Highly integrated process for the production of polyamide 6 from waste containing polyamide 6

Abstract

An integrated method for preparing polyamide 6, comprising (i) providing a flow S MR The stream contains a solid material M containing polyamide 6. R The solid material M R (ii) Including waste; in the depolymerization and purification unit U DP From this stream S MR Preparation of a stream containing purified ε-caprolactam CPL The unit U DP Includes at least one depolymerization subunit U D (iii) Stream S CPL Transferred to polyamide 6 production unit U PA ;(iv) in U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P and a stream comprising water and one or more ε-caprolactam oligomers; (v) optionally subjecting the stream comprising water and one or more ε-caprolactam oligomers to concentration with respect to the one or more ε-caprolactam oligomers in at least one concentration stage to obtain a concentrated stream comprising water and one or more ε-caprolactam oligomers; (vi) conveying the optionally concentrated stream comprising water and one or more ε-caprolactam oligomers to the depolymerization subunit U according to (ii). D At least one of them.

Description

[0001] This invention relates to a highly integrated method for preparing polyamide 6.

[0002] US 4,107,160 A relates to apparatus and continuous methods for recovering caprolactam from solid polycaprolactam waste and / or polycaprolactam extraction water.

[0003] JP 2023 / 108237 A relates to a recycling method for producing recycled polyamide resins by using a depolymerization solution containing caprolactam and oligomers as polymerization raw materials.

[0004] This invention relates to a highly integrated method for preparing polyamide 6 in a polyamide 6 production unit, wherein polyamide 6 is prepared by polymerizing ε-caprolactam. An ε-caprolactam feedstock (educt) stream for use in the polyamide 6 production unit is prepared in a depolymerization and purification unit, where the material containing polyamide 6 is depolymerized to give a crude ε-caprolactam stream, which is then purified to give an ε-caprolactam feedstock stream. A recycled stream is conveyed from the polyamide 6 production unit back to the depolymerization and purification unit, and at least one, preferably multiple, components of this stream are suitably separated and conveyed to different stages carried out in the depolymerization and purification unit according to a preferred method according to the invention. Furthermore, according to another preferred method of the invention, substandard polyamide 6 material from the polyamide 6 production unit is suitably recycled to the depolymerization and purification unit.

[0005] Therefore, the present invention relates to an integrated method for preparing polyamide 6, the method comprising:

[0006] (i) Provide stream S MR The stream contains a solid material M containing polyamide 6. R The solid material M R Includes waste materials;

[0007] (ii) In the depolymerization and purification unit U DP From this stream S MR Preparation of a stream containing purified ε-caprolactam CPL The unit U DP Includes at least one depolymerization subunit U D ;

[0008] (iii) The stream S CPL Transferred to polyamide 6 production unit U PA ;

[0009] (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PAObtain polyamide 6 material M P And streams containing water and one or more ε-caprolactam oligomers;

[0010] (v) Optionally, the stream containing water and one or more ε-caprolactam oligomers is subjected to concentration with respect to the one or more ε-caprolactam oligomers in at least one concentration stage to obtain a concentrated stream containing water and one or more ε-caprolactam oligomers;

[0011] (vi) Optionally concentrated stream comprising water and one or more ε-caprolactam oligomers is conveyed to the depolymerization subunit U according to (ii). D At least one of them.

[0012] Preferably, the optionally concentrated stream comprising water and one or more ε-caprolactam oligomers according to (vi) further comprises ε-caprolactam, i.e., monomeric ε-caprolactam.

[0013] Preferably, according to the present invention, the method includes

[0014] (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P He Liu S EW The stream S EW Contains concentration c EW (W) water, concentration c EW (C) ε-caprolactam and total concentration c EW One or more ε-caprolactam oligomers of (O);

[0015] (v) Make the flow S EW It has been concentrated, including

[0016] (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam and total concentration c C1 (O) one or more ε-caprolactam oligomers, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C) and c C1 (O) > c EW(O), and further from U C1 Obtain the concentration c W1 (W) > c EW (W) water's water flow S W1 ;

[0017] (v.2) Make the flow S C1 Second Concentration Unit U C2 The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers, wherein c C2 (O) > c C1 (O), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, where c W2 (W) >c W1 (W) and c W2 (C) > c W1 (C);

[0018] (vi) Stream S C2 Transmitted to the depolymerization and purification unit U DP middle.

[0019] As described above, from polyamide 6 polymerization unit U PA The obtained stream S EW It comprises water, the monomer ε-caprolactam, and one or more ε-caprolactam oligomers. Typically, this aqueous stream S EW It further comprises one or more additional organic compounds besides the monomer ε-caprolactam and one or more ε-caprolactam oligomers. Therefore, it is preferred that the flow S... EW Further including total concentration c EW (X) includes one or more organic compounds X other than ε-caprolactam and its oligomers, according to the method of (v) including

[0020] (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam, total concentration cC1 (O) one or more ε-caprolactam oligomers and a total concentration of c C1 (X) is one or more organic compounds X, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C), c C1 (O)> c EW (O) and c C1 (X)> c EW (X), and further from U C1 Obtain the concentration c W1 (W) > c EW (W) water's water flow S W1 ;

[0021] (v.2) Make the flow S C1 Second Concentration Unit U C2 The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers and a total concentration of c C2 (X) is one or more organic compounds X, wherein c C2 (O) > c C1 (O) and c C2 (X) > c C1 (X), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, where c W2 (W) > c W1 (W) and c W2 (C) > c W1 (C).

[0022] Typically used as a concentration unit U C1 One or more devices are not limited to any particular design, provided that the invention can be suitably carried out from U. PA The obtained water flow and preferred flow S EW Concentration. Preferably, the concentration unit U C1 It includes one or more of the following: a vessel having internal heat exchange, external heat exchange, or both internal and external heat exchange; and a falling film heat exchanger.

[0023] Typically used as a concentration unit UC2 One or more devices are not limited to any particular design, provided that the invention can be properly transmitted to U. C2 Flow S in C1 Concentration. Preferably, the concentration unit U C2 It includes one or more of the following: a container having internal heat exchange, external heat exchange, or both internal and external heat exchange; and a thin-film evaporator.

[0024] Regarding the aggregation unit U PA There are no specific limitations, provided that a suitable water flow (preferred flow S) is obtained. EW ) and polyamide 6 material M P Preferably, according to the present invention, polymerization is carried out as hydrolytic chain polymerization. Furthermore, the polymerization unit U... PA Preferably, it further includes one or more additional downstream stages, including but not limited to one or more of at least a purification stage (e.g., an extraction stage), at least one molding stage (e.g., a granulation stage), and at least one drying stage. Preferably, according to the invention, (iv) includes...

[0025] (iv.1) The stream S CPL And preferably water-based flow S AQ0 The product is transferred to polymerization stage ST0, from which crude polyamide 6 stream S is obtained. PA1 and water flow S WA1 ;

[0026] (iv.2) The stream S PA1 And preferably water-based flow S AQ1 The material is transferred to the granulation stage ST1, from which coarse granular polyamide 6 material M is obtained. PA2 and water flow S WA2 ;

[0027] (iv.3) The material M PA2 And preferably water-based flow S AQ2 The material is transferred to extraction stage ST2, from which purified granular polyamide 6 material M is obtained. PA3 and water flow S WA3 ;

[0028] (iv.4) The material M PA3 The material is transferred to drying stage ST3, from which polyamide 6 material M is obtained. P and water flow S WA4 .

[0029] Preferably, according to the invention, according to (iv.1), one or more suitable additives A are conveyed to the polymerization stage STO. The additives include, but are not limited to, at least one filler, such as titanium dioxide, zinc oxide, silica, montmorillonite, and multi-walled carbon nanotubes; at least one flame retardant, such as zinc borate, magnesium hydroxide, boehmite, and aluminum diethylphosphinate; at least one reinforcing agent, such as glass fiber and carbon fiber; and / or at least one end-capping agent, such as an amine end-capping agent and a carboxyl end-capping agent. Typical amine end-capping agents include at least one monofunctional acid, such as adipic acid, acetic acid, propionic acid, benzoic acid, stearic acid, and / or terephthalic acid. Typical carboxyl end-capping agents include at least one monofunctional amine such as hexylamine, cyclohexylamine, and benzylamine, and / or at least one low- or polyfunctional amine such as triacetone diamine and one or more polyether amines. Preferably, the flow S... EW At least one organic compound X contained herein is an unreacted organic additive A as described above, or an organic compound obtained during polymerization from one or more additives A and ε-caprolactam and / or ε-caprolactam oligomers or polymers.

[0030] Preferably, flow S EW Includes stream S WA3 At least a portion and optionally the flow S WA1 At least a part of and flow S WA2 At least one or more of the following. More preferably, the method includes taking the stream S obtained from drying according to (iv.4) WA4 At least a portion of it is transferred to the extraction stage according to (iv.3).

[0031] As mentioned above, in U C1 Concentration during the process produces flow S C1 , and U C1 Feed flow, optimal flow S EW In comparison, this stream S C1 The ε-caprolactam, one or more ε-caprolactam oligomers, and preferably one or more organic compounds X are concentrated and further produced as flow S W1 , and U C1 Feed flow, optimal flow S EW In comparison, this stream S W1 Concentration of water in the solution. Specifically, regarding the method of the invention comprising (iv.1) to (iv.4) above, it is preferred that the water from U, according to (v.1) be concentrated. C1 The obtained stream S W1 Transfer back to polyamide 6 production unit U PA More preferably, the flow S W1 As flow S AQ0 S AQ1 and S AQ2 At least a portion of one or more of them is transmitted back to U.PA .

[0032] Regarding the depolymerization and purification unit U DP There are no specific restrictions on how to perform depolymerization and the downstream purification of the crude ε-caprolactam stream obtained from said depolymerization, provided that it originates from U DP Obtaining compliance in U PA The required ε-caprolactam flow S to withstand the polymerization conditions of polyamide 6 CPL Regarding the deagglomeration subunit U D The depolymerization process is preferably hydrolytic depolymerization, and more preferably, no polyamide 6 depolymerization catalysts such as inorganic acids and / or zinc salts such as zinc chloride, zinc acetate or zinc trifluoromethanesulfonate are used for the depolymerization.

[0033] Preferably, the depolymerization and purification unit U DP In at least one depolymerization subunit U D Downstream components include a water ion unit U for separating water from ε-caprolactam. P2 In this case, preferably, the method further includes taking data from U according to (v.2). C2 The obtained stream S W2 Transmit to U P2 .

[0034] Preferably, the depolymerization and purification unit U DP In at least one depolymerization subunit U D The upstream includes the melting and mixing subunit U. M In this case, preferably, the method further includes transferring the stream S C2 Transmitted to sub-unit U M And further includes the flow S MR Transmitted to sub-unit U M From U M Get teleported to U D of flow.

[0035] According to the present invention, the depolymerization and purification unit U DP Preferably, it includes a mixing and melting subunit U. M An aqueous depolymerization mixture is prepared in the mixing and melting subunit, and the aqueous depolymerization mixture is then transferred to the depolymerization subunit U. D Preferably, in U M The preparation of aqueous depolymerization mixtures includes making solid material M in molten subunits. R Melting is performed to obtain a liquid stream, which is then mixed with an aqueous stream in a pre-reaction subunit to obtain another liquid stream. This liquid stream is then fed as a depolymerization mixture to subunit U. DThe pre-reaction subunit preferably includes a mixing unit, preferably a static mixing unit, and more preferably consists of the above, and the melt subunit includes an extruder, preferably a single-screw extruder or a twin-screw extruder, and more preferably consists of the above.

[0036] Generally, it cannot be ruled out that U PA Some of the obtained polyamide 6 materials do not meet the desired specifications. In such cases, the method of the present invention allows for the advantageous disposal of this material (hereinafter referred to as material M). PR ) Recycle to cell U DP Therefore, it is preferable that if from production unit U... PA The obtained polyamide 6 material M P If some of the materials do not meet specifications, the method further includes removing the material M. PR At least some of them are transferred to the depolymerization and purification unit U. DP To depolymerize, more preferably, the material M PR At least some of them are transferred to the mixing and melting subunit U. M M P These specifications preferably include (for example, for the production of textile fibers, particularly suitable for high-speed spinning methods) one or more of the following

[0037] - Relative viscosity, for example, determined according to ISO 307; for example, qualified material M P Typical values ​​are in the range of 2.4 to 2.5;

[0038] - Moisture content, determined, for example, according to ISO 15512; for example, qualified material M P The typical value is at most 0.1% (m / m);

[0039] - The content of hot water extractable compounds, as determined, for example, according to ISO 6427; for instance, a typical value for MP in qualified materials is up to 0.6% (m / m).

[0040] - Viscosity number, for example, determined according to ISO 307 via the Huggins method; for example, qualified material M P Typical values ​​are in the range of 120 to 150 ml / g;

[0041] - Color count, such as APHA value, is determined according to ISO 8112; for example, qualified material M P The typical value is at most 5;

[0042] - Melting point, for example, determined according to ISO 3146; for example, qualified material M P The typical value is approximately 220°C;

[0043] - Density, for example, determined according to ISO 1183; for example, qualified material M P Typical values ​​are between 1.1 and 1.2 g / cm³. 3 Within the range;

[0044] - Compare the number of fragments; for example, qualified material M P The typical value is approximately 80 cells / g;

[0045] - Bulk density; for example, qualified material M P Typical values ​​are between 650 and 800 kg / m³ 3 Within the range;

[0046] - Particle size; for example, qualified material M P Typical values ​​range from 2.0 to 2.5 mm;

[0047] - Pellet shape; for example, a typical shape is cylindrical;

[0048] - Water absorption rate, determined, for example, similar to ISO 62; for example, qualified material M P Typical values ​​are in the range of 8% to 9%;

[0049] - Moisture absorption rate, determined, for example, similar to ISO 62; for example, qualified material M P Typical values ​​are in the range of 2% to 3%;

[0050] -Titanium dioxide content; depends on material M P Specific uses, qualified material M P Typical values ​​are in the range of 0 to 0.05 wt% (e.g. for the production of bright textile fibers), or in the range of 0.2 to 0.4 wt% (e.g. for the production of semi-dull textile fibers), or in the range of 1 to 2 wt% (e.g. for the production of fully dull textile fibers).

[0051] - Content of amino terminal groups; Qualified material M P Typical values ​​range from 40 to 47 mmol / kg.

[0052] Depends on material M P For specific further applications, deviations from one of the stated specifications from the predetermined value or range may be sufficient to classify the corresponding material as non-conforming material M. PR Furthermore, it also depends on the material M. P For specific further applications, as long as one or more other specifications conform to the predetermined value or range, deviations of one or more of the specifications from the predetermined value or range may not be harmful; therefore, even if one or more of the specifications deviate from the predetermined value or range, the corresponding material MP It can still be a qualified material.

[0053] Further information about unit U DP Preferably, it is in U D Downstream and in U P2 The upstream includes the first purification subunit U P1 And in U P2 The downstream of this includes the third purification stage U P3 In this case, preferably, the method further includes taking from U D The obtained ε-caprolactam stream is transferred to U P1 From U P1 Obtain the ε-caprolactam stream and transfer it to U. P2 From U P2 Obtain the ε-caprolactam stream and transfer it to U. P3 From U P3 Get stream S CPL .

[0054] Regarding solid material M R Preferably, it comprises waste, more preferably, is composed of therefrom, wherein the waste more preferably comprises one or more of at least one textile waste and at least one engineering plastic waste, more preferably, is composed of therefrom, and more preferably comprises at least one textile waste, more preferably, is composed of therefrom. Preferably, it contains 10 to 99% by weight, more preferably 30 to 98.5% by weight, more preferably 50 to 98% by weight, more preferably 80 to 98% by weight of M. R Composed of polyamide; or preferably, 10 to 100 wt%, more preferably 30 to 100 wt%, more preferably 50 to 100 wt%, more preferably 80 to 100 wt% of M R Composed of polyamide. If solid material M R If the polyamide 6 content is less than 100% by weight, then it is preferable that the solid material M R It also contains one or more elastic fibers (elastane). Typically, solid materials M, other than polyamide 6, are... RIt may also contain at least one additional polymer compound, wherein the at least one additional polymer compound preferably comprises one or more of the following: 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 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.

[0055] Provided to unit U DP Previously, the collected textile waste can be appropriately sorted. In this regard, the collected textile waste can be spread on a conveyor, which can be done manually and / or mechanically. Subsequently, the spread textile waste is sorted by composition and / or by color. Sorting can be done manually and / or optically. If optically, sorting preferably includes infrared sorting, more preferably near-infrared sorting and / or mid-infrared sorting. Optionally, prior to sorting, the textile waste can be subjected to a suitable metal removal step. If a metal removal step is performed, iron elements are preferably separated, for example, by a suitable magnetic device, and / or non-ferrous elements are preferably separated, for example, by a suitable eddy current separator. After the sorting, the resulting textile waste can be subjected to further processing, such as cutting and / or shredding.

[0056] Typically, solid materials M R It can be provided by any suitable method. Preferably, according to the invention, a solid material M is provided. R Includes providing solid material M in the delivery unit R The delivery unit preferably includes one or more of at least one large bag station and at least one bulk container station; the provided solid material M R The solid material M is conveyed via a first connecting pipeline to a material collection unit, preferably a collection drum, wherein the first connecting pipeline preferably includes one or more of at least one material receiving and discharging unit, at least one first material feeding unit, and at least one first particle separation unit; R The material is transferred from the material collection unit to this unit U via the second connecting pipeline. M The second connecting pipeline preferably includes one or more of at least one second material feeding unit, at least one second particle separation unit, and at least one metal detector. Preferably, the solid material M... RProvided in granular form, wherein the particle size distribution of said particles is preferably characterized by one or more of the following pairs of values, preferably two or more of the following pairs of values, and more preferably three of the following pairs of values:

[0057] - D10 values ​​for particle width in the range of 0.1 to 15 mm and D10 values ​​for particle length in the range of 0.3 to 15 mm;

[0058] - D50 values ​​for particle width in the range of 0.2 to 20 mm and D50 values ​​for particle length in the range of 0.5 to 20 mm;

[0059] - D90 values ​​for particle width in the range of 0.3 to 30 mm and D90 values ​​for particle length in the range of 0.8 to 30 mm.

[0060] Just in subunit U D For hydrolysis and depolymerization, the preferred method is a depolymerization pressure p. D The temperature is in the range of 40 to 140 bar, more preferably in the range of 40 to 125 bar, and even more preferably in the range of 40 to 110 bar; and the depolymerization temperature T D The temperature range is 230°C to 335°C, more preferably 250°C to 320°C, and even more preferably 270°C to 310°C. Preferably, unit U... D Includes z chemical reactors R i , i = 1…z, where z is in the range of 1 to 10, preferably in the range of 1 to 8, more preferably in the range of 1 to 6, more preferably in the range of 1 to 5, more preferably in the range of 1 to 4, and more preferably in the range of 1 to 3. If z > 1, it is preferred that there are at least 2 reactors R. i More preferably, all z reactors R i Series connection, wherein in each reactor R i In the middle, it remains at the depolymerization pressure p Di The depolymerization temperature T Di Among them, T, independently of each other Di Within the range of 230°C to 330°C and p Di Within the range of 40 to 140 bar, preferably where T Di Within the range of 250°C to 320°C and p Di In the range of 40 to 125 bar, more preferably, T Di Within the range of 270°C to 310°C and p Di Within the range of 40 to 110 bar. For z > 1, z reactors R are preferred. iArranged vertically, with R1 being the topmost reactor and R... z It is the bottom reactor, from which R i S obtained i Transferred to R by gravity, preferably solely by gravity. i+1 More preferably, at least one, and preferably all z, reactors R i It is a continuous stirred tank reactor (CSTR). Preferably, each continuous stirred tank reactor R i The reactor R has 2 to 6 compartments, more preferably 2 to 5 compartments, and even more preferably 2 to 4 compartments, which are independently arranged. These compartments are preferably connected in series, more preferably connected in series and arranged vertically, wherein two adjacent compartments are separated by a partition that includes at least one flow opening. Preferably, the reactor R... i The reactor includes at least one compartment comprising at least one agitator, wherein more preferably each reactor R i Each compartment includes at least one agitator, wherein more preferably, each reactor R i Each compartment includes an agitator, and the method includes agitating the depolymerization mixture in a given compartment for at least a portion of the time during which the depolymerization conditions are subjected in the compartment. Preferably, the polyamide 6 depolymerization conditions further include an aqueous depolymerization mixture in subunit U. D In the middle, preferably in z reactors R i The more preferred total residence time t in z continuous stirred tank reactors D The aqueous depolymerization mixture contains at least 85% by weight, preferably at least 90% by weight, more preferably at least 95% by weight, having a t in the range of 30 to 90 min. D More preferably, the aqueous depolymerization mixture in reactor R i The dwell time in is t Di And 0.90 ≤ (t) Di / t Di+1 ) ≤ 1.10, preferably 0.95 ≤ (t) Di / t Di+1 ) ≤ 1.05.

[0061] Preferably, according to the present invention, the purification subunit U P1 Including water ion unit U WS and its downstream high-boiling-point separation subunit U I In subunit UWS, from subunit U D At least a portion of the water contained in the obtained aqueous stream is separated. The resulting crude ε-caprolactam stream is then conveyed to the high-boiling-point separation unit U. IIn this high-boiling-point separation unit, one or more impurities are separated; the impurities preferably contain at least one organic compound having a boiling point higher than ε-caprolactam. Regarding subunit U... WS The specific device design preferably includes one or more of a falling film evaporator, a flash tank, a forced circulation evaporator, and a distillation column, more preferably one or more of a falling film evaporator and a flash tank, and even more preferably a falling film evaporator and a flash tank. Regarding the high-boiling-point separation unit U... I There are no specific limitations, provided that in the unit U I In this process, compounds with higher boiling points than ε-caprolactam can be separated at least partially. M was found to be the most preferred solid material. R The waste will contain certain compounds, which are present in polyamide 6 in subunit U. D Before or after depolymerization, a stream containing ε-caprolactam and compounds with higher boiling points than ε-caprolactam is generated. However, due to the potentially different chemical compositions of the waste, these compounds with higher boiling points than ε-caprolactam will often vary in both content and chemical properties in the stream to be purified. Preferably, subunit U I The system includes an evaporation subunit arranged upstream of another separation unit, wherein more preferably, the evaporation unit includes a stirred reactor, more preferably a stirred tank reactor, more preferably a continuous stirred tank reactor, and the other separation unit includes a droplet separator, more preferably composed of such a separator, which is preferably selected from a group consisting of a hydrocyclone, a demister plate and an absorption tower, more preferably a hydrocyclone.

[0062] Regarding the purification subunit U P2 Preferably, it is a water separator, which more preferably includes one or more of a falling film evaporator, a flash tank, and a distillation column, more preferably a distillation column.

[0063] Preferably, the purification subunit U P3 Includes distillation subunit U DI and crystallizing unit U CR One or more of them, more preferably including distillation subunit U DI and crystallizing unit U CR , of which flow S CPL Preferably from crystal subunit U CR The crystallization subunit is preferably arranged in the distillation subunit U. DI Downstream. Regarding subunit U DI Preferably, it includes at least one distillation column, preferably two or three distillation columns, more preferably two or three distillation columns connected in series. (From U) DI The obtained stream is transmitted to the crystallization sub-unit U. CRThe final purified stream S is obtained from this crystallization subunit. CPL .

[0064] Depends on, for example, one aspect, unit U DP And on the other hand, unit U PA Individual operating hours; for different operating hours, flow S C1 and / or flow S CPL It may be transferred to a suitable buffer unit before being transferred to the corresponding unit. Therefore, for such cases, it is preferable that in U C1 Downstream and in U C2 Upstream of the S stream C1 Transmitted to buffer unit U BC1 And in U DP Downstream and in U PA Upstream of the S stream CPL Transmitted to buffer unit U BCPL .

[0065] Overall, the method of the present invention represents the core of the polyamide 6 production and recycling loop. Therefore, the method of the present invention preferably further includes processing polyamide 6 from U... PA The obtained material M P It is supplied as raw material to polyamide material production units U. TP From this unit U TP M, a polyamide-containing material, was successfully launched into the market. T , wherein, in the material M T Lifespan T MT Subsequently, it was at least partially collected as waste and used as S MR At least a portion of it is transmitted to U DP The material M T Preferably, it is one or more of textile materials and engineering plastic materials, with textile materials being the most preferred.

[0066] Furthermore, the present invention also relates to an integrated polyamide 6 apparatus for performing the methods of the present invention as described herein, wherein the integrated polyamide 6 apparatus includes a depolymerization and purification unit U. DP and polyamide 6 production unit U PA Used to purify ε-caprolactam from U DP Transmit to U PA delivery pipeline L CPL and at least for transferring water-based recirculation flow from U PA Transmit to U DP L delivery pipeline S .

[0067] Preferably, the delivery pipeline L SIncludes two concentration units U C1 and U C2 U C1 Arranged in U PA Downstream of U C2 Arranged in U C1 Downstream and in U DP Upstream of U. More preferably, the integrated polyamide 6 device further includes a U C1 toU PA L delivery pipeline W1 This delivery pipeline is used to transfer from U C1 The obtained water flow S W1 Transmit to U PA Preferably,

[0068] in U C2 Downstream, pipeline L S Includes at least two sub-pipelines L W2 and L C2 The at least two sub-pipelines are used to transfer from U C2 The obtained water flow S W2 via L WS2 Transmit to U DP and for concentrating the stream S C2 via L C2 From U C2 Transmit to U DP Regarding pipeline L CPL Preferably, it includes a buffer unit U. BCPL And the delivery pipeline L S Includes buffer unit U BC1 U BC1 Preferably arranged in U C1 Downstream and in U C2 Upstream. More preferably, the integrated polyamide 6 equipment further includes a delivery pipeline L. MPR It is used to transfer from U PA The obtained polyamide material M PR Transmit to U DP .

[0069] According to another aspect, the present invention relates to a method, preferably a method as described above, comprising the steps of: converting polyamide 6 material M, which is obtainable or acquireable by the method described herein. P or materials M that can be obtained or acquired through methods as described herein. PR or the stream S that can be obtained or acquired through the methods described herein. MRAlternatively, product Ω can be obtained from chemical materials that are available or obtainable as described herein. Furthermore, the present invention relates to a method comprising the steps of: obtaining polyamide 6 material M using an integrated polyamide 6 apparatus as described herein. P ; and preferably converting the polyamide 6 material M P To obtain product Ω.

[0070] Preferably, the product Ω is selected from:

[0071] -Building unit or monolith; or

[0072] - Polymer, preferably polymer A; polymer composition, preferably polymer composition A; or polymer product, preferably polymer product A; or

[0073] - Cleaning polymers, cleaning surfactants, descaling compounds, cleaning biocides, or combinations thereof or formulations thereof; or

[0074] -Agricultural chemical compositions, agricultural chemical formulations, adjuvants, or agricultural chemical active ingredients; or

[0075] - Active pharmaceutical ingredient or its intermediate, pharmaceutical excipient, animal feed additive, human food additive, dietary supplement, aromatic chemical or aromatic composition; or

[0076] - Aqueous polymer dispersions, preferably polyurethane or polyurethane-poly(meth)acrylate hybrid polymer dispersions, emulsions, binders for paper and fiber coatings, UV-curable acrylic polymers for hot melts and coatings, polyisocyanates, hyperbranched polyester polyols, polymer dispersants for inorganic binder compositions, unsaturated polyester polyols, or 100% curable compositions; or

[0077] - Cosmetic surfactants, emollients, waxes, cosmetic polymers, UV filters, other cosmetic ingredients, or combinations thereof or formulations thereof; or

[0078] - Polymer B, polymer composition B, coating composition, other functional composition, foil, molded body, coating or coated substrate.

[0079] The preferred method for obtaining product Ω is:

[0080] M in product Ω P and / or M PR and / or S MRThe content of the chemical material is 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

[0081] M in product Ω P and / or M PR and / or S MR The content of the and / or chemical materials is 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; and preferably wherein the content is determined based on identity preservation and / or segregation and / or mass balance and / or book and claim chain of custody models, preferably based on mass balance, preferably according to the International Sustainability and Carbon Certification (ISCC) standard.

[0082] The publicly disclosed prior art content; Issue 684; paragraphs

[1000] to

[8005] ; ISSN: 2198-4786; publication date: February 12, 2024, shall be regarded as reference RF1, which is incorporated herein by reference in its entirety. Preferably, the product Ω is the product as described in paragraphs

[1000] to

[8005] of reference RF1. Preferably, the method described herein is further a method for producing the product.

[0083] The conversion step for obtaining product Ω preferably includes one or more steps as described below, and can be performed by conventional methods well known to those skilled in the art. The conversion step preferably includes one or more steps selected from the following:

[0084] Recycling, preferably depolymerization, gasification, pyrolysis and / or steam cracking; and / or

[0085] Purification, preferably crystallization, (solvent) extraction, distillation, evaporation, hydrogenation, absorption, adsorption, and / or ion exchange; and / or

[0086] Assembling, preferably foaming, synthesis, chemical transformation, chemical conversion, polymerization and / or blending; and / or

[0087] Molding, preferably foaming, extrusion and / or molding; and / or

[0088] Finishing, preferably coating and / or smoothing.

[0089] Furthermore, one or more of these steps are described in detail in paragraphs

[1000] through

[8005] of reference RF1.

[0090] As used in the context of the product Ω herein, the term "building unit" refers to a compound that is in a gaseous or liquid state under standard conditions of 0°C and 0.1 MPa. Building units are typically used in the chemical industry to form secondary products that offer greater structural complexity and / or higher molecular weight than the building unit upon which the secondary product is based. Building units are preferably selected from the group consisting of free hydrogen, carbon monoxide, carbon dioxide, ethylene oxide, ethylene glycol, syngas containing mixtures of hydrogen and carbon monoxide, alkanes, alkenes, alkynes, and aromatic compounds. Alkanes, alkenes, alkynes, and aromatic compounds particularly contain 1 to 12 carbon atoms, respectively.

[0091] As used in the context of the product Ω herein, the term "monomer" includes molecules that can react with each other to form polymer chains by polymerization. Monomers are preferably selected from the group consisting of: (meth)acrylic acid, salts of (meth)acrylic acid; particularly sodium, potassium, and zinc salts; (meth)acrylaldehyde and (meth)acrylates. (Meth)acrylates containing 1 to 22 carbon atoms, particularly 1 to 8 carbon atoms, are preferred. The terms (meth)acrylic acid, (meth)acrylaldehyde, or (meth)acrylate refer to acrylic acid, acrolein, or acrylates, and where applicable, also refer to methacrylic acid, methacrolein, or methacrylates. Furthermore, monomers may be selected from hexamethylenediamine (HMD) and adipic acid.

[0092] The building blocks may further be intermediate compounds. As used in the context of the product Ω herein, the term "intermediate compound" includes organic reagents that are applied to form compounds with higher molecular complexity. Intermediate compounds may, for example, be selected from the group consisting of phosgene, polyisocyanates, and propylene oxide. Polyisocyanates are particularly aromatic diisocyanates and polyisocyanates, preferably toluene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI).

[0093] The building blocks and monomers, as well as the typical transformation steps used to obtain the building blocks or monomers, are described in more detail in paragraphs

[1000] through

[1012] of reference RF1.

[0094] As used in the context of product Ω herein, the term “polymer A” includes thermoplastic plastics (e.g., polyamides or thermoplastic polyurethanes), thermosetting plastics (e.g., polyurethanes), elastomers (e.g., polybutadiene), or copolymers or mixtures thereof, and is defined in more detail in paragraphs

[2001] through

[2007] of reference RF1. As used in the context of product Ω herein, the term “polymer composition A” includes all compositions comprising the polymer as described above and one or more additives (e.g., reinforcing agents, colorants, modifiers, and / or flame retardants), and is defined in more detail in paragraph

[2008] of reference RF1. As used in the context of product Ω herein, the term “polymer product A” includes any product comprising polymer A and / or polymer composition A as described above, and is defined in more detail in paragraphs

[2009] and

[2010] of reference RF1. One or more steps for obtaining a polymer (preferably polymer A), a polymer composition (preferably polymer composition A), or a polymer product (preferably polymer product A) are described in more detail in paragraph

[2011] of reference RF1.

[0095] As used in the context of this product Ω, the term "industrial polymer" includes rheological polymers based on polycarboxylate, alkoxylated polyalkyleneamine, alkoxylated polyalkyleneimide, polyether, dye-inhibiting and dirt-releasing cleaning polymers, as defined in more detail in paragraphs

[3035] through

[3044] of reference RF1. The term "industrial surfactant" as used in the context of this product Ω includes nonionic, anionic, and amphoteric industrial surfactants, as defined in more detail in paragraphs

[3008] through

[3034] of reference RF1. The term "industrial descaling compound" as used in the context of this product Ω includes nonphosphate-based detergent builders (NPB) and phosphonates (CoP), as described in more detail in paragraphs

[3001] through

[3005] of reference RF1. The term "industrial biocide" as used in the context of this product Ω refers to compounds that kill or inhibit the growth or reproduction of microorganisms, as defined in more detail in paragraphs

[3006] through

[3007] of reference RF1. As used in the context of product Ω herein, the term “industrial solvent” includes alkylamides, alkyl lactamides, alkyl esters, lactates, alkyl diesters, cyclic alkyl diesters, cyclic carbonates, aromatic aldehydes, and aromatic esters, as defined in more detail in paragraphs

[3045] through

[3055] of reference RF1. As used in the context of product Ω herein, the term “industrial dispersant” includes anionic and nonionic industrial dispersants, as defined in more detail in paragraphs

[3056] through

[3058] of reference RF1. The term “composition and / or formulation thereof” with respect to industrial polymers, industrial surfactants, scale-removing compounds, and / or industrial biocides refers to industrial compositions and / or institutional products and / or textiles, as defined in more detail in paragraph

[3059] of reference RF1, and to household care products and / or personal care products. The conversion steps used to obtain industrial polymers, industrial surfactants, scale-removing compounds, and / or industrial biocides are defined in more detail in paragraph

[3060] of reference RF1. The conversion steps for obtaining industrial compositions or formulations of industrial polymers, industrial surfactants, scale-removing compounds and / or industrial biocides are defined in more detail in paragraph

[3061] of reference RF1.

[0096] As used in the context of the product Ω herein, the term "agrochemical composition" typically refers to a composition comprising an agrochemical active ingredient and at least one agrochemical formulation adjuvant. Examples of agrochemical compositions, active ingredients, and adjuvants are described in more detail in paragraph

[4001] of reference RF1. Agrochemical compositions may be in any conventional formulation form. These agrochemical compositions are prepared in known ways, for example, as described in: Mollet and Grubemann, Formulation technology, Wiley VCH, Weinheim, 2001; or Knowles, New developments in crop protection product formulation, Agrow Reports DS243, T&F Informa, London, 2005. The conversion steps for obtaining agrochemical active ingredients and adjuvants can be carried out in a manner similar to one or more production steps of their analogues based on petrochemicals or other precursors not obtained through recycling processes. Additionally, the conversion of compounds mentioned in the sections “Polymers” and “Cosmetic Surfactants, Emollients, Waxes, Cosmetic Polymers, UV Filters, Other Cosmetic Ingredients or Compositions thereof” can be carried out as described in those sections and the corresponding paragraphs in reference RF1.

[0097] As used in the context of product Ω herein, the terms active pharmaceutical ingredient and / or intermediate thereof include substances that provide pharmacological activity or other direct effects or influence the structure or any function of the body in the diagnosis, cure, relief, treatment or prevention of a disease. Intermediates are isolated products generated during a multi-step synthetic route of the active pharmaceutical ingredient. As used in the context of product Ω herein, the term pharmaceutical excipient includes compounds or mixtures of compounds used in compositions for various pharmaceutical applications that are substantially non-pharmaceutical in themselves. Active pharmaceutical ingredients and / or intermediates thereof, as well as pharmaceutical excipients, are defined in more detail in paragraph

[5001] of reference RF1. Transformation steps used to obtain active pharmaceutical ingredients and / or intermediates thereof, as well as pharmaceutical excipients, may include one or more synthetic steps and may be performed by conventional synthesis and techniques well known to those skilled in the art.

[0098] As used in the context of the product Ω herein, the terms animal feed additive, human food additive, dietary supplement include vitamins, provitamins and their active metabolites, including intermediates and precursors, especially vitamins A, B, E, D, K and their esters (like acetate, propionate, palmitate) or their alcohols (like retinol) or their salts or any combination thereof; tetraterpenes, especially isoprene-like compounds, like carotenoids and lutein, including their intermediates and precursors and mixtures and derivatives thereof, especially β-carotene, canthaxanthin, hesperidin, astaxanthin, zeaxanthin, lutein, lycopene, apocarotenoids and any combination thereof; Organic acids, especially formic acid, propionic acid and their salts (such as sodium, calcium or ammonium salts) and any combination thereof, such as, but not limited to, formic acid and sodium formate, propionic acid and ammonium propionic acid, formic acid and propionic acid, formic acid and sodium formate, and mixtures of propionic acid, propionic acid and sodium propionic acid and formic acid and sodium formate; glycerides of carboxylic acids and short and medium-chain fatty acids, conjugated linoleic acid (such as omega-6 fatty acid (C18:2) methyl esters) and 1,2-propanediol; and beverage stabilizers such as polyvinylpyrrolidone polymers or polyvinylimazole / polyvinylpyrrolidone copolymers. Animal feed additives, human food additives and dietary supplements are defined in more detail in paragraph

[5002] of reference RF1. The conversion steps used to obtain animal feed additives, human food additives and dietary supplements may include one or more synthetic steps and may be carried out by conventional synthesis and techniques well known to those skilled in the art.

[0099] As used in the context of the product Ω herein, the terms aromatic chemicals and aromatic compositions include volatile organic compounds with a molecular weight between 70 and 250 g / mol, including those with a carbon skeleton of C5-C6. 16 Functional groups of carbon atoms, the carbon skeleton including straight chains, branches, and rings (e.g., rings with a size of C5-C). 18 The aromatic chemicals are bicyclic or tricyclic aliphatic chains, but do not necessarily contain one or more unsaturated structural elements such as double bonds, triple bonds, aromatic or heteroaromatic groups, and preferably, one or more additional functional groups are selected from alcohols, ethers, esters, ketones, aldehydes, acetals, carboxylic acids, nitriles, thiols, and amines. In one aspect, aromatic chemicals are terpenoid-based aromatic chemicals, such as those selected from monoterpenes and monoterpenoids, sesquiterpenes and sesquiterpenoids, diterpenes, triterpenes, or tetraterpenes. Aromatic chemicals can be combined with other aromatic chemicals to obtain aromatic compositions. Aromatic chemicals and aromatic compositions are defined in more detail in paragraph

[5003] of reference RF1. The transformation steps used to obtain aromatic chemicals and aromatic compositions may include one or more synthetic steps and can be carried out by conventional synthesis and techniques well known to those skilled in the art.

[0100] As used in the context of product Ω herein, the term "aqueous polymer dispersion" includes aqueous compositions comprising a dispersed polymer, and is defined in more detail in the section entitled "Aqueous Polymer Dispersions" of reference RF1

[6001] . The dispersed polymer may be selected from acrylic emulsion polymers, styrene acrylic emulsion polymers, styrene butadiene dispersions, aqueous dispersions comprising composite particles, acrylate alkyd hybrid dispersions, polyurethanes (including UV-curable polyurethanes), and polyurethane-poly(meth)acrylate hybrid polymers. As used in the context of product Ω herein, the term "emulsion polymer" includes polymers prepared by free radical emulsion polymerization. Aqueous polyurethane dispersions are defined in more detail in the section entitled "Polyurethane Dispersions" of reference RF1

[6002] . UV-curable polyurethanes are defined in more detail in the section entitled "Polyurethane Dispersions" of reference RF1

[6017] . Polyurethane-poly(meth)acrylate hybrid polymers are defined in more detail in the section entitled "Polyurethane Dispersions" of reference RF1

[6016] .

[0101] As used in the context of product Ω herein, the term “polymer dispersant” preferably includes polymers containing polyether side chains, particularly polycarboxylate ether polymers and condensation products as defined in more detail in the paragraph entitled “Polymer Dispersants” in reference RF1

[6020] .

[0102] The conversion (polymerization) steps used to obtain aqueous polymer dispersions containing emulsion polymers are defined in more detail in the section entitled “Emulsion Polymerization” in reference RF1

[6003] .

[0103] The conversion (polymerization) steps used to obtain the waterborne polyurethane dispersions are defined in more detail in the section entitled “Methods for the preparation of waterborne polyurethane dispersions”

[6014] and the section entitled “UV-curable waterborne polyurethane dispersions, their preparation and uses and compositions containing them”

[6017] of reference RF1.

[0104] The compositions and uses of aqueous polymer dispersions and polymer dispersants are defined in more detail in the following sections of reference RF1:

[0105] The section titled "Applications of Aqueous Polymer Dispersions"

[6004] ,

[0106] The section titled "Adhesives for Building and Construction Coatings"

[6005]

[0107] The section titled "Adhesives for Paper Coatings"

[6006]

[0108] The section titled "Adhesives for Fiber Bonding"

[6007]

[0109] The section titled "Adhesive Polymers and Adhesive Compositions"

[6008]

[0110] The section titled "Aqueous Polyurethane Dispersions Suitable for Coating Compositions"

[6015]

[0111] The section titled "Waterborne polyurethane-poly(meth)acrylate hybrid polymer dispersions suitable for coating compositions"

[6016]

[0112] The section titled "Waterborne UV-curable polyurethane dispersions, their preparation and uses, and compositions containing them"

[6017]

[0113] Section entitled “Inorganic binder compositions containing polymer dispersants and their uses”

[6018]

[6019] 100% curable coating compositions.

[0114] UV-crosslinkable poly(meth)acrylates and their uses are defined in more detail in the section entitled “UV-crosslinkable poly(meth)acrylates for use in UV-curable solvent-free hot melt adhesives and their use in the preparation of pressure-sensitive self-adhesive products” in reference RF1

[6009] .

[0115] Polyisocyanates, compositions comprising them and their uses are defined in more detail in the section entitled “Polyisocyanates” in reference RF1

[6010] .

[0116] Hyperbranched polyester polyols and their uses are defined in more detail in the section entitled "Organic solvent-based hyperbranched polyester polyols suitable for coating compositions" in reference RF1

[6011] . The conversion steps for obtaining hyperbranched polyester polyols are defined in more detail in the section entitled "Preparation of organic solvent-based hyperbranched polyester polyols" in reference RF1

[6012] . Coating compositions comprising hyperbranched polyester polyols, polyisocyanates, and additives, and substrates coated therewith, are defined in more detail in the section entitled "Organic solvent-based two-component coating compositions comprising hyperbranched polyester polyols and polyisocyanates" in reference RF1

[6013] .

[0117] Unsaturated polyester polyols, solvent-based coating compositions comprising said unsaturated polyester polyols, and substrates for coating with said coating compositions are defined in more detail in the section entitled “Organic solvent-based coating compositions comprising unsaturated polyester polyols” in reference RF1

[6018] .

[0118] 100% curable coating compositions are defined in more detail in section

[6019] of reference RF1.

[0119] Polymer dispersants for use in inorganic binder compositions are defined in more detail in section

[6020] of reference RF1. Inorganic binder compositions containing polymer dispersants and their uses are defined in more detail in section

[6021] of reference RF1. The conversion steps for obtaining polymer dispersants are defined in more detail in section

[6020] of reference RF1. The term “inorganic binder composition” containing polymer dispersants, as used in the context of the product Ω herein, preferably includes, in particular, hydraulic coagulating compositions and compositions containing calcium sulfate, and is defined in more detail in section

[6021] of reference RF1 entitled “Inorganic Binder Compositions Containing Polymer Dispersants and Their Uses Therein.” Specific building material formulations containing polymer dispersants or building products produced from building material formulations containing polymer dispersants are disclosed in more detail in section

[6021] of reference RF1.

[0120] The term “cosmetic surfactant” as used in the context of this product Ω includes nonionic, anionic, cationic, and amphoteric surfactants, and is defined in more detail in paragraph

[7002] of reference RF1. The term “emollient” as used in the context of this product Ω means a compound used to protect, moisturize, and / or lubricate the skin, and is defined in more detail in paragraph

[7003] of reference RF1. The term “wax” as used in the context of this product Ω includes pearlescent agents and opacifiers, and is defined in more detail in paragraph

[7004] of reference RF1. The term “cosmetic polymer” as used in the context of this product Ω includes any polymer that can be used as an ingredient in cosmetic formulations, and is defined in more detail in paragraph

[7005] of reference RF1. The term “UV filter” as used in the context of this product Ω means a compound that blocks or absorbs ultraviolet light, and is defined in more detail in paragraph

[7006] of reference RF1. The term “additional cosmetic ingredient” as used in the context of this product Ω includes any ingredient suitable for the preparation of cosmetic formulations. Several sources disclose acceptable ingredients for cosmetics. For example, the Cosing database on the European Commission's website discloses cosmetic ingredients, and the International Dictionary and Handbook of Cosmetic Ingredients, edited by the Personal Care Products Association (PCPC), discloses cosmetic ingredients. The term "compositions and / or formulations thereof" with respect to cosmetic surfactants, emollients, waxes, cosmetic polymers, UV filters and / or other cosmetic ingredients refers to personal care and / or cosmetic compositions or formulations as defined in more detail in paragraph

[7007] of reference RF1. The conversion steps used to obtain cosmetic surfactants, emollients, waxes, cosmetic polymers, UV filters or other cosmetic ingredients are defined in more detail in paragraph

[7008] of reference RF1.

[0121] The terms “polymer B”, “polymer composition B”, “coating composition”, “other functional composition”, “foil”, “molded body”, “coating” and “coated substrate” are well known to those skilled in the art and are defined in more detail from paragraphs

[8000] to

[8005] of reference RF1.

[0122] The invention is further illustrated by the following set of embodiments and combinations of embodiments derived from the dependent relationships and reverse references shown. In particular, it should be noted that in each instance of reference to a series of embodiments, such as in the context of the term "method as described in any one of embodiments 1 to 4," each embodiment in this series is intended to clearly disclose to those skilled in the art that the wording of this term should be understood by those skilled in the art to be synonymous with "method as described in any one of embodiments 1, 2, 3, and 4." Furthermore, it should be clearly noted that the following set of embodiments represents appropriate structural portions of the general description of preferred aspects of the invention and therefore appropriately supports, but does not represent, the claims of the invention.

[0123] 1. An integrated method for preparing polyamide 6, comprising:

[0124] (i) Provide stream S MR The stream contains a solid material M containing polyamide 6. R The solid material M R Includes waste materials;

[0125] (ii) In the depolymerization and purification unit U DP From this stream S MR Preparation of a stream containing purified ε-caprolactam CPL The unit U DP Includes at least one depolymerization subunit U D ;

[0126] (iii) The stream S CPL Transferred to polyamide 6 production unit U PA ;

[0127] (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P And streams containing water and one or more ε-caprolactam oligomers;

[0128] (v) Optionally, the stream containing water and one or more ε-caprolactam oligomers is subjected to concentration with respect to the one or more ε-caprolactam oligomers in at least one concentration stage to obtain a concentrated stream containing water and one or more ε-caprolactam oligomers;

[0129] (vi) Optionally concentrated stream comprising water and one or more ε-caprolactam oligomers is conveyed to the depolymerization subunit U according to (ii). D At least one of them.

[0130] 2. The method as described in Example 1, wherein the optionally concentrated stream comprising water and one or more ε-caprolactam oligomers further comprises ε-caprolactam.

[0131] 3. The method as described in Example 2, wherein the method includes

[0132] (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P He Liu S EW The stream S EW Contains concentration c EW (W) water, concentration c EW (C) ε-caprolactam and total concentration c EW One or more ε-caprolactam oligomers of (O);

[0133] (v) Make the flow S EW It has been concentrated, including

[0134] (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam and total concentration c C1 (O) one or more ε-caprolactam oligomers, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C) and c C1 (O) > c EW (O), and further from U C1 Obtain the concentration c W1 (W) > c EW (W) water's water flow S W1 ;

[0135] (v.2) Make the flow S C1 Second Concentration Unit U C2The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers, wherein c C2 (O) > c C1 (O), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, wherein,

[0136] c W2 (W) > c W1 (W) and c W2 (C) > c W1 (C);

[0137] (vi) Stream S C2 Transmitted to the depolymerization and purification unit U DP middle.

[0138] 4. The method as described in Example 3, wherein the flow S EW Further including total concentration c EW (X) is one or more organic compounds X other than ε-caprolactam and its oligomers, the method comprising:

[0139] (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam, total concentration c C1 (O) one or more ε-caprolactam oligomers and a total concentration of c C1 (X) is one or more organic compounds X, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C), c C1 (O)> c EW (O) and c C1 (X)> c EW (X), and further from U C1 Obtain the concentration c W1 (W) > cEW (W) water's water flow S W1 ;

[0140] (v.2) Make the flow S C1 Second Concentration Unit U C2 The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers and a total concentration of c C2 (X) is one or more organic compounds X, wherein c C2 (O) > c C1 (O) and c C2 (X) > c C1 (X), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, where c W2 (W) > c W1 (W) and c W2 (C) > c W1 (C).

[0141] 5. The method as described in Example 3 or 4, wherein the concentration unit U C1 It includes one or more of the following: a vessel having internal heat exchange, external heat exchange, or both internal and external heat exchange; and a falling film heat exchanger.

[0142] 6. The method as described in any one of Examples 3 to 5, wherein the concentration unit U C2 It includes one or more of the following: a container having internal heat exchange, external heat exchange, or both internal and external heat exchange; and a thin-film evaporator.

[0143] 7. The method as described in any one of Examples 3 to 6, wherein (iv) includes

[0144] (iv.1) The stream S CPL And preferably water-based flow S AQ0 The product is transferred to polymerization stage ST0, from which crude polyamide 6 stream S is obtained. PA1 and water flow S WA1 ;

[0145] (iv.2) The stream S PA1 And preferably water-based flow S AQ1The material is transferred to the granulation stage ST1, from which coarse granular polyamide 6 material M is obtained. PA2 and water flow S WA2 ;

[0146] (iv.3) The material M PA2 And preferably water-based flow S AQ2 The material is transferred to extraction stage ST2, from which purified granular polyamide 6 material M is obtained. PA3 and water flow S WA3 ;

[0147] (iv.4) The material M PA3 The material is transferred to drying stage ST3, from which the polyamide 6 material MP and aqueous flow S are obtained. WA4 ;

[0148] Wherein the stream S EW Includes the stream S WA3 At least a portion of and optionally the stream S WA1 At least a portion of the and the flow S WA2 At least one or more of the following;

[0149] The method preferably further includes taking the stream S obtained from drying according to (iv.4) WA4 At least a portion of it is transferred to the extraction stage according to (iv.3).

[0150] 8. The method as described in Example 7, further comprising, according to (v.1) from U C1 The obtained stream S WA1 Transmitted back to the polyamide 6 production unit U PA .

[0151] 9. The method as described in Example 8, wherein the stream S W1 As these streams S AQ0 S AQ1 and S AQ2 At least a portion of one or more of them is transmitted back to U. PA .

[0152] 10. The method as described in any one of Examples 3 to 9, wherein the depolymerization and purification unit U DP In at least one depolymerization subunit U D Downstream components include a water ion unit U for separating water from ε-caprolactam. P2 The method further includes taking (v.2) from U C2 The obtained stream S W2 Transmit to U P2 .

[0153] 11. The method as described in any one of Examples 3 to 10, wherein the depolymerization and purification unit U DP In at least one depolymerization subunit U D The upstream includes the melting and mixing subunit U. M The method further includes placing the stream S C2 Transmitted to this subunit U M And further includes the flow S MR Transmitted to this subunit U M From U M Get teleported to U D of flow.

[0154] 12. The method as described in any one of Examples 3 to 11, wherein, from the production unit U PA Some of the obtained polyamide 6 material does not meet specifications, and the method further includes transferring at least some of the material to the depolymerization and purification unit U. DP To depolymerize, preferably at least some of the material is transferred to U. M .

[0155] 13. The method as described in any one of Examples 3 to 12, wherein the depolymerization and purification unit U DP in U D Downstream and in U P2 The upstream includes the first purification subunit U P1 And in U P2 The downstream of this includes the third purification stage U P3 The method further includes taking U D The obtained stream is transmitted to U P1 From U P1 Get teleported to U P2 The flow, from U P2 Get teleported to U P3 The flow, from U P3 Obtain the stream S CPL .

[0156] 14. The method as described in any one of Examples 3 to 13, wherein, in U C1 Downstream and in U C2 Upstream of the S stream C1 Transmitted to buffer unit U BC1 And in U DP Downstream and in U PA Upstream of the S stream CPL Transmitted to buffer unit U BCPL .

[0157] 15. The method as described in any one of Examples 3 to 14, further comprising: from UPA The obtained material M P It is supplied as a raw material to polyamide material production unit U TP From this unit U TP M, a polyamide-containing material, was successfully launched into the market. T , wherein, in the material M T Lifespan T MT Subsequently, it was at least partially collected as waste and used as S MR At least a portion of it is transmitted to U DP The material M T Preferably, it is one or more of textile materials and engineering plastic materials, with textile materials being the most preferred.

[0158] 16. An integrated polyamide 6 apparatus for performing the method as described in any one of Examples 1 to 15, the integrated polyamide 6 apparatus comprising a depolymerization and purification unit U DP and polyamide 6 production unit U PA Used to purify ε-caprolactam from U DP Transmit to U PA L delivery pipeline CPL and at least for transferring water-based recirculation flow from U PA Transmit to U DP L delivery pipeline S .

[0159] 17. The integrated polyamide 6 equipment as described in Example 16, wherein the delivery pipeline L S Includes two concentration units U C1 and U C2 U C1 Arranged in U PA Downstream of U C2 Arranged in U C1 Downstream and in U DP Upstream of.

[0160] 18. The integrated polyamide 6 apparatus as described in Example 17, further comprising a U C1 toU PA L delivery pipeline W1 This delivery pipeline is used to transfer from U C1 The obtained water flow S W1 Transmit to U PA .

[0161] 19. The integrated polyamide 6 apparatus as described in Example 17 or 18, wherein, in U C2 Downstream, the pipeline L S Includes at least two sub-pipelines L W2 and L C2The at least two sub-pipelines are used to transfer from U C2 The obtained water flow S W2 via L WS2 Transmit to U DP and for concentrating the stream S C2 via L C2 From U C2 Transmit to U DP .

[0162] 20. The integrated polyamide 6 apparatus as described in any one of Examples 17 to 19, wherein the delivery pipeline L CPL Includes buffer unit U BCPL And the delivery pipeline L S Includes buffer unit U BC1 U BC1 Preferably arranged in U C1 Downstream and in U C2 Upstream of.

[0163] 21. The integrated polyamide 6 apparatus as described in any one of Examples 16 to 20, further comprising a delivery line L MPR This delivery pipeline is used to transfer from U PA The obtained polyamide material M PR Transmit to U DP .

[0164] 22. A method, preferably as described in any one of Examples 1 to 15, comprising the step of: converting a polyamide 6 material M that is obtainable or acquireable by the method described in any one of Examples 1 to 15. P Or, materials M that can be obtained or acquired through the method described in Example 12 PR or the stream S obtained or acquired by the method described in Example 15 MR The product Ω can be obtained by chemical materials that can be obtained or obtained by any of the methods described in Examples 1 to 15.

[0165] 23. A method comprising the step of: obtaining polyamide 6 material M using an integrated polyamide 6 apparatus as described in any one of Examples 16 to 21. P ; and preferably converting the polyamide 6 material M P To obtain product Ω.

[0166] 24. The method as described in Example 22 or 23, wherein the product Ω is selected from:

[0167] -Building unit or monolith; or

[0168] - Polymer, preferably polymer A; polymer composition, preferably polymer composition A; or polymer product, preferably polymer product A; or

[0169] - Cleaning polymers, cleaning surfactants, descaling compounds, cleaning biocides, or combinations thereof or formulations thereof; or

[0170] -Agricultural chemical compositions, agricultural chemical formulations, adjuvants, or agricultural chemical active ingredients; or

[0171] - Active pharmaceutical ingredient or its intermediate, pharmaceutical excipient, animal feed additive, human food additive, dietary supplement, aromatic chemical or aromatic composition; or

[0172] - Aqueous polymer dispersions, preferably polyurethane or polyurethane-poly(meth)acrylate hybrid polymer dispersions, emulsions, binders for paper and fiber coatings, UV-curable acrylic polymers for hot melts and coatings, polyisocyanates, hyperbranched polyester polyols, polymer dispersants for inorganic binder compositions, unsaturated polyester polyols, or 100% curable compositions; or

[0173] - Cosmetic surfactants, emollients, waxes, cosmetic polymers, UV filters, other cosmetic ingredients, or combinations thereof or formulations thereof; or

[0174] - Polymer B, polymer composition B, coating composition, other functional composition, foil, molded body, coating or coated substrate.

[0175] 25. The method as described in any one of Examples 22 to 24,

[0176] Among them, M in product Ω P and / or M PR and / or S MR The content of the chemical material is 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

[0177] Among them, M in product Ω P and / or M PR and / or S MRThe content of the and / or chemical materials is 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; and preferably wherein the content is determined based on a source retention and / or separation and / or quality balance and / or certificate statement chain of custody model, preferably based on quality balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

[0178] According to the present invention, the terms "one or more ε-caprolactam oligomers" and "at least one ε-caprolactam oligomer" preferably refer to at least one of ε-caprolactam dimer, ε-caprolactam trimer, ε-caprolactam tetramer, ε-caprolactam pentamer, ε-caprolactam hexamer and ε-caprolactam heptamer.

[0179] The term "textile materials" encompasses both textile and non-textile raw materials processed into linear, planar, and three-dimensional structures by various methods. It includes linear textile structures produced from them, such as yarns, twisted yarns, and ropes; sheet-like textile structures, such as woven fabrics, knitted fabrics, braids, stitch-knitted fabrics, nonwovens, and felts; and three-dimensional textile structures, i.e., body structures, such as textile hoses, stockings, or textile semi-finished products; and further includes those finished products made from the aforementioned products through assembly, unassembly, and / or other operations to reach a marketable state for forward transfer to processors, traders, or end consumers. The term "textile waste" encompasses textile materials as defined above, whose inherent value has been consumed from the perspective of their current holder, and therefore, is waste material for said holder.

[0180] As used in the context of this product Ω, the term "engineering plastics" refers to a high-performance plastic grade possessing physical properties that enable them to be used long-term in structural applications, over a wide temperature range, under mechanical stress, and in challenging chemical and physical environments, such as those used to manufacture plastic parts that replace traditional engineering materials like metals and ceramics. Engineering plastics are particularly suitable for the manufacture of mechanical parts in several industries such as automotive, medical, electrical and electronics, aerospace, construction, and consumer goods. As used in the context of this product Ω, the term "engineering plastic waste" encompasses engineering plastic materials as defined above, whose inherent value has been consumed from the perspective of their current owner, and therefore, are end-of-life materials for said owner.

[0181] Brief description of the attached figures

[0182] Abbreviation list

[0183] U DP Depolymerization and purification unit for ε-caprolactam

[0184] U D Included in U DP Depolymerization subunits in

[0185] U PA Polyamide 6 production unit for polymerizing polyamide 6 from ε-caprolactam

[0186] U C1 in U PA Downstream and in U C2 upstream concentration unit

[0187] U C2 in U C1 Downstream and in U DP upstream concentration unit

[0188] U BC1 Used for temporary storage of S C1 buffer unit

[0189] U BCPL Used for temporary storage of S CPL buffer unit

[0190] U M Included in U DP In China, in U D upstream melting and mixing subunits

[0191] U P1 Included in U DP In China, in U D Downstream and in U P2 The upstream ε-caprolactam purification subunit

[0192] U P2 Included in U DP The water ion unit used to separate water from ε-caprolactam

[0193] U P3 Included in U DP In China, in U D The downstream ε-caprolactam purification subunit. S CPL From U P3 Obtained

[0194] U TP in U PA Downstream materials containing polyamide 6 M T Production Unit

[0195] S MR Includes solid material M R flow

[0196] S CPL From UDP The obtained stream contained purified ε-caprolactam

[0197] S from U PA The obtained stream contains water and one or more ε-caprolactam oligomers

[0198] S EW From U PA The obtained stream comprises water, ε-caprolactam, one or more ε-caprolactam oligomers, and optionally one or more organic compounds X other than ε-caprolactam and its oligomers.

[0199] S C1 From U C1 Based on S EW The obtained concentrated stream contains water and one or more ε-caprolactam oligomers.

[0200] S C2 From U C2 Based on S C1 The obtained concentrated stream contains water and one or more ε-caprolactam oligomers.

[0201] S W1 Except S C1 From U C1 The obtained water flow

[0202] S W2 Except S C2 From U C2 The obtained water flow

[0203] S PA1 crude ε-caprolactam product stream obtained from stage ST0

[0204] S PA2 crude ε-caprolactam product stream obtained from stage ST1

[0205] S PA3 crude ε-caprolactam product stream obtained from stage ST2

[0206] S WA1 The aqueous flow obtained from stage ST0 can optionally be S EW Part of

[0207] S WA2 The aqueous flow obtained from stage ST1 can optionally be S EW Part of

[0208] S WA3 The aqueous flow obtained from stage ST2 is preferably S. EW at least part of

[0209] S WA4The aqueous flow obtained from stage ST3 is preferably transported back to stage ST2.

[0210] S AQ0 The source S is to be transferred to stage ST0. W1 Water flow

[0211] S AQ1 The source S is to be transferred to stage ST1. W1 Water flow

[0212] S AQ2 The source S is to be transferred to stage ST2. W1 Water flow

[0213] S WM To be transmitted to U M The supplementary water flow

[0214] S WR U obtained from the purification stage DP - Internal water recirculation flow, which is recirculated to U M

[0215] S CPLO From U DP Other sources to U PA ε-caprolactam feed stream

[0216] ST0 in U PA The ε-caprolactam polymerization stage is carried out.

[0217] ST1 in U PA The ε-caprolactam granulation stage downstream of STO

[0218] ST2 in U PA The ε-caprolactam extraction stage downstream of ST1

[0219] ST3 in U PA The ε-caprolactam drying stage occurs downstream of ST1. M P Preferably obtained from ST3

[0220] M R Solid materials containing polyamide 6, which are contained in flow S MR middle

[0221] M P From U PA The obtained polyamide 6 material

[0222] M PR From U PA Obtained substandard polyamide 6 material

[0223] M T From UTP The obtained material containing polyamide 6

[0224] T MT Material M containing polyamide 6 T lifespan

[0225] Figure 1 A method according to the present invention is shown. According to this method, a mixture containing solid material M... R The flow S MR (It further includes polyamide 6) and is then conveyed to the depolymerization and purification unit U. DP In this process, the depolymerization and purification unit includes a depolymerization subunit U. D Preferably, the solid material comprises waste, more preferably one or more of textile waste and engineering plastic waste, and more preferably textile waste. In U D Upstream of S MR It can be transferred to one or more other suitable preprocessing stages indicated by the dashed arrows. In U D In, it occurs within material M R The depolymerization of polyamide 6 in U, and from U D Obtain the corresponding stream, and then transmit it further via U. DP (As indicated by the dashed arrow), a purified ε-caprolactam stream S is produced. CPL It is then transported as a raw material to the polyamide 6 production unit U. PA In this polyamide 6 production unit, S is included CPL ε-caprolactam in the polymer is appropriately polymerized to obtain polyamide 6 material M. P , take it from U PA Removed from U. PA A stream S containing at least water and one or more ε-caprolactam oligomers is obtained. This stream S is appropriately fed back to the depolymerization and purification unit U. DP This achieves an integrated depolymerization-polymerization process.

[0226] Figure 2 The method according to the invention is illustrated. Further according to... Figure 1 The method shown includes a concentration unit U C1 and U C2 The two concentration stages are carried out. From U PA Get stream S EW That is, a stream containing at least water and one or more ε-caprolactam oligomers (see according to Figure 1 The stream (S) is then transported to the concentration unit U. C1 In this concentration unit, it is concentrated at least with respect to one or more ε-caprolactam oligomers to give a (concentrated) stream S C1 Among them, in UC1 During the concentration process, water is separated and used as an aqueous stream S W1 Obtain. Then obtain the stream S. C1 Transmitted to concentration unit U C2 In this concentration unit, it is further concentrated, at least with respect to one or more ε-caprolactam oligomers, to give a corresponding concentrated stream S. C2 . in U C2 During the concentration process, water is separated and used as an aqueous stream S W2 Obtain. Concentrated Stream S C2 It is properly transferred back to the depolymerization and purification unit U. DP This achieves an integrated depolymerization-polymerization process.

[0227] Figure 3 The method according to the invention is illustrated. Further according to... Figure 2 The method shown illustrates two other preferred integrated methods. First, the concentrate unit U... C1 The obtained water flow S W1 Properly transmit back to U PA As in U PA The feed stream is carried out in one or more stages. Next, it will be drawn from the concentration unit U. C1 The obtained water flow S W1 Appropriately fed as a feedstock to purification unit U P2 That is, including U DP The water ion unit, which is used to separate water from the crude ε-caprolactam stream and is located in the depolymerization subunit U D Downstream of.

[0228] Figure 4 The method according to the invention is illustrated. Further according to... Figure 3 The method shown illustrates the process of polyamide 6 production unit U. PA The preferred configuration. According to this preferred design, the depolymerization and purification unit U... DP The purified ε-caprolactam stream S obtained CPL Transmit to U PA The ε-caprolactam polymerization stage ST0 is then performed. The product stream containing polyamide 6 is then flowed into S... PA1 Appropriately transferred to the ε-caprolactam granulation stage S T1 Then, for the purpose of purifying polyamide 6, the correspondingly obtained particulate stream S... PA2 Appropriately transferred to the ε-caprolactam extraction stage S T2 Then the corresponding purified particle stream S is obtained. PA3 Properly transfer to the ε-caprolactam drying stage S T3The ε-caprolactam drying stage includes one or more suitable drying sub-stages from which polyamide 6 material M is obtained. P The corresponding aqueous flow (S) is obtained from at least one of stages ST0, ST1, and ST2, preferably from at least two of these stages, and more preferably from each of these stages. WA1 S WA2 S WA3 At least the flow S WA3 Optionally (as indicated by the dashed arrow) with S WA1 and / or S WA2 At least a portion of them together as flow S EW At least in part from U PA Removed from the middle. Furthermore, it will be done through U... C1 Medium Concentration Flow S EW The obtained water flow S W1 As one or more raw material streams, it is sent back to U. PA The first part can be transferred to stage S. T0 In the middle, the second part can be transferred to stage S. T1 In the middle, and the third part can be transferred to stage S. T3 Furthermore, a method design is preferred, according to which the process from the drying stage S is designed... T3 Obtain water flow S WA4 Among them, the water-borne SW A4 Transmitted back to extraction stage S T2 .

[0229] Figure 5 The method according to the invention is illustrated. Further according to... Figure 3 and Figure 4 The method shown (U) PA The preferred design was not included Figure 5 (As shown in the diagram), this method illustrates a further preferred design, according to which there are two buffer units, one of which is used to properly buffer the airflow from U. DP toU PA The flow S CPL Supply (buffer unit U) BCPL A buffer unit is used to properly buffer the energy from the concentration unit U. C1 To the concentration unit U C2 The flow S C1 Supply (buffer unit U) BC1 ).

[0230] Figure 6 The method according to the invention is illustrated. Further according to... Figure 3 , Figure 4 (U) PA The preferred design was not included Figure 6 (shown in the image) and Figure 5 The method shown illustrates the depolymerization and purification unit U DP The preferred settings. Based on these settings, the flow S... MR and at least regarding the concentration of one or more ε-caprolactam oligomers, the flow S C2 Both are appropriately transferred to the melting and mixing subunit U. M In this melting and mixing subunit, a suitable depolymerization subunit U for downstream (preferably hydrolysis) is prepared. D The raw material flow. In U D Downstream, the first purification subunit U was installed. P1 The first purification subunit preferably includes at least one or more of a water separation stage and a high-boiling-point separation stage (for organic compounds having a boiling point higher than ε-caprolactam). The corresponding purified ε-caprolactam stream is then transferred from U... P1 Transmitted to the second purification subunit U P2 , such as in Figure 3 As described in the context, the aqueous stream SW2 is also delivered to the second purification subunit, which preferably contains (unpolymerized) ε-caprolactam in addition to water, and the (unpolymerized) ε-caprolactam is contained in stream S EW In U C1 From S EW Separate from and included in S C1 In China, and further in U C2 From S C1 Separation was performed. The obtained crude ε-caprolactam was then separated from the second purified subunit U. P2 Transmitted to the third purification subunit U P3 The third purification subunit preferably includes one or more of a distillation stage and a crystallization stage, wherein from U P3 Obtain purified stream S CPL Then transmit it to U PA .

[0231] Figure 7 The method according to the invention is illustrated. Further according to... Figure 6 The method shown includes the use of polyamide 6 material M PR The recirculation pipelines, these polyamide 6 materials M PR From U PA The material is obtained, and for example, does not undergo further processing into other valuable products because it does not meet one or more desired specifications. According to the integrated method of the invention, this material M... PR Send back to U DP Preferably, it is transferred back to the mixing and melting subunit U. MIn this mixing and melting subunit, it is appropriately prepared for transfer to the depolymerization subunit U. D It is part of the raw material flow.

[0232] Figure 8 This demonstrates how the method according to the invention forms the core of a highly advantageous recycling loop for materials containing polyamide 6. In particular, Figure 8 It shows that it will be from U PA The obtained polyamide 6 material M P Transmitted to Unit U TP In this unit, material M containing polyamide 6 is produced. T Then this material M T After its lifespan, it is properly collected and then appropriately used as raw material (as flow S). MR The components are delivered to the integrated depolymerization-polymerization process of the present invention.

[0233] Figure 9 Further optional and advantageous aspects of the method of the present invention are shown. Regarding unit U... DP In other words, two Us are shown DP Internal recirculation flow, particularly from one or more purification stages, especially in U P1 and U P2 The purification stage yielded two aqueous recirculating streams S WR Furthermore, flow S is shown. WM The stream was transmitted to U DP Especially U M S WM This is a water replenishment flow used to compensate for any water loss that is unavoidable during the implementation of the method of the present invention, despite all integrated measures including water recirculation. Furthermore, flow S is shown. CPL0 It is to be transmitted to U PA The ε-caprolactam feedstock stream, and it can be used as S CPL It can be used as a supplement and can have any properties, whether it comes from another waste depolymerization process, from a conventional source, or from a bio-based process, including, for example, artificial enzyme catalytic cascades.

Claims

1. An integrated method for preparing polyamide 6, comprising: (i) providing a stream S MR comprising a solid material M containing polyamide 6 R wherein the solid material M R comprises waste material; (ii) In the depolymerization and purification unit U DP From this stream S MR Preparation of a stream containing purified ε-caprolactam CPL The unit U DP Includes at least one depolymerization subunit U D ; (iii) The stream S CPL Transferred to polyamide 6 production unit U PA ; (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P And streams containing water and one or more ε-caprolactam oligomers; (v) Optionally, the stream containing water and one or more ε-caprolactam oligomers is subjected to concentration with respect to the one or more ε-caprolactam oligomers in at least one concentration stage to obtain a concentrated stream containing water and one or more ε-caprolactam oligomers; (vi) Optionally concentrated stream comprising water and one or more ε-caprolactam oligomers is conveyed to the depolymerization subunit U according to (ii). D At least one of them.

2. The method as described in claim 1, wherein, The optionally concentrated stream, comprising water and one or more ε-caprolactam oligomers, further comprises ε-caprolactam.

3. The method as described in claim 2, wherein, The method includes (iv) In U PA The middle makes this flow S CPL Exposed to ε-caprolactam polymerization conditions, from U PA Obtain polyamide 6 material M P He Liu S EW The S stream EW Contains concentration c EW (W) water, concentration c EW (C) ε-caprolactam and total concentration c EW One or more ε-caprolactam oligomers of (O); (v) Make the flow S EW It has been concentrated, including (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam and total concentration c C1 (O) one or more ε-caprolactam oligomers, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C) and c C1 (O) > c EW (O), and further from U C1 Obtain the concentration c W1 (W) > c EW (W) water's water flow S W1 ; (v.2) Make the flow S C1 Second Concentration Unit U C2 The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers, wherein c C2 (O) > c C1 (O), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, where c W2 (W) > c W1 (W) and c W2 (C) > c W1 (C); (vi) Stream S C2 Transmitted to the depolymerization and purification unit U DP middle.

4. The method of claim 3, wherein, The stream S EW Further including total concentration c EW (X) is one or more organic compounds X other than ε-caprolactam and its oligomers, the method comprising: (v.1) Make the flow S EW First Concentration Unit U C1 The medium undergoes concentration, from U C1 Obtain concentrated stream S C1 The concentrated stream S C1 Contains concentration c C1 (W) water, concentration c C1 (C) ε-caprolactam, total concentration c C1 (O) one or more ε-caprolactam oligomers and a total concentration of c C1 (X) is one or more organic compounds X, wherein c C1 (W) < c EW (W), c C1 (C) > c EW (C), c C1 (O)>c EW (O) and c C1 (X)> c EW (X), and further from U C1 Obtain the concentration c W1 (W) > c EW (W) water's water flow S W1 ; (v.2) Make the flow S C1 Second Concentration Unit U C2 The medium undergoes concentration, from U C2 Obtain concentrated stream S C2 The concentrated stream S C2 Including total concentration c C2 (O) one or more ε-caprolactam oligomers and a total concentration of c C2 (X) is one or more organic compounds X, wherein c C2 (O) > c C1 (O) and c C2 (X) > c C1 (X), and further from U C2 Obtain water flow S W2 The water flow S W2 Contains concentration c W2 (W) water and concentration c W2 (C) ε-caprolactam, where c W2 (W) > c W1 (W) and c W2 (C) > c W1 (C); The concentration unit U C1 Preferably, it includes one or more of the following: a container having internal heat exchange, external heat exchange, or both internal heat exchange and external heat exchange; and a falling film heat exchanger; and wherein the concentration unit U C2 Preferably, it includes one or more of the following: a container having internal heat exchange, external heat exchange, or both internal and external heat exchange; and a thin-film evaporator.

5. The method as described in claim 3 or 4, wherein, (iv) Including (iv.1) The stream S CPL And preferably water-based flow S AQ0 The product is transferred to polymerization stage ST0, from which crude polyamide 6 stream S is obtained. PA1 and water flow S WA1 ; ( iv.2) This stream S PA1 And preferably water-based flow S AQ1 The material is transferred to the granulation stage ST1, from which coarse granular polyamide 6 material M is obtained. PA2 and water flow S WA2 ; ( iv.3) The material M PA2 And preferably water-based flow S AQ2 The material is transferred to extraction stage ST2, from which purified granular polyamide 6 material M is obtained. PA3 and water flow S WA3 ; ( iv.4) The material M PA3 The material is transferred to drying stage ST3, from which the polyamide 6 material MP and aqueous flow S are obtained. WA4 ; Wherein the stream S EW Includes the stream S WA3 At least a portion of and optionally the stream S WA1 At least a portion of the and the flow S WA2 At least one or more of the following; The method more preferably further includes taking the stream S obtained from drying according to (iv.4) WA4 At least a portion of it is transferred to the extraction stage according to (iv.3).

6. The method of claim 5, further comprising taking from U according to (v.1) C1 The obtained stream S W1 Transmitted back to the polyamide 6 production unit U PA Preferably, the stream S W1 As these streams S AQ0 S AQ1 and S AQ2 One or more of them, at least a portion, are transmitted back to U. PA .

7. The method according to any one of claims 1 to 6, wherein, The depolymerization and purification unit U DP Includes mixing and melting subunits U M An aqueous depolymerization mixture is prepared in the mixing and melting subunit, and the aqueous depolymerization mixture is then conveyed to the depolymerization subunit U. D .

8. The method according to any one of claims 3 to 7, wherein, The depolymerization and purification unit U DP In at least one depolymerization subunit U D Downstream components include a water ion unit U for separating water from ε-caprolactam. P2 The method further includes taking (v.2) from U C2 The obtained stream S W2 Transmit to U P2 .

9. The method according to any one of claims 3 to 8, wherein, The depolymerization and purification unit U DP In at least one depolymerization subunit U D The upstream includes the melting and mixing subunit U. M The method further includes placing the stream S C2 Transmitted to this subunit U M And further includes the flow S MR Transmitted to this subunit U M From U M Get teleported to U D of flow.

10. The method according to any one of claims 3 to 9, wherein, From this production unit U PA Some of the obtained polyamide 6 material does not meet specifications, and the method further includes transferring at least some of the material to the depolymerization and purification unit U. DP To depolymerize, preferably at least some of the material is transferred to U. M .

11. The method according to any one of claims 3 to 10, wherein, The depolymerization and purification unit U DP in U D Downstream and in U P2 The upstream includes the first purification subunit U P1 And in U P2 The downstream of this includes the third purification stage U P3 The method further includes taking U D The obtained stream is transmitted to U P1 From U P1 Get teleported to U P2 The flow, from U P2 Get teleported to U P3 The flow, from U P3 Obtain the stream S CPL .

12. The method according to any one of claims 3 to 11, wherein, in U C1 Downstream and in U C2 Upstream of the S stream C1 Transmitted to buffer unit U BC1 And in U DP Downstream and in U PA Upstream of the S stream CPL Transmitted to buffer unit U BCPL .

13. The method of any one of claims 1 to 12, further comprising transferring from U PA The obtained material M P It is supplied as a raw material to polyamide material production unit U TP From this unit U TP M, a polyamide-containing material, was successfully launched into the market. T ,in, In the material M T Lifespan T MT Subsequently, it was at least partially collected as waste and used as S MR At least a portion of it is transmitted to U DP The material M T Preferably, it is one or more of textile materials and engineering plastic materials, with textile materials being the most preferred.

14. An integrated polyamide 6 apparatus for performing the method as described in any one of claims 1 to 13, the integrated polyamide 6 apparatus comprising a depolymerization and purification unit U DP and polyamide 6 production unit U PA Used to purify ε-caprolactam from U DP Transmit to U PA delivery pipeline L CPL and at least for transferring water-based recirculation flow from U PA Transmit to U DP delivery pipeline L S ; The delivery pipeline L S Includes two concentration units U C1 and U C2 U C1 Arranged in U PA Downstream of U C2 Arranged in U C1 Downstream and in U DP Upstream of the integrated polyamide 6 device, more preferably, it further includes a U C1 to U PA delivery pipeline L W1 The delivery pipeline L W1 Used to transfer from U C1 The obtained water flow S W1 Transmit to U PA Among them, in U C2 Downstream, the pipeline L S More preferably, it includes at least two sub-pipelines L W2 and L C2 The at least two sub-pipelines are used to transfer from U C2 The obtained water flow S W2 via L WS2 Transmit to U DP and for concentrating the stream S C2 via L C2 From U C2 Transmit to U DP ; More preferably, the delivery pipeline L CPL Includes buffer unit U BCPL And the delivery pipeline L S Includes buffer unit U BC1 U BC1 Preferably arranged in U C1 Downstream and in U C2 Upstream; The integrated polyamide 6 equipment preferably further includes a delivery pipeline L. MPR The delivery pipeline L MPR Used to transfer from U PA The obtained polyamide material M PR Transmit to U DP .

15. A method, preferably the method of any one of claims 1 to 13, comprising the following steps: The conversion of polyamide 6 material M, which can be obtained by the method described in any one of claims 1 to 13, is also possible. P or the material M that can be obtained or acquired by the method as described in claim 10. PR or the stream S that can be obtained or acquired through the method as described in claim 13. MR Or, a chemical material that can be obtained or acquired by the method of any one of claims 1 to 13, to obtain product Ω; and / or a method comprising the step of: obtaining polyamide 6 material M using the integrated polyamide 6 apparatus as described in claim 14. P ; and preferably converting the polyamide 6 material M P To obtain product Ω.

Images