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

Abstract

The invention relates to a method comprising the extraction of at least one polyol from a polyol phase, wherein the polyol phase has been obtained through a recycling process (A) comprising an alcoholysis of a polyurethane product (A.1) and a workup of the chemolysis product obtained in the process, with separation of a carbamate 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 at least one carbamate, and working up (α.2) the product mixture to extract the at least one polyol depleted of the at least one carbamate.

Description

[0001] 2022PF30148 - Abroad

[0002] - 1 -

[0003] METHOD FOR RECOVERING AT LEAST ONE POLYOL FROM THE POLYOL PHASE OF A POLYURETHAN ALCOHOL HYSSIS

[0004] The present invention relates to a process comprising the recovery of at least one polyol from a polyol phase, wherein the polyol phase was obtained by a recycling process (A) comprising alcoholysis of a polyurethane product (Al) and work-up of the chemolysis product obtained thereby, separating a carbamate 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 polyol depleted of the at least one carbamate, and work-up (a.2) of the product mixture to obtain the at least one polyol depleted of the at least one carbamate.

[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 2022PF30148 - 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. 2022PF30148 - 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; (C11) washing the product mixture obtained in step (C2). 2022PF30148 - 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 by which polyurethanes composed of polyether polyols and aromatic isocyanates can be degraded 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 degradation).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 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 by SEQ ID No. 1, 2, and 3 therein, 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) urethanization of a polyether polyol polyurethane with at least one low molecular weight alcohol, yielding polyether polyols and low molecular weight urethanes; and b) enzymatic cleavage of the polyether polyols and low molecular weight urethanes produced in process step a).

[0023] - 5 - Low molecular weight urethanes 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.

[0024] WO 2024 / 170559 describes a process for the chemolysis of a urethane (in particular polyurethane) based on an isocyanate component and an alcohol component by reaction with a chemolysis alcohol to form a carbamate 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 with 1 to 4 carbon atoms, wherein a mass ratio of the chemolysis alcohol to the urethane of 1.0 to 4.5 is set.

[0025] 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 can be understood as an alcoholysis followed by a separate hydrolysis of separated carbamates (see No. 2 above).

[0026] 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. 2022PF30148 - Abroad

[0027] - 6 -

[0028] 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 be able to easily remove entrained carbamate impurities from the polyol-rich phase produced in alcoholysis processes.

[0029] 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 means of a recycling process (A) comprising a reaction (Al) of a polyurethane product based on an isocyanate component and a polyol component with a (superstoichiometrically used) chemolysis alcohol [in the absence of substantial amounts of water, i.e., a chemolysis carried out as alcoholysis] to a chemolysis product and a work-up (A.2) of the chemolysis product comprising a separation of a carbamate phase from the chemolysis product, wherein the carbamate phase contains (unreacted) chemolysis alcohol and a first part of a carbamate, an isocyanate of the isocyanate component and the chemolysis alcohol (which was formed in the reaction of the polyurethane product with the chemolysis alcohol), wherein the polyol phase contains (at least) one polyol from the polyol component and a second part of the (at least one) carbamate, wherein the first part of the (at least one) carbamate is (significantly) larger than the second part of the (at least one) carbamate, and wherein the process comprises (see also FIG. 1):.

[0030] (a) reacting (al) the polyol phase with an aqueous hydrolysis reagent (WHR; used in a stoichiometric excess) in the presence of a urethanase preparation (URP) to obtain a (first) product mixture comprising

[0031] (i) (at least) a polyol depleted of (at least one) carbamate,

[0032] (ii) (at least) an amine formed by carbamate hydrolysis, (iii) chemolysis alcohol formed (and released) by carbamate hydrolysis, and (iv) (unreacted, because it was used superstoichiometrically) water, and

[0033] Work-up (a.2) of the (first) product mixture to obtain the (at least one) carbamate-depleted polyol. 2022PF30148 - Abroad

[0034] - 7 -

[0035] 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.

[0036] According to the invention, the chemolysis of the polyurethane product is carried out as alcoholysis, i.e., as a reaction with an alcohol (= chemolysis alcohol) in the absence of substantial amounts of water. Since alcohols are often not completely anhydrous (unless they are dried and stored in the absence of moisture until use), small amounts of water may be present, particularly for this reason, even though water is not specifically used as a chemolysis reagent. However, in alcoholysis according to the invention, water (regardless of its source) is introduced into the chemolysis only in such an amount that the mass fraction of the water present during alcoholysis is 0% to < 4.1%, in particular 0% to 4.0%, preferably 0% to 3.0%, particularly preferably 0% to 2.0%, very preferably 0% to 1.0%, and most preferably 0% to 0.5%, based on the mass of the polyurethane product.The mass of the polyurethane product is defined as its dry mass, excluding any water present. Potential sources of water include, besides the aforementioned possibility of moisture in the chemolysis alcohol, any chemolysis catalyst used, and possibly the polyurethane product itself.

[0037] Water is introduced via the chemolysis catalyst, if used, particularly when it is used as an aqueous solution. The amount of water introduced is known.

[0038] Due to the rather hydrophobic nature of most polyurethane products, any moisture content present is usually negligible. If necessary, the polyurethane products can be dried using known methods, for example by heating them 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.

[0039] If it is uncertain whether a chemolysis alcohol to be used contains significant amounts of water beyond negligible trace amounts, its water content can be determined by Karl Fischer titration; this is the decisive method 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. If only an "overly moist" alcohol is available as a chemolysis alcohol, see 2022PF30148 - Foreign

[0040] - 8 - available, the alcohol can be freed from excess water using drying methods known per se.

[0041] 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, "a polyether polyol" is mentioned 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.

[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 isocyanates encompasses all isocyanates known in the art in connection with urethane chemistry. The expression "one or more isocyanates" 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 phrase "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 can be obtained according to R-NH + COCI ® RN=C=O + 2 HCl.

[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 so-called “split phase” glycolysis,

[0048] FIG. 3 shows the recycling process involving extraction of the chemolysis product with a hydrocarbon,

[0049] FIG. 4 the recycling process by extraction of the chemolysis product with a halogen hydrocarbon, 2022PF30148 - Abroad

[0050] - 9 -

[0051] FIG. 5 shows a possible variant for carrying out step (oc) in the case of water-insoluble amines,

[0052] FIG. 6 shows a first possible variant for carrying out step (oc) in the case of water-soluble amines, and

[0053] FIG. 7 shows a second possible variant for carrying out step (oc) in the case of water-soluble amines.

[0054] The following is a brief summary of various possible embodiments of the invention:

[0055] In a first embodiment of the invention, which can be combined with all other embodiments, the separation of the carbamate phase comprises a (liquid-liquid or solid-liquid) phase separation.

[0056] 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 carbamate 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).

[0057] 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) of the same with an organic hydrocarbon-containing extraction agent, wherein the polyol phase and the carbamate phase are obtained during the extraction by phase separation (in this embodiment: / süss / g- / / üss / g-) (see also FIG. 3).

[0058] In a fourth embodiment of the invention, which is a particular embodiment of the third embodiment, the carbamate phase is extracted with a hydrocarbon, optionally with the addition of an aqueous extraction agent (A.2.2), followed by phase separation into a hydrocarbon phase and an extracted carbamate phase, wherein the hydrocarbon phase is used as an organic hydrocarbon-containing extraction agent in the extraction (A.2.1) of the chemolysis product.

[0059] In a fifth embodiment of the invention, which is a further particular embodiment of the first embodiment, the work-up (A.2) of the chemolysis product comprises mixing (A.2.3) it with a halogen-substituted hydrocarbon and extraction (A.2.4) with an aqueous washing liquid, wherein the polyol phase and the (in this embodiment: aqueous) carbamate phase are obtained during the extraction by phase separation (in this embodiment: / sweet / g / / sweet / g) (see also FIG. 4). 2022PF30148 - Abroad

[0060] - 10 - In a sixth embodiment of the invention, which is an alternative to the seventh embodiment described below, but which can otherwise be combined with all other embodiments, 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 (so that the (at least one) polyol depleted of the (at least one) carbamate remains).

[0061] In a seventh embodiment of the invention, which is an alternative to the sixth embodiment described above, but which can otherwise be combined with all other embodiments, the work-up of the (first) product mixture in step (a.2) comprises separating the (at least one) polyol depleted of the (at least one) carbamate by a (liquid-liquid) phase separation.

[0062] In an eighth embodiment of the earth discovery process, which is a special embodiment of the seventh 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 also FIG. 5).

[0063] In a ninth embodiment of the invention, which is a further special embodiment of the seventh 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. 6).

[0064] In a tenth embodiment of the earth discovery process, which is a further special embodiment of the seventh embodiment, in step (a.2) during 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. 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 the aqueous phase that may have been formed is combined with the aqueous amine phase (see also FIG. 7). 2022PF30148 - Abroad

[0065] - 11 - In an eleventh embodiment of the invention, which is a special embodiment of the eighth to tenth embodiments, the aqueous amine phase is processed (separately) to obtain the amine formed in step (al).

[0066] In a twelfth embodiment of the invention, which is a further particular embodiment of the eighth to tenth embodiments, the aqueous amine phase is combined with the carbamate phase, in particular such that the aqueous amine phase is used as an aqueous extraction agent in a process according to the fourth embodiment.

[0067] In a thirteenth embodiment of the invention, which is a particular embodiment of the eighth 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.

[0068] In a fourteenth 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 fifteenth embodiment of the invention, which can be combined with 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 sixteenth 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 seventeenth embodiment of the invention, which can be combined with all other embodiments, the urethanase preparation is recycled after step (a) has been carried out.

[0072] In an eighteenth embodiment of the invention, which can be combined with all other embodiments, the reaction of the polyurethane product with the chemolysis alcohol 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- 2022PF30148 - Abroad

[0073] - 12 -

[0074] Diazabicyclo(2.2.2)octane, “DABCO”), cesium fluoride, an organotin compound (especially dibutyltin dilaurate, “DBTL”, or monobutyltin oxide, n-Bu-Sn(O)OH, “MBTO”) or a mixture of two or more of the aforementioned chemolysis catalysts.

[0075] In a nineteenth 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, especially 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.;

[0076] In a twentieth 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 comprises a polyether polyol. Particularly preferably, the polyol component comprises 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).

[0077] In a twenty-first 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-

[0078] 1-butanol, cyclopentanol, hexan-2-ol, hexan-3-ol, 2-methylpentan-l-ol, 2-methylpentan-2-ol,

[0079] 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- 2022PF30148 - Abroad

[0080] - 13 -

[0081] Propanediol, benzyl alcohol, furfuryl alcohol or a mixture of two or more of the aforementioned chemolysis alcohols.

[0082] In a twenty-second 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.

[0083] In a twenty-third 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 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.

[0084] In a twenty-fourth embodiment of the invention, which is a particular embodiment of the twenty-third embodiment, the amino acid sequence of the (at least one) polypeptide is defined by the amino acid sequence according to SEQ ID NO.: 4 or the variant thereof.

[0085] In a twenty-fifth 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

[0086] (ß) Work-up of the (possibly pretreated, in particular extracted) carbamate phase, wherein the work-up of the carbamate phase comprises one of the following reactions:

[0087] (ß.l) Hydrolysis of the first part of the (at least one) carbamate with a further aqueous hydrolysis reagent to give (at least) one amine;

[0088] (ß.2) Hydrogenolysis of the first part of the (at least one) carbamate with hydrogen to give (at least) one amine;

[0089] (ß.3) Cleavage of the first part of the (at least one) carbamate into the isocyanate of the isocyanate component and the chemolysis alcohol; or

[0090] (ß.4) Reaction of the first part of the (at least one) carbamate with a polyol to form an OH-terminated prepolymer.

[0091] In a twenty-sixth embodiment of the invention, which is a particular embodiment of the twenty-fifth embodiment, the aqueous amine phase obtained in a process comprising the eighth, ninth, tenth or thirteenth embodiment is used as a component, optionally the sole component, of the further aqueous hydrolysis reagent or is added to the hydrolysis reagent formed in step (β.1) (at least 2022PF30148 - Abroad

[0092] - 14 - an) amine (especially prior to its isolation from the hydrolysate obtained in step (ß.1)) added.

[0093] In a twenty-seventh embodiment of the invention, which can be combined with all embodiments comprising the step (ß.1) of hydrolysis of the first part of the (at least one) carbamate, the hydrolysis is preceded and / or followed (indirectly or directly) by evaporation of a fraction of the chemolysis alcohol, wherein the hydrolysis is preceded and / or followed (indirectly or directly) by evaporation of water.

[0094] In a twenty-eighth embodiment of the invention, which is a particular embodiment of the twenty-seventh embodiment, the fraction of the chemolysis alcohol is returned to the recycling process.

[0095] In a twenty-ninth embodiment of the invention, which is a particular embodiment of the twenty-seventh and twenty-eighth embodiments, evaporated water is recycled into step (al) and / or into step (ß.l).

[0096] In a thirtieth embodiment of the invention, which can be combined with all embodiments comprising the step (β.1) of hydrolysis of the first part of the (at least one) carbamate, the hydrolysis is carried out in the presence of a hydrolysis catalyst comprising

[0097] (I) an (organic or inorganic) Brpnsted base selected from (i) a hydroxide (in particular sodium hydroxide, tetramethylammonium hydroxide, potassium hydroxide or tetrabutylammonium hydroxide), (ii) a carbonate (in particular an alkali metal carbonate such as sodium or potassium carbonate), (iii) a hydrogen carbonate (in particular an alkali metal hydrogen carbonate such as sodium or potassium hydrogen carbonate), (iv) an orthophosphate or metaphosphate, preferably orthophosphate (in particular an alkali metal phosphate or alkali metal hydrogen phosphate), or (v) a mixture of two or more of the aforementioned Brpnsted bases, and / or

[0098] (II) a urethanase preparation, in particular the urethanase preparation as used in step (al), was performed.

[0099] In a thirty-first embodiment of the invention, which can be combined with all embodiments comprising step (β.2) of the hydrogenolysis of the first part of the (at least one) carbamate, the hydrogenolysis is carried out in the presence of a hydrogenolysis catalyst comprising palladium (in particular Pd / C, PdCh or Pd(OAc)z), copper, nickel (in particular Raney nickel), manganese (in particular having Mn complexes 2022PF30148 - Abroad

[0100] - 15 - a tridentate chelating ligand binding via P and N donor atoms as well as CO and / or halogen ligands) or platinum (especially platinum(IV) oxide).

[0101] In a thirty-second embodiment of the invention, which can be combined with all embodiments comprising step (β.1) of hydrolysis or step (β.2) of hydrogenolysis of the first part of the (at least one) carbamate, the (at least one) amine obtained in step (β.1) or step (β.2) is phosgenated to an isocyanate (i.e., to the corresponding isocyanate).

[0102] In a thirty-third embodiment of the invention, which is a particular embodiment of the thirty-second embodiment, the isocyanate is reacted with a polyol, in particular with the polyol obtained by distillation and / or stripping according to the sixteenth embodiment, to form a polyurethane.

[0103] In a thirty-fourth embodiment of the invention, which can be combined with all embodiments comprising the step (ß.3) of cleavage of the first part of the (at least one) carbamate, the carbamate cleavage is carried out in the presence of a carbamate cleavage catalyst comprising

[0104] (I) a metal-free or metal-containing Brensted or Lewis acid catalyst or

[0105] (II) a metal-free or metal-containing Brensted or Lewis basic catalyst was used.

[0106] In a thirty-fifth embodiment of the invention, which can be combined with all embodiments comprising step (β.4) of reacting the first part of the (at least one) carbamate with a polyol to form an OH-terminated prepolymer, this reaction is carried out in the presence of a catalyst comprising a carbonate, a hydrogen carbonate, a hydroxide, an orthophosphate, a monohydrogen orthophosphate, a metaphosphate, an orthovanadate (all of the aforementioned catalysts being preferably used in the form of their sodium or potassium salts), a titanium alkoxide (in particular tetra-n-butyl titanate, Ti(O-nBu)4), a tertiary amine (in particular 1,4-diazabicyclo(2,2,2)octane, “DABCO”), cesium fluoride, a stannate (in particular dibutyltin dilaurate, “DBTL”, or monobutyltin oxide, n-Bu-Sn(O)OH, “MBTO”), or a mixture of two or more of the aforementioned catalysts. carried out.

[0107] The embodiments and further possible configurations of the invention briefly described above are explained in more detail below. All previously described embodiments and the further configurations described below of 2022PF30148 - Abroad

[0108] - 16 -

[0109] Unless the context clearly indicates otherwise to a person skilled in the art, or unless something else is expressly stated, inventions can be combined with each other and in any way.

[0110] PROVISION OF THE POLYURETHANE PRODUCT

[0111] 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.

[0112] 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-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 methylenediphenyl diisocyanate"). H12MDI, especially the 4,4'-isomer; obtainable by phosgenation of diaminodicyclohexylmethane, H12MDA, itself obtainable by nuclear hydrogenation of 2-core MDA), xylylene diisocyanate (XDI;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 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).

[0113] 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 besides TDI, and the polyol component comprises at least 2022PF30148 - Abroad

[0114] - 17 - a polyether polyol and preferably no other polyols other than polyether polyols).

[0115] Preferably, the provision of the polyurethane product already includes preparatory steps for the subsequent reaction with the chemolysis alcohol. 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.

[0116] Since the chemolysis is to be carried out as alcoholysis, it is important to ensure that the polyurethane products to be recycled are as free of moisture as possible. Due to the rather hydrophobic nature of most polyurethanes, any moisture content present is usually negligible. If necessary, the polyurethane products can be dried using known methods, for example, by heating them in a dry air or nitrogen stream (preferably nitrogen) until the air or nitrogen stream no longer shows an elevated water content after contact with the polyurethane.

[0117] 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 further transport, the prepared polyurethane product can also be compressed to achieve a higher mass-to-volume ratio.

[0118] PERFORMING ALCOHOL HYSSIS

[0119] With regard to the execution of the alcoholysis, 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.

[0120] Preferably, in the alcoholysis, a mass ratio of (1) chemolysis alcohol to (2) the polyurethane product (m(l) / m(2); where m represents mass) in the range of 0.5 to 2.5 is established. The reaction with the chemolysis alcohol preferably takes place at a temperature of 135 °C to 240 °C, particularly preferably 180 °C to 200 °C, and preferably at a pressure of 900 mbar(abs.) to 1200 mbar( a bs.), especially preferably 980 mbar( a bs.) up to 1020 mbar( a The reaction should be carried out, in particular, under exclusion of oxygen. Before introducing the polyurethane product into the reactor used for alcoholysis, it should preferably be inerted. Methods for this are known (see in particular WO 2022 / 128871 Al). 2022PF30148 - Foreign

[0121] - 18 -

[0122] It is advantageous to add a catalyst to carry out alcoholysis. 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.

[0123] 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.

[0124] REPROCESSING OF THE CHEMOYL PRODUCT

[0125] There are various alternatives for processing the alcoholysis 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.

[0126] In general, the separation of the carbamate phase will involve a (liquid-liquid or solid-liquid) phase separation. In the simplest case, such a phase separation occurs spontaneously after completion of the alcoholysis and cooling of the product mixture (so-called "split-phase" glycolysis). The chemolysis product decomposes (spontaneously) into the polyol phase and the carbamate 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.

[0127] However, it may also be appropriate to bring about a phase separation yielding the polyol phase and carbamate phase by means of an extraction process, for example, if spontaneous phase separation is not possible with the chosen combination of polyurethane product and 2022PF30148 - Abroad

[0128] - 19 -

[0129] chemolysis alcohol does not occur or does not occur at a rate sufficient for technical processes, or the separation of polyols and carbamates is not complete enough without the addition of an extraction solvent.

[0130] The process according to the invention can, for this purpose, be combined, for example, with the procedure described in WO 2020 / 260387. In the terminology of the present invention, the “first alcohol phase (21)” described therein corresponds to the carbamate phase and the “first solvent phase (41)” described therein corresponds to the polyol phase. In this embodiment, the work-up (A.2) of the chemolysis product comprises an extraction (A.2.1) of the same with an organic hydrocarbon-containing extraction solvent. The polyol phase and the carbamate phase are obtained during the extraction by a / 7ss / g- / / ss / g phase separation. This is illustrated graphically in FIG. 3 (OEM = organic extraction solvent; KW = hydrocarbon). The carbamate phase obtained is preferably extracted with a (fresh) hydrocarbon, optionally with the addition of an aqueous extraction solvent (A.2.2), followed by phase separation into a hydrocarbon phase and an extracted carbamate phase. The hydrocarbon phase obtained in this process can advantageously be recycled back into the extraction (A.2.1) of the chemolysis product and used there as an organic hydrocarbon-containing extraction solvent.

[0131] The process according to the invention can also be successfully combined with the procedure described in WO 2022 / 063764. In the terminology of the present invention, the “first aqueous phase (61)” described therein corresponds to the carbamate phase and the “first solvent phase (41)” described therein corresponds to the polyol phase. In this embodiment, the work-up (A.2) of the chemolysis product comprises mixing (A.2.3) it with a halogen-substituted hydrocarbon and extraction (A.2.4) with an aqueous washing liquid, wherein the polyol phase and the (in this embodiment: aqueous) carbamate phase are obtained during extraction by a / 7ss / g / / ss / g phase separation. This is illustrated graphically in FIG. 4 (HC = halogenated hydrocarbon; WWF = aqueous washing liquid).

[0132] Regardless of the precise method used to separate the carbamate 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.

[0133] POLYOL PHASE REPROCESSING, PERFORMANCE OF STEP (a)

[0134] For further processing of the polyol phase, it is first reacted in one step (oc.l) with an aqueous hydrolysis reagent in the presence of a urethanase preparation, followed by work-up of the (first) product mixture obtained in a 2022PF30148 - Abroad

[0135] - 20 -

[0136] Step (a.2) to obtain the polyol depleted at (at least one) carbamate.

[0137] Suitable aqueous hydrolysis reagents for step (oc.l) 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 (oc.l) (e.g., aqueous distillate streams from the distillative purification of amines), 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, these enter the aqueous portion of the (first) product mixture after completion of the enzymatic carbamate cleavage. 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 separate the urethanase preparation by ultrafiltration.The urethanase preparation separated in this way can then be recycled.

[0138] 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.

[0139] 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.

[0140] The (first) product mixture obtained in step (oc.l) is worked up in step (oc.2). In the simplest case, the (at least one) amine formed by carbamate hydrolysis and 2022PF30148 - Abroad are

[0141] - 21 - The chemolysis alcohol formed by carbamate hydrolysis is separated from the (first) product mixture by distillation and / or stripping, leaving behind the (at least one) carbamate-depleted polyol. 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 (at least one) carbamate-depleted polyol can also be carried out using other work-up methods, such as those described below.

[0142] Preferably, the separation of the polyol depleted of the carbamate (at least one) preferably includes 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, 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 shown in FIG. 5 graphically represented (WS = aqueous acid).

[0143] 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. 6.

[0144] If an emulsion forms as described in WO 2020 / 260387 Al, 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. 7 (LM = organic solvent).

[0145] The aqueous amine phase obtained in the variants described above can be processed (separately) to recover the amine formed in step (al). However, it is preferred to use 2022PF30148 - Abroad

[0146] - 22 - to combine this aqueous amine phase with the carbamate phase. In the embodiment described above, comprising extraction of the carbamate phase (A.2.2) with a hydrocarbon with the addition of an aqueous extraction solvent, this can be easily achieved by using the aqueous amine phase as a component of the aqueous extraction solvent (optionally as the sole component).

[0147] 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.

[0148] REPROCESSING THE CARBAMATE PHASE

[0149] Preferably, the carbamate phase is also processed to obtain further valuable materials (step (β)). Such processing can, in particular, include one of the following transformations:

[0150] (ß.l) Hydrolysis of the first part of the (at least one) carbamate with a further aqueous hydrolysis reagent to give (at least one) amine;

[0151] (ß.2) Hydrogenolysis of the first part of the (at least one) carbamate with hydrogen to give (at least one) amine;

[0152] (ß.3) Cleavage of the first part of the (at least one) carbamate into the isocyanate of the isocyanate component and the chemolysis alcohol; or

[0153] (ß.4) Reaction of the first part of the (at least one) carbamate with a polyol to form an OH-terminated prepolymer.

[0154] The procedures according to (ß.1) to (ß.4) are known in themselves and are therefore only briefly referred to below.

[0155] If the carbamate phase is hydrolyzed according to step (β.1), it is preferred to use the aqueous amine phase from step (oc.2) described above as a component, or optionally as the sole component, of the further aqueous hydrolysis reagent, or to add it to the (at least one) amine formed in the hydrolysis in step (β.1) (especially before its isolation from the hydrolysate obtained in step (β.1)). If the aqueous amine phase is acidic (acidic extraction in the case of water-insoluble amines), care must be taken to ensure that the pH of the aqueous hydrolysis reagent used is within the pH tolerance range of the urethanase preparation used. 2022PF30148 - Abroad

[0156] - 23 -

[0157] In principle, such hydrolysis can be carried out analogously to the direct hydrolysis of polyurethanes (see the literature cited above, in particular the review article [1]). The amines obtained in this way can then be used for all purposes known in the field for such amines. Preferably, the recovered amines are phosgenated back to the corresponding isocyanates using methods known per se. 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.

[0158] The hydrolysis may be preceded and / or directly or indirectly followed by the evaporation of a fraction of the chemolysis alcohol, just as the hydrolysis may be preceded and / or (depending on the boiling point of the chemolysis alcohol relative to the boiling point of water; in some cases, co-evaporation of water during the evaporation of chemolysis alcohol cannot be avoided without reasonable effort) directly or indirectly followed. The separation of volatile components prior to hydrolysis can eliminate the need for pressure during the hydrolysis process. It is preferred to recycle the separated chemolysis alcohol back into the recycling process. Evaporated water can be recycled as a component of the (further) aqueous hydrolysis reagent in step (oc.l) and / or step (β.l).

[0159] The hydrolysis of the carbamate phase can occur in the presence of a catalyst. Particularly suitable hydrolysis catalysts include...

[0160] (I) (Organic or inorganic) Brpnsted bases selected from (i) a hydroxide (in particular sodium hydroxide, tetramethylammonium hydroxide, potassium hydroxide or tetrabutylammonium hydroxide), (ii) carbonates (in particular an alkali metal carbonate such as sodium or potassium carbonate), (iii) hydrogen carbonates (in particular an alkali metal hydrogen carbonate such as sodium or potassium hydrogen carbonate), (iv) orthophosphates or metaphosphates, preferably orthophosphate (in particular an alkali metal phosphate or alkali methylhydrogen phosphate) or (v) mixtures of two or more of the aforementioned Brpnsted bases, and / or

[0161] (II) Urethanase preparations, in particular the same ones used in step (oc.l).

[0162] Amines can also be obtained from the carbamate phase by hydrogenolysis (β.2). A process starting directly from polyurethanes, which is also applicable to the present step (D.II), is described in "Hydrogenative Depolymerization of Polyurethanes Catalyzed by Manganese Pincer Complex" by Viktoriia Zubar et al., published in ChemSusChem 10.1002 / cssc.202101606 [2]. Reference is also made to the literature cited in [2]. The uses of the amine are the same as described for (β.1). Suitable hydrogenolysis catalysts include, in particular, those comprehensively described in 2022PF30148 - Ausland.

[0163] - 24 -

[0164] Palladium (especially Pd / C, PdCh or Pd(OAc)2), copper, nickel (especially Raney nickel), manganese (especially Mn complexes having a tridentate chelating ligand binding via P and N donor atoms as well as CO and / or halogen ligands) or platinum (especially platinum(IV) oxide).

[0165] Regardless of how exactly the amines were obtained, they are preferably purified using known methods before further use. Such purification includes, in particular, the distillative removal of low-boiling components and, if necessary, also inverted distillation of the amine (provided its boiling point allows evaporation without decomposition).

[0166] However, carbamates can also be directly cleaved back to the corresponding isocyanates (β.3), either purely thermally or in the presence of carbamate cleavage catalysts. Particularly suitable for this purpose are metal-free or metal-containing Brensted or Lewis acidic catalysts, or metal-free or metal-containing Brensted or Lewis basic catalysts. For further details, see W. Leitner et al., Carbon2Polymer-Chemical Utilization of CO in the Production of Isocyanates, Chapter 4, "Carbamate Cleavage", published in Chem. Ing. Tech. 2018, 90, 1504-1512 [3] and the literature cited therein. The work-up method according to (β.3) directly yields the isocyanate of the isocyanate component, thus making further phosgenation unnecessary. Separation of different isocyanates is readily possible using well-known techniques (recrystallization, distillation).

[0167] Finally, it is possible (β.4) to react the carbamates with a polyol to form an OH-terminated prepolymer. Chemically, this is a urethanization and thus, in principle, the same type of reaction that underlies the alcoholysis of polyurethanes (see the literature cited above, in particular the review article [1]). For this, the carbamate is reacted with a polyol, whereby the OH groups of the polyol are added stoichiometrically or superstoichiometrically, in particular slightly superstoichiometrically (e.g., 5 to 10% excess on a molar basis), to the existing carbamate functionalities. This reaction leads to OH-terminated prepolymers. These can be used for all applications known in the field; in particular, they can be used in a reaction with isocyanates as prepolymers for elastomers, flexible and rigid foam applications, thermoplastic polyurethanes, coatings, and adhesives.

[0168] The polyol used in step (β.4) has a boiling point higher than that of the chemolysis alcohol used. In a particularly preferred embodiment, the chemolysis alcohol is continuously removed from the reaction mixture by distillation during the reaction with the polyol. 2022PF30148 - Abroad

[0169] - 25 -

[0170] The reaction can be carried out in the presence of a catalyst comprising a carbonate, a hydrogen carbonate, a hydroxide, an orthophosphate, a mono-hydrogen orthophosphate, a metaphosphate, an orthovanadate (all of the aforementioned catalysts being preferably used in the form of their sodium or potassium salts), a titanium alkoxide (in particular tetra-n-butyl titanate, Ti(O-nBu)4), a tertiary amine (in particular 1,4-diazabicyclo(2.2.2)octane, “DABCO”), cesium fluoride, a stannate (in particular dibutyltin dilaurate, “DBTL”, or monobutyltin oxide, n-Bu-Sn(O)OH, “MBTO”) or a mixture of two or more of the aforementioned catalysts.

[0171] Typical suitable polyols are divalent polyols (especially ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butenediol, 1,4-butynediol, neopentyl glycol, 1,5-pentanediol, methylpentanediols (such as 3-methyl-1,5-pentanediol), 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, bis-(hydroxymethyl)cyclohexanes (such as 1,4-bis-(hydroxymethyl)cyclohexane), triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, tripropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols and polyester polyols, e.g.from ethylene glycol and adipic acid), trivalent polyols (especially trimethylolpropane, glycerol, trishydroxyethyl isocyanurate), tetravalent polyols (especially pentaerythritol) and polyols that can be obtained from renewable raw materials (especially sorbitol, hexitol, sucrose, starch, starch hydrolysates, cellulose, cellulose hydrolysates and hydroxy-functionalized fats and oils, especially castor oil), as well as all modification products of these aforementioned polyols with varying amounts of e-caprolactone. Polyether polyols can also be used as polyols for step (β.4), especially those with a number-averaged molar mass M determined according to DIN 55672-1 (2016-03). nin the range of 18 g / mol to 8000 g / mol and exhibiting a functionality of 2 to 3 (calculated from the H-functional starters used in the production of the polyether polyols). Polyether polyols composed of repeating ethylene oxide and propylene oxide units are preferred, preferably with a proportion of 35% to 100% propylene oxide units, and particularly preferably with a proportion of 50% to 100% propylene oxide units. These can be statistical copolymers, gradient copolymers, alternating copolymers, or block copolymers of ethylene oxide and propylene oxide. The polyols obtained by the process according to the invention can also be used, provided they meet the other requirements for the production of prepolymers. 2022PF30148 - Foreign

[0172] - 26 -

[0173] 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 be present in the polyol phase as a result of extraction processes during workup. This will be further illustrated in the following examples.

[0174] 2022PF30148 - Abroad

[0175] - 27 -

[0176] RECYCLING PROCESS Alcoholysis of a soft foam under I and

[0177] A used (so-called "end of / / / e") polyurethane flexible foam based on a TDI isocyanate component and a polyether polyol polyol component was mechanically reduced to a particle size of approximately 15 to 20 mm and inerted by vacuuming and nitrogen addition. The pretreated polyurethane flexible foam was then reacted with an equal mass of diethylene glycol (DEG) and 1 wt% (based on the mass of the polyurethane flexible foam) of DABCO (1,4-diazabicylco[2.2.2]octane) at 200 °C for 3 h in a stirred tank reactor (alcolysis). See also FIG. 3; simplified there.

[0178] The resulting chemolysis product was filtered and extracted with cyclohexane as solvent (mass ratio of cyclohexane to filtered chemolysis product: 3 : 1), for which three so-called M / xer-Sett / er units were used:

[0179] (1) First, the filtered chemolysis product was extracted in a first mixer-settler reaction with cyclohexane (originating from (2); see below), after a first phase separation

[0180] (1-i) an upper phase (= polyol phase) comprising cyclohexane and the polyether polyol formed in alcoholysis, as well as small amounts of TDA and carbamates and

[0181] (1-ii) a lower phase (= carbamate phase) comprising water, carbamates and DEG as well as small amounts of the polyether polyol, TDA and cyclohexane were obtained.

[0182] (2) The lower phase (1-ii) obtained in (1) was extracted in a second mixer-settler reaction with fresh cyclohexane and water (originating from (3); see below), after a second phase separation

[0183] (2-i) an upper phase comprising cyclohexane and small amounts of the polyether polyol and

[0184] (2-ii) A lower phase (= extracted carbamate phase) comprising water, carbamates, DEG, and small amounts of TDA and cyclohexane was obtained. The upper phase (2-i), consisting mainly of cyclohexane, was fed into the first mixer-settler reactor. 2022PF30148 - Abroad

[0185] - 28 -

[0186] (3) A sample was taken from the upper phase (1-i) obtained in (1) and used for step (oc) (see Example 3). The main part of the upper phase (1-i) was extracted in a third mixer-settler apparatus with fresh water, followed by a third phase separation.

[0187] (3-i) an upper phase comprising cyclohexane and the polyether polyol formed in alcoholysis and

[0188] (3-ii) A lower phase comprising water and small amounts of TDA and carbamates was obtained. The lower phase (3-ii), consisting predominantly of water, was fed into the second mixer-settler unit. The described division of phase (1-i) was due to the available laboratory equipment. In an industrial application, step (oc) would be carried out in the third mixer-settler unit itself. As the experiments from Example 3 show, a carbamate-free aqueous phase (3-ii) would be expected in this case.

[0189] Conversion of the polyol phase with an aqueous hydrolysis reagent in the presence of a urethanase preparation

[0190] Example 2: Production of the urethanase preparation

[0191] 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.

[0192] 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. 2022PF30148 - Abroad

[0193] - 29 -

[0194] 3: Conversion of the solution to a urethanase preparation (see also FIG.

[0195] 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 2. 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.

[0196] 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 sampling time point and each enzyme, 3 mL of these solutions were mixed with 5 mL of the polyol phase (1-i) from Example 1 in 10 mL sample vials. Incubation was carried out at 40 °C and 400 rpm in an Eppendorf ThermoMixer™ C with a SmartBlock™ P / ates attachment. After completion of the reaction, 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.

[0197] Analytics

[0198] The cyclohexane phase (polyol phase (1-i) from Example 1 or the carbamate-depleted polyol dissolved in cyclohexane from Example 3) was first separated by X 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. 2022PF30148 - Abroad

[0199] - 30 -

[0200] Results

[0201] Table 1: Carbamate content in the polyol phase from Example 1 and in phases from Example 3

[0202] Notes:

[0203] [a] Carbamate content in the untreated polyol phase from Example 1 (reference experiment) or in the cyclohexane phases from Example 3 (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.

[0204] [b] N. a.: Not applicable.

[0205] Example 4: Experiments on the depletion of carbamates in polyol-rich phases with different urethanase preparations

[0206] Enzyme production

[0207] 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.

[0208] Enzyme reaction

[0209] 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. 2022PF30148 - Abroad

[0210] - 31 -

[0211] 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).

[0212] Analytics

[0213] 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 without derivatization using this method. 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.

[0214] Results

[0215] Table 2: Overview of the activity of the enzymes in Example 4.

Claims

2022PF30148 - Abroad - 32 - 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 to form a chemolysis product and the work-up (A2) of the chemolysis product comprising the separation of a carbamate phase from the chemolysis product, wherein the carbamate phase contains chemolysis alcohol and a first part of a carbamate of an isocyanate of the isocyanate component and the chemolysis alcohol, wherein the polyol phase contains a polyol from the polyol component and a second part of the carbamate, wherein the first part of the carbamate is larger than the second part of the carbamate, and wherein the process comprises: (a) Reaction (al) of the polyol phase with an aqueous hydrolysis reagent 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 carbamate phase comprises a phase separation.

3. The method of claim 2, a) wherein the chemolysis product decomposes into the polyol phase and the carbamate 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) of the same with an organic hydrocarbon-containing extraction solvent and the polyol phase and the carbamate phase are obtained by phase separation during the extraction; or 2022PF30148 - Abroad - 33 - c) wherein the work-up (A.2) of the chemolysis product comprises a mixing (A.2.3) of the same with a halogen-substituted hydrocarbon and an extraction (A.2.4) with an aqueous washing liquid, wherein the polyol phase and the carbamate phase are obtained during the extraction by phase separation.

4. The method of claim 3, comprising b), wherein the carbamate phase is extracted with a hydrocarbon, optionally with the addition of an aqueous extraction agent (A.2.2), followed by phase separation into a hydrocarbon phase and an extracted carbamate phase, wherein the hydrocarbon phase is used as an organic hydrocarbon-containing extraction agent in the extraction (A.2.1) of the chemolysis product.

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 2022PF30148 - Abroad - 34 - c) in which, in step (a.2) in the phase separation, an emulsion phase and optionally an aqueous phase are formed in addition to the polyol depleted of the 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.

8. The method of claim 7, wherein the aqueous amine phase is combined with the carbamate phase.

9. Method according to any one of claims 1 to 8, 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 defined in 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 of the carbamate phase, wherein the work-up of the carbamate phase comprises one of the following reactions: (ß.l) Hydrolysis of the first part of the carbamate with another aqueous hydrolysis reagent to give an amine; (ß.2) Hydrogenolysis of the first part of the carbamate with hydrogen to form an amine; (ß.3) Cleavage of the first part of the carbamate into the isocyanate of the isocyanate component and the chemolysis alcohol; or 2022PF30148 - Abroad - 35 - (ß.4) Reaction of the first part of the carbamate with a polyol to form an OH-terminated prepolymer.

14. The method of claim 13, wherein step (β.1) or step (β.2) is included, 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 is used.

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