C and the mixture is stirred for 5 to 30 minutes with a rotational speed of 3 to 8,000 rpm, and then, the comminuted and decolourised raw material is rinsed in acetone until the decolourising solvent is removed, and next, in the fourth step, glycolysis is carried out, wherein an excess of ethylene glycol is added to the reactor in a amount of 20 to 500% of the stoichiometric amount in relation to the terephthalic acid monomer present in the solution, and an excess of the catalyst is added in an amount of 5 to 20% of the stoichiometric amount in relation to the terephthalic acid monomer present in the solution, wherein the reaction is carried out for 5 to 60 minutes at a temperature of at most 160°C under atmospheric pressure, and next, in the fifth step, precipitation of terephthalic acid from ethylene glycol is carried out, wherein the sodium salt of terephthalic acid or potassium salt of terephthalic acid being in a mixture with glycol is reacted with sulfuric(VI) acid with a concentration of 20 to 96%, and moreover, sulfuric(VI) acid is being added to the mixture until it reaches a pH value from the range of 1 to 5, and then, the obtained solution is filtered, wherein terephthalic acid is collected on the filter in the form of a precipitate, and next, in the sixth step, the filtered solution is crystallised and ethylene glycol and crystallised sodium sulfate(VI) or potassium sulfate(VI) are obtained.

2. The method according to claim 1, characterised in that in the first step, the raw material for recycling is comminuted mechanically.

3. The method according to claim 1 or 2, characterised in that in the first step, the raw material for recycling is comminuted to particle size of 1x1 mm to 70x70 mm.

4. The method according to any of claims from 1 to 3, characterised in that if textile waste is used as the raw material for recycling, then in the first step, after the comminution, the waste is cleansed by dry-cleaning in tetrachloroethylene at a temperature of 10 to 60°C, and then driedat a temperature of 40 to 60°C.

5. The method according to any of claims from 1 to 4, characterised in that in the second step, stirring is carried out using a mechanical stirrer and / or a sonicator.

6. The method according to any of claims from 1 to 5, characterised in that in the second step, a mixture of dimethyl succinate, dimethyl adipate, and dimethyl glutarate is used as the mixture of esters of dicarboxylic acids.

7. The method according to claim 6, characterised in that in the mixture of esters of dicarboxylic acids, dimethyl succinate is used in a amount of 5 to 60% by wt., dimethyl adipate is used in an amount of 5 to 80% by wt., and dimethyl glutarate is used in an amount of 30 to 90% by wt.

8. The method according to any of claims from 1 to 7, characterised in that in the second step, heating is carried out using microwaves and / or indirect heating.

Images