Process for recycling polyurethane waste through remonomerization by hydro ammonolysis

Abstract

The present invention is directed to a process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (I1) and polyol (P1), depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, separation of the amine component and the polyol components with or without the aid of an additional ammonia dosage obtained in step b), to amine rich and a amine poor phase, and treatment of the polyol components in the amine poor phase to form a polyol (P2). Furthermore, the present invention is directed to the polyol composition or polyol fragments and the isocyanate composition obtained in said process and the use of the polyol composition and the isocyanate composition or the preparation of polyurethanes or polyisocyanurates.

Description

[0001] Process for recycling polyurethane waste through remonomerization by hydro ammonolysis

[0002] The present invention is directed to a process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11 ) and polyol (P1 ), depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, separation of the amine component and the polyol components and / or polyol fragments with or without the aid of an additional ammonia dosage obtained in step b), to amine rich and a amine poor phase, and treatment of the polyol components in the amine poor phase to form a polyol (P2). Furthermore, the present invention is directed to the polyol composition and the isocyanate composition obtained in said process and the use of the polyol composition and the isocyanate composition or the preparation of polyurethanes or polyi- socyanurates.

[0003] Products containing polyurethane materials are widely used in industry and in everyday applications. Because of the tremendous and still increasing prevalence of polyurethane materials, there is a large amount of waste of polyurethane materials (e.g., from old mattresses or seating furniture, car seats, refrigerators or insulation boards). This waste of polyurethane materials should be used appropriately and as ecologically friendly as possible. One way of such use of polyurethane materials is the recovery of raw materials from the polyurethane materials. Apart from so-called mechanical recycling methods, which teach a physical comminution, chemical recycling processes are known.

[0004] Remonomerization strategies discussed in the literature and patents include hydrolysis, glycolysis, aminolysis and acidolysis. For example WO 2021 / 023889 A1 discloses a method for alcoholizing and hydrolyzing polyurethane materials.

[0005] In general, hydrolysis techniques lead to a CO2release, which dissolves in water as carbonic acid under pressure and leads to a deactivation of the mostly basic catalysts. Especially in the literature, frequently used inorganic strong bases, such as sodium hydroxide or potassium hydroxide irreversibly deactivate. In addition, poorly soluble salts are often formed, which represent a challenge in the process engineering process. Another aspect is the splitting of polyester polyols. These consist mainly of dicarboxylic acids and glycols. The ester bonds are not stable in a hydrolytic remonomerization strategy and there is a cleavage of the polyester polyols into the monomer building blocks. The released acids react with the bases used as catalysts to carboxylate salts and with the released amine (toluene diamine or methylene diphenyl diamine) to ammonium salts, which can lead to a reduction in the yield of valuable products. For further processing the salts must be converted back into the corresponding acids, which is associated with a further process engineering effort.

[0006] In many processes, the problem is an irreversible reaction of the catalysts used with carbon dioxide, especially in hydroglycolysis under pressure. On the one hand, this leads to a reduced yield of polyols and amine monomers. In addition, insoluble solids are formed, which make downstream processing technically difficult. The circularity of the catalyst is also no longer given.

[0007] In view of the above, it is an object of the present invention to provide a process to recover raw materials from polyurethane materials which is as simple as possible, and which allows to recover raw materials having an optimized quality.

[0008] The problem is solved according to the present invention by a process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11 ) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water, c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase d) treatment of the polyol components in the amine poor phase to form a polyol (P2).

[0009] The process according to the present invention comprises steps a), b), c), d), e) and f) but may comprise further steps. It has been found that the specific sequence of process steps according to the present invention allows to recover raw materials from polyurethane or polyisocyanurate materials in high quality in a simple manner.

[0010] It has surprisingly been found that using the specific depolymerization conditions and purification steps, the ammonia present reacts with CO2 to form metastable carbamates or ammonium carbonates. The reaction mixture preferably is filtered and purified by a subsequent extraction. In the extract, the amine-rich phase is obtained, while the polyols or polyol fragments remain in an amine poor phase. The thermolabile ammonium carbonate can be separated using suitable separation techniques. For example the ammonium carbonate may be separated and decomposition may be achieved using mild conditions allowing versatile use of the components.

[0011] It has been found that the process is particularly suitable for the recycling and remonomeriza- tion of polyurethane or polyisocyanurate foams. Thus, according to the present invention, the polyurethane or polyisocyanurate material preferably is a polyurethane or polyisocyanurate foam, in particular a flexible or rigid polyurethane foam.

[0012] It has been found that the presence of the ammonium carbonate significantly improves the phase separation. According to the process of the present invention, it is possible to recover both starting material components from the polyurethane. The polyurethane components are either recovered directly, for example the polyols or fragments of those, or are obtained as valuable synthesis building blocks such as polyamines which may readily be converted to polyisocyanates.

[0013] According to step a), a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), is provided.

[0014] In the context of the present invention, a “comminuted polyurethane or polyisocyanurate material” means the material is obtained from a material and the comminuted polyurethane or polyisocyanurate is for example used in shredded form, in the form of granules, flakes, as an agglomerate, or as a powder. The polyurethane or polyisocyanurate materials can be comminuted by conventional methods, for example by shredding, e.g. in a rotation mill or rotary mill at room temperature, to a particle size of ordinarily less than 500 mm, for example to a particle size in the range of from 10 to 500 mm, preferably to a particle size of less than 20 mm, or ground, e.g. by known cold grinding processes. Preferably, for a milled material a particle size of less than 5 mm is selected, for example a particle size in the range of 0.01 mm to 5 mm, and preferably in the range of 0.01 mm to 1 mm.

[0015] The properties of the polyurethane or polyisocyanurate materials might vary in broad ranges. Preferably, polyurethane materials are used in the process of the present invention.

[0016] The polyurethane or polyisocyanurate materials used in the present invention are preferably obtained from items produced from polyurethane materials at a time after use for the purpose for which they were manufactured or polyurethane material waste from production processes. Before subjecting to the process of the present invention, the items may be subjected to sorting steps and / or to mechanical comminution. That is, further sorting and bringing the items into appropriate sizes, e.g., by shredding, sieving or separation by rates of density, i.e. by air, a liquid or magnetically. Optionally, these fragments may then undergo processes to eliminate impurities, e.g. paper labels. Furthermore, steps to remove blowing agents may be included in the process. Suitable methods are in principle known to the person skilled in the art.

[0017] Herein, the term “polyurethane material waste” includes end-of-life polyurethane materials and production rejects of PU materials or waste generated through further processing of PU materials. In this context, the term “spent polyurethane material” denotes an item produced from a polyurethane material at a time when it has already been used for the purpose for which it was manufactured. “Production rejects of polyurethane materials" denotes polyurethane material waste occurring in production processes of PU materials.

[0018] Generally, polyurethane materials are produced by a reaction between a polyisocyanate component and a polyol component. Typically, further materials, in particular additives, such as flame retardants (e.g. phosphorous-based), polymerization catalysts (e.g. tertiary amines), fillers and surfactants as siloxanes can be added in the production process of the polymers. The properties of a polyurethane material are influenced by the chemistry of polyisocyanate and polyol components used and the recipe applied in polymerization. For example, the starting materials may influence the crosslinking density of the polymers in a three-dimensional network. Rigid polyurethanes are typically obtained from monomers with a comparably low molecular weight and high functionality creating a highly crosslinked, dense network. Typically, the polyol substance comprises or consists of one or more polyols having a molecular weight of about 400 to about 4000 g / mol,a nominal OH functionality of about 1 to 6, preferably between 1 to 4.5 is used, in particular in the range of from 1 to 4.1 , more preferable in the range of from 1 to 3.9, most preferable in the range of from 1.1 to 3.5. and having an OH number of about 25 mg KOH / g to about 800 mg KOH / g, in particular from 25 to 500 mgKOH / g, preferably from 25 to 350 mgKOH / g, more preferable from 30 to 70 mgKOH / g.

[0019] Industrially and consequently in large quantities, especially methylenedi(phenylisocyanate) (MDI) or its polymeric forms or tolylene 2,4 and 2,6-diisocyanate (TDI) are used as polyisocyanate components for the production of PU rigid foams and PU flexible foams. For a representative composition of these PU foams, see for example US 9,023,907 B2,WO 2015 / 121057 and WO 2013 / 139781.

[0020] Organic polyisocyanates that can be used in the preparation of polyurethanes are any of the known organic polyisocyanates, preferably aromatic polyfunctional isocyanates. In the context of the present invention, the term polyisocyanate encompasses isocyanates with 2 or more isocyanate groups, i.e. also di isocyanates.

[0021] Suitable polyisocyanate components used for the production of the polyurethanes or polyisocy- anurates comprise any of the polyisocyanates known for the production of polyurethanes or pol- yisocyanurates. These comprise the aliphatic, cycloaliphatic, and aromatic difunctional or polyfunctional isocyanates known from the prior art, and also any desired mixtures thereof. Examples are diphenylmethane 2,2’-, 2,4’-, and 4,4’-diisocyanate, the mixtures of monomeric diphenylmethane diisocyanates with diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), isophorone diisocyanate (IPDI) and its oligomers, toluene 2,4- and 2,6- diisocyanate (TDI), and mixtures of these, tetramethylene diisocyanate and its oligomers, hexamethylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), and mixtures thereof.

[0022] Preferably, toluene 2,4- and / or 2,6-diisocyanate (TDI) or a mixture thereof, monomeric diphenylmethane diisocyanates, and / or diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), and mixtures of these. Other possible isocyanates are mentioned by way of example in "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.2 and 3.3.2.

[0023] The organic and polyisocyanates may be used individually or in the form of mixtures. Common polyols used in huge quantities are, e.g., selected from the group consisting of polyether polyols, polyester polyols, polyetherester polyols and mixtures thereof.

[0024] Polyetherols are by way of example produced from epoxides, for example propylene oxide and / or ethylene oxide, or from tetrahydrofuran with starter compounds exhibiting hydrogen-ac- tivity, for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example sucrose, sorbitol or mannitol, with use of a catalyst. Mention may be made here of basic catalysts and double-metal cyanide catalysts, as described by way of example in WO 2006 / 034800, EP 0090444, or WO 2005 / 090440.

[0025] Polyesterols are by way of example produced from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals, and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are mentioned by way of example in "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.

[0026] Polyesterpolyols may for example be selected from polyester alcohols whose OH numbers are in the range from 25 to 800 mg KOH / g, in particular from 25 to 500 mgKOH / g, preferably 25 to 350 mgKOH / g, in particular from 30 to 70 mgKOH / g. The polyester alcohols used are mostly prepared via condensation of polyhydric alcohols, preferably polyetherpolyols with a molecular weight up to 800 g / mol, preferably up to 650 g / mol, or diols, having from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms, with polybasic carboxylic acids having from 2 to 12 carbon atoms, e.g. succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, or preferably phthalic acid, isophthalic acid, terephthalic acid, or the isomeric naphthalenedicarboxylic acids. Also cyclic anhydrides may be used such as for example phthalic acid dianhydride.

[0027] According to step b) of the process of the present invention, the comminuted polyurethane or polyisocyanurate provided in step a) is depolymerized in the presence of water and / or ammonia and optionally, in presence of an additional solvent, which has a miscibility gap with water.

[0028] Water and optionally ammonia are added in suitable amounts to achieve depolymerization of the polyurethane or polyisocyanurate.

[0029] In principle, suitable conditions for the depolymerization may vary in broad ranges. The reaction may be for example carried out in a stirred tank or stirred tank cascade or plug flow reactor. Typically, the weight ratio of ammonia to the polyurethane or polyisocyanurate material is in the range of 3 to 1 (kg / kg) until 0.2 to 1 (kg / kg). The reaction temperature preferably is in a range of 170°C to 250°C. The weight ratio of water to polyurethane or polyisocyanurate material is preferably in a range of 1 to 1 (kg / kg) to 10 to1 (kg / kg) and the weight ratio of the organic solvent which contains a miscibility gap with water to polyurethane or polyisocyanurate material is preferably in the range of 0.2 to 1 (kg / kg) to 5 to 1 (kg / kg). Typically, the reaction time is between 0.5 and 10 h and the reaction pressure may typically be between 5 and 80 bar. .

[0030] Suitable solvents are in principle known to the person skilled in the art and may for example be selected from toluene, cyclohexane, xylene, dioxane or chlorobenzene.

[0031] Besides the depolymerization sequence in a stirred tank reactor the reaction can be divided in two reaction sections where the first section only leads to a partial degradation of the polyurethane to generate a conveyable mash and the second reaction sequence provides the total depolymerization. For the first reaction sequence a kneader, an extruder or a plug flow reactor can be utilized at temperature from 100°C - 250°C whereas in the second section a stirred tank or a stirred tank cascade is required.

[0032] During depolymerization of the polyurethane or polyisocyanurate material, a mixture containing a polyol substance and an amine substance is formed. Due to the addition of water or due to water being present in the composition, a hydrolysis of the polyurethane or polyisocyanurate material occurs. The presence of at least equimolar amounts of water can lead to about 100% amine liberation. According to the present invention, ammonia may be added in step b).

[0033] After depolymerization, the process of the invention typically yields a polyamine comprising an amino group attached to the carbon atom to which in the initial polyisocyanate an isocyanate group was bound, e.g., methylene diphenyl diamines (MDA), oligomeric and polymeric polymethylene polyphenylene polyamine, toluenediamines (TDA), in particular 2,4 toluenediamine or 2,6-toluenediamine, hexamethylene diamine (HDA), and naphthylene diamines (NDA). The commonly used polyols as described above preferably also can be re-isolated. Thus, the process preferably further yields polyol components comprising polyols or fragments of polyols, e.g., polyester polyols, fragments of polyester polyols, low molecular weight polyols such as ethylene glycol or propylene glycol, or high molecular weight polyether polyols based on glycerol, sorbitol, ethylene glycol, polypropylene glycol and polytetramethylene glycol.

[0034] The components obtained in the depolymerization may be separated. It is also possible in the context of the present invention to separate by-products such as for example carbon dioxide, or waste materials prior to a separation of the amine component and the polyol components.

[0035] According to step c) of the process of the invention, the amine component and the polyol components are separated obtained in step b), to amine rich and an amine poor phase, with or without the aid of an additional ammonia dosage preferably to a pH value of the amine poor phase to a value higher as 9, and with or without an extraction agent.

[0036] Preferably, the process comprises allowing the mixture to settle. According to the present invention, it is possible that one or more phases are formed and the components of the mixture may be separated by suitable separation steps. According to the present invention, it is for example possible to extract the mixture via an organic anhydrous solvent which is not or partially miscible with water.

[0037] In particular in embodiments, in which the amine substance is recovered, it can be beneficial if an excess of water is removed from the mixture, before allowing the mixture to settle, preferably by evaporation of the excess of water. In particular, for evaporation of the excess of water, the mixture is heated and / or a vacuum is applied. For example, an excess of water is removed by using flash evaporation or applying vacuum to the already heated mixture. For example, a water removal step may be performed for about 120 minutes or less, in particular about 90 minutes or less, for example about 75 minutes or less, for example about 60 minutes or less. Preferably, the water removal step is performed for about 10 minutes or more, in particular for about 30 minutes or more, for example for about 40 minutes or more.

[0038] The amine poor phase may also comprise ammonia carbonates which may be separated from the remaining components. Decomposition may be achieved using mild conditions such as for example a temperature treatment at a temperature in the range of from 40 to 80°C, allowing versatile use of the components. Carbondioxide may be separated off and may be dried and further purified by known conventional methods. Carbondioxide may be isolated and used as such. According to the present invention, carbondioxide may be used for processes converting CO2 to CO, eg. reverse water-gas-shift, and re-use of CO in production of isocyanates. It is also possible to use the carbondioxide obtained in the process for further processes, for example as a reactant for urea or soda. Thus, according to a further embodiment, the present invention is also directed to the process as disclosed above, wherein carbon dioxide released in the process is used as reactant for urea or soda or as carbon precursor for the synthesis of organic or inorganic molecules . For example, soda could be produced via an alkaline washing step. Ammonia could be recycled as catalyst according to the present invention.

[0039] According to step d) of the process according to the present invention, the polyol components or polyol fragments in the amine poor phase are treated to form a polyol (P2). Typically, the amine poor phase comprises polyol components such as glycols and may also comprise mono- or-di- acids in case polyesterpolyols are present in the polyurethane or polyisocyanurate. Diacids may also be present in the form of diammonium salts. In case ammonium salts are present in the composition, the treatment according to step d) may comprise further treatments such as for example thermal treatments and / or vapor stripping to obtain the free acid prior to re-esterfication of the polyol fragments. Suitable conditions for example for re-esterfication are known to the person skilled in the art. The ratio of acids and polyalcohols is typically adjusted to obtain a mixture which is then suitable as a starting material for esterification of the acids and polyalcohols. Preferably, the ratio of acids is adjusted to a molar ratio of acid groups to hydroxy groups in the range of from 1 :1.03 to 1 :2.5, in particular to 1 :1.05 to 1 :2.0.

[0040] The process may for example comprise steps such as adding diacids to the mixture; adding polyalcohols to the mixture; adding esterification catalysts, for example titan tetrabutanolate; removal of diols by evaporation / distillation; or removal of solvent from the mixture. The process may furthermore comprise suitable treatment steps to achieve condensation of polyalcohols and acids in the mixture. In particular suitable to achieve re-condensation of polyols and acids. Suitable conditions for example for re-esterfication are known to the person skilled in the art and may for example include condensation of alcohols and acids by heating under vacuum and removal of condensation product, online analytics to follow reaction progress and optionally adjust monomer composition.

[0041] The amine poor phase may also be treated to remove further by-products or solvents.

[0042] Ammonia which may be a by-product in the treatment can be recycled and used in the depolymerization according to step b) or may also be recycled in step c) according to the present invention.

[0043] After work-up, the polyol-containing phase may be used at least proportionally in new PU formulations. After purification, the polyamine preferably can be converted back to the corresponding isocyanate, for example by means of phosgenation, and as such can then be used at least proportionally as an isocyanate component in PU production. Alternatively, an reactive extraction of the polyamine with hydrogen chloride can be utilized as purification method according to the present invention. The formed polyamine-hydrochloride can be converted back to the corresponding isocyanate by means of direct phosgenation or can be converted back to the amine via thermal HCI cleavage or can be transferred to an existing amine production plant. Suitable processes and reaction conditions are in principle known to the person skilled in the art.

[0044] The process according to the present invention comprises steps a), b), c) and d), but may also comprise further steps. The process may for example comprise further purification steps or heat treatments. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process comprises further purification steps.

[0045] Suitable treatment steps are in principle known to the person skilled in the art. Suitable treatment and / or purification steps may be carried out between steps a) and b), or between steps b) and c), or between steps c) and d). In the context of the present invention it is also possible that step b) is carried out directly after step a). It is also possible that step c) is carried out directly after step b). Furthermore, it is possible that step d) is carried out directly after step c).

[0046] According to the present invention, steps a) and b) might also be combined and carried out in the same apparatus. It is also possible that the composition provided in step a) might also comprise solvents, for example solvents which might be used in step b) of the process according to the present invention.

[0047] The work-up of the depolymerization product, in particular the isolation of the polyamine and the polyol can be realized case dependent, for example by extractive work-up, precipitation of the amine component as a hydrochloride, chromatography or distillation under reduced pressure. Preferably, the work up comprises several steps. According to one aspect of the invention, solids may be removed from the mixture before or after the mixture is allowed to settle, preferably by one or more of the following: filtration, centrifugation, decantation.

[0048] It is for example possible to remove components such as for example solid components or flame retardants from the comminuted polyurethane or polyisocyanurate material by suitable methods such as for example extraction. Other extractable components are for example other and sometimes even solid additives. The flame retardants may also be purified via additional extraction, adsorption, crystallization, or distillation process steps and reused. According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process further comprises a step a1 ) a1 ) at least partial extraction of flame retardants from the comminuted polyurethane or polyisocyanurate material.

[0049] Suitable conditions for step a1) are for example disclosed in EP 22205386.0.

[0050] According to a further embodiment, the present invention is also directed to the process as disclosed above, wherein the process further comprises a step b1 ) b1) removal of particulate solids from the reaction mixture.

[0051] Suitable methods for removal of particulate solids are in principle known to the person skilled in the art. For example, filtration units or a centrifuge may be used. Preferably, a filtration step is carried out according to the present invention using a filtration unit, more preferably a filter, more preferably a pocket filter, a bag filter, a membrane filter, a candle filter, an agitated pressure filter, a vacuum belt filter, a frame & plate filter, or a nutsche filter.

[0052] For filtration, preferably filter membranes having an average mesh size of about 30 pm or less may be used. It can be beneficial to use a cascade of filters. For example, a first filter membrane of the cascade of filters has an average mesh size of about 250 pm to about 290 pm. A second filter membrane of the cascade of filters preferably has an average mesh size of about 50 pm to about 90 pm and, in particular, a third filter membrane of the cascade of filters has an average mesh size of 20 pm or less.

[0053] In the alternative or additionally, centrifugation is a preferred solid-liquid-separation method.

[0054] Further separation steps may be carried out, for example separation steps to separate gaseous components such as for example carbon dioxide. Suitable separation methods are known to the person skilled in the art, such as for example evaporation or adsorption steps. In work-up by distillation, compounds are separated according to their volatility, with more volatile compounds being separated first. Additives, water or solvents used in the depolymerization can also be removed via distillation prior further work-up of the polyol-polyamine mixtures. Generally, the “volatility” of a liquid may be described using its vapor pressure, wherein a high vapor pressure indicates a high volatility, and vice versa.

[0055] In the event that the polyamine is more volatile than the polyol as it is for example the case for TDA, monomeric MDA and NDA, the polyamine is recovered from the depolymerization product via distillation, preferably via distillation at reduced pressure. After distilling-off the polyamine, a distillation bottoms remains which contains the polyol.

[0056] Suitable conditions for the distillation are in principle known to the person skilled in the art and are for example disclosed in EP22178796.3 or EP22178797.1.

[0057] Alternatively, the polyol may be recovered by extraction from the depolymerization mixture using a suitable extractant or a pair of extractants. It is also possible to precipitate the polyamine component in the form of it's hydrochloride by adding HCI and extracting the polyol component with a suitable solvent for example as described in DE2854940A1 , which is preferably dissolving the polyol component but not the hydrochlorides of the polyamine component. It is also possible to adjust the conditions in the extraction step to recover the polyamine component using aqueous HCL as extraction medium. The hydrochloride of the polyamine component can after separation then either be transferred to the free polyamine by adding a base but also directly used in the phosgenation to generate new polyisocyanates for the polyurethane synthesize. Also thermal cleavage of the hydrochloride is possible in the context of the present invention. It is for example possible to feed the amine hydrochloride directly in a process for the preparation of the respective amine. For example in case of MDA*HCI or PMDA*HCI the hydrochloride can be directly fed to an MDA synthesis plant at a position prior to the neutralization step.

[0058] Further, in particular for recovering the polyol substance, the process comprises preferably a work-up of the phase, which is polyol substance rich by purification of the polyol substance. The purification may comprise one or more of the following:

[0059] - filtration;

[0060] - centrifugation;

[0061] - decantazion;

[0062] - distillation;

[0063] - full or partial evaporation of the phase in one or more evaporators;

[0064] - contacting the phase with an ion exchange material;

[0065] - contacting the phase with one or more adsorbents.

[0066] Preferably, the process further comprises work-up of the mixture by purification of the amine substance, for example including distillation, in order to purify the amine substance. Therefore, according to a further embodiment, the present invention is directed to the process as disclosed above, wherein the process further comprises step e) e) purification of the amine rich phase.

[0067] The process of the present invention therefore also comprises embodiments, wherein step e) comprises the extraction of the amine component using aqueous HCL According to a further embodiment, the present invention therefore is also directed to the process as disclosed above, wherein the hydrochloride of the polyamine component is formed in the process and the hydrochloride is transferred to the free polyamine by adding a base or by thermal cleavage or the hydrochloride is directly used in the phosgenation.

[0068] It is understood that the separation process described above can be combined with any of the various embodiments of the inventive process described herein.

[0069] With the process of the present invention, about 90 % or more, preferably about 97 % or more, of the polyol substances or monomer fragments of those which is theoretically recoverable from the polyurethane material can be released. Due to decomposition of monomers or incomplete recovery, the yield of the polyol substances or monomer fragments of those is at least 30 %, preferably at least 40 % in particular at least 60% .

[0070] According to a further aspect, the present invention is also directed to the polyol composition obtained or obtainable according to the process of the present invention.

[0071] Preferably, the polyol composition for flexible foams comprises or consists of one or more polyols having a molecular weight of about 2500 to about 3500 g / mole, a nominal OH functionality of about 3 and having an OH number of about 48 mg KOH / g to about 56 mg KOH / g.

[0072] Preferably, the polyol composition for rigid foams comprises or consists of one or more polyols having a molecular weight of about 400 to about 800 g / mole, a nominal OH functionality of about 2-3 and having an OH number of about 200 mg KOH / g to about 300 mg KOH / g.

[0073] Furthermore, according to a further embodiment, the polyol composition may comprise or consist of one or more polyols having a molecular weight of about 3000 to about 6500 g / mole, a nominal OH functionality of about 3 and having an OH number of about 20 mg KOH / g to about 50 mg KOH / g.

[0074] According to a further aspect, the present invention is also directed to the use of the polyol composition according to the present invention or a polyol composition obtained or obtainable according to the process of the present invention for the preparation of polyurethanes or polyiso- cyanurates. Furthermore, the polyol fragments obtained in the process may be used as building blocks for the preparation of high molecular polyester polyols or as carbon precursor for chemicals, or as feed stock for a pyrolysis or gasification process. The present invention further relates to a process for preparing a polyurethane material by reacting the polyol substance obtained by the process according to the present invention with an isocyanate substance, preferably the isocyanate substance obtained by a process of the present invention.

[0075] According to a further embodiment, the present invention relates to the use of the polyol composition according to the present invention or a polyol composition obtained or obtainable according to the process as disclosed above for the preparation of polyurethanes or polyisocyanu- rates.

[0076] The present invention further relates to a process for preparing a polyurethane material by reacting the polyol substance obtained by the process according to the present invention with an isocyanate substance, preferably the isocyanate substance obtained by a process of the present invention.

[0077] Furthermore, the invention relates to a process for producing an isocyanate substance from an amine substance obtained by a process according to the present invention. The advantages and / or features described in connection with the process for recovering an amine substance also apply for the process for producing an isocyanate substance.

[0078] Preferably, the amine substance resulting from the recovery process is fed into a purification section of an amine producing plant, an amine storage tank or an isocyanate producing plant, for example in the phosgenation section of an isocyanate production plant.

[0079] For the use of the amine substance in the isocyanate production, the amine substance needs to be essentially free of polyol substance, residual metals and silicon compounds. In the context of the present invention, “essentially free” means that the content of the respective components is less than 1 wt.%, in particular less than 0.5 wt.%, more preferable less than 0.25 wt.%.

[0080] Preferably the amine substance is phosgenated so that an isocyanate substance is formed. For example TDA may be phosgenated to prepare TDI or MDA may be phosgenated to prepare MDL Furthermore, pMDA may be phosgenated to prepare pMDI and NDA may be phosgenated to prepare NDL Suitable conditions for the phosgenation are in principle known to the person skilled in the art.

[0081] According to a further embodiment, the present invention therefore is also directed to the process as disclosed above, wherein the process further comprises step e) f) conversion of the amine component to obtain an isocyanate composition.

[0082] In the context of the present invention, the term “isocyanate composition” encompasses all isocyanates known to the person skilled in the art in connection with polyurethane chemistry, such as, in particular, toluene diisocyanate (TDI; prepared from toluene diamine, TDA) or the di- and polyisocyanates of the diphenylmethane series (MDI; prepared from the di- and polyamines of the diphenylmethane series, MDA). The expression "isocyanate composition" also encompasses embodiments in which two or more different isocyanates (e.g. mixtures of MDI and TDI) have been used in the preparation of the polyurethane material. This also applies within one isocyanate class (that is to say, for example, also applies to various MDI types). Also further isocyanates such as hexamethylene diisocyanate (HDI) and its oligomers or naphthylene diisocyanate (NDI) may be present. The totality of all isocyanates used in the preparation of the polyurethane material is referred to as the isocyanate composition (of the polyurethane material). The isocyanate composition comprises at least one isocyanate.

[0083] The conversion according to step (f) may for example be achieved by phosgenation or also by phosgene-free conversion. Suitable processes are for example liquid phosgenation, gasphase phosgenation or gas-liquid phosgenation or a phosgenation via salt or a phosgene-free conversion for example carbamate cleavage. Suitable conditions for the phosgenation are in principle known to the person skilled in the art and are for example disclosed in Ullmann’s Encyclopedia of Industrial Chemistry, 7thed. Vol. 20, 2012, p. 63-82, WO 99 / 54289 A, WO 2004 / 056756 A (liquid phosgenation); Ullmann’s Encyclopedia of Industrial Chemistry, 4thed. Vol. 13, 2012, p. 353, DE 25 870847 A, EP 1532107 A, EP 0570799 A EP 0289840 A (gasphase phosgenation); or EP 2044009 A1 , WO 2013 / 060836 A, WO 2013 / 079517 A (gas-liquid phosgenation). An example of gas-liquid phosgenation process is disclosed in WO 2022 / 106716, examples of gas phase phosgenation processes are disclosed in EP 1761483 B1 , EP 2079684 B1 , EP 2188247 B1 , EP 2408738 B1 and EP 2539314 B1 and examples of phosgene-free conversion are disclosed in WO2018 / 185168 and EP 3 250 622 B1 .

[0084] Preferably, the phosgenation comprises admixing a solvent to the amine component and stirring, more preferably at a temperature in the range of from 50 to 180 °C, more preferably in the range of from 70 to 140 °C, more preferably in the range of from 80 to 120 °C, obtaining a polyamine mixture; and bringing the polyamine mixture in contact with phosgene in a reactor and heating the obtained mixture to a temperature in the range of from 90 to 140 °C, more preferably in the range of from 110 to 130 °C, obtaining a mixture comprising one or more polyisocyanates.

[0085] The present invention is also directed to the isocyanate composition obtained or obtainable according to the process as disclosed above. Furthermore, the present invention is directed to the use of the isocyanate composition according to the present invention or the isocyanate composition obtained or obtainable according to the process according to the present invention for the preparation of polyurethanes or polyisocyanurates. For example TDI or MDI produced according to the present invention can be used as isocyanate substance to produce polyurethane material by reacting it with a polyol obtained according to the present invention or any other suited polyol component. In embodiments, in which the recycled amine substance obtained by the process according to the present invention can be phosgenated together with virgin MDA or TDA to achieve virgin like isocyanates which can be utilized to produce polyurethane materials.

[0086] The produced polyurethane material can be any suitable polyurethane application, preferably in the same application. The polyurethane material can for example be used in mattresses or furniture parts (primarily TDI) or car seats or in appliance or construction applications (primarily pMDI)

[0087] Further embodiments of the present invention can be found in the claims and the examples. It will be appreciated that the features of the subject matter / processes / uses according to the invention that are mentioned above and elucidated below are usable not only in the combination specified in each case but also in other combinations without departing from the scope of the invention. For example, the combination of a preferred feature with a particularly preferred feature or of a feature not characterized further with a particularly preferred feature etc. is thus also encompassed implicitly even if this combination is not mentioned explicitly.

[0088] Illustrative embodiments of the present invention are listed below, but these do not restrict the present invention. In particular, the present invention also encompasses those embodiments which result from the dependency references and hence combinations specified hereinafter.

[0089] 1 . A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11 ) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2).

[0090] 2. The process according to embodiment 1 , wherein the process further comprises step e) e) purification of the amine rich phase.

[0091] 3. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase.

[0092] 4. The process according to any one of embodiments 1 to 3, wherein step e) comprises the extraction of the amine component using aqueous HCI.

[0093] 5. The process according to any one of embodiments 1 to 4, wherein the process further comprises step e) f) conversion of the amine component to obtain an isocyanate composition.

[0094] 6. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition. 7. The process according to any one of embodiments 1 to 6, wherein the process comprises further purification steps.

[0095] 8. The process according to any one of embodiments 1 to 7, wherein the process further comprises a step a1) a1) at least partial extraction of flame retardants from a comminuted polyurethane or pol- yisocyanurate material.

[0096] 9. The process according to any one of embodiments 1 to 8, wherein the process further comprises a step b1) b1 ) removal of particulate solids from the reaction mixture.

[0097] 10. The process according to embodiment 5, wherein carbon dioxide released in the process is used as reactant for urea, soda or as carbon precursor for the synthesis of organic or inorganic molecules.

[0098] 11. Polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 10.

[0099] 12. Polyol composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition. Polyol composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2). Use of the polyol composition according to any one of embodiments 11 to 13 or a polyol composition obtained or obtainable according to the process of any one of embodiments 1 to 10 for the preparation of polyurethanes or polyisocyanurates. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 1 to 108. Isocyanate composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition. composition obtained or obtainable according to the process of any one of embodiments 1 to 10 for the preparation of polyurethanes or polyisocyanurates.

[0100] 18. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2).

[0101] 19. The process according to embodiment 18, wherein the process further comprises step e) e) purification of the amine rich phase.

[0102] 20. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase. The process according to any one of embodiments 18 to 20, wherein step e) comprises the extraction of the amine component using aqueous HCL The process according to any one of embodiments 18 to 21 , wherein the process further comprises step e) f) conversion of the amine component to obtain an isocyanate composition. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition. The process according to any one of embodiments 18 to 23, wherein the process comprises further purification steps. The process according to any one of embodiments 18 to 24, wherein the process further comprises a step a1) a1) at least partial extraction of flame retardants from a comminuted polyurethane or polyisocyanurate foam. The process according to any one of embodiments 18 to 25, wherein the process further comprises a step b1) b1 ) removal of particulate solids from the reaction mixture. 27. The process according to embodiment 23, wherein carbon dioxide released in the process is used as reactant for urea, soda or as carbon precursor for the synthesis of organic or inorganic molecules

[0103] 28. Polyol composition obtained or obtainable according to the process of any one of embodiments 18 to 27.

[0104] 29. Polyol composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition.

[0105] 30. Polyol composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2). 31 . Use of the polyol composition according to any one of embodiments 28 to 30 or a polyol composition obtained or obtainable according to the process of any one of embodiments 18 to 27 for the preparation of polyurethanes or polyisocyanurates.

[0106] 32. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 18 to 27.

[0107] 33. Isocyanate composition obtained or obtainable according to the process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate foam which is obtained from isocyanate (11 ) and polyol (P1 ), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and / or ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2), e) purification of the amine rich phase, f) conversion of the amine component to obtain an isocyanate composition.

[0108] 34. Use of the isocyanate composition according to embodiment 32 or 33 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 18 to 27 for the preparation of polyurethanes or polyisocyanurates.

[0109] 35. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2). A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, and, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2). A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1 ), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, and, in presence of an additional solvent, which has a miscibility gap with water. c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with an ex-traction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2). The process according to any one of embodiments 35 to 37, wherein the solvent, which has a miscibility gap with water is selected from organic solvents. 39. The process according to any one of embodiments 35 to 37, wherein the solvent, which has a miscibility gap with water is selected from toluene, cyclohexane, xylene, dioxane or chlorobenzene.

[0110] 40. The process according to any one of embodiments 35 to 39, wherein the process further comprises step e) e) purification of the amine rich phase.

[0111] 41. The process according to any one of embodiments 35 to 40, wherein step e) comprises the extraction of the amine component using aqueous HCI.

[0112] 42. The process according to any one of embodiments 35 to 40, wherein the process further comprises step e) f) conversion of the amine component to obtain an isocyanate composition.

[0113] 43. The process according to any one of embodiments 35 to 42, wherein the process comprises further purification steps.

[0114] 44. The process according to any one of embodiments 35 to 43, wherein the process further comprises a step a1) a1) at least partial extraction of flame retardants from a comminuted polyurethane or polyisocyanurate material.

[0115] 45. The process according to any one of embodiments 35 to 44, wherein the process further comprises a step b1) b1 ) removal of particulate solids from the reaction mixture.

[0116] 46. The process according to embodiment 42, wherein carbon dioxide released in the process is used as reactant for urea, soda or as carbon precursor for the synthesis of organic or inorganic molecules.

[0117] 47. Polyol composition obtained or obtainable according to the process of any one of embodiments 35 to 45.

[0118] 48. Use of the polyol composition according to embodiment 47 or a polyol composition obtained or obtainable according to the process of any one of embodiments 35 to 46 for the preparation of polyurethanes or polyisocyanurates. 49. Isocyanate composition obtained or obtainable according to the process according to any one of embodiments 35 to 46.

[0119] 50. Use of the isocyanate composition according to embodiment 49 or an isocyanate composition obtained or obtainable according to the process of any one of embodiments 35 to 46 for the preparation of polyurethanes or polyisocyanurates.

[0120] Brief description of the figures:

[0121] Figure 1 shows the results of the extraction process for example 1 . Blue columns (left) represent the extraction yields in a flask setup whereas orange columns (right) show the yields in a soxhlet setup.

[0122] Figure 2 shows the ATR analyses results of the amine rich phase after the depolymerization (chloro benzene was evaporated) for example 2. As references a spectrum of pure MDA and a spectrum of silicon oil was added.

[0123] Figure 3a shows the pressure and temperature in dependence to the time of the autoclave during the hydro ammonolysis for example 2.

[0124] Figure 3b shows the pressure and temperature in dependence to the time of the autoclave during the hydro ammonolysis for example 3.

[0125] Figure 3c shows the pressure and temperature in dependence to the time of the autoclave during the hydro ammonolysis for example 4.

[0126] Figure 3d shows the pressure and temperature in dependence to the time of the autoclave during the hydro ammonolysis for example 5.

[0127] Figure 4: shows the ATR analyses results of the amine rich phase after the depolymerization (chloro benzene was evaporated) for example 3 As references a spectrum of pure MDA was added.

[0128] The present invention can be further explained and illustrated on the basis of the following examples. However, it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention in any way.

[0129] Examples

[0130] I. Explanation of terms PU flexible foam consists of TDI (Toluenediisocyanate, isomers: 2,4 TDI and 2,6 TDI) and long chain Polyether polyols (Polyol 1). The foam contains foaming catalysts, a blowing agent and stabilizers as well.

[0131] End of life (EoL foam) flexible PU foam was sorted by a spectroscopic method to minimize the content of high resilience (HR) polyols and Styrene acrylonitrile resin (SAN) polymer particles.

[0132] PU rigid foam consists of polymeric isocyanate (pMDI) and polyether and / or polyester polyols. The foam contains foaming catalysts, blowing agents and stabilizers as well.

[0133] II. Materials used

[0134] Polyol 1 is a trifunctional polyether polyol with a OH-number of 48 mg / g and predominantly secondary hydroxyl groups.

[0135] Polyol 2 (polyester-polyols containing predominately on terephthalic acid, fatty acids, di or trifunctional glycols and short chain polyether polyols (M = 350-600 g / mol). The OH number is about 245 mg / g.

[0136] Polyol 3: Polyester polyol based phthalic acid, diethylene glycol and monoethylene glycol, the OH number is about 240 mg / g.

[0137] Isocyanate 1 : TDI (Toluenediisocyanate, isomers: 2,4 TDI and 2,6 TDI)

[0138] Isocyanate 2 (pMDI-1 ) is polymeric isocyanate with a typical NCO content of 31.5 g / 100g and a viscosity at 25°C of about 550 mPas. It is available as a commercial product from BASF.

[0139] III. Methods used

[0140] 1 . ATR-analysis: ATR spectroscopy was carried out to check the absence of the urea vibration the hydro ammonolysis process. FT-IR analyses were carried out with a Nicolet iS50 spectrometer. The resolution was 4 cm-1

[0141] 2. High performance liquid-chromatography (HPLC): HPLC analyses was carried out to determine 2,4-TDA and 2,6-TDA and 2,2-, 2,4-, 4,4-MDA.

[0142] HPLC-setup: Agilent Technologies “1200 Series”

[0143] Column: Fluofix (5 pm, 250 x 4.6 mm)

[0144] Detection: 205 nm Temperature: 25°C

[0145] Injection volume: 10 pL Mobile phase: (A)1000 mL water + 1 ml H3PO4, (B) 950 mL Acetonitrile + 50 mL water + 1 mL H3PO4

[0146] 3. GC-analysis: Quantification of 2,2-, 2,4-, 4,4-MDA, 3-ring MDA, 4-ring MDA, and 5-ring MDA. The detailed description of the GC method is listed below:

[0147] GC-setup: Agilent 7890A Column: DB-5HT (30m x 0,32mm x 0,1 pm) Temperature program: 80oC-5min-6°C / min-370°C-30min Injection temperature: 340°C Injection volume: 1 pL Detector temperature: 340°C Carrier gas : Hydrogen (Constant Pressure 10psi) Split ratio: 15:1

[0148] 4. Amine number determination

[0149] Amine number titration is carried out according to DIN 53176. The amine number was utilized to calculate the amount of pMDA. Thereof the theoretical amine number of hydrolyzed M50 was estimated. Based on the NCO number of M50 the amount of amine groups was calculated under the assumption that each mol NCO is transformed to an amine group. The theoretical value of the amine number of hydrolyzed M50S is between 500 and 510 mg / g KOH.

[0150] 5. Silicium, Phosphorus analyses

[0151] Silcium and phosphorus determination were carried out to quantify the amount of silicon stabilizers and flame retardants ( phosphoric acid esters) in the different fractions. The analyses were carried out via atomic absorption spectrometry (AAS).

[0152] 6. Elementary analysis of Carbon, Nitrogen, Oxygen and Hydrogen

[0153] IV Examples

[0154] 1. Model foam:

[0155] 1.1 Soft / flexible foam (MF1 )

[0156] Flexible foam: Hydro ammonolysis of foam synthesized from isocyanate 1 (2,4 TDI and 2,6 TDI), polyols and additives like catalysts, surfactants, blowing agents required for foaming (30.9 wt.-% TDI and 61 .9 wt.-% polyol 1 ). Surfactants: Silicone oils

[0157] Blowing agents: Water, CO2

[0158] Catalysts: Usually tertiary amines

[0159] 1.2 Rigid foams (MF2)

[0160] PIR-construction foam: Hydro ammonolysis of a foam synthesized from isocyanate 2, polyols and different additives like e. g. catalysts, surfactants, blowing agents required for foaming (71 .4 wt.-% M50S; 18.4 wt.-% polyols primarily polyol 2 and 3 containing predominately aromatic dicarboxylic acids, like phthalic acid and terephthalic acid and glycols as well as short-chain polyether polyols)

[0161] Surfactants: Silicone oils

[0162] Blowing agents: Water, Cyclopentane

[0163] Catalysts: Usually tertiary amines) and potassium salts

[0164] 2. EoL / lndustrial production waste

[0165] 2.1 Flexible foam (EF1)

[0166] Foam based on TDI and polyols similar to polyol 1

[0167] Additives and impurities: Foaming catalysts, stabilizers, SAN-polymer particles, HR- polyols, metals, inorganic salts (e g. CaCO3)

[0168] 2.2 PU rigid foam (EF2)

[0169] Foam based on isocyanate 3 and a mixture of polyols similar to polyol 2 and 3

[0170] Additives and impurities: Foaming catalysts, stabilizers, metals, inorganic salts

[0171] 3.1 Example 1 : Solid / liquid extraction of flame retardants (halogenated or none halogenated phosphoric acid esters) of the PU rigid foam (MF 2)

[0172] All utilized extraction medias are listed below in table 1 .

[0173] Table 1: Overview extraction media a) Extraction in a round flask

[0174] 30 g milled foam was mixed with the extraction medias (850 g). The mixture was stirred and heated up to the boiling temperature of the extraction media. The extraction time was 16 h. After 16 h the mixture was cooled down to room temperature and filtrated. The foam was washed several times with extraction media. The filtrate was concentrated via vacuum evaporation. To document the extraction process Chlorine, Phosphorus and Silica were analyzed of the virgin foam, the foam after extraction and the extraction phase. Based on this data the mass balance of these three elements was between 95 -105 %. The extraction yield was calculated by the ratio of phosphorus between the liquid extract and the non-extracted foam and normalized to the mass balance.

[0175] PhosphorusExtract

[0176] V1Extraction =

[0177] Phosphorus fOamb) Soxhlet extraction

[0178] 12 g milled foam was put into Soxhlet sleeve, and 500 extraction media was added in a support flask. The Soxhlet extraction was carried out for 5 h. After 5 h the mixture was cooled down to room temperature. The extracted foam was washed several times with extraction media. The extract was concentrated via vacuum evaporation. To document the extraction process Chlorine, Phosphorous and Silica was analyzed of the virgin foam, the foam after extraction and the extraction phase. Based on this data the mass balance of these three ele- ments was between 95 -105 %. The extraction yield was calculated by the ratio of phosphorus between the liquid extract and the non-extracted foam and normalized to the mass balance.

[0179] PhosphorusExtract

[0180] V1Extraction =

[0181] Phosphorusfoam

[0182] The results are shown in figure 1 .

[0183] 1H-N M R was carried out to detect the characteristic signals of the flame retardant (TCPP). .2 Example 2: Hydro ammonolysis of extracted PU rigid foam (MF2) a) Hydro ammonolysis

[0184] 100 g of an extracted model foam, 1000 g water and 300 g Ammonia(gaseOus) and 300g Chlorobenzene (MCB) were charged to a stirred autoclave (3.5 L autoclave). Before the reaction mixture was heated to 230 °C, the reactor was closed and its contents purged three times with nitrogen to ensure an inert atmosphere. Afterwards 300 g Ammonia(gaseOus) was transferred to the reactor . The hydrolysis reaction was carried out at 230 °C and approximately 70-80 bar (depending on the vapor pressure of the mixture water / pMDA / NHs and the emitted CO2) for 8 h. After the reaction the autoclave was cooled down to 80°C and 160 g MCB was added to the reaction mixture. After stirring the mixture was cooled down to room temperature and was flushed several times with nitrogen. To evaluate the conversion of the depolymerization reaction ATR analyses and NMR analyses of the organic phase were carried out.

[0185] The pressure and temperature curve in dependence to the reaction time of the autoclave during the hydro ammonolysis are shown in figure 3a.

[0186] The ATR analysis of the amine rich phase indicates that after MCB removal the main part is pMDA. As impurity some vibrations of silicons are visible. They correspond to the stabilizer of the cleaved foam. 1 H-NMR of the organic phase after MCB removal indicates that the major compound is MDA. Small impurities are oleic acid or oleamide. Specification of the impurities was done by 1 H / 13C-HSQC-NMR technique. No signals attributed to carbamate, isocyanurate or urea could be detected in the HSQC-spectra. Thereof, full conversion could be expected. The spectra are shown in figure 2. b) Phase separation

[0187] The reaction discharge was transferred to a stirred tank and the mixture was heated up to 80°C to release ammonia. Afterwards the phases were separated, the organic phase (amine rich phase) was washed 3-times with water and the water phase (amine poor phase) was washed with 3-times with MCB. All fractions were evaporated to remove water or MCB. Table 2 shows the analyses results after the phase separation:

[0188] Table 2: Analytic results after the phase separation. The chosen analytic method is mentioned in brackets. .3 Example 3: Hydro ammonolysis of extracted PU rigid foam (EF2) a) Hydro ammonolysis

[0189] 100 g of an extracted of PU rigid foam waste, 1000 g water and 300 g Ammonia(gaseOus) and 300g Chlorobenzene (MCB) were charged to a stirred autoclave (3.5 L autoclave). Before the reaction mixture was heated to 230 °C, the reactor was closed and its contents purged three times with nitrogen to ensure an inert atmosphere. Afterwards 300 g Ammonia(gaseOus) was transferred to the reactor. The hydrolysis reaction was carried out at 230 °C and approximately 70-80 bar (depending on the vapor pressure of the mixture water / pMDA / NHs and the emitted CO2) for 8 h. After the reaction the autoclave was cooled down to 80°C and 160 g MCB was added to the reaction mixture. After stirring the mixture was cooled down to room temperature and was flushed several times with nitrogen. To evaluate the conversion of the depolymerization reaction ATR analyses and NMR analyses of the organic phase was carried out.

[0190] The pressure and temperature curve in dependence to the reaction time of the autoclave during the hydro ammonolysis is shown in figure 3b.

[0191] The ATR analysis of the amine rich phase indicates that after MCB removal the main part is pMDA. As impurity some vibrations of silicons are visible. They correspond to the stabilizer of the cleaved foam. 1 H-NMR of the organic phase after MCB removal indicates that the major compound is MDA. Small impurities are oleic acid or oleamide. Specification of the impurities was done by 1 H / 13C-HSQC-NMR technique. No signals attributed to carbamate, isocyanurate or urea structures could be detected in the HSQC-spectra which are shown in figure 4. Thereof, full conversion could be expected. b) Filtration

[0192] First, the reaction mixture was filtrated under pressure (3 bar) at 80°C (over night) using a depth filter with 15 pm pore size. At this step 20 wt.-% of solids related to the foam waste weight were separated. c) Phase separation

[0193] The filtrated reaction discharge was transferred to stirred tank and the mixture was heated up to 80°C to release ammonia. Afterwards the phases were separated, the organic phase (amine rich phase) was washed 3-times with water and the water phase (amine poor phase) was washed 3-times with MCB. All fractions were evaporated to remove water or MCB. Table 3 shows the analyses results after the phase separation:

[0194] Tab!e3: Analytic results after the phase separation. The chosen analytic method is mentioned in brackets.

[0195] Example 4: Hydro ammonolysis of PU flexible foam (MF1) a) Hydro ammonolysis

[0196] 10 g PU flexible foam, 50 g water and 30 g Ammonia(gaseOus) were charged to a stirred autoclave (0.3 L autoclave). Before the reaction mixture was heated to 230 °C, the reactor was closed, and its contents purged three times with nitrogen to ensure an inert atmosphere. The hydrolysis reaction was carried out at 230 °C and approximately 70-80 bar (depending on the vapor pressure of the mixture water / TDA / NH3and the emitted CO2) for 8 h. After the reaction the autoclave was cooled down and was flushed several times with nitrogen.

[0197] The pressure and temperature curve in dependence to the reaction time of the autoclave during the hydro ammonolysis are shown in figure 3c. b) Filtration

[0198] First, the reaction mixture was filtrated under pressure (3 bar) at 80°C (over the night) using a depth filter with 15 pm pore size (mresidue: 3.7 g). c) Phase separation

[0199] The filtrated reaction discharge was transferred to separating funnel and the mixture was heated up to 80°C to release ammonia. Afterwards the phases were separated and evaporated under vacuum. To evaluate the TDA yield of the depolymerization reaction HPLC analyses of the organic and the water phase residue were carried out. Based on the initial content of TDI derived TDA a yield about 81 % could be reached.

[0200] Tabie4: Analytic results after the phase separation. The chosen analytic method is mentioned in brackets.

[0201] Example 5: Hydro ammonolysis of PU flexible foam (EF1) a) Hydro ammonolysis

[0202] 10 g of PU flexible foam, 50 g water and 30 g Ammonia(gaseOus) were charged to a stirred autoclave (0.3 L autoclave). Before the reaction mixture was heated to 230 °C, the reactor was closed, and its contents purged three times with nitrogen to ensure an inert atmosphere. Afterwards 30 g Ammonia(gaseOus) was transferred to the reactor. The hydrolysis reaction was carried out at 230 °C and approximately 70-80 bar (depending on the vapor pressure of the mixture water / TDA / NHs and the emitted CO2) for 8 h. After the reaction the autoclave was cooled down and was flushed several times with nitrogen.

[0203] The pressure and temperature in dependence to the reaction time of the autoclave during the hydro ammonolysis is shown in figure 3d. b) Filtration

[0204] First, the reaction mixture was filtrated under pressure (3 bar) at 80°C (over the night) using a depth filter with 15 pm pore size (mreSidue: 3.45 g). c) Phase separation

[0205] The reaction discharge was transferred to separating funnel and the mixture was heated up to 80°C to release ammonia. Afterwards the phases were separated and evaporated under vacuum. To evaluate the TDA yield of the depolymerization reaction HPLC analyses of the organic and the water phase residue were carried out. 1.4 g TDI derived TDA could be recovered. Table5: Analytic results after the phase separation. The chosen analytic method is mentioned in brackets.

[0206] 6 Example 6: Purification of organic phase (model system)

[0207] For the pMDA-hydrochloride formation a model system was used: The model system represents a mixture of oelic acid, PU foam stabilizer based on silicon and pMDA a) Precipitation of pMDA as Hydrochloride

[0208] 53 g pMDA (N-content: 14.2 wt.-%), 2g silicon-based stabilizer (Si-content: 13.2 wt.-%), 3 g oleic acid and 250 g MCB were mixed. The mixture was heated up to 80°C to get a homogeneous solution. Via a small pipe gaseous hydrogen chloride was dosed to the mixture. For one hour 3.5 Liter was added.

[0209] The precipitate was filtered and washed several times with MCB. 56 g precipitate could be gained. (Yield: 95 %). The residue was analyzed to detect impurities. A silicon content of 0.14 g could be detected. Due to the silicon mass of the stabilizer the founded mass of silicon in the precipitate correlate to 1 g stabilizer. b) Reactive extraction of pM DA as hydrochloride

[0210] 20 g pMDA (N-content: 14.2 wt.-%), 6.3g silicon-based stabilizer (Si-content: 13.2 wt.-%), 3 g oleic acid, 150 g MCB and 80 g 5 wt.-% aqueous HCL solution were mixed. The mixture was heated up to 80°C, stirred for 30 min and cooled to room temperature. The phases were separated in a funnel. The organic and aqueous phase were evaporated to remove the solvent and both residues were characterized to determine the silica, nitrogen, chlorine content and the acid number.

[0211] Table 6: Analytic results of aqueous and organic phase after solvent removal.

[0212] Literature cited:

[0213] WO 2021 / 023889 A1

[0214] US 9,023,907 B2

[0215] WO 2015 / 121057

[0216] WO 2013 / 139781

[0217] "Kunststoffhandbuch [Plastics handbook], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1 , 3.2 and 3.3.2.

[0218] WO 2006 / 034800

[0219] EP 0090444

[0220] WO 2005 / 090440

[0221] EP 22205386.0

[0222] EP22178796.3

[0223] EP22178797.1

[0224] DE2854940A1

[0225] Ullmann’s Encyclopedia of Industrial Chemistry, 7thed. Vol. 20, 2012, p. 63-82

[0226] WO 99 / 54289 A

[0227] WO 2004 / 056756 A

[0228] Ullmann’s Encyclopedia of Industrial Chemistry, 4thed. Vol. 13, 2012, p. 353

[0229] DE 25 870847 A

[0230] E P 1532107 A

[0231] EP 0570799 A

[0232] EP 0289840 A

[0233] EP 2044009 A1

[0234] WO 2013 / 060836 A

[0235] WO 2013 / 079517 A

[0236] WO 2022 / 106716

[0237] EP 1761483 B1

[0238] EP 2079684 B1

[0239] EP 2188247 B1

[0240] EP 2408738 B1

[0241] EP 2539314 B1

[0242] WO2018 / 185168

[0243] E P 3 250 622 B1

Claims

Claims1. A process for recycling of polyurethane or polyisocyanurate containing waste comprising the steps of a) providing a composition comprising a comminuted polyurethane or polyisocyanurate material which is obtained from isocyanate (11) and polyol (P1), b) depolymerization of the comminuted polyurethane or polyisocyanurate provided in step a) in the presence of water and ammonia, and optionally, in presence of an additional solvent, which has a miscibility gap with water; c) separation of the amine component and the polyol components or polyol fragments with or without the aid of an additional ammonia dosage and with or without an extraction agent obtained in step b), to amine rich and an amine poor phase; d) treatment of the polyol components in the amine poor phase to form a polyol (P2).

2. The process according to claim 1 , wherein the solvent, which has a miscibility gap with water is selected from organic solvents.

3. The process according to claim 1 or 2, wherein the process further comprises step e) e) purification of the amine rich phase.

4. The process according to any one of claims 1 to 3, wherein step e) comprises the extraction of the amine component using aqueous HCI.

5. The process according to any one of claims 1 to 4, wherein the process further comprises step e) f) conversion of the amine component to obtain an isocyanate composition.

6. The process according to any one of claims 1 to 5, wherein the process comprises further purification steps.

7. The process according to any one of claims 1 to 6, wherein the process further comprises a step a1) a1) at least partial extraction of flame retardants from a comminuted polyurethane or polyisocyanurate material.

8. The process according to any one of claims 1 to 7, wherein the process further comprises a step b1) b1 ) removal of particulate solids from the reaction mixture.

9. The process according to claim 5, wherein carbon dioxide released in the process is used as reactant for urea, soda or as carbon precursor for the synthesis of organic or inorganic molecules.

10. Polyol composition obtained or obtainable according to the process of any one of claims 1 to 8.

11. Use of the polyol composition according to claim 10 or a polyol composition obtained or obtainable according to the process of any one of claims 1 to 9 for the preparation of polyurethanes or polyisocyanurates.

12. Isocyanate composition obtained or obtainable according to the process according to any one of claims 1 to 9.

13. Use of the isocyanate composition according to claim 12 or an isocyanate composition obtained or obtainable according to the process of any one of claims 1 to 9 for the preparation of polyurethanes or polyisocyanurates.

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