Highly integrated caprolactam recycling process

Abstract

The present invention is a recycling method for recovering ε-caprolactam from a solid material M containing polyamide 6, comprising: (i) providing a stream S containing the solid material M M ; (ii) preparing an aqueous depolymerization mixture based on S M ; (iii) subjecting the depolymerization mixture prepared according to (ii) to polyamide 6 depolymerization conditions in a reaction unit U R to obtain a liquid aqueous stream S R containing ε-caprolactam dissolved in water at a concentration cS R , wherein the stream S R further contains one or more impurities; (iv) passing the liquid aqueous stream S R through an evaporation unit U E to obtain a liquid aqueous stream S SL from S SR containing ε-caprolactam dissolved in water at a concentration c SL >c L , and further obtaining one or more aqueous vapor streams S R from S V ; (v) passing the aqueous stream S R through a heat-consuming purification unit U L to obtain a stream S P containing ε-caprolactam at a concentration c SCPL >>c SLの from S SCPL , and further obtaining one or more aqueous streams S CPL from S L , wherein at least a part of the heat consumed in U L is provided by at least one of the one or more streams S RW , thereby obtaining at least one at least partially condensed aqueous stream S P from at least one of the one or more streams S V ; (vi) recycling at least a part of at least one stream S V and feeding at least a part of at least one stream S VW into the reaction unit U VW ; (vii) recycling at least a part of at least one stream S RW to the reaction unit U RThe present invention relates to a method that includes the step of recirculating the process.

Description

[Technical Field]

[0001] The present invention relates in particular to a highly integrated recycling process for recycling ε-caprolactam from polymers prepared from ε-caprolactam, especially from solid materials containing polyamide 6. [Background technology]

[0002] Polyamide, specifically the formula (-NH-(CH2)5-CO-) n Polyamide 6, characterized by [specific characteristics], can be found in many materials such as packaging, automotive engineering plastics, and fiber filaments. The latter accounts for approximately 40% of the global market for polyamide 6. Currently, only a small portion of fiber filaments is recycled, yet it accounts for a significant portion of global CO2 emissions. Therefore, there is a need to recycle polyamide 6 from such materials. Methods exist for alkali depolymerization of polyamides. However, such methods have a certain CO2 footprint and are energy-intensive. Therefore, there is a need to improve methods for depolymerizing polyamides that can overcome these problems. [Overview of the project] [Problems that the invention aims to solve]

[0003] Therefore, in order to achieve the above objectives, a highly integrated recycling method is required. Accordingly, the present invention provides a method for subjecting waste containing polyamide 6 to hydrolysis and depolymerization, and for advantageously processing the resulting liquid aqueous streams, combining thermal integration and water recovery modes to make the overall method as efficient and economically advantageous as possible. [Means for solving the problem]

[0004] Therefore, the present invention relates to a recycling method for recovering ε-caprolactam from a solid material M containing polyamide 6, wherein the method is (i) Providing a stream S containing a solid material M M ; (ii) Preparing an aqueous depolymerization mixture based on S M ; (iii) Subjecting the depolymerization mixture prepared according to (ii) to polyamide 6 depolymerization conditions in a reaction unit U R to obtain a liquid aqueous stream S containing ε-caprolactam dissolved in water at a concentration cS R where the stream S R further contains one or more impurities; R (iv) Passing the liquid aqueous stream S R through an evaporation unit U E to obtain a liquid aqueous stream S containing ε-caprolactam dissolved in water at a concentration c SL > c SR from S SL and further obtaining one or more aqueous vapor streams S L from S R ; V R (v) Passing the aqueous stream S L through a heat-consuming purification unit U P to obtain a stream S containing ε-caprolactam at a concentration c SCPL >> c SLの [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​reaction unit U R The step of recirculating Regarding methods, including those mentioned above.

[0005] According to (i), stream S containing solid material M The following is provided. Preferably, the solid material M includes, more preferably, waste, wherein the waste includes, more preferably, one or more of at least one fibrous waste and at least one engineering plastic waste, more preferably, and more preferably, at least one fibrous waste. Preferably, 10 to 99% by weight, more preferably 30 to 98.5% by weight, more preferably 50 to 98% by weight, and more preferably 80 to 98% by weight of M consists of polyamide, or preferably, 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 80 to 100% by weight of M consists of polyamide. If the polyamide 6 content of the solid material M is less than 100% by weight, the solid material M may preferably further contain one or more elastanes. Generally, the solid material M may contain, in addition to polyamide 6, at least one other polymer compound, which preferably includes at least one polyamide 6.6, at least one polyethylene terephthalate, at least one polyurethane, at least one polyester, at least one polyether, at least one polyvinyl chloride, at least one natural fiber material, such as wool and cotton, at least one cellulose material, at least one natural elastomer, at least one synthetic elastomer, at least one copolymer from two or more of the polymer compounds including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers, and at least one rubber material, which includes at least one natural rubber material and at least one synthetic rubber material.

[0006] Preferably, the solid material M is in the form of granules, and the average diameter of the granules is preferably in the range of 0.5 to 10 mm, more preferably in the range of 1 to 7 mm, and more preferably in the range of 2 to 4 mm.

[0007] According to (ii), the aqueous depolymerization mixture is S M It is prepared based on Stream S. There are no specific restrictions on the method of preparing this depolymerization mixture, however, Stream S M Provided by Liquid Aqueous Stream S W It provides, preferably 90 to 100% by weight of S W It consists of water, Stream S M and liquid aqueous stream S W (iii) Chemical reaction unit U R To supply U R It may be preferable to obtain an aqueous depolymerization mixture. Preferably, the depolymerization mixture subjected to the polyamide 6 depolymerization conditions according to (iii) is the mass m of the polyamide 6 contained in the solid material M. P S W The amount of water contained in m W m W / kg:m P The mixture ratio is in the range of 1:1 to 20:1, more preferably 2:1 to 15:1, and more preferably 5:1 to 10:1.

[0008] According to (iii), the depolymerization mixture is reaction unit U R The polyamide 6 is subjected to depolymerization conditions. The depolymerization conditions are the polyamide 6 depolymerization temperature T D and polyamide 6 depolymerization pressure p D Includes, T D It is in the range of 230 to 330°C, p D The pressure is in the range of 40 to 140 bar, preferably T D It is in the range of 250 to 320°C, p D The pressure is in the range of 40 to 125 bar, more preferably T D It is in the range of 270 to 310°C, p D It is in the range of 40 to 110 bar.

[0009] Preferably, the chemical reaction unit U R comprises z chemical reactors R i where i = 1... z, and z is in the range of 1 to 10, more preferably in the range of 2 to 8, more preferably in the range of 2 to 6, more preferably in the range of 2 to 5, more preferably in the range of 2 to 4, and more preferably 3 or 4. Preferably, z > 1 and at least two reactors R i , more preferably z reactors R i are connected in series, and when z reactors R i are connected in series, the solid materials M and S W are preferably in R i with i = 1, and the aqueous liquid stream S containing ε-caprolactam dissolved in water i is removed from R i and supplied to R i+1 with i < z, S R is removed from R<00​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​i heating the reactor contents of R by passing through the heating jacket thereof i includes. The heating medium is preferably a high-temperature oil. R i Other heating media known to those skilled in the art can be used to pass through the heating jacket of R. Preferably, when z > 1, z reactors R i are arranged vertically, R1 is the uppermost reactor, and R z is the lowermost reactor, and R i The S obtained from i moves to R by gravity, more preferably by gravity only i+1 .

[0010] Preferably, the overall residence time in the chemical reaction unit U R is in the range of 15 to 160 minutes, more preferably in the range of 20 to 120 minutes, more preferably in the range of 25 to 100 minutes, more preferably in the range of 30 to 90 minutes.

[0011] Preferably, the aqueous liquid stream S R has a temperature T in the range of 230 to 330 °C, more preferably in the range of 250 to 320 °C, more preferably in the range of 270 to 310 °C R .

[0012] Preferably, according to the present invention, in order to prepare the depolymerization mixture, a polyamide 6 depolymerization catalyst such as a mineral acid and / or a zinc salt such as zinc chloride, zinc acetate or zinc triflate is not added.

[0013] When the solid material M contains one or more elastans, the aqueous liquid stream S R contains, for example, one or more decomposition products formed from one or more elastans during the depolymerization reaction in U R . Additionally or alternatively, one or more decomposition products forming one or more elastans may also be formed in a melting unit upstream of the reaction unit U, where the solid material M is properly melted in the melting unit and then U R . RThis results in a liquid stream passing through. In this case, S according to step (ii) of the method of the present invention. M The preparation of aqueous depolymerization mixtures based on is preferably as follows: (ii.1) A step of melting a solid material M provided in accordance with (i) in a melting unit to obtain a liquid stream, wherein the melting unit preferably includes a kneader or extruder, more preferably an extruder, and the melting temperature is preferably in the range of 230 to 330°C, more preferably in the range of 250 to 320°C, more preferably in the range of 270 to 310°C, (ii.2) Step of providing a liquid aqueous stream, (ii.3) A step of mixing the stream obtained according to (ii.1) with the stream provided according to (ii.3) in a pre-reaction unit to obtain a liquid reaction supply stream, wherein the pre-reaction unit preferably includes a mixing unit, more preferably a static mixing unit, (ii.4) The stream obtained according to (i.3) as a depolymerization mixture is used in the chemical reaction unit U R This may include the step of supplying to.

[0014] For example, the one or more degradation products from one or more elastanes preferably include aniline, butanediol, butanediol oligomers, such as butanediol dimers and butanediol trimers, and at least one of 4,4'-methylenedianiline (MDA) and its isomers, such as 2,4'-methylenedianiline and 2,2'-methylenedianiline.

[0015] According to (iv), liquid aqueous stream S R The evaporation unit U E They were led through to S R From, c SL >c SR concentration c SL Aqueous aqueous Stream S containing ε-caprolactam dissolved in water L Having obtained S R From one or more water vapor streams S V To obtain.

[0016] Preferably, the evaporation unit U E comprises two or more evaporation sub-units, and the method comprises obtaining at least at least two vapor streams S V1 and S V2 and passing the vapor stream S V1 through at least one heat-consuming unit, and passing the vapor stream S V2 through at least one heat-consuming unit, wherein the vapor streams S V1 and S V2 are different from each other in either pressure and / or temperature. More preferably, the method comprises subjecting an aqueous liquid stream S E (j), 1 ≦ j ≦ n, n ≧ 1 to reduced pressure in an evaporation unit U E and obtaining an aqueous vapor stream S R containing ε-caprolactam dissolved in water and an aqueous liquid stream S E (j) from each sub-unit U Vj and S Lj where S Vj has a temperature T Vj and a pressure p Vj and S Lj has a temperature T Lj and a pressure p Lj and at least one evaporation sub-unit U E (j), more preferably all evaporation sub-units U E (j) comprises, more preferably consists of, a flash drum. Preferably, n > 1 and when j < n, the method comprises passing an aqueous liquid stream S E (j) obtained from the evaporation sub-unit U Lj as a feed stream to the evaporation sub-unit U E (j + 1). More preferably, the n evaporation sub-units U E (j) are connected in series. More preferably, n > 1 and when j < n, T V(j+1) < T Vj , p V(j+1) < p Vj , TL(j+1) <T Lj , and p L(j+1) <p Lj That is the case.

[0017] Optionally, the method is U E Aqueous liquid stream S to the upstream heat exchange unit R The step of passing the heat through the heat exchange unit and the cooling stream S R This includes the step of obtaining

[0018] According to (v), Aqueous Stream S L This is the heat consumption purification unit U P They were led through to S L Therefore, concentration c SCPL Stream S containing ε-caprolactam CPL Obtaining c SCPL >>c SL And furthermore, S L From one or more water-based stream S RW Obtaining U P At least a portion of the heat consumed is absorbed by one or more streams S V Provided by at least one of the following, thereby providing at least one stream S V From at least one at least partially condensed aqueous stream S VW To obtain. The abbreviation ">>" used in this context refers to concentration c SCPL is concentration c SL It shows a significantly higher value than, preferably, the purification unit U P The final stream S obtained from this CPL This comprises, and preferably consists of, a substantially pure ε-caprolactam.

[0019] Preferably, purification unit U P This is the heat consumption water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C One or more of the following, preferably a heat-consuming water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit UC Two or more of the following, Comfortable Heat Consumption Water Separation Unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C Including U WS , U D and U C At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V It is supplied by at least one of the following: more preferably by the purification unit U P This is the heat consumption water separation unit U WS , heat consumption distillation unit U D , and heat consumption crystallization unit U C Including U WS is U D Located upstream of U D is U C It is located upstream.

[0020] Preferably, according to the present invention, the purification unit U P However, the heat consumption water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C The method includes, and the concentration c SL Stream S containing ε-caprolactam L to U WS The steps of supplying to U WS From concentration c UWS Stream S containing ε-caprolactam UWS Steps to obtain and Stream S UWS distillation unit U D The steps of supplying to U D From concentration c UD Stream S containing ε-caprolactam UD Steps to obtain and Stream S UD Crystallization unit U C The steps of supplying to U C From concentration c SCPL Stream S containing ε-caprolactam CPL A step to obtain c SL <c UWS <cUD <c SCPL It includes the step.

[0021] Preferably, at least one stream S V U WS Used to provide at least a portion of the heat consumed by U. WS By supplying to the stream S V At least one of them is condensed at least partially. Alternatively or additionally, at least one stream S V U D Used to provide at least a portion of the heat consumed by U. D By supplying to the stream S V At least one of them is condensed at least partially. Alternatively or additionally, at least one stream S V U C Used to provide at least a portion of the heat consumed by U. C By supplying to the stream S V At least one of is condensed at least partially. Therefore, the method preferably includes one or more of (i-1), (i-2), and (i-3), preferably at least two or more of (i-1), (i-2), and (i-3), more preferably (i-1), (i-2), and (i-3), (i-1)U WS From at least one at least partially condensed aqueous stream S VW1 Steps to obtain (i-2)U D From at least one at least partially condensed aqueous stream S VW2 Steps to obtain (i-3)U C From at least one at least partially condensed aqueous stream S VW3 Steps to obtain More preferably, one or more S VW1 S VW2 and S VW3 Preferably two or more SVW1 S VW2 and S VW3 , more preferably, S VW1 S VW2 and S VW3 Water treatment unit U W It is supplied to.

[0022] Water separation unit U WS So, liquid water stream S L Water is separated from it. WS S L Therefore, preferably, Stream S UWS This is obtained and purified relative to ε-caprolactam, S UWS Preferably, further downstream purification subunits, more preferably purification subunit U D You will be led through to U WS From S L Based on (v), one or more aqueous streams S RW At least one of the following is obtained, which is preferably a water treatment unit U W It is supplied to.

[0023] Comfortable, water separation unit U WS However, at least two heat-consuming water separation subunits U WS1 and U WS2 Preferably, two heat-consuming water separation subunits U are coupled in series. WS1 and U WS2 Includes, Stream S L U WS1 It is supplied to U WS1 and U WS2 At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V The method is provided by at least one of the following. More preferably, the method is provided by one or more of (ii-1) and (ii-2), preferably (ii-1) and (ii-2), (ii-1)U WS1 From at least one at least partially condensed aqueous stream S VW11 Steps to obtain (ii-2)UWS2 From at least one at least partially condensed aqueous stream S VW12 Steps to obtain Includes.

[0024] Although not limited to any particular purification unit, according to the present invention, U WS1 Preferably, the evaporation unit comprises a film evaporator, more preferably a flow-through film evaporator, and the film evaporator is more preferably equipped with heating means for providing heat for evaporation. Optionally, unit U WS1 It may include two or more evaporation subunits, preferably two or more series-coupled evaporation subunits. Preferably, U WS2 It includes, more preferably consists of, a distillation column equipped with heating means for providing heat for distillation. Preferably, at least one aqueous stream S RW1 U WS1 Obtained from, more preferably, at least one aqueous stream S RW2 U WS2 Obtained from S RW1 and S RW2 At least one of, more preferably S RW1 and S RW2 Water treatment unit U W It is supplied to.

[0025] U WS1 Downstream and U WS2 Upstream of this is the second refining subunit U WS2 Before passing through, impurities are removed. WS1 Separation unit U helps separate ε-caprolactam obtained from aqueous streams. I It is even more preferable that the following are arranged. Therefore, the method is preferably U WS1 From Water-based Stream S UWS1 Steps to obtain and Stream S UWS1 Separating unit U I The steps of supplying to U I From Water-based Stream S UISteps to obtain and Stream S UI Unit U WS2 The steps include supplying to U I In this case, one or more impurities are S UWS1 Separated from, and thereby U I From impurity stream S I To obtain the above impurities, preferably according to (ii), S R It contains at least one impurity contained in U. According to the present invention, I In this context, the ε-caprolactam oligomer compound is Stream S UWS1 It is preferable to separate from U. I Regarding the separation of impurities in, the method is more preferably, (a)U WS1 Stream S obtained from UWS1 Aqueous liquid mixture M containing E Steps to prepare (b)(a) Mixture M E The water vapor stream S is subjected to evaporation conditions in the evaporation unit E1. UI and aqueous liquid flow S I Steps to obtain (c)(b) Stream S I to the first stream S I1 and the second stream S I2 The step of dividing into S I1 and S I2 is S I Step, which has the same chemical composition (d) Optionally, the stream S obtained according to (c) I2 This includes the step of passing it to an appropriate downstream processing stage, (a) Aqueous liquid mixture M E The step of preparing is stream S UWS1 Stream S I1The process includes the step of mixing with (b). The evaporation in the evaporation unit E1 according to (b) is preferably carried out in one or more stirred vessels, or in one or more membrane evaporators, or in one or more stirred vessels and one or more membrane evaporators, and the evaporation in the evaporation unit E1 according to (b) is preferably carried out in one or more continuous stirred tank reactors, or in one or more downward-flowing membrane evaporators, or more preferably in one or more continuous stirred tank reactors and one or more downward-flowing membrane evaporators, and the evaporation in the evaporation unit E1 according to (b) is more preferably carried out in one or more continuous stirred tank reactors, and more preferably, if the evaporation in E1 is carried out in one or more continuous stirred tank reactors, the continuous stirred tank reactors are arranged in parallel.

[0026] Purification subunit U D In this regard, it is preferable to include at least one distillation column, preferably two or three distillation columns, more preferably two or three series-connected distillation columns. According to the present invention, at least a portion of the heat consumed in one or more of the distillation columns is preferably supplied to Unit U W At least one at least partially condensed stream S is passed through VW2 Stream S is obtained V Preferably provided by at least one of the streams S V At least a portion of it is used as a heat transfer medium, U D A heat exchanger for at least one distillation column, preferably U D Each of the two or three distillation columns has a heat exchanger, more preferably U D The water passes through a heat exchanger used for sump evaporation in each of the two or three distillation columns.

[0027] U D The obtained Stream S is obtained from the same source and further purified relative to ε-caprolactam. UD Preferably, the crystallization unit U C They are then taken to the final stream S. CPLThis can be obtained. Crystallization unit U C There are no specific constraints regarding the design of the U. Preferably, C At least a portion of the heat consumed is absorbed by at least one stream S V Provided at least partially by S V Based on this, preferably unit U W At least one at least partially condensed stream S is passed through VW3 You can obtain this.

[0028] Regarding the recirculation by (vi), (vi) is, (vi.1) at least one stream S VW Preferably one or more streams S VW1 S VW2 and S VW3 At least one, more preferably one or more, streams S VW11 S VW12 S VW2 and S VW3 At least one of, more preferably all of, stream S VW1 S VW2 and S VW3 , more preferably all stream S VW11 S VW12 S VW2 and S VW3 , and at least one stream S RW Preferably one or more streams S RW1 and S RW2 At least one of, more preferably all of, stream S RW1 and S RW2 water treatment unit U W To supply U W From at least one aqueous recirculation stream S W Steps to obtain (vi.2) at least one aqueous stream S W at least partially react unit U R Preferably, the step includes recirculating the material.

[0029] Comfortable, water treatment unit U W This is the water recovery unit U WR and wastewater unit U WW (vi.1) is equipped with, (vi.1.1) at least one stream S VW Preferably one or more streams S VW1 S VW2 and S VW3 At least one, more preferably one or more, streams S VW11 S VW12 S VW2 and S VW3 At least one of, more preferably all of, stream S VW1 S VW2 and S VW3 , more preferably all stream S VW11 S VW12 S VW2 and S VW3 , and at least one stream S RW Preferably one or more streams S RW1 and S RW2 At least one of, more preferably all of, stream S RW1 and S RW2 Water recovery unit U WR To supply U WR From at least one aqueous recirculation stream S W and at least one aqueous stream S SW Steps to obtain (vi.1.2) at least one stream S SW wastewater unit U WW To supply U WW From at least one wastewater stream S WW This further includes the step of obtaining [the result].

[0030] According to the present invention, S W It is preferable that 91-100% by weight, more preferably 92-100% by weight, and more preferably 95-100% by weight, of the mixture consist of water. RBefore being passed through, the temperature is changed, preferably by heating, and / or the pressure is changed, preferably by increasing the pressure, etc., in the stream S W It is possible to appropriately pre-process at least one of these.

[0031] Furthermore, according to the present invention, it may be preferable that at least one appropriate stage of fresh water be added to the process in order to compensate for water loss. Such fresh water may be added, for example, to at least one of the streams and / or to unit U R It can be added directly.

[0032] According to the method of the present invention, reaction unit U R At least one solid-liquid separation unit is located downstream of the stream, preferably stream S L and S R It may be preferable that at least one of the components passes through at least one solid-liquid separation unit before being passed to the next downstream unit. Preferably, such a solid-liquid separation unit includes one or more of a centrifuge, a decanter, a decanter centrifuge, and a filter.

[0033] According to the present invention, the finally purified ε-caprolactam stream S CPL Based on this, a complete recirculation loop can be achieved. In particular, this is for stream S CPL This is due to the excellent color properties and purity of the crystallized ε-caprolactam obtained as follows. According to this recirculation loop, Stream S CPL Preferably, polyamide 6 manufacturing unit U PP It was passed through to U PP The polyamide 6 produced is preferably at least partially produced in the fiber material manufacturing unit U TP It is supplied as a raw material for U TP Fiber material M manufactured in T Preferably, the fiber material is brought to market and has a lifespan T MT Afterwards, textile waste is collected by the textile material collection unit U TC Collected in, preferably unit U Mvia U TC From S M as U R Appropriately provided to U M The unit preferably includes one or more silos and / or one or more hoppers and / or one or more truck unloading stations and / or one or more big bag unloading stations. TP And / or in the process of manufacturing fibrous materials in one or more other manufacturing units, it is also possible to obtain remaining materials that cannot be used, for example, polyamide 6 in the form of fiber cutting. Such remaining materials M R In the context of this invention, this is also referred to as "textile waste," and this textile waste M R It can be used as a solid material M or as part of a solid material M, preferably in unit U TC and / or Unit U M Reaction unit U via one of the following R It can be supplied to. Specifically, according to the present invention, Stream S M teeth, Material M T Includes M R does not include, or material M R Includes, Material M T does not include, or material M T and material M R Includes.

[0034] If desired and / or as needed, one or more streams S as shown in Figure 2 NCPL to U PP It can be passed through further, S NCPL This includes non-recycled ε-caprolactam, i.e., ε-caprolactam from conventional sources. Furthermore, as desired and / or as needed, one or more streams S as shown in Figure 2. NPA6 to U TP It can be passed through further, S NPA6 This includes non-recycled polyamide 6, i.e., polyamide 6 from conventional sources.

[0035] According to a further aspect, the invention also relates to crystallized ε-caprolactam, i.e. stream S that can be obtained or is obtained by the above method. CPL It relates to.

[0036] Preferably, when the crystallized ε-caprolactam is determined as described in Reference Example 1, it exhibits an APHA color (sometimes also called Hazen) of at most 5, preferably at most 4, more preferably at most 3, more preferably at most 2, more preferably at most 1.5, and even more preferably at most 1.

[0037] Preferably, the crystallized ε-caprolactam is determined as described in Reference Example 2, and shows a purity of at least 99.8% by weight, preferably at least 99.9% by weight, more preferably at least 99.95% by weight, based on the total weight of S. CPL It shows a purity of at least 99.8% by weight, preferably at least 99.9% by weight, more preferably at least 99.95% by weight, based on the total weight of S.

[0038] The crystallized ε-caprolactam obtained or obtainable by the method of the invention has an ε-caprolactam oligomer content in the range from 0 to 10 ppm by weight, more preferably in the range from 0 to 5 ppm by weight, even more preferably in the range from 0 to 1 ppm by weight, and / or a 6-aminocaproic acid content in the range from 0 to 10 ppm by weight, more preferably in the range from 0 to 5 ppm by weight, even more preferably in the range from 0 to 1 ppm by weight, and preferably shows.

[0039] Furthermore, the crystallized ε-caprolactam obtained or obtainable by the method of the invention has a triisopropyl borate content in the range from 0 to 100 ppm by weight, more preferably in the range from 0 to 50 ppm by weight, even more preferably in the range from 0 to 10 ppm by weight, more preferably in the range from 0 to 5 ppm by weight, even more preferably in the range from 0 to 1 ppm by weight, and preferably shows.

[0040] In particular, when the solid material M provided according to (i) contains one or more elastans, the crystallized ε-caprolactam obtained or obtainable by the method of the present invention has a polytetrahydrofuran content in the range from 0 to 10 weight ppm, more preferably in the range from 0 to 5 weight ppm, more preferably in the range from 0 to 1 weight ppm, and / or an aniline content in the range from 0 to 10 weight ppm, more preferably in the range from 0 to 5 weight ppm, more preferably in the range from 0 to 1 weight ppm, and / or a methylene diphenyl diamine (MDA), isomers and oligomer content in the range from 0 to 10 weight ppm, more preferably in the range from 0 to 5 weight ppm, more preferably in the range from 0 to 1 weight ppm, and / or a butanediol content in the range from 0 to 500 weight ppm, more preferably in the range from 0 to 300 weight ppm, more preferably in the range from 0 to 100 weight ppm, more preferably in the range from 0 to 50 weight ppm, more preferably in the range from 0 to 10 weight ppm, and / or an ethylene glycol content in the range from 0 to 500 weight ppm, more preferably in the range from 0 to 300 weight ppm, more preferably in the range from 0 to 100 weight ppm, more preferably in the range from 0 to 50 weight ppm, more preferably in the range from 0 to 10 weight ppm, and it is preferred to show.

[0041] In connection with the present invention, the term "ε-caprolactam oligomer" includes ε-caprolactam dimers and higher oligomers, such as ε-caprolactam trimers, ε-caprolactam tetramers, ε-caprolactam pentamers, ε-caprolactam hexamers. The term "6-aminocaproic acid" includes 6-aminocaproic acid and its oligomers, including higher oligomers such as 6-aminocaproic acid dimers, 6-aminocaproic acid trimers, 6-aminocaproic acid tetramers, 6-aminocaproic acid pentamers, 6-aminocaproic acid hexamers. The term "aniline" encompasses aniline itself and its derivatives, such as aniline containing one or more methyl groups and / or one or more halogen residues and / or one or more additional amino groups and / or one or more benzyl groups. Examples of such aniline derivatives include N-methylaniline and aminotoluene. Methylenedianiline, as described below, is not an aniline derivative according to the present invention: The term "methylenedianiline" encompasses 4,4'-methylenedianiline (MDA) and its isomers, such as 2,4'-methylenedianiline and 2,2'-methylenedianiline. The term "butanediol" encompasses butanediol itself and its oligomers, including higher oligomers such as butanediol dimers and butanediol trimers. The term "ethylene glycol" encompasses ethylene glycol itself and its oligomers, including higher oligomers such as diethylene glycol and triethylene glycol.

[0042] In each case, each content refers to the individual compound encompassed by each general term. For example, with respect to ε-caprolactam oligomer content, the term "ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight" refers to ε-caprolactam dimer content in the range of 0 to 10 ppm by weight, ε-caprolactam trimer content in the range of 0 to 10 ppm by weight, ε-caprolactam tetramer content in the range of 0 to 10 ppm by weight, ε-caprolactam pentamer content in the range of 0 to 10 ppm by weight, ε-caprolactam hexamer content in the range of 0 to 10 ppm by weight, and so on.

[0043] In a further embodiment, the present invention also relates to a polymer material, preferably a polyamide 6, obtained or obtained by the above-described method. CPL With regard to the use, the use preferably further includes using the polymer material, preferably the polyamide 6, as a raw material for preparing a fiber material.

[0044] Furthermore, the present invention relates to the above-described method, wherein the method involves a polyamide 6 generating unit U PP Stream S CPL Further including providing U PP The polyamide 6 produced is preferably used in the fiber material production unit U TP It is supplied as a raw material for Unit U, and then Unit U TP teeth, (A) Textile materials M brought into the market T The fiber material M is obtained. T Useful life T MT Afterwards, at least partially as textile waste, textile material collection unit U TC Collected, (B) Remaining ingredients M R It is obtained as textile waste. (A) at least a portion of the textile waste described in (A), or (B) at least a portion of the textile waste described in (A) and (B) at least a portion of the textile waste described in (B), preferably U M via S M as U R It will be provided appropriately.

[0045] Furthermore, the present invention relates to the above-described method, wherein the method involves a polyamide 6 generating unit U PP Stream S CPL Further including providing U PP The polyamide 6 produced is preferably manufactured in an engineering plastics material manufacturing unit U TP It is supplied as a raw material for Unit U, and then Unit U TP teeth, (A) Engineering plastic material M brought to market T The engineering plastic material M is obtained. T Useful life T MT Afterwards, at least partially as engineering plastic waste, engineering plastic collection unit U TC Collected, (B) Remaining ingredients MR It is obtained as engineering plastic waste. (A) at least a portion of the engineering plastic waste described in (A), or (B) at least a portion of the engineering plastic waste described in (A) and (B) at least a portion of the engineering plastic waste described in (B), preferably U M via S M as U R It will be provided appropriately.

[0046] Unit U TC Downstream and Unit U R Upstream of, preferably unit U M Upstream, the collected textile waste can be properly sorted. In this regard, the collected textile waste can be spread on a conveyor, and this spreading can be done manually and / or mechanically. The spread textile waste is then subjected to sorting by either composition and / or color. Sorting can be done manually and / or optically. When performed optically, sorting preferably includes infrared sorting, more preferably near-infrared sorting and / or mid-infrared sorting. Optionally, before sorting, the textile waste can be subjected to an appropriate metal removal step. When a metal removal step is performed, ferrous elements are preferably separated, for example, by appropriate magnetic means, and / or non-ferrous elements are preferably separated, for example, by appropriate eddy current separation means. After the sorting, the obtained textile waste is U R Before being supplied to, preferably U M via U R Before being supplied, it can be subjected to further processing such as cutting and / or grinding.

[0047] Furthermore, the present invention provides a method for stream S CPL The present invention relates to a crystallized ε-caprolactam obtained or that can be obtained as such, wherein the crystallized ε-caprolactam exhibits one or more of the following properties: APHA colors determined as described in Reference Example 1, with a maximum of 5, preferably a maximum of 4, more preferably a maximum of 3, more preferably a maximum of 2, more preferably a maximum of 1.5, and more preferably a maximum of 1. A purity of at least 99.8% by weight, preferably at least 99.9%, and more preferably at least 99.95%, as determined as described in Reference Example 2.

[0048] Optionally or preferably, the crystallized ε-caprolactam exhibits one or more of the following properties: ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, 6-aminocaproic acid content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and more preferably in the range of 0 to 1 ppm by weight.

[0049] Optionally, or preferably, the crystallized ε-caprolactam further exhibits the following properties: Triisopropyl borate content in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and more preferably in the range of 0 to 1 ppm by weight.

[0050] If the solid material M contains one or more elastanes, optionally or preferably, the crystallized ε-caprolactam exhibits one or more of the following properties: Polytetrahydrofuran content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Aniline content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight. Methylene diphenyl diamine (MDA) with an isomer and oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and even more preferably in the range of 0 to 1 ppm by weight, a butanediol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, even more preferably in the range of 0 to 100 ppm by weight, still more preferably in the range of 0 to 50 ppm by weight, and most preferably in the range of 0 to 10 ppm by weight, and / or an ethylene glycol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, even more preferably in the range of 0 to 100 ppm by weight, still more preferably in the range of 0 to 50 ppm by weight, and most preferably in the range of 0 to 10 ppm by weight. <000*********<000*********Furthermore, the present invention relates to the use of the S obtained or obtainable by the above-described method for preparing polyamide 6, CPL wherein said use further preferably comprises using said polyamide 6 as a raw material for preparing at least one of at least one fiber material and at least one engineering plastic material, more preferably for preparing at least one fiber material.

[0052] Furthermore, the present invention relates to the use of the above-described method for preparing high-purity ε-caprolactam from a solid material M, preferably polyamide 6 and preferably containing one or more elastans, wherein said high-purity ε-caprolactam exhibits one or more of the following characteristics: an ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and even more preferably in the range of 0 to 1 ppm by weight, a 6-aminocaproic acid content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and even more preferably in the range of 0 to 1 ppm by weight, Triisopropyl borate content in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Polytetrahydrofuran content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Aniline content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight. Methylenediphenyldiamine (MDA), isomers, and oligomers in a range of 0 to 10 ppm by weight, more preferably in a range of 0 to 5 ppm by weight, more preferably in a range of 0 to 1 ppm by weight. Butanediol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, and / or Ethylene glycol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, and more preferably in the range of 0 to 10 ppm by weight.

[0053] Furthermore, the present invention relates to a method for preparing one or more polymers and polymer products obtained or obtained by the above method. CPL Preferably, the above S CPL A method for using or preparing one or more polymers and polymer products, wherein S obtained or obtained by the above method. CPL Preferably, the above-mentioned S CPL The method comprises using as a starting material.

[0054] Furthermore, the present invention relates to the use or method described above, wherein the polymer, or polymer product, or polymer and polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foils, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams, and rigid foams.

[0055] Furthermore, the present invention relates to a polymer, or a polymer product, or a polymer and a polymer product comprising polyamide 6 and optionally at least one further polymer compound, wherein the polyamide 6 is at least partially S CPL The use or method obtained from or obtained from the S CPL However, the S obtained by the method described in any one of Embodiments 1 to 14, preferably the S described in any one of Embodiments 17 to 20 CPL The use or method relates to a method wherein the at least one further polymer compound preferably comprises one or more polyamides 6.6, at least one polyethylene terephthalate, at least one polyurethane, at least one polyester, at least one polyether, at least one polyvinyl chloride, at least one natural fiber material, such as wool and cotton, at least one cellulose material, at least one natural elastomer, at least one synthetic elastomer, at least one copolymer of two or more of the polymer compounds, including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers, and at least one rubber material, including one or more of at least one natural rubber material and at least one synthetic rubber material.

[0056] Furthermore, the present invention relates to the above use or method, wherein the polymer, or polymer product, or polymer and polymer product is one of the following, or part of one of the following: Automotive parts, preferably cylinder head covers, engine covers, intake radiator housings, intake radiator flaps, intake pipes, intake manifolds, connectors, gear wheels, fan wheels, coolant boxes, heat exchanger housings or housing components, coolant coolers, intake radiators, thermostats, water pumps, radiators, fastening components or parts of battery systems for electric transport, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, automotive exteriors for A, B, C or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights, taillights, airbags, and / or cushions. Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and / or jackets, Electrical components, preferably electrical components, electronically passive components, electronically active components, printed circuit boards, housing components, wheels, lines, switches such as microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, diodes such as lamps and LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, such as reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and / or spring tongues for electrical and / or electronic components. Consumer and / or pharmaceuticals, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and / or bottles, mattresses, cushions, insulation materials, Packaging for the food industry, preferably single-layer and / or multi-layer inflated films, cast films (single-layer and / or multi-layer), biaxially oriented films, and laminate films.

[0057] Furthermore, the present invention relates to a polymer, or a polymer product, or a polymer and a polymer product, S CPL The S contains polyamide 6 obtained from or obtained from CPL However, the use or method described herein is obtained or obtained by the method described in Embodiment 28 in an amount of 1% by weight or more, preferably 2% by weight or more, more preferably 5% by weight or more, more preferably 15% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 60% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight or more, more preferably 95% by weight or more, and / or 100% by weight or less, preferably 95% by weight or less, more preferably 90% by weight or less, more preferably 50% by weight or less, more preferably 25% by weight or less, more preferably 10% by weight or less.

[0058] The present invention is further described by the following set of embodiments and combinations of embodiments arising from the dependencies and backreferences shown. In particular, in each example in which the scope of an embodiment is referred to, for example in the context of the term, for example, “Any one of Embodiments 1 to 3,” it should be noted that all embodiments within this scope are expressly disclosed to those skilled in the art, i.e., the wording of this term should be understood by those skilled in the art as synonymous with “Any one of Embodiments 1, 2, and 3.” Furthermore, it should be explicitly noted that the following set of embodiments represents a well-structured portion of a general description directed toward preferred aspects of the present invention and therefore adequately supports, but does not represent, the claims of the present invention.

[0059] 1. A recycling method for recovering ε-caprolactam from a solid material M containing polyamide 6, wherein the method is: (i) Stream S containing solid material M M Steps to provide, (ii)S M A step of preparing an aqueous depolymerization mixture based on the following: (iii)(ii) The depolymerization mixture prepared according to the reaction unit U R Under conditions of polyamide 6 depolymerization, concentration c SR Aqueous aqueous Stream S containing ε-caprolactam dissolved in water R A step to obtain stream S R The step further contains one or more impurities, (iv) Liquid Aqueous Stream S R Evaporation unit U E Pass through, c SL >c SR concentration c SL Aqueous aqueous Stream S containing ε-caprolactam dissolved in water L to S R Obtained from, and further one or more water vapor streams S V to S R Steps to be learned from, (v) Water-based Stream S LHeat consumption purification unit U P Pass through, c SCPL >>c SLの concentration c SCPL Stream S containing ε-caprolactam CPL to S L Obtained from, S L From one or more water-based stream S RW This is a further step to obtain U P At least a portion of the heat consumed is absorbed by one or more streams S V Provided by at least one of the following, thereby providing at least one stream S V From at least one at least partially condensed aqueous stream S VW To obtain, step, (vi) at least one stream S in part VW reaction unit U R Recirculate to at least partially at least one stream S RW reaction unit U R The step of recirculating Methods that include...

[0060] 2. The method according to Embodiment 1, wherein the solid material M comprises, more preferably, waste, wherein the waste comprises, more preferably, one or more of, at least one fibrous waste and at least one engineering plastic waste, more preferably, at least one fibrous waste, more preferably, and preferably 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 80 to 100% by weight of M is polyamide 6, and the polyamide 6 content of the solid material M is less than 100% by weight, wherein the solid material M optionally further comprises one or more elastanes.

[0061] 3. The recirculation by (vi) (vi.1) at least one stream S VW and at least one stream S RW water treatment unit UW To supply U W From at least one aqueous recirculation stream S W Steps to obtain (vi.2) at least one aqueous stream S W at least partially react unit U R The method according to Embodiment 1 or 2, comprising the step of recirculating.

[0062] 4. Water treatment unit U W However, the water recovery unit U WR and wastewater unit U WW (vi.1) includes, (vi.1.1) at least one stream S VW and at least one stream S RW Water recovery unit U WR To supply U WR From at least one aqueous recirculation stream S W and at least one aqueous stream S SW Steps to obtain (vi.1.2) at least one stream S SW wastewater unit U WW To supply U WW From at least one wastewater stream S WW The method according to Embodiment 3, further comprising the step of obtaining

[0063] 5. Refining Unit U P This is the heat consumption water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C One or more of the following, preferably a heat-consuming water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C Two or more of the following, Comfortable Heat Consumption Water Separation Unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C Including U WS , U D and UC At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V The method according to any one of embodiments 1 to 4, supplied by at least one of the following:

[0064] 6. One or more of (i-1), (i-2), and (i-3), preferably at least two or more of (i-1), (i-2), and (i-3), more preferably including (i-1), (i-2), and (i-3), (i-1)U WS From at least one at least partially condensed aqueous stream S VW1 Steps to obtain (i-2)U D From at least one at least partially condensed aqueous stream S VW2 Steps to obtain (i-3)U C From at least one at least partially condensed aqueous stream S VW3 Steps to obtain The method is as described in claim 3, one or more S VW1 S VW2 and S VW3 Preferably two or more S VW1 S VW2 and S VW3 , more preferably, S VW1 S VW2 and S VW3 Water treatment unit U W The method according to Embodiment 5, supplied to [the specified location].

[0065] 7. Stream S RW At least one of them is U WS The method according to embodiment 5 or 6, obtained from.

[0066] 8. Refining Unit U P However, the heat consumption water separation unit U WS , heat consumption distillation unit U D and heat consumption crystallization unit U C The method includes, and the concentration c SLStream S containing ε-caprolactam L to U WS The steps of supplying to U WS From concentration c UWS Stream U containing ε-caprolactam WS Steps to obtain and Stream S UWS distillation unit U D The steps of supplying to U D From concentration c UD Stream S containing ε-caprolactam UD Steps to obtain and Stream S UD Crystallization unit U C The steps of supplying to U C From concentration c SCPL Stream S containing ε-caprolactam CPL A step to obtain c SL <c UWS <c UD <c SCPL The method according to any one of Embodiments 1 to 7, comprising the steps of:

[0067] 9. Water separation unit U WS However, at least two heat-consuming water separation subunits U WS1 and U WS2 Preferably, two heat-consuming water separation subunits U are coupled in series. WS1 and U WS2 Includes, Stream S L U WS1 It is supplied to U WS1 and U WS2 At least a portion of the heat consumed by one or more of them is transferred to one or more streams S V The method according to any one of embodiments 1 to 8, provided by at least one of the embodiments.

[0068] 10. One or more of (ii-1) and (ii-2), preferably (ii-1) and (ii-2), (ii-1)U WS1 From at least one at least partially condensed aqueous stream S VW11 Steps to obtain (ii-2)U WS2 From at least one at least partially condensed aqueous stream S VW12 Steps to obtain The method according to Embodiment 9, including the method described in Embodiment 9.

[0069] 11. At least one aqueous stream S RW1 U WS1 Obtained from, at least one aqueous stream S RW2 U WS2 Obtained from, S RW1 and S RW2 At least one of, preferably S RW1 and S RW2 U W The method according to embodiment 10, supplied to [the relevant authority].

[0070] 12.U WS1 Downstream and U WS2 upstream of the separation unit U I It is arranged, and the method is U WS1 From Water-based Stream S UWS1 Steps to obtain and Stream S UWS1 Separating unit U I The steps of supplying to U I From Water-based Stream S UI Steps to obtain and Stream S UI Unit U WS2 The steps include supplying to U I In this case, one or more impurities are S UWS1 Separated from, and thereby U I From impurity stream S I To obtain the above impurities, preferably according to (ii), S R The method according to any one of embodiments 9 to 11, comprising at least one impurity contained in.

[0071] 13. Evaporation Unit U E The method includes two or more evaporation subunits, and the method comprises at least two steam streams S V1 and S V2 Steps to obtain and steam stream SV1 The steps include passing the steam stream S through at least one heat consumption unit and passing it through the steam stream S V The process includes passing 2 through at least one heat consumption unit, and the steam stream S V1 and S V2 The method according to any one of embodiments 1 to 12, wherein the pressure and / or temperature differ from each other.

[0072] 14.U R At least one solid-liquid separation unit is located downstream of the stream, preferably stream S L and S R The method according to any one of embodiments 1 to 13, wherein at least one of passes through at least one solid-liquid separation unit before being passed through to the next downstream unit.

[0073] 15. Polyamide 6 Production Unit U PP Stream S CPL Further including providing U PP The polyamide 6 produced is preferably used in the fiber material production unit U TP It is supplied as a raw material for Unit U, and then Unit U TP teeth, (A) Textile materials M brought into the market T The fiber material M is obtained. T Useful life T MT Afterwards, at least partially as textile waste, textile material collection unit U TC Collected, (B) Remaining ingredients M R It is obtained as textile waste. (A) at least a portion of the textile waste described in (A), or (B) at least a portion of the textile waste described in (A) and (B) at least a portion of the textile waste described in (B), preferably U M via S M as U R The method according to any one of Embodiments 1 to 14, as appropriately provided.

[0074] 16. Polyamide 6 Production Unit UPP Stream S CPL Further including providing U PP The polyamide 6 produced is preferably manufactured in an engineering plastics material manufacturing unit U TP It is supplied as a raw material for Unit U, and then Unit U TP teeth, (A) Engineering plastic material M brought to market T The engineering plastic material M is obtained. T Useful life T MT Afterwards, at least partially as engineering plastic waste, engineering plastic collection unit U TC Collected, (B) Remaining ingredients M R It is obtained as engineering plastic waste. (A) at least a portion of the engineering plastic waste described in (A), or (B) at least a portion of the engineering plastic waste described in (A) and (B) at least a portion of the engineering plastic waste described in (B), preferably U M via S M as U R The method according to any one of Embodiments 1 to 14, as appropriately provided.

[0075] 17. The following characteristics, APHA colors determined as described in Reference Example 1, with a maximum of 5, preferably a maximum of 4, more preferably a maximum of 3, more preferably a maximum of 2, more preferably a maximum of 1.5, and more preferably a maximum of 1. Stream S by any one of the methods in Embodiments 1 to 14, exhibiting one or more purity levels as determined in Reference Example 2, at least 99.8% by weight, preferably at least 99.9%, and more preferably at least 99.95%. CPL Crystallized ε-caprolactam obtained or acquired as such.

[0076] 18. The following characteristics, ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, The crystallized ε-caprolactam according to Embodiment 17, exhibiting one or more 6-aminocaproic acid content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and more preferably in the range of 0 to 1 ppm by weight.

[0077] 19. The following characteristics, The crystallized ε-caprolactam according to Embodiment 17 or 18, exhibiting a triisopropyl borate content in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, and more preferably in the range of 0 to 1 ppm by weight.

[0078] 20. Preferably, the solid material M described in Embodiment 2 comprises one or more elastanes, and the crystallized ε-caprolactam has the following properties: Polytetrahydrofuran content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Aniline content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight. Methylenediphenyldiamine (MDA), isomers, and oligomers in a range of 0 to 10 ppm by weight, more preferably in a range of 0 to 5 ppm by weight, more preferably in a range of 0 to 1 ppm by weight. Butanediol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, and / or A crystallized ε-caprolactam according to any one of embodiments 17 to 19, wherein the ethylene glycol content is in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, and more preferably in the range of 0 to 10 ppm by weight.

[0079] 21. S obtained by the method of any one of Embodiments 1 to 15 for preparing polyamide 6 CPL Preferably, S as described in any one of embodiments 17 to 20 CPL Use of the polyamide 6, which preferably further comprises using the polyamide 6 as a raw material for preparing one or more of at least one fibrous material and at least one engineering plastic material, more preferably as a raw material for preparing at least one fibrous material.

[0080] 22. The high-purity ε-caprolactam has the following characteristics: ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, 6-aminocaproic acid content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Triisopropyl borate content in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Polytetrahydrofuran content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Aniline content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight. Methylenediphenyldiamine (MDA), isomers, and oligomers in a range of 0 to 10 ppm by weight, more preferably in a range of 0 to 5 ppm by weight, more preferably in a range of 0 to 1 ppm by weight. Butanediol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, and / or The use of the method according to any one of Embodiments 1 to 14 for preparing high-purity ε-caprolactam from waste containing a solid material M, preferably polyamide 6 and preferably one or more elastanes, exhibiting one or more ethylene glycol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, and more preferably in the range of 0 to 10 ppm by weight.

[0081] 23. S obtained by the method of any one of Embodiments 1 to 14 for preparing one or more polymers and polymer products CPL Preferably, S as described in any one of embodiments 17 to 20 CPL A method for using or preparing one or more polymers and polymer products, wherein the method is obtained or obtained by the method described in any one of Embodiments 1 to 14. CPL Preferably, S as described in any one of embodiments 17 to 20 CPL A method comprising using as a starting material.

[0082] 24. The method or use according to Embodiment 23, wherein the polymer, or polymer product, or polymer and polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foils, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams and rigid foams.

[0083] 25. A polymer, or a polymer product, or a polymer and a polymer product comprising polyamide 6 and optionally at least one further polymer compound, wherein the polyamide 6 is at least partially S CPL Obtained from or obtained from the S CPL However, the S obtained by the method described in any one of Embodiments 1 to 14, preferably the S described in any one of Embodiments 17 to 20 CPL The use or method according to Embodiment 23 or 24, wherein the at least one further polymer compound preferably comprises one or more polyamides 6.6, at least one polyethylene terephthalate, at least one polyurethane, at least one polyester, at least one polyether, at least one polyvinyl chloride, at least one natural fiber material, e.g., wool and cotton, at least one cellulose material, at least one natural elastomer, at least one synthetic elastomer, at least one copolymer of two or more of the polymer compounds, including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers, and at least one rubber material comprising one or more of at least one natural rubber material and at least one synthetic rubber material.

[0084] 26. A polymer, or a polymer product, or a polymer and a polymer product, is one of the following, or part of one of the following: Automotive parts, preferably cylinder head covers, engine covers, intake radiator housings, intake radiator flaps, intake pipes, intake manifolds, connectors, gear wheels, fan wheels, coolant boxes, heat exchanger housings or housing components, coolant coolers, intake radiators, thermostats, water pumps, radiators, fastening components or parts of battery systems for electric transport, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, automotive exteriors for A, B, C or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights, taillights, airbags, and / or cushions. Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and / or jackets, Electrical components, preferably electrical components, electronically passive components, electronically active components, printed circuit boards, housing components, wheels, lines, switches such as microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, diodes such as lamps and LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, such as reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and / or spring tongues for electrical and / or electronic components. Consumer and / or pharmaceuticals, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and / or bottles, mattresses, cushions, insulation materials, Packaging for the food industry, preferably single-layer and / or multi-layer inflated film, cast film (single-layer and / or multi-layer), biaxially oriented film, laminate film, or the method according to any one of embodiments 23 to 25.

[0085] 27. Polymers, or polymer products, or polymers and polymer products, S CPL The S contains polyamide 6 obtained from or obtained from CPL The use or method according to any one of Embodiments 23 to 26, obtained by or by the method described in Embodiment 28, in an amount of 1% by weight or more, preferably 2% by weight or more, more preferably 5% by weight or more, more preferably 15% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 60% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight or more, more preferably 95% by weight or more, and / or 100% by weight or less, preferably 95% by weight or less, more preferably 90% by weight or less, more preferably 50% by weight or less, more preferably 25% by weight or less, more preferably 10% by weight or less.

[0086] As far as Embodiment 27 is concerned, the respective amounts are preferably determined based on identity retention and / or separation and / or mass balance and / or book and claims management models, more preferably based on mass balance, and more preferably based on International Sustainability and Carbon Certification (ISCC) standards. As far as Embodiments 23 to 27 is concerned, the preparation of polymers, polymer products, or polymers and polymer products may involve one or more synthesis steps and can be carried out by conventional synthesis and techniques well known to those skilled in the art. Examples of synthesis steps are provided in "Industrial Organic Chemistry," Vol. 3, Wiley-VCH, 1997, ISBN: 978-3-527-28838-0, "Kunststoffhandbuch," Vol. 11 of 17 supplementary volumes, Carl Hanser Verlag, especially Vol. 6, "Polyamides," 1st edition, 1966, "Injection Molding Reference Guide, 4th edition, CreateSpace Independent Publishing Platform," 2011, ISBN: 978-1466407824, and in International Publication Nos. 2008 / 155271 and International Publication Nos. 2013 / 139827, respectively, which are incorporated herein by reference.

[0087] When used in the context of this invention, the term "bar" refers to "bar(abs)," that is, bar (absolute pressure), and is sometimes also referred to as "bara."

[0088] As used herein, the term “Elastane” is also known as “Spandex,” and common trade names for spandex include Lycra, Elaspan, Acepora, Creora, Inviya, Roica, Dorlastan, Linel, or ESPA.

[0089] The term “textile material” encompasses fibrous and non-textile raw materials processed into linear, planar, and spatial structures by various methods. This includes linear fibrous structures produced from textile materials, such as yarns, twisted yarns, and ropes; sheet-like fibrous structures, such as woven fabrics, knitted fabrics, braids, stitch-bonded fabrics, nonwoven fabrics, and felts; and three-dimensional fibrous structures, i.e., main structures, such as fibrous hoses, stockings, or fibrous semi-finished products; and further, finished products made from the aforementioned products that are assembled, opened up, and / or otherwise made marketable for processing, trading, or end consumers. The term “textile waste” encompasses the fibrous materials defined above, whose inherent value has been consumed from the perspective of the current owner, and thus the material is at the end of its lifespan for the owner.

[0090] As used herein, the term “engineering plastics” refers to high-performance plastic grades that have physical properties enabling long-term use in structural applications, wide temperature ranges, under mechanical stress, and in challenging chemical and physical environments, used to manufacture plastic components as alternatives to conventional engineering materials such as metals and ceramics. Engineering plastics are particularly applicable to the manufacture of mechanical components across several industries, including automotive, medical, electrical and electronic, aerospace, construction, and consumer products. As used herein, the term “engineering plastic waste” encompasses the engineering plastic materials defined above, whose inherent value has been consumed from the perspective of the current owner, and thus the material is at the end of its lifespan for that owner.

[0091] In the context of the present invention, the phrase "X is one or more of A, B, and C" should be understood as disclosing that X is either A, B, or C, or A and B, or A and C, or B and C, or A, B, and C. In this regard, those skilled in the art can translate the above abstract terms into concrete examples, for example, X is a chemical element and A, B, and C are specific elements such as Li, Na, and K, or X is a temperature and A, B, and C are specific temperatures such as 10°C, 20°C, and 30°C. In this regard, it should be noted that it is possible to extend the above terms to less specific realizations of the features, for example, "X is one or more of A and B" to disclose that X is either A, or B, or A and B, or for more specific realizations of the features, for example, "X is one or more of A, B, C, and D" to disclose that X is either A, or B, or C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or A and B and D, or B and C and D.

[0092] The present invention will be explained with reference to the following figures and reference examples. [Brief explanation of the drawing]

[0093] [Figure 1]The present invention describes a method. In this method, a waste stream SM containing polyamide 6 is passed through a reaction unit UR, where the waste is subjected to polyamide 6 depolymerization conditions (depolymerization by hydrolysis in an aqueous medium). From the reaction unit UR, a liquid aqueous stream SR containing ε-caprolactam and one or more impurities is obtained and removed. This stream SR is then passed through an evaporation unit UE, from which a liquid aqueous stream SL and one or more aqueous vapor streams SV are obtained and removed. In Figure 1, only one vapor stream SV is shown. Stream SL has a higher ε-caprolactam concentration than stream SR. Stream SL is then passed through a heat-consuming purification unit UP, where further purification of the ε-caprolactam takes place. From the stream SL supplied to UP, a product stream SCPL containing ε-caprolactam at a significantly higher concentration than that of stream SL is finally obtained. According to the method of the present invention, at least a portion of the heat consumed in the purification unit UP is at least partially supplied by at least one of one or more vapor streams SV, and based on SV, one or more at least partially condensed aqueous streams SVW are obtained and removed from UP. Figure 1 shows only one stream SVW. Furthermore, one or more aqueous streams SRW are obtained from SL from the purification unit UP. At least one stream SVW is then at least partially recycled to the reaction unit UR, and at least one stream SRW is also at least partially recycled to the reaction unit UR. [Figure 2]A method including a complete recirculation loop is shown. The method according to Figure 2 shows the further use of stream SCPL, i.e., purified ε-caprolactam. According to the present invention, stream SCPL is passed through a polyamide 6 production unit UPP, where it is used as a starting material. If necessary, one or more further streams SNCPL can be passed through the UPP, the streams containing non-recycled ε-caprolactam, i.e., ε-caprolactam from a conventional source. The prepared polyamide 6 materials are then passed through a unit UTP, where they are used as starting materials for preparing polyamide 6-containing materials, preferably polyamide 6-containing fibrous materials. If necessary, one or more further streams SNPA6 can be passed through the UTP, the streams containing non-recycled polyamide 6, i.e., polyamide 6 from a conventional source. Depending on the type of material prepared in the UTP, further streams containing one or more starting materials other than polyamide 6 can also be passed through the UTP. The materials, preferably fibrous materials MT obtained from the UTP, are then put on the market and remain there for a given lifetime TMT. Subsequently, each end-of-life material is appropriately collected in a collection unit UTC, preferably a fiber material collection unit, and from there appropriately passed to the reaction unit UR, preferably via a unit UM for supplying the stream SM as a stream SM or as part of the stream SM. Such a unit UM usually includes any apparatus capable of appropriately passing the solid material M to the reaction unit UR. Preferably, the UM includes apparatus such as one or more silos, one or more hoppers, one or more truck unloading stations, one or more big bag unloading stations. Furthermore, Figure 2 shows that in the manufacturing unit UTP, the remaining material MR is obtained from the manufacturing method, i.e., material not included in MT. For example, MR may be in the form of textile cuttings. This material can be supplied to the UR directly via the UTC and / or via the UM as a stream SM or as part of the stream SM. This recirculation loop shown in Figure 2 applies to any of the figures, however, Figures 3-6 below are not explicitly shown. [Figure 3] A method having preferred water treatment steps is shown. The method shown in Figure 3 shows preferred treatment of streams SVW and SRW already shown in Figures 1 and 2. According to this method, streams SVW and SRW are passed through a water treatment unit UW, from which stream SW is obtained, which is then recycled to a reaction unit UR as (at least partially) aqueous stream SW (or a portion thereof). Furthermore, from the UW, one or more wastewater streams SWW are obtained that are not recycled to the method. Preferably, the water treatment unit UW comprises a water recovery unit UWR and optionally a wastewater unit UWW. Preferably, streams SVW and SRW are passed through a water treatment unit UW, where they are appropriately purified and / or appropriately collected to obtain one or more aqueous recirculation streams. The streams obtained from such purification may then be passed through a wastewater treatment unit UWW. [Figure 4]A preferred method using a heat-consuming purification unit UP is shown. The method shown in Figure 4 shows a preferred method for purifying stream SL with respect to ε-caprolactam. According to this method, stream SL is first passed through a water separation unit to obtain one or more streams SRW, and then preferably through a water treatment unit UW, as already shown in Figure 2 and, according to a preferred design, as shown in Figure 3. Furthermore, at least one of streams SV is passed through the UWS to at least partially satisfy the heat demand of the UWS, and based on this at least one stream SV passed through the UWS, one or more at least partially condensed streams SVW1 are obtained, which are preferably further passed through a water treatment unit UW. Next, streams SUWS containing ε-caprolactam are preferably passed through a distillation unit UD for further purification with respect to ε-caprolactam. Furthermore, at least one of streams SV is passed through the UD to at least partially satisfy the heat demand of the UD, and based on this at least one stream SV passed through the UD, one or more at least partially condensed streams SVW2 are obtained, which are preferably further passed through a water treatment unit UW. The stream SUD containing ε-caprolactam is then preferably passed through the crystallization unit UC for further purification of the ε-caprolactam. Furthermore, at least one of the streams SV is passed through UC to at least partially satisfy the heat demand of UC, and based on this at least one stream SV passed through UC, one or more at least partially condensed streams SVW3 are obtained, which are preferably further passed through the water treatment UW. [Figure 5]A preferred method having a water separation unit UWS is shown. The method shown in Figure 5 shows a preferred method for separating water from stream SL in a water separation unit UWS. According to this method, stream SL is first passed through a first stage of water separation performed in unit UWS1. From UWS1, the stream containing ε-caprolactam is then passed through an intermediate treatment stage UI from which impurities can be removed. The thus purified stream obtained from UI is then passed further through a second stage of water separation performed in unit UWS2. From unit UWS2, a stream SUWS2 containing ε-caprolactam is obtained, which corresponds to the stream SUWS shown in Figure 4, and is then preferably passed through a distillation unit UD. From the intermediate unit UI, streams SI containing the separated impurities are removed and can be further used depending on the amount and / or chemical properties of the impurities. According to this method, one or more aqueous streams SRW1 are obtained, and are then preferably passed through a water treatment unit UW, as already shown in Figure 2 and, according to a preferred design, as shown in Figure 3. Furthermore, this method yields one or more aqueous streams SRW2, which are then preferably passed through a water treatment unit UW, as already shown in Figure 2 and, according to a preferred design, as shown in Figure 3. Preferably, at least one of the streams SV is further passed through UWS1 to at least partially meet the heat demand of UWS1, and based on this at least one stream SV passed through UWS1, one or more at least partially condensed streams SVW11 are obtained, which are preferably further passed through a water treatment UW. Preferably, at least one of the streams SV is further passed through UWS2 to at least partially meet the heat demand of UWS2, and based on this at least one stream SV passed through UWS2, one or more at least partially condensed streams SVW12 are obtained, which are preferably further passed through a water treatment UW. [Figure 6]A method involving the preferred use of different steam streams SV is shown. The method shown in Figure 6 shows a more preferred method of supplying heat to a purification unit UP, based on the preferred method design according to Figure 5. According to this method, one or more steam streams SV1 and one or more steam streams SV2 are obtained from an evaporation unit UE which may include, for example, two or more evaporation subunits (not shown), and one or more streams SV1 have a different pressure and temperature than stream SV2. Thus, streams SV1 and SV2 can be used to supply heat to units having different heat demands. For example, as shown in Figure 6, stream SV1 is used to provide at least a portion of the heat consumed by UWS1 and UC, and stream SV2 is used to provide at least a portion of the heat consumed by UWS2 and UD. Thus, based on stream SV1, one or more at least partially condensed streams SVW11 and SVW3 are obtained, which are preferably further passed through a water treatment UW. Furthermore, based on stream SV2, one or more at least partially condensed streams SVW12 and SVW2 are obtained, which are preferably further passed through a water treatment UW.

[0094] Reference example Reference Example 1: Determination of APHA color of crystallized ε-caprolactam The APHA color was determined according to ISO 8112. In principle, the absorbance E of a 50 wt% ε-caprolactam aqueous solution is measured at a wavelength λ=390 nm in a cuvette of length l=5 cm and expressed in Hazen units (platinum-cobalt scale). To do this, the measured absorbance E is multiplied by a coefficient f=150.

[0095] The Hazen unit (platinum-cobalt scale) is defined as the color of a solution containing 1 mg of platinum in the form of hexachloroplatinate (IV) in 1 liter of water in the presence of 2 mg of cobalt(II) chloride hexahydrate. The Hazen unit corresponds to the APHA unit. A standard solution of 500 Hazen units is prepared as follows: 1,000 g of cobalt(II) chloride hexahydrate (CoCl2·6 H2O) and 1,245 g of potassium hexachloroplatinate (IV) (K2PtCl6) are dissolved in 100 ml of hydrochloric acid containing 1.19 g / ml of a. The solution is transferred to a 1000 ml volumetric flask and filled into the calibration mark. Thus, the solution contains 500 mg of platinum and corresponds to 500 Hazen units.

[0096] Dissolve 50 ± 0.1 g of ε-caprolactam in 50 ml of distilled water in a 250 ml Erlenmeyer flask. Mix the solutions and let stand until the bubbles disappear. Fill two cuvettes of the spectrophotometer (suitable for measurement at wavelength λ=390 nm) with distilled water, place them in the beam path, and adjust the spectrophotometer to E=0 at λ=390 nm. Then, remove the distilled water from the sample cuvette and then fill this cuvette with the ε-caprolactam solution. Next, measure the absorbance E of this solution against the comparison cuvette containing distilled water at λ=390 nm (E=0). 390 ) will be decided.

[0097] The number of colors X (in Hazen units, platinum-cobalt scale) is given by X = E·f = 150·E 390 It is calculated as follows. X is rounded to the next integer.

[0098] Reference Example 2: Determination of the purity of crystallized ε-caprolactam The purity of the crystallized ε-caprolactam and the amounts of each impurity were determined by GC-FID / MS using a GC (Agilent 7890A) combined with two MSDs (Agilent 5975C) for electron impulse ionization and chemical ionization.

[0099] According to the present invention, impurities are S CPLWhen present, especially when one or more elastanes are included in the solid material M, diol compounds, such as butanediol and ethylene glycol, and optionally their oligomers, have been found to be the main impurities. The method of the present invention contains S with other impurities only at very low weight ppm values. CPL As far as calculations of the purity of crystallized ε-caprolactam are concerned, these other impurities could be ignored, given the discovery that they resulted in the composition.

[0100] The diol compounds were calibrated by GC after extrapolating the respective percentage values ​​obtained from the measurements to their respective weight % / weight ppm values, and then measured quantitatively, i.e., in weight %. By subtracting these measured weight % values ​​from 100 weight %, the crystallization S CPL This purity can be obtained. [Explanation of symbols]

[0101] List of abbreviations unit U M Supply Stream S M Units that provide U R Reaction / Depolymerization Unit U E Evaporation unit U P Purification unit U W Water treatment unit U WR Water recovery unit U WW Drainage unit U WS Water separation unit U WS1 Upstream water separation unit U WS2 Downstream water separation unit U I intermediate separation U D Distillation unit U C Crystallization unit U PP PA6 Material Generation Unit U TP Fiber material production unit U TC Textile material collection unit stream S M PA6 Waste Stream S R Product stream obtained from depolymerization S L Liquid stream obtained from an evaporation unit containing CPL (ε-caprolactam) S CPL Final solid CPL product S V One or more water vapor streams obtained from the evaporation unit. S V1 Water vapor stream obtained from the evaporation unit S V2 Water vapor stream obtained from the evaporation unit S VW S V One or more at least partially condensed streams obtained from S VW1 U WS Condensed stream obtained from S VW11 U WS1 Condensed stream obtained from S VW12 U WS2 Condensed stream obtained from S VW2 U D Condensed stream obtained from S VW3 U C Condensed stream obtained from S RW One or more aqueous streams (reaction water streams) S RW1 U WS1 Aqueous stream obtained from S RW2 U WS2 Aqueous stream obtained from S W Water Removal Unit U WR Recirculated water stream obtained from SSW Wastewater system U WW U WR streams separated by S WW wastewater stream S UWS Water separation unit U WS CPL-containing stream obtained from S UWS1 Water separation subunit U WS1 CPL-containing stream obtained from S UWS2 Water separation subunit U WS2 CPL-containing stream obtained from S UI Impurity separation unit U I CPL-containing stream obtained from S UD Distillation unit U D CPL-containing stream obtained from S I U I A stream containing impurities obtained from S NCPL Non-recirculating CPL stream S NPA6 Non-recirculating PA6 stream others T MT Textile material M T lifespan M T U TP Fiber materials produced M R U TP Materials containing polyamide 6 remaining from production

Claims

1. A recycling method for recovering ε-caprolactam from a solid material M containing polyamide 6, wherein the method is (i) Stream S containing the solid material M Ｍ Steps to provide, (ii) S Ｍ A step of preparing an aqueous depolymerization mixture based on the following: The depolymerization mixture prepared according to (iii)(iii) is reacted in the reaction unit U Ｒ Under conditions of polyamide 6 depolymerization, concentration c ＳＲ Aqueous Stream S containing ε-caprolactam dissolved in water Ｒ A step to obtain the stream S Ｒ The step further includes one or more impurities, (iv) the liquid aqueous stream S Ｒ is passed through an evaporation unit U Ｅ to obtain a liquid aqueous stream S containing ε-caprolactam dissolved in water at a concentration c ＳＬ > c ＳＲ and further obtain one or more aqueous vapor streams S ＳＬ from S Ｌ from S Ｒ where S Ｖ is obtained from S Ｒ ; (v) The aqueous stream S Ｌ Heat consumption purification unit U Ｐ Pass through, c ＳＣＰＬ >>c ＳＬ concentration c ＳＣＰＬ Stream S containing ε-caprolactam ＣＰＬ to S Ｌ Obtained from, S Ｌ From one or more Aqueous Stream S ＲＷ This is a further step to obtain U Ｐ At least a portion of the heat consumed in the one or more streams S Ｖ Provided by at least one of the at least one stream S Ｖ From at least one at least partially condensed aqueous stream S ＶＷ To obtain, step, (vi) at least one stream S, at least partially ＶＷ reaction unit U Ｒ The stream is then recirculated, and at least partially into at least one stream S ＲＷ to the reaction unit U Ｒ The step of recirculating Methods that include...

2. The method according to claim 1, wherein the solid material M comprises, more preferably, waste, wherein the waste comprises, more preferably, one or more of at least one fibrous waste and at least one engineering plastic waste, more preferably, at least one fibrous waste, more preferably, and preferably 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, and more preferably 80 to 100% by weight of M is polyamide 6, and if the polyamide 6 content of the solid material M is less than 100% by weight, the solid material M optionally further comprises one or more elastanes.

3. The step of recirculating by (vi) (vi. 1) The at least one stream S ＶＷ and the at least one stream S ＲＷ water treatment unit U Ｗ To supply U Ｗ from at least one aqueous recirculation stream S Ｗ Steps to obtain (vi.2) The at least one aqueous stream S Ｗ at least partially the reaction unit U Ｒ The step of recirculating The method according to claim 1 or 2, including the method according to claim 1 or 2.

4. The water treatment unit U Ｗ However, the water recovery unit U ＷＲ and wastewater unit U ＷＷ (vi. 1) includes, (vi. 1.1) The at least one stream S ＶＷ and the at least one stream S ＲＷ to the water recovery unit U ＷＲ To supply U ＷＲ From the at least one aqueous recirculation stream S Ｗ and at least one aqueous stream S ＳＷ Steps to obtain (vi. 1.2) The at least one stream S ＳＷ to the wastewater unit U ＷＷ To supply U ＷＷ From at least one wastewater stream S ＷＷ Steps to obtain The method according to claim 3, further comprising:

5. The aforementioned purification unit U Ｐ However, the heat consumption water separation unit U ＷＳ , heat consumption distillation unit U Ｄ and heat consumption crystallization unit U Ｃ One or more of the following, preferably a heat-consuming water separation unit U ＷＳ , heat consumption distillation unit U Ｄ and heat consumption crystallization unit U Ｃ Two or more of the following, Comfortable Heat Consumption Water Separation Unit U ＷＳ , heat consumption distillation unit U Ｄ and heat consumption crystallization unit U Ｃ Includes U ＷＳ , U Ｄ and U Ｃ At least a portion of the heat consumed in one or more of the streams S Ｖ Provided by at least one of the following: The above method preferably involves one or more of (i-1), (i-2), and (i-3), more preferably at least two or more of (i-1), (i-2), and (i-3), more preferably (i-1), (i-2), and (i-3), (i-1)U ＷＳ From at least one at least partially condensed aqueous stream S ＶＷ１ Steps to obtain (i-2)U Ｄ From at least one at least partially condensed aqueous stream S ＶＷ２ Steps to obtain (i-3)U Ｃ From at least one at least partially condensed aqueous stream S ＶＷ３ Steps to obtain It further includes, The above method preferably involves one or more S ＶＷ１ S ＶＷ２ and S ＶＷ３ Preferably two or more S ＶＷ１ S ＶＷ２ and S ＶＷ３ , more comfortable S ＶＷ１ S ＶＷ２ and S ＶＷ３ The water treatment unit U described in claim 3 Ｗ Further including supplying to The method according to any one of claims 1 to 4.

6. The aforementioned stream S ＲＷ At least one of them is U ＷＳ The method according to claim 5, obtained from.

7. the purification unit U Ｐ is a heat-consuming water separation unit U ＷＳ a heat-consuming distillation unit U Ｄ and a heat-consuming crystallization unit U Ｃ and the method includes a step of supplying the stream S ＳＬ containing ε-caprolactam at a concentration c Ｌ to U ＷＳ a step of obtaining a stream U ＷＳ containing ε-caprolactam at a concentration c ＵＷＳ from U ＷＳ a step of supplying the stream S ＵＷＳ to the distillation unit U Ｄ a step of obtaining a stream S Ｄ containing ε-caprolactam at a concentration c ＵＤ from U ＵＤ a step of supplying the stream S ＵＤ to the crystallization unit U Ｃ a step of obtaining a stream S Ｃ containing ε-caprolactam at a concentration c ＳＣＰＬ from U ＣＰＬ where c ＳＬ < c ＵＷＳ < c ＵＤ < c ＳＣＰＬ < c and this is a step The method according to any one of claims 1 to 6, including

8. The water separation unit U ＷＳ However, at least two heat-consuming water separation subunits U ＷＳ１ and U ＷＳ２ Preferably, two heat-consuming water separation subunits U are coupled in series. ＷＳ１ and U ＷＳ２ Including the stream S Ｌ U ＷＳ１ It is supplied to U ＷＳ１ and U ＷＳ２ At least a portion of the heat consumed in one or more of the streams S Ｖ The method according to any one of claims 1 to 7, provided by at least one of the following.

9. One or more of (ii-1) and (ii-2), preferably (ii-1) and (ii-2), (ii-1)U ＷＳ１ From at least one at least partially condensed aqueous stream S ＶＷ１１ Steps to obtain (ii-2)U ＷＳ２ From at least one at least partially condensed aqueous stream S ＶＷ１２ Steps to obtain The method according to claim 8, including the method described in claim 8.

10. At least one aqueous stream S ＲＷ１ U ＷＳ１ Obtained from, at least one aqueous stream S ＲＷ２ U ＷＳ２ Obtained from, S ＲＷ１ and S ＲＷ２ At least one of, preferably S ＲＷ１ and S ＲＷ２ U Ｗ The method according to claim 9, supplied to.

11. U ＷＳ１ Downstream and U ＷＳ２ upstream of the separation unit U Ｉ The arrangement is configured, and the method is U ＷＳ１ From Water-based Stream S ＵＷＳ１ The steps of obtaining the stream S ＵＷＳ１ to the separation unit U Ｉ The steps of supplying to U Ｉ From Water-based Stream S ＵＩ The steps of obtaining the stream S ＵＩ to the unit U ＷＳ２ The steps include supplying to U Ｉ In this case, one or more impurities are S ＵＷＳ１ Separated from, thereby U Ｉ From impurity stream S Ｉ To obtain the above impurities, preferably according to (ii), S Ｒ The method according to any one of claims 8 to 10, comprising at least one impurity contained in.

12. The aforementioned evaporation unit U Ｅ The method includes two or more evaporation subunits, and the method includes at least two vapor streams S Ｖ１ and S Ｖ２ The steps of obtaining the steam stream S Ｖ１ The steps of passing the steam stream S through at least one heat consumption unit and Ｖ２ The step of passing the steam stream S through at least one heat consumption unit is included. Ｖ１ and S Ｖ２ The method according to any one of claims 1 to 11, wherein the pressure and / or temperature are different from each other.

13. Polyamide 6 Production Unit U ＰＰ The stream S ＣＰＬ Further includes providing U ＰＰ The polyamide 6 produced is preferably used in the fiber material production unit U ＴＰ It is provided as a raw material for the unit U ＴＰ teeth, (A) Textile material M brought into the market Ｔ The fiber material M is obtained. Ｔ Useful life T ＭＴ Afterwards, at least partially as textile waste, textile material collection unit U ＴＣ Collected, (B) Remaining ingredients M Ｒ It is obtained as textile waste. At least a portion of the textile waste described in (A), or at least a portion of the textile waste described in (B), or at least a portion of the textile waste described in (A) and at least a portion of the textile waste described in (B), preferably supplied to the supply unit U Ｍ via S Ｍ as U Ｒ To be appropriately provided The method according to any one of claims 1 to 12.

14. A method according to any one of claims 1 to 12, which exhibits one or more of the following characteristics, for a stream S ＣＰＬ A crystallized ε-caprolactam obtained or acquired as, APHA color of up to 5, preferably up to 4, more preferably up to 3, more preferably up to 2, more preferably up to 1.5, more preferably up to 1, A purity of at least 99.8% by weight, preferably at least 99.9%, more preferably at least 99.95%, Furthermore, preferably exhibiting one or more of the following characteristics: ε-caprolactam oligomer content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, 6-aminocaproic acid content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Triisopropyl borate content in the range of 0 to 100 ppm by weight, more preferably in the range of 0 to 50 ppm by weight, more preferably in the range of 0 to 10 ppm by weight, Furthermore, preferably, the solid material M according to claim 2 further exhibits one or more of the following characteristics, and more preferably, comprises one or more elastanes. Polytetrahydrofuran content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Aniline content in the range of 0 to 10 ppm by weight, more preferably in the range of 0 to 5 ppm by weight, more preferably in the range of 0 to 1 ppm by weight, Methylenediphenyldiamine (MDA), isomers, and oligomers in a range of 0 to 10 ppm by weight, more preferably in a range of 0 to 5 ppm by weight, more preferably in a range of 0 to 1 ppm by weight. Butanediol content in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, more preferably in the range of 0 to 100 ppm by weight, and / or The ethylene glycol content is in the range of 0 to 500 ppm by weight, more preferably in the range of 0 to 300 ppm by weight, and more preferably in the range of 0 to 100 ppm by weight. Crystallized ε-caprolactam.

15. S obtained by the method according to any one of claims 1 to 12 for preparing polyamide 6 ＣＰＬ Preferably, S as described in claim 14 ＣＰＬ Use of the polyamide 6, which preferably further comprises using the polyamide 6 as a raw material for preparing one or more of at least one fibrous material and at least one engineering plastic material, more preferably as a raw material for preparing at least one fibrous material.

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