Method for extracting at least one polyol from the polyol phase of a polyurethane hydroalcoholysis

Abstract

The invention relates to a method comprising the extraction of a polyol from a polyol phase, wherein the polyol phase has been obtained through a recycling process (A) comprising a hydroalcoholysis (A.1) of a polyurethane product and a workup of the chemolysis product obtained in the process, with separation of an amine phase from said chemolysis product (A.2), wherein the method comprises: reacting (α.1) the polyol phase with an aqueous hydrolysis reagent in the presence of a urethane preparation to obtain a product mixture comprising at least one polyol depleted of the carbamate, and working up (α.2) the product mixture to extract the at least one polyol depleted of the carbamate.

Description

[0001] 2024PF30148 - Abroad

[0002] - 1 -

[0003] METHOD FOR RECOVERING AT LEAST ONE POLYOL FROM THE POLYOL PHASE OF A POLYURETHANE HYDROALCOHOLYSE

[0004] The present invention relates to a process comprising the recovery of a polyol from a polyol phase, wherein the polyol phase was obtained by a recycling process (A) comprising hydroalcohollysis (Al) of a polyurethane product and work-up of the chemolysis product obtained thereby by separating an amine phase from the same (A.2), wherein the process comprises: reacting (al) the polyol phase with an aqueous hydrolysis reagent in the presence of a urethanase preparation to obtain a product mixture comprising at least one carbamate-depleted polyol and work-up (a.2) of the product mixture to obtain the at least one carbamate-depleted polyol.

[0005] Polyurethane products, especially polyurethane foams, have a wide range of applications in industry and everyday life. Polyurethane foams are typically divided into rigid and flexible foams. All polyurethane products share the basic polyurethane structure, which is formed by the polyaddition reaction of a polyhydric isocyanate and a polyol. For example, a polyurethane based on a diisocyanate O=C=NRN=C=O and a diol HO-R'-OH (where R and R' denote organic groups) can be described as follows:

[0006] - [O-R'-O-(O=C)-HN-R-NH-(C=O)] - can be represented.

[0007] Precisely because of the great economic success of polyurethane products, large quantities of polyurethane waste (e.g., from old mattresses or seating furniture) are generated, which must be put to good use. The technically simplest method of reuse is incineration, utilizing the heat released for other processes, such as industrial manufacturing. However, this method does not allow for closing the material cycle. Another type of reuse is so-called "physical recycling," in which polyurethane waste is mechanically shredded and used in the production of new products. This type of recycling naturally has its limitations, which is why there has been no shortage of attempts to recover the raw materials underlying polyurethane production through chemical cleavage of the urethane bonds ("chemolysis") (so-called "chemical recycling").The recovered starting materials primarily consist of polyols (in the example above, HO-R'-OH). In addition, amines (in the example above, H₂N-R-NH₂) can also be obtained by hydrolytic cleavage of the urethane bond. These amines can be phosgenated after processing to isocyanates (in the example above, to O=C=NRN=C=O). A summary of polyurethane recycling processes known up to the end of 2017 is provided in the review article by Simon, Borreguero, Lucas, and Rodriguez in Waste Management 2024PF30148 - International.

[0008] - 2 -

[0009] 2018, 76, 147 - 171 [1], Glycolysis is highlighted there as being particularly important (see No. 2 below).

[0010] Various approaches to chemical recycling have been developed in the past. Five of them are briefly summarized below:

[0011] 1. Hydrolysis of urethanes by reaction with water to obtain amines and polyols with the formation of carbon dioxide.

[0012] 2. Glycolysis (alcohollysis) of urethanes by reaction with alcohols, whereby the polyols incorporated into the urethane groups are replaced by the alcohol used and thus released. This process is usually referred to in the literature as transesterification (more precisely: transurethanization). This type of chemical recycling is commonly referred to as glycolysis in the literature, regardless of the specific type of alcohol used, although this term is actually only applicable to glycols, and one should therefore speak more generally of alcoholysis. After separation into a polyol-rich and a carbamate-rich phase, the carbamate-rich phase can be hydrolyzed to obtain amines, for which chemical (see, e.g., WO 2020 / 260387 Al and WO 2022 / 063764 Al) or enzymatic (WO 2021 / 032513 Al) catalysts are generally used. If, on the other hand, the unchanged product mixture of alcoholysis (i.e.,(without prior separation of the polyols formed) hydrolyzes, this is called a hydrolysis.

[0013] 3. Hydroglycolysis (hydroalcohollysis) of urethane bonds. It is also possible, of course, to add alcohol and water from the beginning, in which case the hydrolysis and glycolysis processes described above occur in parallel.

[0014] 4. Aminolysis of urethane bonds by reaction with primary or secondary amines, whereby the polyols incorporated into the urethane groups can be replaced by the amine used and thus released. In this case, the urethane groups are converted to urea groups. Similarly, the R-NH (C=O) bonds in the urethanes can also be cleaved, and the R-NH groups replaced by the amine used in the aminolysis, releasing the amine R-NH₂ corresponding to the originally used isocyanate. If amino acids with primary or secondary amino groups are used, the alcohol groups of the amino alcohol used can also react with urethane bonds, potentially leading to the formation of carbamates. According to most of the prior art, aminolysis can be followed by hydrolysis in a separate step.

[0015] 5. A reaction procedure corresponding to hydroglycolysis, in which amines or amino alcohols and water are used as reagents, without prior separation of the released polyols, is described in WO 2023 / 083968 Al and referred to there as aminohydrolysis. 2024PF30148 - Foreign

[0016] - 3 -

[0017] Few of the chemical recycling processes described in the literature are permanently operated on an industrial scale; many have not even reached the pilot stage [1]. Given the generally increased environmental awareness and the growing efforts to make industrial processes as sustainable as possible – both of which fundamentally support chemical recycling – this clearly demonstrates that the chemical recycling of polyurethane products is far from being technically and economically mature. Challenges exist, in particular, regarding the purity of the recovered products. In general, the known recycling processes include processing steps that yield a first polyol-rich phase (polyol phase) and a second carbamate-, urea-, and / or amine-rich phase, for example, through phase separation steps, possibly in conjunction with extraction steps.A recurring problem here is providing the obtained phases with as little contamination as possible from the other target product, which can be challenging due to the prevailing solubility equilibria. Particularly in alcoholysis processes (see No. 2 above), there is a risk of contamination of the crude polyol phase with carbamates, which are more difficult to separate than the corresponding amines.

[0018] WO 2020 / 260387 Al describes a process for recovering raw materials from polyurethane products comprising the steps (A) providing a polyurethane product based on an isocyanate and a polyol; (B) reacting the polyurethane product with a (mono- or polyhydric) alcohol in the presence of a catalyst, obtaining a first product mixture; (C) recovering polyols from the first product mixture, comprising (Cl) mixing the first product mixture obtained in step (B), without prior separation of any water present in the first product mixture, with an organic solvent that is not completely miscible with the alcohol used in step (B), and phase separation into a first alcohol phase and a first solvent phase; (C.(ll) Work up the first solvent phase to obtain polyols; and preferably (D) obtain amines by hydrolytic cleavage of the carbamates contained in the first alcohol phase. The crude polyol obtained in the example still contains a total of 2.5 wt% of TDA and carbamates.

[0019] WO 2022 / 063764 Al describes a process for recovering polyols and optionally amines from polyurethane products, comprising the steps of: (A) providing a polyurethane product based on an isocyanate component and a polyol component; (B) reacting the polyurethane product with an alcohol in the presence of a catalyst, yielding a first product mixture containing alcohol, polyols, and carbamates, and optionally water; (C) working up the first product mixture, comprising: (C1) mixing the first product mixture obtained in step (B) with an organic solvent miscible with the alcohol used in step (B), optionally followed by separation of solid components, to obtain a second product mixture; (C1) washing the product mixture obtained in step (C2). 2024PF30148 - Foreign

[0020] - 4 - second product mixture with an aqueous washing liquid, wherein carbamates contained in the second product mixture are partially hydrolyzed with the release of amines and alcohol, and phase separation into a first solvent phase containing the organic solvent used in step (Cl) and polyols, and a first aqueous phase containing water, alcohol, carbamates, and amines; and (C.11) work-up of the first solvent phase to recover the polyols; and optionally (D) work-up of the first aqueous phase to recover an amine corresponding to an isocyanate of the isocyanate component. The polyol phase obtained in the example (“first solvent phase”) contains a total of 1.5 wt% of TDA and carbamates. If the easily separable components solvent and chemolysis alcohol are excluded, the proportion is even 5.9 wt%.

[0021] WO 2021 / 032513 Al describes a process for degrading polyurethanes composed of polyether polyols and aromatic isocyanates to polyether polyols and aromatic amines. The process comprises the steps a) urethanization of a polyether polyol polyurethane with at least one low molecular weight alcohol having at least two hydroxyl groups per molecule and a molecular weight of not more than 500 g / mol, yielding polyether polyols and low molecular weight urethanes; and b) enzymatic cleavage of the low molecular weight urethanes produced in process step a), releasing at least one amine and the at least one low molecular weight alcohol used in process step a). The example section describes a chemically catalyzed alcoholysis of a polyurethane product based on a polyether polyol with spontaneous phase separation (so-called urethane separation).Split-phase glycolysis is described as a process consisting of an upper polyol phase and a lower phase containing the majority of the chemolysis alcohol as well as carbamates formed by urethanization. After phase separation, the lower phase is subjected to an enzymatic reaction to cleave the carbamates, releasing toluenediamine. No information is provided regarding the carbamate / amine content of the upper polyol phase or its workup.

[0022] WO 2022 / 171586 Al (also published as US 2024 / 117144 Al) describes a process for recovering raw materials (i.e., polyols and optionally amines) from polyurethane foams by chemolysis. The chemolysis is characterized by the reaction of a polyurethane foam with an alcohol and water in the presence of a catalyst at a temperature in the range of 130 °C to 195 °C, wherein the mass ratio of (total) alcohol and (total) water to the polyurethane foam is in the range of 0.5 to 2.5, and the mass of water is 4.0% to 10% of the mass of alcohol. The catalyst comprises a metal salt selected from a carbonate, a hydrogen carbonate, an orthophosphate, a monohydrogen orthophosphate, a metaphosphate, or a mixture of two or more of the aforementioned metal salts.Initially, only the alcohol and catalyst can be mixed with the polyurethane foam, while the water is gradually added only after the polyurethane foam has dissolved. It is also possible to use 2024PF30148 - Abroad.

[0023] - 5 - At the beginning of the chemolysis, add some of the water along with the alcohol and the catalyst, and gradually add the remaining amount of water after the polyurethane foam has dissolved. Regardless of the specific variant, the procedure described here corresponds to hydroalcohollysis (see No. 3 above).

[0024] WO 2023 / 194440 A1 describes a process for the degradation of polyester polyurethanes into low-molecular-weight degradation products comprising the steps of: a) cleavage of the ester groups contained in the polyester polyurethane; and b) treatment of the polyurethane with a polypeptide exhibiting urethanase activity and selected from the group consisting of polypeptides as defined therein by SEQ ID No. 1, 2, and 3, and variants of these polypeptides, wherein the variants are obtained by the addition, deletion, or substitution of up to 15% of the amino acids contained in the respective polypeptide defined by SEQ ID No. 1, 2, or 3; with the proviso that process steps a) and b) may be carried out in any order or simultaneously.WO 2023 / 194440 Al further describes a process comprising the steps a) the urethanization of a polyether polyol polyurethane with at least one low molecular weight alcohol, yielding polyether polyols and low molecular weight urethanes; and b) the enzymatic cleavage of the low molecular weight urethanes obtained in process step a) with a polypeptide exhibiting urethanase activity and selected from the group consisting of polypeptides as defined by SEQ ID NO.: 1, 2 and 3 and variants of these polypeptides, wherein the variants are obtained by the addition, deletion or exchange of up to 15% of the amino acids contained in the respective polypeptide defined by SEQ ID NO.: 1, 2 or 3.

[0025] WO 2023 / 099420 A1 describes a process for recovering at least one raw material from a polyurethane product, comprising the steps (A) providing a polyurethane product based on an isocyanate component and a polyol component, wherein the isocyanate component comprises only such isocyanates whose corresponding amines have a boiling point at 1013 mbar( a (bs.) of a maximum of 410 °C, preferably in the range of 170 °C to 400 °C; (B) Chemolysis of the polyurethane product with an alcohol and water (= hydroalcohollysis); (C) Work-up of the product of the chemolysis, comprising (Cl) extraction with an organic solvent whose boiling point is at 1013 mbar( abs.) in the range of 40 °C to 120 °C, at a temperature in the range of 10 °C to 60 °C, followed by (C.II) phase separation into a first product phase and a second product phase and (D) work-up of the first product phase to obtain the polyol, comprising (DI) separation of organic solvent by distillation and / or stripping and (DI I) separation of amine dissolved in the first product phase by distillation to obtain the polyol.

[0026] WO 2024 / 170559 Al describes a process for the chemolysis of a urethane (especially polyurethane) based on an isocyanate component and an alcohol component by reaction with a chemolysis alcohol to form a carbamate 2024PF30148 - Foreign

[0027] - 6 - of an isocyanate of the isocyanate component and the chemolysis alcohol, in particular for the purpose of obtaining starting materials for the manufacture of chemical products, wherein the chemolysis of the urethane with the chemolysis alcohol is carried out in the absence of a chemolysis catalyst at a temperature in the range of 185 °C to 245 °C and the chemolysis alcohol is selected from unbranched monoalcohols having 1 to 4 carbon atoms, wherein a mass ratio of the chemolysis alcohol to the urethane of 1.0 to 4.5 is set.

[0028] In one approach to the work-up of the chemolysis product, the carbamate formed is separated by extraction with an organic solvent, optionally with the addition of water, and / or by solid-liquid phase separation, yielding a liquid alcohol phase (especially a polyol phase) in addition to the carbamate. Excess chemolysis alcohol is removed by distillation before or after separation. The carbamates obtained in this way can be used in various ways, particularly for the hydrolytic production of the corresponding amines. Suitable hydrolysis catalysts include both chemical catalysts, especially Brensted bases, and biological catalysts, especially urethanases.Regardless of the choice of catalyst, the route to amines described here is to be understood as alcoholysis followed by separate hydrolysis of the separated carbamates (see No. 2 above). Hydrolytic cleavage of carbamates present in the liquid alcohol phase (polyol phase) is not described.

[0029] In a second variant, the further processing of the chemolysis product can also be carried out by hydrolyzing it directly, i.e., without separating a liquid alcohol phase (polyol phase). This procedure corresponds to hydroalcohollysis (see No. 3 above). Suitable hydrolysis catalysts include both chemical catalysts, especially Brensted bases, and biological catalysts, especially urethanases. In this variant, the entire chemolysis product is hydrolyzed. An amine phase and a liquid alcohol phase (polyol phase) are obtained from the resulting hydrolyzed product mixture by extraction. Hydrolytic cleavage of carbamates present in the liquid alcohol phase (polyol phase) is not described for this variant either.

[0030] The recycling processes described above can still be improved. In particular, challenges persist regarding the most complete possible separation of polyols and amines (or the precursor compounds of amines, the carbamates and, if applicable, ureas). This is especially important for products manufactured in very large quantities, such as toluene diisocyanate (TDI) and polyether polyol-based polyurethane foams. It would be particularly desirable to easily separate the polyol-rich phase obtained in hydroalcohollysis processes from entrained carbamate impurities, which, despite 2024PF30148 - Abroad

[0031] - 7 -

[0032] It is not possible to completely rule out the possibility of chemolysis taking place in the presence of water.

[0033] Taking this need into account, an object of the present invention is a process comprising the recovery of (at least) one polyol from a polyol phase by a recycling process (A) comprising a reaction (Al) [hydroalcohollysis] of a polyurethane product based on an isocyanate component and a polyol component with a (particularly superstoichiometrically used) chemolysis alcohol and (particularly superstoichiometrically used) water to a chemolysis product and a work-up (A.2) of the chemolysis product comprising a separation of an amine phase from the chemolysis product, wherein the polyol phase contains (at least) a polyol from the polyol component and (at least) a carbamate of an isocyanate of the isocyanate component and of the chemolysis alcohol (which was formed in the reaction of the polyurethane product with the chemolysis alcohol and was not completely cleaved in the reaction with water), wherein the amine phase contains chemolysis alcohol and (at least) an amine corresponding to an isocyanate of the isocyanate component, and wherein the process comprises (see also FIG. 1):.

[0034] (a) Reaction (al) of the polyol phase with an aqueous hydrolysis reagent (in a stoichiometric excess) in the presence of a urethanase preparation to obtain a (first) product mixture comprising (i) (at least) a polyol depleted of (at least one) carbamate, (ii) (at least) an amine formed by carbamate hydrolysis, (iii) chemolysis alcohol formed by carbamate hydrolysis, and (iv) (unreacted, because it was used in a superstoichiometric amount,) water, and

[0035] Work-up (a.2) of the (first) product mixture to obtain the (at least one) carbamate-depleted polyol.

[0036] It was found, quite unexpectedly, that enzymatic hydrolysis of the carbamates, which are present in comparatively small (yet still disruptive) amounts in the relatively nonpolar polyol phase, is successful under mild conditions, particularly in a two-phase system. In contrast, the previously described enzymatic carbamate hydrolysis processes (see the literature cited above) deal with the reaction of carbamates in single-phase aqueous systems.

[0037] According to the invention, the chemolysis of the polyurethane product is carried out as hydroalcohollysis, i.e., as a reaction with an alcohol and water. The water is thereby (as 2024PF30148 - Abroad)

[0038] - 8 - such a substance and / or, for example, as a component of the alcohol or an aqueous catalyst solution) is added to the chemolysis in such an amount that the mass fraction of water is at least 4.1%, in particular at least 4.2%, preferably 4.2% to 15%, particularly preferably 4.2% to 10%, very preferably 4.2% to 10%, and most preferably 4.2% to 7.0%, based on the mass of the polyurethane product. The mass of the polyurethane product is defined as its dry mass, excluding any water that may be present in the polyurethane product. Due to the rather hydrophobic nature of most polyurethane products, any moisture content they may contain is usually negligible.However, if a polyurethane product contains significant amounts of water, it can be dried to determine its dry mass using known methods, for example, by heating it in a dry air or nitrogen stream (preferably nitrogen) until the mass of the polyurethane product no longer changes with further heating in the air or nitrogen stream. Since this drying process serves only to adjust the desired water content for chemolysis, it is sufficient to treat a representative sample of the polyurethane product in this way to determine its water content and to take this into account when determining any additional amount of water that may be required.

[0039] The water content of the chemolysis alcohol can be determined, if necessary, by Karl Fischer titration; this is the method decisive for the purposes of the present invention. Karl Fischer titration has been described extensively and is well known to those skilled in the art. Various embodiments of the basic principle of Karl Fischer titration generally yield sufficiently consistent results for the purposes of the present invention. In case of doubt, Karl Fischer titration as described in DIN 51 777, Part 1, March 1983, is decisive for the purposes of the present invention.

[0040] In the terminology of the present invention, the term polyols encompasses all polyols known in the field of urethane chemistry. The expression "a polyol" naturally also includes embodiments in which two or more different polyols are used in the manufacture of the polyurethane product. Therefore, when, for example, the term "a polyether polyol" is used below, this terminology naturally also includes embodiments in which two or more different polyether polyols are used in the manufacture of the polyurethane product. For the sake of linguistic simplicity, this is not necessarily explicitly mentioned below, but is considered to be included unless expressly stated otherwise. The entirety of all polyols used in the manufacture of the polyurethane product is referred to as the polyol component (of the polyurethane product). The polyol component comprises at least one polyol.2024PF30148 - Abroad.

[0041] - 9 -

[0042] The term “polyol from the polyol component” refers to the polyols used in the manufacture of the polyurethane product (provided that these can be recovered chemically essentially unchanged, which is regularly the case with polyether polyols) or their monomeric or oligomeric degradation products with two or more OH groups obtained in the recycling process.

[0043] In the terminology of the present invention, the term isocyanate encompasses all isocyanates known in the art in connection with urethane chemistry. The expression "an isocyanate" naturally also includes embodiments in which two or more different isocyanates (e.g., mixtures of TDI and other isocyanates) are used in the manufacture of the polyurethane product, unless otherwise expressly stated, for example, by the formulation "exactly one isocyanate." The entirety of all isocyanates used in the manufacture of the polyurethane product is referred to as the isocyanate component (of the polyurethane product). The isocyanate component comprises at least one isocyanate.

[0044] An amine corresponding to an isocyanate is that amine by whose phosgenation the isocyanate is formed according to R-NH + COCl. 2 HCl can be obtained.

[0045] The attached illustrations show block diagrams, in which

[0046] FIG. 1 provides an overview of the method according to the invention,

[0047] FIG. 2 shows the recycling process in a “sp / / tphase” hydroalcohollysis,

[0048] FIG. 3 shows the recycling process involving extraction of the chemolysis product with an organic extraction agent.

[0049] FIG. 4 shows the recycling process involving the separation of amines from the chemolysis product by distillation.

[0050] FIG. 5 shows a possible variant for carrying out step (oc) in the case of vaporizable amines,

[0051] FIG. 6 shows a possible variant for carrying out step (oc) in the case of water-insoluble amines,

[0052] FIG. 7 shows a first possible variant for carrying out step (oc) in the case of water-soluble amines, and

[0053] FIG. 8 shows a second possible variant for carrying out step (oc) in the case of water-soluble amines. 2024PF30148 - Abroad

[0054] - ID ¬

[0055] The following is a brief summary of various possible embodiments of the invention:

[0056] In a first embodiment of the invention, which can be combined with all other embodiments, the separation of the amine phase comprises a (liquid-liquid or solid-liquid) phase separation.

[0057] In a second embodiment of the invention, which is a particular embodiment of the first embodiment, the chemolysis product (spontaneously) decomposes into the polyol phase and the amine phase, which are separated from each other (without further intermediate steps) by the (liquid-liquid or solid-liquid) phase separation (which in this embodiment constitutes step A.2) (see also FIG. 2).

[0058] In a third embodiment of the invention, which is a further particular embodiment of the first embodiment, the work-up (A.2) of the chemolysis product comprises an extraction (A.2.1) with an organic extraction agent, and the polyol phase and the amine phase are obtained during the extraction by phase separation (in this embodiment: F / sweet / g / / sweet / g) (see also FIG. 3).

[0059] In a fourth embodiment of the invention, which can be combined with all other embodiments, provided that these do not provide for the separation of the amine phase by means other than distillation, the separation of the amine phase comprises a distillation (which in this embodiment constitutes step A.2), optionally in conjunction with a stripping, in which the chemolysis alcohol, the (at least one) amine and water are distilled off and the polyol phase remains (see also FIG. 4).

[0060] In a fifth embodiment of the invention, which can be combined with all other embodiments, provided that these do not provide for the separation of the (at least one) polyol depleted of the (at least one) carbamate by a (liquid-liquid) phase separation, in the work-up of the (first) product mixture in step (a.2) water, the (at least one) amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis are separated from the (first) product mixture by distillation and / or stripping (see also FIG. 5).

[0061] In a sixth embodiment of the invention, which can be combined with all other embodiments, provided that these do not provide for the isolation of the (at least one) carbamate-depleted polyol by separation of water, the (at least one) amine formed by carbamate hydrolysis, and the chemolysis alcohol formed by carbamate hydrolysis by distillation and / or stripping, the work-up of the (first) product mixture in step (a.2) comprises separating the (at least one) carbamate-depleted polyol by (liquid-liquid) phase separation. 2024PF30148 - Abroad

[0062] - 11 - In a seventh embodiment of the invention, which is a particular embodiment of the sixth embodiment, in step (a.2) in a first (liquid-liquid) phase separation the (first) product mixture is separated into an organic phase containing the (at least one) amine formed by carbamate hydrolysis and the (at least one) polyol depleted of the (at least one) carbamate, and an aqueous phase containing the chemolysis alcohol formed by carbamate hydrolysis, wherein the organic phase is extracted with an aqueous acid to obtain a (second) product mixture, followed by a second (liquid-liquid) phase separation of the (second) product mixture into the (at least one) polyol depleted of the (at least one) carbamate and an aqueous amine phase (containing the (at least one) amine formed by carbamate hydrolysis in protonated form) (see [reference to relevant section]). (also FIG. 6).

[0063] In an eighth embodiment of the invention, which is a further special embodiment of the sixth embodiment, in step (a.2) in the (liquid-liquid) phase separation, in addition to the (at least one) polyol depleted of the (at least one) carbamate, an aqueous amine phase is formed containing the (at least one) amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis (see also FIG. 7).

[0064] In a ninth embodiment of the invention, which is a further particular embodiment of the sixth embodiment, in step (a.2) in the (liquid-liquid) phase separation, an emulsion phase and optionally an aqueous phase are formed in addition to the (at least one) polyol depleted of the (at least one) carbamate, wherein the emulsion phase is extracted with an organic solvent comprising a hydrocarbon (a.3), followed by a phase separation into a solvent phase and an aqueous amine phase, and wherein the aqueous phase that may have been formed is combined with the aqueous amine phase (see also FIG. 8).

[0065] In a tenth embodiment of the invention, which is a special embodiment of the seventh to ninth embodiments, the aqueous amine phase is processed (separately) to obtain the amine formed in step (al).

[0066] In an eleventh embodiment of the invention, which is a further special embodiment of the seventh to ninth embodiments, the aqueous amine phase is combined with the amine phase.

[0067] In a twelfth embodiment of the invention, which is a particular embodiment of the seventh to eleventh embodiments, the chemolysis alcohol formed in step (al) is separated from the aqueous phase or the aqueous amine phase, and the chemolysis alcohol thus obtained is returned to the recycling process. 2024PF30148 - Abroad

[0068] - 12 - In a thirteenth embodiment of the invention, which can be combined with all other embodiments except those providing for immobilization of the urethanase preparation, the urethanase preparation is dissolved or suspended in the aqueous hydrolysis reagent.

[0069] In a fourteenth embodiment of the invention, which differs from all other embodiments except those which provide for dissolving or suspending the urethanase preparation in the aqueous hydrolysis reagent, the urethanase preparation is immobilized on a solid support.

[0070] In a fifteenth embodiment of the invention, which can be combined with all other embodiments, the (at least one) carbamate-depleted polyol obtained in step (a.2) is further purified by distillation and / or stripping.

[0071] In a sixteenth embodiment of the invention, which can be combined with all other embodiments, urethanase preparation is recycled after step (a) has been carried out.

[0072] In a seventeenth embodiment of the invention, which can be combined with all other embodiments, the conversion of the polyurethane product in (Al) is carried out in the presence of a chemolysis catalyst, wherein the chemolysis catalyst is a carbonate, a hydrogen carbonate, a hydroxide, an orthophosphate, a mono-hydrogen orthophosphate, a metaphosphate, an orthovanadate (where all the aforementioned chemolysis catalysts are preferably used in the form of their alkali or alkaline earth metal salts, in particular in the form of their sodium or potassium salts), a carboxylate (preferably an acetate, in particular sodium or potassium acetate, or also tin(II)-2-ethylhexanoate), a titanium alkoxide (in particular tetra-n-butyl titanate, Ti(O-nBu)4), an organic amine, in particular a tertiary amine (such as in particular 1,4-diazabicyclo(2.2.2)octane, “DABCO”), cesium fluoride, an organotin compound (in particular dibutyltin dilaurate, “DBTL”, or monobutyltin oxide, n-Bu-Sn(O)OH, “MBTO”) or a mixture of two or more of the aforementioned chemolysis catalysts.

[0073] In an eighteenth embodiment of the invention, which can be combined with all other embodiments, the isocyanate component comprises toluene diisocyanate (TDI; producible by phosgenation of toluenediamine, TDA), di- and polyisocyanates of the diphenylmethane series (MDI; producible by phosgenation of the di- and polyamines of the diphenylmethane series, MDA), 1,5-naphthylene diisocyanate (NDI; producible by phosgenation of 1,5-naphthylenediamine, NDA), 1,5-pentane diisocyanate (PDI; producible by phosgenation of 1,5-pentaneediamine, PDA), 1,6-hexamethylene diisocyanate (HDI; producible by phosgenation of 1,6-hexamethylenediamine, HDA), isophorone diisocyanate (IPDI; producible by phosgenation of isophoronediamine, IPDA), diisocyanatodicyclohexylmethane (“saturated Methylenediphenylene diisocyanate", H12MDI 2024PF30148 - Abroad

[0074] - 13 - in particular the 4,4'-isomer; obtainable by phosgenation of diaminodicyclohexylmethane, H12MDA, itself obtainable by nuclear hydrogenation of 2-core MDA), xylylene diisocyanate (XDI; obtainable by phosgenation of xylylenediamine, XDA), para-phenylene diisocyanate (PPDI; obtainable by phosgenation of para-phenylenediamine) or a mixture of two or more of the aforementioned isocyanates.

[0075] In a nineteenth embodiment of the invention, which can be combined with all other embodiments, the polyol component comprises a polyether polyol, a polyester polyol, a polyether ester polyol, a polycarbonate polyol, a polyether carbonate polyol, a polycarbonate polyester polyol, a polyacrylate polyol, or a mixture of two or more of the aforementioned polyols. Preferably, the polyol component contains a polyether polyol. Particularly preferably, the polyol component is a polyether polyol (i.e., it does not contain any other polyols besides polyether polyols; however, a mixture of two or more different polyether polyols is included and does not exceed the scope of this embodiment).

[0076] In a twentieth embodiment of the invention, which can be combined with all other embodiments, the chemolysis alcohol comprises methanol, ethanol, n-propanol, α-propanol, sec-butanol, α-butanol, tert-butanol, n-butanol, 2-pentanol, 3-pentanol, α-amyl alcohol (3-methyl-1-butanol), 2-methyl-2-butanol, neo-pentanol (2,2-dimethyl-1-propanol), 2-methyl-1-butanol, 3-methyl-2-butanol, 2-methyl-

[0077] 1-butanol, cyclopentanol, hexan-2-ol, hexan-3-ol, 2-methylpentan-l-ol, 2-methylpentan-2-ol,

[0078] 2-methylpentan-3-ol, 4-methylpentan-2-ol, 3-methylpentan-l-ol, 3-methylpentan-2-ol, 3-methylpentan-3-ol, 2,2-dimethylbutan-l-ol, 3,3-dimethylbutan-l-ol, 3,3-dimethylbutan-2-ol, 2,3-dimethylbutan-l-ol, 2,3-Dimethylbutan-2-ol, 2-ethylbutan-l-ol, 4-methylpentan-2-ol, cyclohexanol, phenol, 2-ethylhexan-l-ol, 1,4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl glycol, triethylene glycol, glycerin, 2-methyl-1,3-propanediol, benzyl alcohol, furfuryl alcohol or a mixture of two or more of the aforementioned chemolysis alcohols.

[0079] In a twenty-first embodiment of the invention, which can be combined with all other embodiments, step (oc.l) is carried out at 10 °C to 80 °C, preferably 20 °C to 50 °C.

[0080] In a twenty-second embodiment of the invention, which can be combined with all other embodiments, the urethanase preparation contains (at least) one polypeptide defined by one of the amino acid sequences according to SEQ ID NO.: 1 to 6 or has a variant thereof, wherein the variant is obtained by the addition, deletion or exchange of up to 15% of the amino acids contained in the respective amino acid sequences according to SEQ ID NO.: 1 to 6.

[0081] In a twenty-third embodiment of the invention, which is a particular embodiment of the twenty-second embodiment, the amino acid sequence of the 2024PF30148 - foreign country

[0082] - 14 -

[0083] (at least one) polypeptide defined by the amino acid sequence according to SEQ ID NO.: 4 or the variant thereof.

[0084] In a twenty-fourth embodiment of the invention, which can be combined with all other embodiments, the process comprises the recovery of a further valuable material in addition to the (at least one) polyol from the polyurethane product by

[0085] (ß) Working up the amine phase by distillative purification to obtain the (at least one) amine.

[0086] In a twenty-fifth embodiment of the invention, which is a particular embodiment of the twenty-fourth embodiment, the (at least one) amine is phosgenated to an isocyanate (i.e., to the corresponding isocyanate).

[0087] In a twenty-sixth embodiment of the invention, which is a particular embodiment of the twenty-fifth embodiment, the isocyanate is reacted with a polyol, in particular with the polyol obtained by distillation and / or stripping according to the fifteenth embodiment, to form a polyurethane.

[0088] The embodiments and further possible configurations of the invention briefly described above are explained in more detail below. Unless the context clearly indicates otherwise to a person skilled in the art, or unless expressly stated otherwise, all previously described embodiments and the further configurations of the invention can be combined with one another as desired.

[0089] PROVISION OF THE POLYURETHANE PRODUCT

[0090] To carry out the recycling process (A), a polyurethane product is first provided. The process according to the invention can be applied both to the recycling of used (so-called end-of-life) polyurethane products and to polyurethane waste from production. In the case of reusing a used polyurethane foam, suitable sorting preferably ensures that only polyurethane products that are as similar as possible to one another (e.g., only mattresses) are subjected to the recycling process (A) together.

[0091] The polyurethane products are preferably those whose isocyanate component is toluene diisocyanate (TDI; producible by phosgenation of toluenediamine, TDA), di- and polyisocyanates of the diphenylmethane series (MDI; producible by phosgenation of the di- and polyamines of the diphenylmethane series, MDA), 1,5-naphthylene diisocyanate (NDI; producible by phosgenation of 1,5-naphthylenediamine, NDA), 1,5-pentane diisocyanate (PDI; producible by phosgenation of 1,5-pentanediamine, PDA), 1,6-hexamethylene diisocyanate (HDI; producible by phosgenation of 2024PF30148 - Abroad

[0092] - 15 -

[0093] 1,6-Hexamethylenediamine, HDA), isophorone diisocyanate (IPDI; obtainable by phosgenation of isophoronediamine, IPDA), diisocyanatodicyclohexylmethane (“saturated methylenediphenylene diisocyanate”, H12MDI, in particular the 4,4'-isomer; obtainable by phosgenation of diaminodicyclohexylmethane, H12MDA, itself obtainable by nuclear hydrogenation of 2-core MDA), xylylene diisocyanate (XDI; obtainable by phosgenation of xylylenediamine, XDA), para-phenylene diisocyanate (PPDI; obtainable by phosgenation of para-phenylenediamine), or a mixture of two or more of the aforementioned isocyanates. The polyol component preferably comprises a polyether polyol, a polyester polyol, a polyether ester polyol, a polycarbonate polyol, a polyether carbonate polyol, a polycarbonate polyester polyol, a polyacrylate polyol, or a mixture of two or more of the aforementioned polyols. Preferably, the polyol component contains a polyether polyol.Particularly preferred is the polyol component a polyether polyol (i.e., it does not contain any other polyols other than polyether polyols; however, a mixture of two or more different polyether polyols is included and does not leave the scope of this embodiment).

[0094] Particularly preferably, the polyurethane product is a polyurethane foam, and in particular a TDI- and polyetherpolyol-based polyurethane foam (i.e., the isocyanate component comprises TDI and preferably no other isocyanates other than TDI, and the polyol component comprises at least one polyetherpolyol and preferably no other polyols other than polyetherpolyols).

[0095] Preferably, the preparation of the polyurethane product already includes preparatory steps for the subsequent reaction with the chemolysis alcohol and water. These steps primarily involve the mechanical comminution of the polyurethane products. Such preparatory steps are known in the field; for example, reference is made to the literature cited in [1]. Depending on the properties of the polyurethane product, it may be advantageous to "freeze" it before mechanical comminution to facilitate the comminution process.

[0096] Before, during, or after mechanical comminution, the polyurethane product can be treated with (aqueous or alcoholic) disinfectants. Such disinfectants preferably include hydrogen peroxide, chlorine dioxide, formaldehyde, alkali metal hypochlorites (especially sodium hypochlorite), and / or peracetic acid (aqueous disinfectants) or ethanol, isopropanol, and / or 1-propanol (alcoholic disinfectants).

[0097] It is also conceivable to carry out the described preparatory steps at a location spatially separate from the chemolysis site. In this case, the prepared polyurethane product is filled into suitable transport vehicles, such as silo trucks, for onward transport. For onward transport, the prepared polyurethane product can also be compressed to achieve a higher mass-to-volume ratio. 2024PF30148 - Abroad

[0098] - 16 -

[0099] PERFORMANCE OF HYDROALCOHOLYSE

[0100] With regard to the execution of the hydroalcohollysis, the process according to the invention is not subject to any special restrictions; it can be carried out as is known from the prior art.

[0101] The hydroalcohollysis in step (Al) is preferably carried out at temperatures of 135 °C to 240 °C, more preferably 180 °C to 200 °C. There are no special requirements regarding the pressure. The reaction can be carried out at both reduced and increased pressure; for example, at a pressure of 200 mbaqabs. to 16000 mbaqabs., more preferably 500 mbaqabs. to 6000 mbaqabs., more preferably 900 mbaqabs. to 1300 mbaqabs., and particularly at ambient pressure.

[0102] Preferably, step (Al) is carried out such that the mass ratio of (total amount of alcohol used) and (total amount of water used) to the polyurethane product (i.e., [m(alcohol) + m(water)] / m(polyurethane product), m = mass) is in the range of 0.5 to 2.5, wherein the mass of the water is 2.0% to 10% of the mass of the alcohol. Within the scope of the present invention, the quantitative data relating to water refer to the water added as a reagent for the hydrolytic cleavage of carbamate. In comparison, any amounts of water that may already be present from moisture in the alcohol and / or polyurethane product used are small. Moisture in the alcohol or polyurethane product used refers to trace amounts of moisture such as may occur on an industrial scale.It is of course possible to premix the alcohol with water to be used for hydrolytic cleavage or to wet the polyurethane product with water to be used for hydrolytic cleavage. Such embodiments do not deviate from the scope of the invention, and the water added in this way must, of course, be taken into account in the quantitative specifications mentioned above; that is, the amount of water to be added, if necessary, must be reduced accordingly. If the catalyst is used as an aqueous solution, the water used as a solvent must likewise be taken into account in the quantitative specifications mentioned above; that is, the amount of water to be added, if necessary, must be reduced accordingly.

[0103] It is not necessary to add all the water at the beginning of step (Al). In this case, the above-mentioned quantity of "2.0% to 10% of the mass of the alcohol" refers to the total amount of water added by the end of the reaction time of step (B). The same applies if the alcohol is added gradually. 2024PF30148 - Abroad

[0104] - 17 -

[0105] It is also possible, in particular, to apply the polyurethane product in step (Al)

[0106] (I) first add only (i) the alcohol or (ii) the alcohol and an initial part of the water, and then

[0107] (II) to add water or a second part of the water, in particular only after the polyurethane product has dissolved.

[0108] In this context, the expression "dissolved" does not necessarily imply the presence of a "true" solution in the sense of a perfectly homogeneous mixture. It is quite possible that the polyurethane product will be a cloudy "solution"; such a situation does not exceed the scope of the present invention.

[0109] During the execution of step (Al) in steps (I) and (II), it is particularly preferred to add the water, or the second part of the water, continuously or in portions in step (II) such that the temperature of the liquid phase during step (II) deviates from the temperature of the liquid phase in step (I) by a maximum of 20 °C, preferably by a maximum of 15 °C, particularly preferably by a maximum of 10 °C, very preferably by a maximum of 5.0 °C, and extremely preferably by a maximum of 1.0 °C. This ensures that the temperature is always high enough to guarantee the chemolysis progresses. If a portion of the water is added at the beginning of the chemolysis (= variant (ii)), it is preferred that the first portion of the water constitutes up to 4.0%, particularly 2.0% to 4.0%, of the total mass of water added in step (Al) (i.e., in (I) and (II) combined).In a two-stage hydroalcohollysis process, the pressure can be controlled such that in step (I) a comparatively low pressure is maintained, particularly in the range of 200 mbar to 2000 mbar, preferably 500 mbar to 1500 mbar, particularly preferably 900 mbar to 1300 mbar, and most preferably ambient pressure, and in step (II) a higher pressure is selected, particularly a pressure in the range of 6000 mbar to 16000 mbar.

[0110] It is advantageous to add a catalyst to carry out hydroalcohollysis. This preferably comprises a carbonate, a hydrogen carbonate, a hydroxide, an orthophosphate, a mono-hydrogen orthophosphate, a metaphosphate, an orthovanadate (where all the aforementioned chemolysis catalysts are preferably used in the form of their alkali or alkaline earth metal salts, in particular in the form of their sodium or potassium salts), a carboxylate (preferably an acetate, in particular sodium or potassium acetate, or also tin(II)-2-ethylhexanoate), a titanium alkoxide (in particular tetra-n-butyl titanate, Ti(O-nBu)4), an organic amine, in particular a tertiary amine (such as in particular 1,4-diazabicyclo(2,2,2)octane, "DABCO"), cesium fluoride, an organotin compound (in particular dibutyltin dilaurate, "DBTL", or monobutyltin oxide, n-Bu-Sn(O)OH, "MBTO"), or a mixture of two or more of the aforementioned Chemolysis catalysts. 2024PF30148 - International

[0111] - 18 -

[0112] Methanol, ethanol, n-propanol, / so-propanol, sec-butanol, / so-butanol, tert-butanol, n-butanol, 2-pentanol, 3-pentanol, / so-amyl alcohol (3-methyl-l-butanol), 2-methyl-2-butanol, neo-pentanol are particularly suitable as chemolysis alcohol (2,2-Dimethyl-l-propanol), 2-methyl-l-butanol, 3-methyl-2-butanol, 2-methyl-l-butanol, cyclopentanol, hexan-2-ol, hexan-3-ol, 2-methylpentan-l-ol, 2-methylpentan-2-ol, 2-methylpentan-3-ol, 4-methylpentan-2-ol, 3-methylpentan-l-ol, 3-Methylpentan-2-ol, 3-Methylpentan-3-ol, 2,2-Dimethylbutan-l-ol, 3,3-Dimethylbutan-l-ol, 3,3-Dimethylbutan-2-ol, 2,3-Dimethylbutan-l-ol, 2,3-Dimethylbutan-2-ol, 2-Ethylbutan-l-ol, 4-Methylpentan-2-ol, Cyclohexanol, Phenol, 2-Ethylhexan-l-ol, 1,4-Butanediol, Ethylene glycol, Diethylene glycol, Propylene glycol, Dipropylene glycol, Methyl glycol, Triethylene glycol, Glycerin, 2-Methyl-l,3-Propanediol, Benzyl alcohol, Furfuryl alcohol or a mixture of two or more of the aforementioned chemolysis alcohols.

[0113] REPROCESSING OF THE CHEMOYL PRODUCT

[0114] There are various alternatives for processing the hydroalcoholysis process product. Which one is most suitable in a specific case depends on the nature of the polyurethane product to be recycled and the chemolysis alcohol used, and can be easily determined through preliminary tests if necessary.

[0115] In certain embodiments, the separation of the amine phase includes a (liquid-liquid or solid-liquid) phase separation. In the simplest case, such a phase separation occurs spontaneously after completion of the hydroalcohollysis and cooling of the product mixture (“split-phase” hydroalcohollysis). The chemolysis product decomposes (spontaneously) into the polyol phase and the amine phase, which are separated from each other (without further intermediate steps) by the (liquid-liquid or solid-liquid) phase separation (which in this embodiment constitutes step A.2). This is illustrated graphically in FIG. 2.

[0116] However, it may also be appropriate to bring about phase separation yielding the polyol and amine phases by an extraction process, for example, if spontaneous phase separation does not occur with the chosen combination of polyurethane product and chemolysis alcohol, or does not occur at a rate sufficient for industrial processes, or if the separation of polyols and amines is not sufficiently complete without the addition of an extraction solvent. In this case, step (A.2) comprises extraction (A.2.1) with an organic extraction solvent. This is illustrated graphically in FIG. 3.

[0117] Preferably, an organic solvent with a boiling point of 1013 mbar is used as the organic extraction agent. abs.) in the range of 40 °C to 120 °C. Suitable organic solvents include, in particular, aliphatic hydrocarbons (e.g., hexane), cycloaliphatic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., toluene), or mixtures of two or 2024PF30148 - Abroad

[0118] - 19 - more of the aforementioned solvents. The extraction is preferably carried out at a temperature of 10 °C to 80 °C (e.g., ambient temperature).

[0119] The extraction product is two-phase and is separated into its phases in the subsequent phase separation. Adding additional water during extraction can be advantageous to facilitate this phase separation. In the case of water-soluble amines such as TDA, a relatively nonpolar polyol phase (containing the polyol and the organic extraction solvent) and a relatively polar amine phase (containing the amine, excess water from the hydroalcohollysis, and any additional water added) are obtained. In the case of water-insoluble amines, an acid (e.g., hydrochloric acid, hydrogen chloride, or sulfuric acid) can be added, protonating the amine, which then passes into the aqueous phase (= amine phase) as the amine salt of the acid. After separation of the polyol phase, the amine can be recovered by neutralization with a base.

[0120] It is self-evident to those skilled in the art that the separation need not necessarily be perfect in the sense that all polyol passes into the polyol phase and all amine into the amine phase. Due to the prevailing solubility equilibria, small amounts of the amine regularly pass into the polyol phase. It is also not unusual for small amounts of the polyol to pass into the amine phase; this is, of course, not outside the scope of the present invention.

[0121] Unless dealing with amines that cannot be evaporated without decomposition (such as pMDA), the separation into the amine phase and polyol phase can also be achieved by distillation, in which the amine (e.g., TDA), the chemolysis alcohol, and water are distilled off. If the boiling point of the amine is significantly higher than that of the chemolysis alcohol (which will often be the case), fractional distillation can be performed, whereby the chemolysis alcohol and water are distilled off first, and then the amine at a higher temperature. In this embodiment, the amine phase is thus the distillate of the distillation (or a fraction thereof), while the polyol phase is the bottoms product of the distillation. This is illustrated graphically in FIG. 4.

[0122] Common types of evaporators are suitable for distillation, such as falling film evaporators, natural circulation evaporators, boiler evaporators, forced circulation evaporators or flash evaporators.

[0123] It is preferred that a second distillation and / or stripping follows a first distillation using one of the aforementioned evaporator types. Such a second distillation is preferably carried out using a thin-film evaporator, short-path evaporator, or flash evaporator, in particular a thin-film or short-path evaporator. Stripping serves to remove any remaining residues that were not separated by previous distillation steps.

[0124] - 20 -

[0125] The removal of amine is preferably carried out with steam or an inert gas such as nitrogen, particularly in columns, preferably columns filled with packing or structured packing.

[0126] Regardless of the precise method used to separate the amine phase, this step can be preceded and / or followed by solids separation. Solids to be separated can include, for example, byproducts from the original application of the polyurethane product, precipitated catalysts, or polymers (such as styrene-acrylonitrile copolymers, SAN) from polymer-filled polyols in the polyol component of the polyurethane product.

[0127] POLYOL PHASE REPROCESSING, PERFORMANCE OF STEP (a)

[0128] For further processing of the polyol phase, it is first reacted in a step (al) with an aqueous hydrolysis reagent in the presence of a urethanase preparation according to the invention, followed by work-up of the (first) product mixture obtained in a step (a.2) to obtain the polyol depleted of (at least one) carbamate.

[0129] Suitable aqueous hydrolysis reagents for step (al) include water of varying qualities, such as demineralized water, steam condensate, or aqueous streams generated elsewhere in the process that can be recycled to step (al) (e.g., aqueous distillate streams from amines recovered during distillation purification), as well as tap water or process water. The urethanase preparation can be dissolved or suspended in the aqueous hydrolysis reagent. The enzymatic carbamate cleavage is then advantageously carried out as an extraction process, for example, in conventional M / xer-Sett / er apparatus. It is also possible to immobilize the urethanase preparation on a solid support. In this case, the polyol phase can, for example, be passed through a column filled with the immobilized urethanase preparation.An immobilized urethanase preparation offers the advantage of easy reuse and allows for simple continuous processing. With non-immobilized urethanase preparations, after completion of the enzymatic carbamate cleavage, the urethanase enters the aqueous portion of the (first) product mixture. This aqueous portion can be separated from the other components and—if necessary, after removing dissolved amines and chemolysis alcohols—re-contacted with further polyol phase. If amines and chemolysis alcohols are not removed, they accumulate, which can lead to inactivation of the urethanase preparation. In this case, a portion of the aqueous portion can be removed and replaced with a fresh solution (or suspension) of urethanase preparation. It is also possible to reactivate the urethanase preparation by ultrafiltration (2024PF30148 - Abroad).

[0130] - 21 - to separate. The urethanase preparation separated in this way can then be recycled.

[0131] The enzymatic cleavage of carbamate is preferably carried out at temperatures of 10 °C to 80 °C, preferably 20 °C to 50 °C. Regarding the choice of the urethanase preparation, it is preferred that it contains (at least) one polypeptide defined by one of the amino acid sequences according to SEQ ID NO. 1 to 6 or a variant thereof, wherein the variant is obtained by the addition, deletion, or substitution of up to 15% of the amino acids contained in the respective polypeptide by one of the amino acid sequences as in SEQ ID NO. 1 to 6. Particularly preferred is the amino acid sequence of the (at least one) polypeptide defined by the amino acid sequence according to SEQ ID NO. 4 or a variant thereof.

[0132] The urethanase preparation can also be a whole-cell preparation, a preparation of lysed cells, purified enzyme, or secreted enzyme. Furthermore, the enzyme can be in immobilized form, as mentioned above.

[0133] The (first) product mixture obtained in step (oc.1) is worked up in step (oc.2). In the simplest case, the (at least one) amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis are separated from the (first) product mixture by distillation and / or stripping, leaving behind the (at least one) polyol depleted of the (at least one) carbamate. This is illustrated graphically in FIG. 5. If necessary, the distillation separation can be preceded and / or followed by solids separation as described above, e.g., if the polyol should still contain fine SAN particles. The polyol thus obtained can, if necessary, be further purified by methods known per se, in particular again by distillation and / or stripping.Of course, such further purification of the polyol depleted of (at least one) carbamate can also be carried out using other processing methods such as those described below.

[0134] However, the separation of the polyol depleted by the carbamate (at least one) can also include a (liquid-liquid) phase separation.In the case of water-insoluble amines, it is advantageous to proceed as follows: In a first (liquid-liquid) phase separation, the (first) product mixture is separated into an organic phase containing the (at least one) amine formed by carbamate hydrolysis and the (at least one) polyol depleted of the (at least one) carbamate, and an aqueous phase containing the chemolysis alcohol formed by carbamate hydrolysis. The organic phase is then extracted with an aqueous acid to obtain a (second) product mixture. This is followed by a second (liquid-liquid) phase separation of the (second) product mixture into the (at least one) polyol depleted of the (at least one) carbamate and an aqueous amine phase (containing the (at least one) amine formed by carbamate hydrolysis in protonated form). This is illustrated graphically in FIG. 6 (WS = aqueous acid). 2024PF30148 - Abroad.

[0135] - 22 -

[0136] In the case of water-soluble amines, the simplest procedure involves separating a phase containing the polyol depleted of the carbamate (at least one) from an aqueous amine phase containing the amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis in a (liquid-liquid) phase separation of the (first) product mixture. This is illustrated graphically in FIG. 7.

[0137] If an emulsion forms as described in WO 2020 / 260387 Al for the work-up of an alcoholysis product (which cannot be ruled out even in hydroalcoholysis), i.e., in step (a.2) an emulsion phase and optionally an aqueous phase are formed alongside the phase containing the polyol depleted of the carbamate (at least one), the preferred procedure is to extract the emulsion phase with an organic solvent comprising a hydrocarbon (a.3), followed by phase separation into a solvent phase and an aqueous amine phase, and combining any aqueous phase formed with the aqueous amine phase. This is illustrated graphically in FIG. 8 (LM = organic solvent).

[0138] The aqueous amine phase obtained in the variants described above can be processed (separately) to recover the amine formed in step (a). However, it is preferred to combine this aqueous amine phase with the amine phase from step (a.2) and process them together further.

[0139] The chemolysis alcohol formed in step (al) can be separated from the aqueous phase or the aqueous amine phase and returned to the recycling process.

[0140] PROCESSING OF THE AMINUM PHASE

[0141] Preferably, the amine phase is also processed to obtain further valuable components (step (β)). Such processing can, in particular, include distillative purification of the amine phase to obtain the (at least one) amine. In this distillation, chemolysis alcohol and water are separated from the amine. If necessary, the amine itself can also be distilled overhead to purify it (provided its boiling point allows evaporation without decomposition). Should the amine phase still contain residual carbamates, these are also removed in such a distillation. In the case of non-distillable amines, any necessary removal of residual carbamates can also be carried out by hydrolysis, in particular enzymatic hydrolysis as described here.

[0142] The amines thus obtained can then be used for all purposes known in the scientific community for such amines. Preferably, the recovered amines are phosgenated back to the corresponding isocyanates using methods known per se. 2024PF30148 - Abroad

[0143] - 23 -

[0144] The isocyanates obtained in this way can in turn be reacted with polyols to form polyurethanes. Polyols obtained by the process according to the invention can also be used.

[0145] The inventive method of enzymatic hydrolysis of the comparatively small amounts of carbamates in the polyol phase using a urethanase preparation has numerous advantages, such as mild reaction conditions (lower energy input due to comparatively low temperatures, no pressure reaction required), harmless catalysts (enzymes), and avoidance of byproduct formation. Furthermore, the enzymatic hydrolysis is also successful in the presence of nonpolar solvents, which may well be present in the polyol phase as a result of extraction processes during workup.

[0146] This will be further illustrated in the following examples.

[0147] 2024PF30148 - Abroad

[0148] - 24 -

[0149] Examples:

[0150] REACTION OF A POLYOL PHASE WITH AN AQUEOUS HYDROLYSEREAGENT IN THE PRESENCE OF A URETHANASE PREPARATION

[0151] Example 1: Production of a urethanase preparation

[0152] For the preparation of the urethanase preparations and control preparations, 4.5 mL of LB medium ("lysogeny broth") was inoculated in a first batch with E. coli BL21(DE3) pET21a_LV ("empty vector") and in a second batch with E. coli BL21(DE3) pET21a_Aes72 from cryocultures and incubated overnight at 37 °C and 200 rpm in an incubator shaker. All cultures were treated with 100 pg / mL of ampicillin. Subsequently, 200 mL of ZYP-5052 medium was inoculated with 200 pL of the overnight cultures. Cultivation was carried out for 4.75 to 5 h at 37 °C and 200 rpm, followed by 20.5 to 21.25 h at 20 °C and 200 rpm in an incubator shaker. The cells were separated by centrifugation at 8000 g and 4 °C for 20 min in a large-capacity centrifuge. The cell pellets were suspended in 10 mL of 20 mM potassium phosphate buffer, pH 7.5, and digested using ultrasound. The Bandelin Sonopuls instrument with an MS73 microtip was used.The analysis was performed for two cycles with 50% amplitude, 1 pulse, 1 s pause for a total of 2 min.

[0153] The insoluble cell components were then separated by centrifugation at 8000 g and 4 °C for 20 min in a large-capacity centrifuge. The supernatant was filtered through a 0.2 pm PES syringe filter and frozen at -80 °C. The whole-cell extract solution was freeze-dried and the lyophilisate was stored at 4 °C.

[0154] Example 2: Reaction of a polyol phase with an aqueous hydrolysis reagent in the presence of the urethanase preparation (see also FIG. 7)

[0155] For the enzyme reaction, 189 mg / mL whole-cell extract solutions of E. coli BL21(DE3) pET21a_LV and E. coli BL21(DE3) pET21a_Aes72 were prepared in 100 mM potassium phosphate buffer, pH 7.5. The dry enzyme preparations were made as described in Example 1. The whole-cell extract solutions were treated (rebuffered) using size exclusion chromatography (the so-called "gravity flow / low protocol") on previously equilibrated PD-10 disposable desalting columns (Cytiva Life Sciences™) in 100 mM potassium phosphate buffer, pH 7.5. 2.5 mL of protein solution was applied. Elution of the proteins from the PD-10 disposable desalting column was performed differently from the manufacturer's protocol, using 7 mL of 100 mM potassium phosphate buffer, pH 7.5, in two 3.5 mL steps.

[0156] The presence of Aes72 in the second fraction was verified using 4-nitrophenylbutyrate (pNPB). The hydrolysis of pNPB to 4-nitrophenol is indicated by the yellow coloration of the product. The two fractions were combined, and 6 mL of the unbuffered whole-cell extract solutions were diluted with 3 mL of 100 mM Kpi pH 7.5. For each sample time point 2024PF30148 - Abroad

[0157] - 25 - and each enzyme was treated with 3 mL of these solutions mixed with 5 mL of a polyol phase in 10 mL sample vials.

[0158] The polyol phase was a cyclohexane solution of a polyether polyol, obtained by reacting a used (so-called “End of / / / e”) polyurethane soft foam based on a TDI isocyanate component and a polyether polyol polyol component – ​​after pretreatment of the soft foam by mechanical comminution to a particle size of approximately 15 to 20 mm and inerting by vacuuming and nitrogen addition – with the same mass of diethylene glycol (DEG) and 1 wt%, based on the mass of the polyurethane soft foam, of DABCO (1,4-diazabicylco[2.2.2]octane) at 200 °C for 3 h, followed by extraction of the chemolysis product thus obtained with cyclohexane.Although the polyol phase was not obtained in accordance with the invention (since the soft foam was reacted without the addition of water), the results can nevertheless serve as proof of principle that a polyol phase with low residual carbamates, such as can also be obtained from hydroalcohollysis, can be successfully depleted of carbamates by step (oc).

[0159] Incubation was carried out at 40 °C and 400 rpm in an Eppendorf ThermoMixer™ C with a SmartBlock™ P / ates attachment. After the reaction was complete, the phases were separated by sedimentation. The resulting phases were each transferred to new sample containers (the upper phase, the cyclohexane phase – the carbamate-depleted polyol dissolved in cyclohexane – using a syringe and needle, and the lower phase – the aqueous amine phase – using a pipette). The samples were stored at -20 °C until analysis.

[0160] Analytics

[0161] The cyclohexane phase (polyol phase or the carbamate-depleted polyol dissolved in cyclohexane from Example 2) was first separated by 1 The 1H NMR was analyzed and measured. By adding an internal standard, the carbamate-CHz signal for the carbamate structures was evaluated and their degradation observed. The aqueous amine phase was treated using 13 C NMR analyzed.

[0162] 2024PF30148 - Abroad

[0163] - 26 -

[0164] Results

[0165] Table: Carbamatan content in the polyol phase and in phases from Example 2

[0166] Notes:

[0167] [a] Carbamate content in the untreated polyol phase (reference experiment) or in the cyclohexane phases from Example 2 (experiments according to the invention and comparison experiment). In the aqueous amine phases from Example 3, carbamates could not be detected in either experiment 3a according to the invention or in comparison experiment 3b.

[0168] [b] N. a.: Not applicable.

[0169] Example 4: Principle search for the depletion of carbamates in polyol-rich phases with different urethanase preparations

[0170] Enzyme production

[0171] The enzyme preparations were produced as described in Example 2. While the genes for Aes72, Aesl74, AesGö56, and GatA197 were also localized to pET21a as described there, pET26b was used for the genes of UMG-8 and UMG-11.2, with the N-terminal secretion signal being removed during cloning. For the latter constructs, 50 pg / mL of kanamycin was used instead of ampicillin during cultivation.

[0172] Enzyme reaction

[0173] For the enzyme reaction, 11 mL of a polyol-rich organic phase (obtained by alcoholysis of a polyurethane foam based on a TDI isocyanate component and a polyether polyol polyol component with equal masses of DEG, extraction of the resulting chemolysis product with toluene, and phase separation) were mixed with 3.3 pL of water. 2024PF30148 - Abroad

[0174] - 27 -

[0175] (Although the polyol-rich phase was not obtained in accordance with the invention here either (since the polyurethane foam was reacted without the addition of water), the results can nevertheless serve as proof of principle that a polyol phase with low residual carbamates, such as can also be obtained from hydroalcohollysis, can be successfully depleted of carbamates by step (oc).)

[0176] A spatula tip of whole-cell extract lyophilisate (approximately 3 mg) was added to HPLC vials and suspended in 200 pL of 100 mM potassium phosphate buffer, pH 7.5. The suspension was then mixed with 500 pL of the water-saturated, polyol-rich organic phase. Incubation was carried out at 30 °C and 800 rpm for 24 h in an Eppendorf ThermoMixer™ C with a SmartBlock™ P / ates attachment. After completion of the reaction, the samples were transferred to 1.5 mL reaction tubes and centrifuged for 30 min at 13,300 rpm and 4 °C in a refrigerated centrifuge. 50 pL of the aqueous (lower) phase were taken and mixed with 50 pL of stop solution (50 mM NaOH, 20% acetic acid, 50% acetonitrile) to inactivate the enzymes. The samples were then mixed with 900 pL of 280 mM NaOH. Subsequently, 200 pL of each sample were transferred to a 0.2 pm PVDF filter plate and filtered by centrifugation at 4 °C and 600 rpm for 12 min.The aqueous phases obtained were analyzed using high-performance liquid chromatography (HPLC).

[0177] Analytics

[0178] HPLC was performed on an Agilent Technologies 1260 Infinity II series instrument (Santa Clara, USA) equipped with a multisampler and a DAD (diode array detector) for UV and visible light. For all measurements, the Zorbax Eclipse Plus-C18 column with a particle size of 5 pm and dimensions of 4.6 x 150 mm (Agilent Technologies, Santa Clara, USA) with a corresponding guard column was used. For all methods, 5 pL of sample was injected, and the column was heated to 40 °C. The flow rate was generally 1.0 mL / min. Method ER_June2021-2 was used for the detection of aromatic amines. Due to their high intrinsic absorption, aromatic amines could be quantified at 210 nm and 232 nm using this method without derivatization. Mobile solvent A was ddH₂O with 5% (v / v) acetonitrile, and mobile solvent B was acetonitrile with 5% (v / v) ddH₂O. Data analysis was performed using OpenLAB CDS 2.4 software, version 2.204.0.661 (Agilent Technologies, Santa Clara, USA). The enzymes used were classified as inactive (-), slightly active (+), and active (++) based on the peak area of ​​the 2,4-TDA and 2,6-TDA produced. 2024PF30148 - Foreign.

[0179] - 28 -

[0180] Results

[0181] Table 2: Overview of the activity of the enzymes in Example 4.

Claims

2024PF30148 - Abroad - 29 - 1. A process comprising the recovery of a polyol from a polyol phase obtained by a recycling process (A) comprising the reaction (A1) of a polyurethane product based on an isocyanate component and a polyol component with a chemolysis alcohol and water to form a chemolysis product and the work-up (A2) of the chemolysis product comprising the separation of an amine phase from the chemolysis product, wherein the polyol phase contains a polyol from the polyol component and a carbamate of an isocyanate of the isocyanate component and the chemolysis alcohol, wherein the amine phase contains chemolysis alcohol and an amine corresponding to an isocyanate of the isocyanate component, and wherein the process comprises: (a) Reaction (al) of the polyol phase with an aqueous hydrolysis reagent (in a stoichiometric excess) in the presence of a urethanase preparation to obtain a product mixture comprising (i) a polyol depleted of carbamate, (ii) an amine formed by carbamate hydrolysis, (iii) chemolysis alcohol formed by carbamate hydrolysis, and (iv) water, and Work-up (a.2) of the product mixture to obtain the polyol depleted of the carbamate.

2. The method of claim 1, wherein the separation of the amine phase comprises a phase separation.

3. The method of claim 2, a) wherein the chemolysis product decomposes into the polyol phase and the amine phase, which are separated from each other by phase separation; or b) wherein the work-up (A.2) of the chemolysis product comprises an extraction (A.2.1) with an organic extraction agent and the polyol phase and the amine phase are obtained by phase separation during the extraction. 2024PF30148 - Abroad - 30 - 4. The method of claim 1, wherein the separation of the amine phase comprises distillation, optionally in conjunction with stripping, in which the chemolysis alcohol, the amine and water are distilled off and the polyol phase remains.

5. A method according to any one of claims 1 to 4, wherein in the work-up of the product mixture in step (a.2) water, the amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis are separated from the product mixture by distillation and / or stripping.

6. Method according to any one of claims 1 to 4, wherein the work-up of the product mixture in step (a.2) comprises separating the polyol depleted of the carbamate by phase separation.

7. The method of claim 6, a) in which, in step (a.2), the product mixture is separated in a first phase separation into an organic phase containing the amine formed by carbamate hydrolysis and the polyol depleted of carbamate, and an aqueous phase containing the chemolysis alcohol formed by carbamate hydrolysis, wherein the organic phase is extracted with an aqueous acid to obtain a further product mixture, followed by a second phase separation of the further product mixture into the polyol depleted of carbamate and an aqueous amine phase; or b) in which, in step (a.2), an aqueous amine phase containing the amine formed by carbamate hydrolysis and the chemolysis alcohol formed by carbamate hydrolysis is obtained in addition to the polyol depleted of carbamate in the phase separation; or c) in which, in step (a.2) in the phase separation, in addition to the polyol depleted of the carbamate, an emulsion phase and optionally an aqueous phase are formed, wherein the emulsion phase is extracted with an organic solvent comprising a hydrocarbon (a.3), followed by a phase separation into a solvent phase and an aqueous amine phase, and wherein the aqueous phase that may have been formed is combined with the aqueous amine phase. 2024PF30148 - Abroad - 31 - 8. The method of claim 7, wherein the aqueous amine phase is combined with the amine phase.

9. Method according to one of the preceding claims, wherein the carbamate-depleted polyol obtained in step (a.2) is further purified by distillation and / or stripping.

10. Method according to any one of claims 1 to 9, wherein step (al) is carried out at 10 °C to 80 °C.

11. A method according to any one of claims 1 to 10, wherein the urethanase preparation contains a polypeptide defined by one of the amino acid sequences according to SEQ ID NO.: 1 to 6 or a variant thereof, wherein the variant is obtained by the addition, deletion or exchange of up to 15% of the amino acids contained in the respective polypeptide sequence defined by one of the amino acid sequences according to SEQ ID NO.: 1 to 6.

12. The method of claim 11, wherein the amino acid sequence of the polypeptide is defined by the amino acid sequence according to SEQ ID NO.: 4 or a variant thereof.

13. A method according to any one of claims 1 to 12, comprising the recovery of a further valuable material besides the polyol from the polyurethane product by (ß) Work up the amine phase by distillative purification to obtain the amine.

14. The method of claim 13, wherein the amine is phosgenated to an isocyanate.

15. The method of claim 14, wherein the isocyanate is reacted with a polyol to form a polyurethane.

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