Method for recovering raw materials from polyurethane foam

Abstract

The present invention relates to a process for preparing a polyurethane foam based on an isocyanate component and a polyol component, the polyurethane foam comprising a cellular structure containing one or more volatile accompanying substances, i.e. component X selected from the group consisting of oxygen, a blowing agent, a disinfectant and a mixture of two or more of the above, component X comprising at least oxygen, and a process for chemically decomposing the polyurethane foam with a chemical decomposition agent, the process being carried out by degassing the polyurethane foam before contacting it with the chemical decomposition agent, so as to remove at least oxygen, preferably all components of component X or any gaseous decomposition products formed thereof, at a pressure of 960 mbar or less. (abs.) and a temperature of 120° C. or less to obtain a degassed polyurethane foam, followed by reacting the degassed polyurethane foam with a chemical decomposition agent in an inert gas atmosphere in the presence of a catalyst, and post-treating the product mixture obtained by the chemical decomposition; step (C) of obtaining at least one polyol; and, optionally, step (D) of obtaining at least one amine corresponding to the isocyanate of the isocyanate component.

Description

[Technical field]

[0001] The present invention relates to a process for preparing a polyurethane foam based on an isocyanate component and a polyol component, the polyurethane foam having a cell structure containing one or more volatile accompanying substances, i.e. component X selected from the group consisting of oxygen, blowing agents, disinfectants and mixtures of two or more of the above-mentioned accompanying substances, component X comprising at least oxygen, and a process for chemically decomposing the polyurethane foam with a chemical decomposition agent, the process being carried out by degassing the polyurethane foam before contacting it with the chemical decomposition agent, so as to remove at least oxygen, preferably all the constituents of component X or any gaseous decomposition products thereof which may have been formed, at a pressure of 960 mbar or more. (abs.) and removing the polyurethane foam in gaseous form from the chemical decomposition device through a gas removal device at a pressure of 0.1 to 1.5 and a temperature of 120° C. or less to obtain a degassed polyurethane foam, followed by reacting the degassed polyurethane foam with a chemical decomposition agent in an inert gas atmosphere in the presence of a catalyst and post-treating the product mixture obtained by the chemical decomposition; step (C) recovering at least one polyol; and, optionally, step (D) recovering at least one amine corresponding to the isocyanate of the isocyanate component. [Background technology]

[0002] Polyurethane foams have various applications in industry and in everyday life. They are usually divided into rigid foams (used, for example, as thermal insulation) and flexible foams (used, for example, in the manufacture of cushioned furniture). Despite these differences, the basic polyurethane structure is common to all polyurethane foams, which is formed by the polyaddition reaction of multifunctional isocyanates with polyols, for example in the case of polyurethanes based on diisocyanates O=C=NRN=C=O and diols HO-R'-OH, where R and R' represent organic groups: ~~~[O-R'-O-(O=C)-HN-R-NH-(C=O)]~~~ It can be expressed as:

[0003] Due to the great economic success of polyurethane foam, a large amount of polyurethane waste is generated (e.g. from old mattresses or seated furniture) which needs to be used rationally. The technically easiest recycling method to implement is incineration, where the heat of combustion released is utilized in other processes, e.g. industrial processes. However, this method does not allow to complete the raw material loop. Another recycling method is called "physical recycling", where polyurethane waste is mechanically comminuted and used to manufacture new products. This recycling method has clear limitations, which does not eliminate attempts to recover the raw materials on which polyurethane is produced by re-cleaving the polyurethane bonds (called "chemical recycling"). These raw materials to be recovered mainly comprise polyols (i.e. in the above example, HO-R'-OH). In addition, it is also possible to recover amines by hydrolytic cleavage of the urethane bonds (i.e. in the above example, H 2 NR-NH 2 ), which after work-up can be phosgenated to form the isocyanate (in the above example, forming O=C=NRN=C=O).

[0004] A variety of chemical recycling approaches have been developed so far. The four most important can be briefly summarized as follows: 1. Hydrolysis of urethanes by reaction with water to recover amines and polyols and form carbon dioxide. 2. Glycolysis of urethanes by reaction with alcohols. The polyol incorporated in the urethane group is released by replacing it with the alcohol used. This process is commonly referred to in the literature as transesterification (more correctly, transurethanization). Regardless of the exact nature of the alcohol used, this method of chemical recycling is called glycolysis in the literature, a term that in fact applies only to glycols. Therefore, in the present invention, the term alcoholysis is used generally. Glycolysis may be followed by hydrolysis. If the hydrolysis is carried out in the presence of the still unchanged glycolysis mixture, it is called hydroglycolysis. 3. Hydroglycolysis of urethane compounds by reaction with alcohol and water. Of course, it is also possible to add alcohol and water from the beginning, in which case the above-mentioned processes of glycolysis and hydrolysis proceed in parallel. 4. Acidolysis of urethane compounds to form acylurea compounds by reaction with carboxylic acids.

[0005] An overview of known polyurethane recycling methods is given in the review by H. K. et al., J. Appl. Phys. 2003, 133:1311-1322 (2003).

[0006] Patent document 1 describes the chemical degradation of polyurethanes involving mechanical grinding and reaction with water and alcohol using carbodiimide as a catalyst in an inert gas atmosphere in the presence of an antioxidant at 218°C to 399°C and a pressure of 50 kPa to 150 kPa for 3 to 5 hours.

[0007] US Pat. No. 5,399,436 describes a method for continuous glycolytic cutting of polyurethane polymer waste, in particular polyurethane foam waste, in a multiscrew machine by adding an optionally preheated diol at a cutting temperature above 250° C., while maintaining at least such a pressure that the polyurethane-diol mixture is in the liquid phase, discharging the glycolyzate mixture after a short residence time of 2 to 30 minutes in the reaction screw, and quenching the glycolyzate mixture. In a preferred embodiment, the air introduced into the screw machine together with the polymer waste can escape through holes in the housing upstream of the introduction funnel, which is advantageously under slightly reduced pressure and opposite to the conveying direction. US Pat. No. 5,399,436 does not disclose that volatile accompanying substances present in the cell structure of the polyurethane foam, such as in particular oxygen, blowing agents and / or disinfectants, are removed through the holes in the housing. Nor is this anticipated in the described arrangement, instead it is actually anticipated that only the air entering the machine together with the foam waste during the introduction process (air around the foam waste) is removed.

[0008] US Pat. No. 5,399,633 describes a method for continuous hydrolytic cleavage of polymer waste, in which waste hydrolyzable polymer materials are introduced into a screw machine together with water and optionally a hydrolysis catalyst, in which the mixture of water and polymer waste is exposed to temperatures of 100° C. to 300° C. for 2 to 100 minutes in a reaction zone with intense mass and heat transfer, at pressures of 5 bar to 100 bar, and the liquid-gas mixture formed during hydrolysis is continuously conveyed to a spinneret fixedly connected to the screw machine, from which the gas escapes through a control valve that keeps the screw machine pressure constant in the spinneret and the liquid escapes through a control valve that keeps the liquid level constant in the spinneret. In a preferred embodiment, the air introduced with the polymer waste is removed through a hole in the housing located upstream of the inlet funnel of the polymer material in the conveying direction, to which a slight vacuum is applied. US Pat. No. 5,399,633 does not disclose that volatile accompanying substances present in the cell structure of the polyurethane foam, such as, in particular, oxygen, blowing agents and / or disinfectants, are removed through the holes in the housing. Also, this is not to be expected from the essentially slight vacuum and compression of the foam after addition of the chemical decomposition reagent (here water), but instead, as in the case of US Pat. No. 5,993,133, it must be assumed that in fact only the air that enters the machine together with the polymer waste during the introduction process (the air surrounding the polymer waste) is removed.

[0009] US Pat. No. 5,399,633 discloses a method for producing polyols from polyurethane waste, in which foam flakes, ground flexible foam or chopped material are introduced into a reactor containing waste from the synthesis of polyesters previously heated to a temperature above 70° C. The mixture of polyurethane waste and waste from the synthesis of polyesters is further heated and converted by a controlled catalytic transesterification reaction at a temperature between 120° C. and 250° C. In a preferred embodiment, the polyurethane waste is introduced by pneumatic transport with a gentle nitrogen flow. Removal of volatile accompanying substances present in the cell structure of the polyurethane foam, such as, in particular, oxygen, blowing agents and / or disinfectants, is not anticipated in this method.

[0010] US Pat. No. 5,399,633 describes a method for producing polyols from polyurethane waste and a specific device for carrying out said method. In this case, according to US Pat. No. 5, a pre-comminuted flexible foam is metered in from above via a clamping screw and a squeeze ring, while the gas present in the foam is removed. However, it is doubtful whether the oxygen present in the cell structure of the polyurethane foam can actually be at least essentially completely removed without applying a reduced pressure before the start of the chemical decomposition. This is even more true for accompanying substances that potentially impair recycling and that may be present in the cell structure of the polyurethane foam, such as blowing agents or disinfectants (sometimes in liquid form), since these boil at a significantly higher level than oxygen.

[0011] US Pat. No. 6,399,436 describes a method and an apparatus for treating polyurethanes obtained from waste materials by alcoholysis or acidolysis. This involves first mechanically grinding the polyurethane to obtain the starting material, followed by treatment with a solvent at a temperature above 120° C. At least at the beginning of the solvent treatment, which results in the liquefaction of the starting material and is carried out at a reaction temperature below 200° C., the mechanical grinding of the already chemically decomposed starting material is continued. This method, according to US Pat. No. 6,436,436 results in shorter treatment times at lower temperatures, until the starting material is completely dissolved, without causing any discoloration that may impair the quality or leaving any undissolved residues. The starting material is naturally dissolved by at least partial reaction of the polyurethane bonds.

[0012] The installation for carrying out the process comprises a mixer fed from a reservoir vessel connected at the outlet side to a reactor, in which shear elements exerting shear forces and capable of rotating in both directions act on the starting materials, these shear elements being arranged on a hollow heatable shaft and surrounded by a reactor shell consisting of hollow heatable sectors. This reactor improves the heat transfer to the materials so that a uniform temperature distribution and thus relatively short reaction and dissolution times can be achieved. EP 1 339 636 A1 discloses an embodiment in which the starting materials are pre-milled while being mixed with a proportion of polyol, which is subsequently used as a solvent component, in a heatable kneading mixer with two co-rotating shafts with sigma blades. According to EP 1 339 636 A1, this achieves a good pre-wetting of the polyurethane particle surfaces with the solvent, releases part of the gas trapped in the polyurethane cell area, reduces the harmful oxygen content, avoids agglomeration of the polyurethane particles as a result of subsequent mechanical stresses, especially in the downstream reaction zone, and decisively increases the meterability and thermal conductivity of the starting materials. Substantial removal of atmospheric oxygen can be brought about by subsequent evacuation of the mixture in the same piece of equipment and / or by subsequent purging with a protective gas, for example nitrogen, at standard pressure, according to US Pat. No. 6,399,323. However, it should be noted here that the presence of solvents (=chemical decomposition agents) that wet the polyurethanes prevents effective degassing.

[0013] In addition to the mentioned processes of physical recycling (mechanical grinding of polyurethane products and their addition in the production of new polyurethane products) and chemical recycling (chemical cleavage of urethane bonds to recover polyols, preferably also amines), it is also necessary to mention "upcycling", which is in an intermediate position. In the case of upcycling, as in chemical recycling, a chemical change occurs in the polyurethane, but it does not go as far as recovering the raw materials (polyols and amines) originally used in the synthesis, but aims at converting the reused polyurethane into a useful different polymer product. For example, DT Sheppard et al. in Non-Patent Document 2 describe the treatment of crosslinked polyurethane foam with dibutyltin dilaurate in dichloromethane, followed by mechanical processing of the foam thus treated in a twin-screw mixer or twin-screw extruder with removal of air to obtain a film or fiber.

[0014] Of the processes for recycling polyurethanes in the literature, only a few are sustainably carried out on an industrial scale, and many have not even reached pilot scale (Non-Patent Document 1). Given the general growing environmental awareness and the increasing efforts to make industrial processes as sustainable as possible, it is clearly shown that the recycling of polyurethane products is still by no means mature from a technical and economic point of view. The opportunities for physical recycling are obviously very limited. Upcycling can open the way to a viable reuse of polyurethane products and is effective in this respect, but it does not close the raw material cycle. Only chemical recycling offers the possibility to recover the used polyols, preferably also the amines, and to use these in the production of new polyurethane products of comparable quality to the original one. In this respect, there are challenges, especially with regard to the purity of the recovered products. In the case of reuse in the production of polyurethane foams, it is necessary to recover polyols as free as possible from amine impurities, in order not to have a negative effect on the foaming properties, for example. If the additional aim is the recovery of amines, these must of course also be obtained with maximum purity. Furthermore, an economical recycling process must ensure that the reagents used (e.g. the alcohols used) can be recovered as completely as possible and reused (i.e. recycled).

[0015] Recycled polyurethane products usually still contain various auxiliaries and additives (stabilizers, catalysts, etc.), which must be separated from the actual recycled product and disposed of in an economically viable and environmentally friendly way. In the case of polyurethane foams, special mention must also be made of the blowing agents and oxygen present in the foam's cell structure. In addition to these auxiliaries and additives, which are present for reasons related to production, preparatory steps prior to the actual chemical recycling can introduce further foreign substances into the recycled polyurethane product. It is common to treat recycled polyurethane foams, for example from old mattresses or seating furniture, with disinfectants, for example. These foreign substances can impair the chemical recycling and / or the subsequent use of the recovered raw materials in new manufacturing processes.

[0016] Oxygen may cause oxidation reactions, especially of amines. The presence of oxygen is also problematic from a safety point of view, given that it results in operating temperatures that are above the flash point of the alcohol used in alcoholysis, for example. The foaming agents used, such as pentane, are chemically inert, but for this particular reason also accumulate and must be periodically purged with product losses. The presence of the foaming agent may also increase the off-gas load and make the after-treatment of the off-gas more difficult. Certain commonly used disinfectants, such as ethanol, may form carbamates upon chemical decomposition, some of which are more difficult to cleave to release amines than the carbamates of the actual chemical decomposition reagent (usually glycols or glycol derivatives). Even if the carbamate cleavage is successful, such alcoholic disinfectants may be mixed as impurities in the unconverted chemical decomposition reagent during after-treatment, complicating its recovery. Other commonly used disinfectants, such as hydrogen peroxide or sodium hypochlorite, may be decomposed to release oxygen. The prior art has not yet provided a satisfactory solution to such problems. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] China Patent Application Publication No. 106279760 [Patent Document 2] DE 3232461 [Patent Document 3] DE 2442387 [Patent Document 4] German Patent Application Publication No. 19719084 [Patent Document 5] German Patent Application Publication No. 102004014165 [Patent Document 6] European Patent Application Publication No. 0031538 [Non-patent literature]

[0018] [Non-Patent Document 1] Simon, Borreguero, Lucas and Rodriguez in Waste Management 2018, 76, 147 - 171 [Non-Patent Document 2] Reprocessing Postconsumer Polyurethane Foam Using Carbamate Exchange Catalysis and Twin-Screw Extrusion (ACS Cent. Sci. 2020 6 (6), 921-927) Summary of the Invention [Problem to be solved by the invention]

[0019] Therefore, further improvements are needed in the field of chemical recycling of polyurethane foams, and in particular, it would be desirable to remove as much potentially troublesome accompanying substances, such as blowing agents, oxygen or disinfectants, from the polyurethane foam as practically possible before the actual chemical recycling begins without interfering with subsequent processing steps. [Means for solving the problem]

[0020] Thus, taking into account the requirements outlined, the present invention provides a method for recovering raw materials (i.e. polyol and optionally amine) from a polyurethane foam based on an isocyanate component and a polyol component and having a cellular structure comprising a component X selected from the group consisting of oxygen, a blowing agent, a disinfectant and a mixture of two or more of the above, component X comprising at least oxygen, by reacting the polyurethane foam with a chemical decomposition agent, comprising: (A) preparing polyurethane foam 1 in a container 100; (B) chemically decomposing polyurethane foam 1 in a chemical decomposition apparatus comprising: (i) an inlet apparatus 200; (ii) a chemical decomposition reactor 300 connected to the inlet apparatus; (iii) an outlet apparatus 400 connected to the chemical decomposition reactor; and (iv) a gas removal apparatus 500 disposed within the vessel and / or within the inlet apparatus; In addition, chemical decomposition is (BI) introducing the polyurethane foam from the vessel into an inlet apparatus and thence into a chemical decomposition reactor where the polyurethane foam is contacted with a chemical decomposition reagent prior to (α) removing at least oxygen (i.e., (i) the oxygen present in component X, and (ii) any oxygen formed by decomposition reactions of the constituents of component X), preferably all of the constituents of component X or any gaseous decomposition products thereof, from a chemical decomposition device at 960 mbar (abs.) Removing in gaseous form through a gas removal device at a pressure of 100°C or less and a temperature of 120°C or less; to obtain a degassed polyurethane foam 2. (B.II) reacting the degassed polyurethane foam 2 with a chemical decomposition reagent 4 in a chemical decomposition reactor 300 in the presence of a catalyst and in an inert gas atmosphere to obtain a product mixture; (B.III) discharging the product mixture from the chemical decomposition reactor 300 via an outlet device 400; followed by working up the product mixture; Contains; (C) recovering (at least) the polyol (from the polyol component obtained by chemical decomposition or from its decomposition products); (D) optionally recovering (at least) the amine corresponding to the isocyanate from the isocyanate component; The present invention provides a method comprising:

[0021] Surprisingly, it has been found that the removal of volatile accompanying substances defined by component X according to the invention, before initially contacting the polyurethane foam with a chemical decomposition agent, results in a particularly careful depletion of such accompanying substances, thereby overcoming or at least minimizing the problems outlined above. In particular, oxygen, whether present from the beginning or formed in situ as a result of the decomposition of disinfectants such as, for example, hydrogen peroxide or sodium hypochlorite, is successfully removed by the method according to the invention, which in particular avoids oxidation reactions of amines. This is because it is a feature of the method according to the invention that it can successfully remove not only accompanying substances present on the surface or in an attached form, but also volatile accompanying substances present within the cell structure of the polyurethane foam.

[0022] This is because, as known to those skilled in the art, polyurethane foams have a cell structure (also called pore structure) that can be influenced by chemical or chemical engineering parameters in the foaming operation. In the production of polyurethane foams, a blowing agent is used, which is gaseous under the production conditions of the foam, leading to the formation of foam cells (also called foam pores) connected to each other via the lamellae. The polyurethanes to be reused usually contain accompanying substances that are volatile and potentially interfere with chemical decomposition, which may be present not only in the cells (i.e. cavities) but also in the lamellae (e.g. when the lamellae are filled with disinfectants).

[0023] The present invention therefore relates to the removal of volatile accompanying substances from polyurethane foam before the start of chemical recycling, i.e. before the polyurethane foam to be reused is first contacted with a chemical decomposition agent. Volatile accompanying substances in this context, i.e. component X, are understood in the context of the present invention to mean oxygen, a blowing agent, a disinfectant or a mixture of two or more of the above, in particular when the volatile accompanying substances (i.e. component X or its constituents) are removed at a lower pressure p U , upper pressure p O , lower limit temperature T U and upper limit temperature T O is gaseous or decomposes to form gaseous decomposition products in at least a portion of the pressure and temperature ranges defined by p U =0.1mbar (abs.) , p O =960mbar (abs.) , T U = -20°C, in particular (i.e., the volatile accompanying substances present in the cell structure are at normal conditions (i.e., at a temperature of 0°C and 1.000 bar (abs.) (pressure) when liquid), 16°C, and T O =120°C.

[0024] Pressure p U and p O can be determined by conventional manometers. This of course also applies to the pressures p1 and p2, which are explained further below. Although in purely linguistic terms it may be described as "volatile accompanying substances", it is understood that the presence of further compounds not included in the definition of component X in the context of the present invention is not excluded and that recycling such polyurethane foams by the method according to the invention does not go beyond the scope of the present invention.

[0025] The mentioned conditions are met for oxygen. This is also true for blowing agents (e.g. pentane) that are usually used in polyurethane foam production. Also, most of the conventional disinfectants can be converted into gas phase or gaseous decomposition products under the mentioned conditions, so that troublesome substances can be discharged through a gas remover. Examples of decomposable volatile accompanying substances are hydrogen peroxide and sodium hypochlorite, both of which tend to decompose, especially to form oxygen, and therefore can be removed as "gaseous decomposition products" through a gas remover.

[0026] In the terminology of the present invention, the term isocyanate encompasses all isocyanates known to the skilled artisan in connection with polyurethane chemistry, such as in particular tolylene diisocyanate (TDI; which can be, and preferably is, prepared from tolylene diamine (TDA)), di- and polyisocyanates of the diphenylmethane series (MDI; which can be, and preferably is, prepared from di- and polyamines of the diphenylmethane series (MDA)), pentane 1,5-diisocyanate (PDI; which can be, and preferably is, prepared from pentane-1,5-diamine (PDA)), hexamethylene 1,6-diisocyanate (HDI; which can be, and preferably is, prepared from hexamethylene-1,6-diamine (HDA)), isophorone diisocyanate (IPDI; which can be, and preferably is, prepared from isophorone diamine (IPDA)) and xylylene diisocyanate (XDI; which can be, and preferably is, prepared from xylylene diamine (XDA)). The term "isocyanate" naturally encompasses embodiments in which two or more different isocyanates (e.g., a mixture of MDI and TDI) are used to make the polyurethane product, unless expressly stated otherwise, e.g., by the term "exactly one isocyanate." Collectively, all isocyanates used to make the polyurethane product are referred to as the isocyanate component (of the polyurethane product). The isocyanate component comprises at least one isocyanate. Similarly, collectively, all polyols used to make the polyurethane product are referred to as the polyol component (of the polyurethane product). The polyol component comprises at least one polyol.

[0027] In the terminology of the present invention, the term polyol includes all polyols known to those skilled in the art in the context of polyurethane chemistry, such as, in particular, polyether polyols, polyester polyols, polyether ester polyols and polyether carbonate polyols. The term "polyol" also includes, of course, embodiments in which two or more different polyols are used to produce a polyurethane product. Thus, for example, when referring to "polyether polyol" (or "polyester polyol", etc.), this term also includes, of course, embodiments in which two or more different polyether polyols (or two or more different polyester polyols, etc.) are used to make a polyurethane product.

[0028] Carbamate in the present terminology refers to the urethane formed by reaction with the alcohol in step (B).

[0029] The amine corresponding to an isocyanate refers to an amine that can be phosgenated to produce an isocyanate: R-NH 2 +COCl 2 →RN=C=O+2HCl. Similarly, the nitro compound corresponding to an amine is the nitro compound that can be reduced to give the amine: R-NO 2 +3H 2 →R-NH 2 +2H 2 O.

[0030] All pressure numbers are in terms of absolute pressure, indicated by adding the suffix "abs." to the pressure unit (e.g. "mbar (abs.) ").

[0031] The invention therefore relates to the recycling of polyurethane foams in which oxygen is always present, but whose cell structure contains oxygen, (at least) a blowing agent and / or (at least) a (volatile) disinfectant (or one that can decompose to form volatile products), i.e. one, more than one or all of the volatile concomitants mentioned. In the terminology of the present invention, the expression "component X" is used in this context as a general term for all volatile concomitants present.

[0032] The process according to the invention ensures at least essentially complete removal of any oxygen present (from any source). Preferably, all constituents of component X or their gaseous decomposition products are at least essentially complete. In this respect, the invention offers two alternative solutions, which will be elucidated in detail below. What they all have in common is that in (B)(I)(α), oxygen, preferably all constituents of component X or their gaseous decomposition products, is removed at a pressure of "960 mbar (abs.) and at a temperature of 120° C. or less (···) in gaseous form". This means that at least the oxygen present, but also preferably the blowing agent and sanitizing agent, if present (it is not essential that all the mentioned volatile accompanying substances are present; for example, sanitizing of polyurethane foams is not required in all cases), are at least essentially completely removed from the polyurethane foam before the actual chemical decomposition reactions begin.

[0033] It is a particular feature of the first alternative solution that the removal of volatile accompanying substances is essentially brought about by a large pressure drop followed by a pressure increase. For this purpose, the polyurethane foam is degassed in (BI) by: (1) In the first step, at a first temperature T1 in the range of -20°C to 120°C and 0.1 mbar (abs.) ~100mbar (abs.)(wherein the first pressure is adapted to a first temperature such that all constituents of component X to be removed in (B)(I)(α), which in any case are not present in gaseous form like oxygen, are converted into the gas phase or decompose to form gaseous products), Also, (2) In the second step, the pressure is increased to 2.0 bar, which is higher than the first pressure, by supplying an inert gas. (abs.) The material is exposed to a second pressure p2 which is equal to or less than 0.5 V.

[0034] Thus, "degassed polyurethane foam 2" in this context refers to polyurethane foam from which the specified type of volatile accompanying substances has been removed and which has been saturated with inert gas.

[0035] It is a special feature of the second alternative solution that the removal of the volatile accompanying substances is essentially brought about by mechanical compression of the polyurethane foam (the volatile accompanying substances are forced out of the cell structure of the polyurethane foam and drawn into the reduced pressure area). For this purpose, the polyurethane foam is subjected to a degassing process in (BI) by: (1) In the first step, a first temperature T1 in the range of -20°C to 120°C and 0.1 mbar (abs.) ~960mbar (abs.) , especially 100 mbar (abs.) ~960mbar (abs.) to a device for mechanical compression arranged in the inlet device (wherein the first pressure is adapted to a first temperature such that all constituents of component X to be removed in (B)(I)(α), which in any case are not gaseous like oxygen, are converted into the gas phase or decompose to form gaseous products, the gas removal device being upstream of the device for mechanical compression), Also, (2) In the second step, the mixture is compressed at 5 bar in a mechanical compression device. (abs.) ~200bar (abs.) (which forces the volatile components out of the cell structure and draws them into the region of the inlet device upstream of the device for mechanical compression and then removes them via the gas removal device).

[0036] Thus, "degassed polyurethane foam 2" in this context refers to polyurethane foam from which the specified type of volatile accompanying substances has been removed and which has been compressed (sent in compressed form to chemical decomposition which takes place in an inert gas atmosphere).

[0037] The accompanying drawings show specific ways of implementing these two alternative solutions. [Brief description of the drawings]

[0038] [Figure 1] FIG. 1 shows a first alternative of the method according to the invention (first alternative solution) using a flexible lining, for example made of polyethylene. [Figure 2a] FIG. 2 shows a second alternative of the method according to the invention (first alternative solution) using a locking system. [Figure 2b] FIG. 2 shows a second alternative of the method according to the invention (first alternative solution) using a locking system. [Diagram 3] FIG. 3 shows a third alternative of the method according to the invention (first alternative solution) using a device for mechanical comminution. [Figure 4] FIG. 4 shows a fourth alternative of the method according to the invention (second alternative solution) using a device for mechanical compression. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] A summary of various possible embodiments of the present invention will now follow.

[0040] In a first embodiment of the invention, which corresponds to the first alternative and forms part of the first alternative solution, the container and / or the inlet device are provided with an internal flexible lining which collapses in a first step upon the establishment of a first pressure, thereby compressing the polyurethane foam, and which expands again in a second step upon the supply of an inert gas, which establishes a second pressure.

[0041] In a second embodiment of the invention, which is a particular configuration of the first embodiment and which can be combined with all other embodiments of the first alternative, the flexible lining is a film of polyethylene, polypropylene, aluminum, polyvinyl chloride, polyetheretherketone, polystyrene, polycarbonate, polyester, polyethylene terephthalate, or a composite of the aforementioned materials.

[0042] In a third embodiment of the present invention, which is a specific configuration of the first embodiment and which can be combined with all other embodiments of the first alternative, the first and second steps are repeated, in particular, 2 to 5 times.

[0043] In a fourth embodiment of the invention, which is a specific configuration of the first embodiment and which can be combined with all other embodiments of the first alternative, the second pressure is 1.8 bar. (abs.) less than or equal to the ambient pressure.

[0044] In a fifth embodiment of the present invention, which is a specific configuration of the first embodiment and which can be combined with all other embodiments of the first alternative, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0045] In a sixth embodiment of the present invention, which is a specific configuration of the first embodiment and which can be combined with all other embodiments of the first alternative, the second step is carried out at a second temperature T2 which is in the range of -20°C to 120°C, preferably 0°C to 80°C, more preferably 16°C to 80°C, and which in particular corresponds to the first temperature (i.e. no specific change in temperature is made when transitioning from the first step to the second step).

[0046] In a seventh embodiment of the invention, corresponding to the second alternative and also forming part of the first alternative solution, the inlet device comprises a first locking zone (upstream of the chemical decomposition reactor) with a closable feed device for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, wherein step (BI) comprises the following steps: (BI1.a) closing the removal device of the first locking area, introducing polyurethane foam into the first locking area, and closing the feed device of the first locking area; (BI2.a) performing the first step of (BI) in a first lock region; (BI3.a) carrying out the second step of (BI) by feeding inert gas in the first lock zone to obtain a degassed polyurethane foam; (BI4.a) transferring the degassed polyurethane foam obtained in (BI3.a) to a chemical decomposition reactor; Includes.

[0047] In an eighth embodiment of the invention, which is a particular configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, the inlet device comprises, in addition to the first locking area, a second locking area with a closable feed device for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, wherein a first portion of polyurethane foam is introduced into a first locking zone in step (BI1.a) so that a first portion of degassed polyurethane foam is obtained in step (BI3.a), step (BI) comprising the following steps: (BI1.b) closing the removal device of the second locking area, introducing a second portion of the polyurethane foam into the second locking area, and closing the feed device of the second locking area; (BI2.b) performing the first step of (BI) in a second lock region; (BI3.b) in a second lock zone, carrying out a second step of (BI) by feeding inert gas to obtain a second portion of degassed polyurethane foam; (BI4.b) transferring a second portion of the degassed polyurethane foam to a chemical decomposition reactor; wherein steps (BI1.a) to (BI4.a) are combined with steps (BI1.b) to (BI4.b) to continuously transfer the degassed polyurethane foam to a chemical decomposition reactor.

[0048] In a ninth embodiment of the present invention, which is a specific configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0049] In a tenth embodiment of the present invention, which is a specific configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, the polyurethane foam is first contacted with a chemical degradation reagent in a chemical degradation reactor.

[0050] In an eleventh embodiment of the present invention, which is a specific configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, the second step is carried out at a second temperature T2 which is in the range of -20°C to 120°C, preferably 0°C to 80°C, more preferably 16°C to 80°C, and which in particular corresponds to the first temperature (i.e. no specific change in temperature is made when transitioning from the first step to the second step).

[0051] In a twelfth embodiment of the present invention, which is a particular configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, and which is not limited to the addition of the chemical decomposition reagent in the chemical decomposition reactor, the polyurethane foam is in contact with the chemical decomposition reagent (optionally already with the catalyst) in the first lock zone and / or the second lock zone even after the second step, and in particular is wetted.

[0052] In a thirteenth embodiment of the present invention, which is a particular configuration of the twelfth embodiment, the chemical decomposition reagent when contacted with the polyurethane foam in the first locking zone and / or the second locking zone is at a temperature in the range of 120°C to 240°C, particularly greater than 120°C to 240°C.

[0053] In a fourteenth embodiment of the present invention, which is a specific configuration of the seventh embodiment and which can be combined with all other embodiments of the second alternative, the second pressure is 1.8 bar. (abs.) less than or equal to the ambient pressure.

[0054] In a fifteenth embodiment of the present invention, which corresponds to the third alternative and is likewise part of the first solution alternative, the polyurethane foam is conveyed and comminuted during a first step (BI) through a device for mechanical comminution arranged in a first part of the inlet device, and wherein a second step is performed in such a way that the polyurethane foam after mechanical comminution is conveyed under a second pressure into an inert gas atmosphere through a second part downstream of the first part of the inlet device.

[0055] In a sixteenth embodiment of the present invention, which is a specific configuration of the fifteenth embodiment and which can be combined with all other embodiments of the third alternative, the conveying of the polyurethane foam in the first and second parts of the inlet device is carried out by: (At least) a screw shaft, (At least) pistons, (At least) a conveyor belt, Vibration and / or It is done by gravity.

[0056] In an 18th embodiment of the present invention, which is a particular configuration of the 15th embodiment and which can be combined with all other embodiments of the third alternative, the device for mechanical comminution comprises a cutting mill, a knife mill, an impact cup and / or a hammer mill.

[0057] In a nineteenth embodiment of the present invention, which is a specific configuration of the eighteenth embodiment, the apparatus for mechanical comminution includes an impact cup and / or a hammer mill, wherein the first temperature is in the range of -20°C to less than 0°C.

[0058] In a twentieth embodiment of the present invention, which is a specific configuration of the fifteenth embodiment and which can be combined with all other embodiments of the third alternative except the nineteenth embodiment, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0059] In a twenty-first embodiment of the present invention, which is a specific configuration of the fifteenth embodiment and which can be combined with all other embodiments of the third alternative, the polyurethane foam is first contacted with a chemical decomposition reagent in a chemical decomposition reactor.

[0060] In a 22nd embodiment of the present invention, which is a specific configuration of the 15th embodiment and which can be combined with all other embodiments of the third alternative, the second step is carried out at a second temperature T2 which is in the range of -20°C to 120°C, preferably 0°C to 80°C, more preferably 16°C to 80°C, and which in particular corresponds to the first temperature (i.e. no specific change in temperature is made when transitioning from the first step to the second step).

[0061] In a 23rd embodiment of the present invention, which is a particular configuration of the 15th embodiment and which can be combined with all other embodiments of the third alternative, although it is not limited to the addition of the chemical decomposition reagent in the chemical decomposition reactor, the polyurethane foam is in contact with the chemical decomposition reagent (optionally already with the catalyst) in the second part of the inlet device even after the second step, and in particular is wetted.

[0062] In a twenty-fourth embodiment of the invention, which is a particular configuration of the twenty-third embodiment, the chemical decomposition reagent when contacted with the polyurethane foam in the second portion of the inlet device is at a temperature in the range of from 120°C to 240°C, in particular from greater than 120°C to 240°C.

[0063] In a twenty-fifth embodiment of the present invention, which is a specific configuration of the fifteenth embodiment and which can be combined with all other embodiments of the third alternative, the second pressure is 1.8 bar. (abs.) less than or equal to the ambient pressure.

[0064] In a 26th embodiment of the present invention, which corresponds to the fourth alternative and is a specific configuration of the second alternative solution and which can be combined with all other embodiments of the fourth alternative, the gas removal device is arranged in the inlet device.

[0065] In a twenty-seventh embodiment of the present invention, which is a particular configuration of the twenty-sixth embodiment and which can be combined with all other embodiments of the fourth alternative, the device for mechanical compression comprises an extruder (including multi-zone screws, as well as single-screw and multi-screw extruders), a roller or a piston.

[0066] In a 28th embodiment of the present invention, which is a particular configuration of the 26th embodiment and which can be combined with all other embodiments of the fourth alternative, the polyurethane foam is in contact with the chemical decomposition reagent in the inlet device even after passing through the device for mechanical compression (i.e. after the second step) and is in particular wetted.

[0067] In a twenty-ninth embodiment of the invention, which is a specific configuration of the twenty-eighth embodiment, the chemical decomposition reagent is at a temperature in the range of 120°C to 240°C when contacted with the polyurethane foam in the inlet apparatus.

[0068] In a 30th embodiment of the present invention, which is a specific configuration of the 26th embodiment and which can be combined with all other embodiments of the fourth alternative, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0069] In a thirty-first embodiment of the present invention, which is a particular configuration of the twenty-sixth embodiment and which can be combined with all other embodiments of the fourth alternative, the second step is carried out at a second temperature T2 which is in the range of -20°C to 120°C, preferably 0°C to 80°C, more preferably 16°C to 80°C, and which in particular corresponds to the first temperature (i.e. no particular change in temperature is made when transitioning from the first step to the second step).

[0070] In a thirty-second embodiment of the present invention, which can be combined with all four alternative embodiments, step (B.II) is carried out at a temperature range of 140°C to 240°C, preferably 160°C to 240°C, more preferably 180°C to 220°C.

[0071] In a thirty-third embodiment of the present invention, which can be combined with all four alternative embodiments, step (B.II) is carried out at 960 mbar (abs.) Over 1.8 bar (abs.) The process is carried out at a pressure in the range of 1000 to 2000 psi, particularly at ambient pressure.

[0072] In a thirty-fourth embodiment of the present invention, which may be combined with all embodiments of all four alternatives, component X is oxidized under standard conditions (i.e. at a temperature of 0° C. and 1.000 bar (abs.) at least one component that is liquid (at a pressure of at least 1000 psi), where the first temperature is at least 16° C.

[0073] In a thirty-fifth embodiment of the invention, which can be combined with all embodiments of all four alternatives, the blowing agent comprises (among others) pentane, hydrochlorofluorocarbons, dichloromethane, or a mixture of two or more of the above blowing agents; Disinfectants include (and are especially) hydrogen peroxide, chlorine dioxide, formaldehyde, peracetic acid, alkali metal hypochlorites (especially sodium hypochlorite), ethanol, isopropanol, 1-propanol, or a mixture of two or more of the above mentioned disinfectants.

[0074] In a thirty-sixth embodiment of the present invention, which can be combined with all the embodiments of all four alternatives, the isocyanate component contains an isocyanate selected from tolylene diisocyanate (TDI), di- and polyisocyanates of the diphenylmethane series (MDI), pentane 1,5-diisocyanate (PDI), hexamethylene 1,6-diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), or a mixture of two or more of the abovementioned isocyanates. Particular preference is given to polyurethane foams based on mixtures of TDI and MDI for the isocyanate component. Very particular preference is given to polyurethane products based exclusively on TDI for the isocyanate component.

[0075] In a thirty-seventh embodiment of the present invention, which may be combined with all embodiments of all four alternatives, the polyol component contains a polyol selected from polyether polyols, polyester polyols, polyether ester polyols, polyether carbonate polyols, or a mixture of two or more of the aforementioned polyols. The polyol component is preferably a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., does not contain any polyol other than a polyether polyol; however, a mixture of two or more different polyether polyols is included and does not fall within the scope of this embodiment).

[0076] In a thirty-eighth embodiment of the present invention, which can be combined with all embodiments of all four alternatives, the isocyanate component contains tolylene diisocyanate (TDI) and di- and polyisocyanates (MDI) of the diphenylmethane series (in particular only TDI) and the polyol component contains a polyether polyol (in particular a polyether polyol, i.e. no further polyols other than the polyether polyol, although mixtures of two or more different polyether polyols are included without departing from the scope of this embodiment).

[0077] In a thirty-ninth embodiment of the present invention, which may be combined with all embodiments of all four alternatives, the chemical degradation reagent comprises an alcohol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl glycol, triethylene glycol, glycerol, 2-methylpropane-1,3-diol, or a mixture of two or more of the aforementioned alcohols.

[0078] In a fortieth embodiment of the present invention which is a specific configuration of the forty-second embodiment, the chemical degradation reagent comprises water.

[0079] In a forty-first embodiment of the present invention, which can be combined with all embodiments of all four alternatives, the catalyst is selected from alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal salts of carboxylic acids (especially acetates), alkaline earth metal salts of carboxylic acids (especially acetates), Lewis acids (especially dibutyltin dilaurate, tin octoate, monobutyltin oxide or tetrabutyl titanate), and / or organic amines (especially diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undec-7-ene or 1,4-diazabicyclo[2.2.2]octane).

[0080] In a 42 embodiment of the present invention, which can be combined with all embodiments of all four alternatives, the chemical decomposition agent when contacted with the polyurethane foam is at a temperature in the range of 120°C to 240°C, in particular greater than 120°C to 240°C.

[0081] The above briefly outlined embodiments of the present invention and further possible embodiments are elucidated in more detail below. Unless otherwise stated or clearly seen from the context, all embodiments and other configurations of the present invention can be combined with each other as desired.

[0082] Preparation of polyurethane foam for chemical recycling In step (A) of the method according to the present invention, a polyurethane foam to be chemically recycled is provided.

[0083] The polyurethane foams can in principle be of any type, in particular flexible and rigid foams are useful, flexible foams (e.g. from used mattresses, furniture cushioning or car seats) being preferred. Such polyurethane foams are produced using blowing agents. Apart from water-blown foams (which in this case hydrolyze in situ to release carbon dioxide), in particular pentane is a commonly used blowing agent. In the recycling of used polyurethane foams, it is conceivable that hydrochlorofluorocarbons, which were previously commonly used as blowing agents, are used. A further possible blowing agent is dichloromethane.

[0084] In addition, polyurethane foams based on isocyanates selected from tolylene diisocyanate (TDI), di- and polyisocyanates of the diphenylmethane series (MDI), pentane 1,5-diisocyanate (PDI), hexamethylene 1,6-diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI) and mixtures of two or more of the abovementioned isocyanates are preferred for the isocyanate component. Particularly preferred are polyurethane foams based on mixtures of TDI and MDI for the isocyanate component. Very particular preferred are polyurethane products based exclusively on TDI for the isocyanate component.

[0085] With regard to the polyol component, polyurethane foams based on a polyol selected from the group consisting of polyether polyols, polyester polyols, polyether ester polyols, polyether carbonate polyols, or a mixture of two or more of the aforementioned polyols are preferred. The polyol component is preferably a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., does not contain any polyol other than a polyether polyol; however, a mixture of two or more different polyether polyols is included and does not fall within the scope of this embodiment).

[0086] Most preferably, the polyurethane foam is a foam in which the isocyanate component contains only tolylene diisocyanate (TDI) and di- and polyisocyanates (MDI) of the diphenylmethane series, in particular TDI, and the polyol component contains a polyether polyol (in particular a polyether polyol, i.e. no further polyols other than the polyether polyol, although mixtures of two or more different polyether polyols are included without departing from the scope of this embodiment).

[0087] Preferably, step (A) already comprises a preparatory step for the cleavage of the urethane bonds in step (B.II). This is in particular the mechanical comminution of the polyurethane foam. Such preparatory steps are known to those skilled in the art. See, for example, "Polyurethane Foams: A Guide to the Use of Polyurethane Foams in Polyurethane Foams," Journal of Polyurethane Foams, Vol. 1, No. 1, pp. 1111-1115, 2002. Depending on the characteristics of the polyurethane foam, it may be advantageous to "freeze" the polyurethane foam before mechanical comminution in order to facilitate the comminution operation.

[0088] Before, during or after mechanical comminution, the polyurethane foam may be treated with a disinfectant (aqueous or alcoholic). Such disinfectants are preferably hydrogen peroxide, chlorine dioxide, formaldehyde, alkali metal hypochlorites (especially sodium hypochlorite) and / or peracetic acid (aqueous disinfectants), or ethanol, isopropanol and / or 1-propanol (alcoholic disinfectants). In particular, when carrying out such a disinfection treatment, the compounds present within the cell structure are oxidized under standard conditions, i.e. at a temperature of 0° C. and at 1.000 bar. (abs.) In this case, it is preferable to select a value of 16° C. as the minimum value of the first temperature.

[0089] The foam thus prepared is finally transferred to a vessel (reference number 100 in the figures) connected to an inlet device, which may include any conventional vessel known in the art, such as a silo or container for solids.

[0090] It is also conceivable that the above preparation step is carried out at a site spatially separated from the chemical decomposition side. In that case, the prepared foam is filled into a suitable transport vehicle, for example a silo vehicle, for further transport. For further transport, the prepared foam may be additionally compressed to achieve a higher mass-to-volume ratio. At the site of the chemical decomposition reactor, the foam is subsequently filled into a container. It is also conceivable that the transport vehicle used is directly connected to the inlet device, in which case the transport vehicle shall be considered as a container in the terminology of the present invention.

[0091] Chemical Decomposition of Polyurethane Foam Step (B) of the method according to the invention comprises chemical decomposition of the polyurethane foam prepared in step (A). (i) an inlet device (reference numeral 200 in the figure); (ii) a chemical decomposition reactor (reference numeral 300 in the figure) connected to an inlet device; (iii) an outlet device (reference numeral 400 in the figure) connected to the chemical decomposition reactor; (iv) at least one gas removal device (reference number 500 in the figure) for removing compounds present in the cell structure; The process is carried out in a chemical decomposition apparatus having a

[0092] Step (B) comprises the following substeps: (BI) introducing the polyurethane foam from a vessel into an inlet apparatus and thence into a chemical degradation reactor where the polyurethane foam is contacted with a chemical degradation reagent prior to introduction of the polyurethane foam into a chemical degradation reactor; (α) removing at least oxygen (i.e., (i) the oxygen present in component X, and (ii) any oxygen formed by decomposition reactions of the constituents of component X), preferably all of the constituents of component X or their gaseous decomposition products, from a chemical decomposition device at 960 mbar (abs.) Removing in gaseous form through a gas removal device at a pressure of 100°C or less and a temperature of 120°C or less; to obtain a degassed polyurethane foam; (B.II) reacting the degassed polyurethane foam with a chemical decomposition reagent in a chemical decomposition reactor in the presence of a catalyst and in an inert gas atmosphere to obtain a (first) product mixture; and (B.III) discharging the (first) product mixture from the chemical decomposition reactor through an outlet device.

[0093] During step (BI), the polyurethane foam is degassed, i.e. the volatile accompanying substances present in the cellular structure are removed from the cells and / or lamellae of the cellular structure of the polyurethane foam and vented via at least one gas outlet device 500. There are various ways to achieve this.

[0094] In a first alternative of step (BI) which is part of the first solution alternative and is shown in FIG. 1, a first pressure p1 of 0.1 mbar is applied to the vessel (100 in FIG. 1) and / or to the inlet device (not shown in FIG. 1, but equally possible) in a first step. (abs.) ~100mbar (abs.) In a second step, the inner flexible lining 600 is provided which is collapsed by adjusting the pressure to a value in the range of 1.8 bar, thereby compressing the polyurethane foam, and which is expanded again by supplying an inert gas 3 to establish a second pressure p2. The second pressure is preferably 1.8 bar. (abs.)and specifically corresponds to ambient pressure (i.e. the second step involves expansion to ambient pressure). In this and other figures "M" stands for motor and refers to a motor-driven device, in this example a device for opening and closing the inlet and outlet of the vessel 100.

[0095] 1 shows the filling of the container 100 with polyurethane foam 1. The valve 110 in the lower region of the container, its connection with the inlet device 200 and the gas removal device (500; valve 510 in the "closed" position) are closed.

[0096] The execution of the first step is shown in the center of Figure 1. The inlet of the vessel 100, the valve 110 and the connection to the inlet device 200 are closed. A vacuum is applied using the gas removal device 500 (valve 510 in "open" position) to reduce the pressure in the flexible lining 600 to p1.

[0097] On the right side of Fig. 1 the second step and the subsequent conveyance of the degassed polyurethane foam 2 to the inlet device 200 are shown. In the second step the pressure in the flexible lining is increased to p2 by adding inert gas 3 via the now opened valve 110. After the connection with the inlet device is opened the degassed polyurethane foam 2 is conveyed to the inlet device 200 (i.e. it simply falls into it under gravity).

[0098] Preferably, in the first alternative, no deliberate change in temperature is made during the transition from the first to the second step, the temperature of the steps being in the range of -20°C to 120°C. Preferably, both the first and second steps are carried out at temperatures in the range of 0°C to 80°C. If the compound to be removed is liquid under standard conditions (which does not mean that no significant vapour pressure can exist), a lower temperature limit of 16°C has been found to be useful. It has been found to be advantageous to repeat the first and second steps, in particular 2 to 5 times, before the polyurethane foam thus degassed is sent to the reaction in step (B.II).

[0099] The flexible lining used in this alternative is preferably a film / foil of polyethylene, polypropylene, aluminium, polyvinyl chloride, polyetheretherketone, polystyrene, polycarbonate, polyester, polyethyleneterephthalate or a composite of the above mentioned materials.

[0100] First step pressure up to 100mbar (abs.) The flexible lining is collapsed and the polyurethane foam is compressed by lowering the pressure to 100° C. This forces the volatile accompanying substances out of the foam's cell structure and is discharged via a gas remover. After establishing a second pressure by feeding an inert gas (in particular nitrogen, argon or helium), the degassed polyurethane foam can be conveyed to the chemical decomposition reactor by vibration, mechanically or pneumatically or simply under gravity. In this alternative, the chemical decomposition reagent and catalyst are added only after the polyurethane foam has left the area of ​​the chemical decomposition reactor with the flexible lining. In particular, the chemical decomposition reagent and catalyst are added only to the chemical decomposition reactor. Preferably, the chemical decomposition reagent is added at a temperature, in particular higher than the first temperature, preferably in the range of 120° C. to 240° C.

[0101] In a second alternative for step (BI) which is also part of the first solution alternative and is shown in Fig. 2a, 2b, the inlet device comprises a first locking area 121 (upstream of the chemical decomposition reactor) with a closable feed device for the polyurethane foam 1 prepared in step (A) and a closable removal device for the degassed polyurethane foam 2, wherein step (BI) comprises the following steps: (BI1.a) closing the removal device of the first locking area, introducing polyurethane foam into the first locking area, and closing the feed device of the first locking area; (BI2.a) In the first locking region, the first pressure is set to 0.1 mbar. (abs.) ~100mbar (abs.) and performing the first step (BI); (BI3.a) In the first lock region, the second pressure is increased to p1 to 2.0 bar by supplying an inert gas. (abs.) to a value in the specified range and carrying out a second step (BI) to obtain a degassed polyurethane foam; (BI4.a) transferring the degassed polyurethane foam obtained in (BI3.a) to a chemical decomposition reactor; Includes.

[0102] In the simplest configuration of this embodiment, there is only one lock region, and therefore the expression "first lock region" does not necessarily imply the presence of multiple lock regions.

[0103] However, the use of at least two locking zones, operated alternately, provides more options for the continuous transfer of polyurethane foam to the chemical decomposition reactor. In this embodiment of the second alternative embodiment of the invention, the inlet device comprises, in addition to the first locking zone, a second locking zone with a closable feeding device for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, wherein a first portion of polyurethane foam is introduced into a first locking zone in step (BI1.a), step (BI) comprising the following steps: (BI1.b) closing the removal device of the second locking area, introducing a second portion of the polyurethane foam into the second locking area, and closing the feed device of the second locking area; (BI2.b) In the second locking region, the first pressure is set to 0.1 mbar. (abs.) ~100mbar (abs.) and performing the first step (BI); (BI3.b) In the second lock region, the second pressure is increased to p1 to 2.0 bar by supplying an inert gas. (abs.) to a value in the specified range to carry out a second step (BI) to obtain a second portion of degassed polyurethane foam; (BI4.b) transferring a second portion of the degassed polyurethane foam to a chemical decomposition reactor; wherein steps (BI1.a) to (BI4.a) are combined with steps (BI1.b) to (BI4.b) to continuously transfer the degassed polyurethane foam 2 to a chemical decomposition reactor.

[0104] In the left half of FIG. 2a, a lock 220 is shown with a first locking area 221 and a second locking area 222. The second locking area 222 is of the same configuration as the first locking area, which is not specifically shown in the figure. The access to the second locking area 222 is closed. The polyurethane foam 1 is about to be introduced into the first locking area 221. The first locking area 221 is closed in the downward direction (i.e. towards the chemical decomposition reactor). After the filling operation is finished, the inlet to the first locking area 221 is closed, as shown in the right half of FIG. 2a. The valve 510 associated with the gas removal device 500 is opened and a pressure p1 is established by a pressure drop (first step). In parallel, the polyurethane foam 1 can be introduced into the second locking area 222. When the pressure p1 is reached in the first locking area 221, the valve 510 is closed and a pressure p2 is established by the addition of an inert gas 3 via the valve 210 (left half of FIG. 2b). A chemical decomposition reagent can be similarly supplied via valve 210. Once pressure p2 is reached, valves 210 and 510 are closed, and the polyurethane foam 2, now degassed and optionally wet with chemical decomposition reagent, can be further conveyed to the chemical decomposition reactor (right half of FIG. 2b).

[0105] With regard to temperature and pressure, the statements made above for the first alternative apply correspondingly to the second alternative.

[0106] In this alternative, the chemical decomposition reagent can be added to the polyurethane foam not only in the chemical decomposition reactor, but also immediately after the second step (i.e. after the degassing operation has ended), i.e. in the first and / or second locking zone. The chemical decomposition reagent added in both cases is in particular at a temperature higher than the first temperature, preferably in the range of 120°C to 240°C. It is likewise possible to add a catalyst at this early stage (in particular as a solution in the chemical decomposition reagent). If the chemical decomposition reagent is added at an early stage of the first and / or second locking zone, the polyurethane foam is preferably wetted therewith. The addition of the chemical decomposition reagent at an early stage of the first and / or second locking zone does not of course mean that no further chemical decomposition reagent and / or further catalyst is added to the chemical decomposition reactor.

[0107] In this alternative, the polyurethane foam can be introduced into the first or second locking area by vibration, mechanically or pneumatically. After filling the locking area with polyurethane foam, it is closed. After applying the vacuum, the air outlet valve is closed again. The pressure in the first step is a maximum of 100 mbar. (abs.) By lowering the pressure to 100° C., the volatile components are sucked out of the cell structure of the foam and discharged via a gas outlet device. After a second pressure is established by supplying an inert gas (in particular nitrogen, argon or helium), the degassed polyurethane foam can be conveyed to a chemical decomposition reactor. This can again be achieved by vibration, mechanically or pneumatically, or simply as a result of gravity. If the polyurethane foam is contacted with the chemical decomposition reagent at an early stage in the first locking zone or in the second locking zone, the apparent density of the polyurethane foam increases, as a result of which it can easily fall into the reactor. Furthermore, if the cell structure of the polyurethane foam already contains the chemical decomposition reagent, it becomes easier to mix the polyurethane foam with the chemical decomposition reagent already present in the chemical decomposition reactor.

[0108] In a third alternative of step (BI), also forming part of the first solution alternative and shown in FIG. 3, the polyurethane foam is subjected to a first pressure p1 of 0.1 mbar during the first step of (BI). (abs.) ~100mbar (abs.) to a value within a specified range, the polyurethane foam 11 is conveyed through a device for mechanical comminution 230 arranged in the first part 201 of the inlet device and crushed, in which a second step is performed such that the polyurethane foam 11 after mechanical comminution is conveyed under a second pressure through a second part 202 downstream of the first part of the inlet device into an inert gas atmosphere (in particular a nitrogen, argon or helium atmosphere). This conveying can be performed by (at least) a screw shaft, (at least) a piston, (at least) a conveyor belt, vibration and / or gravity.

[0109] The device 230 for mechanical comminution can be, for example, a cutting mill, a knife mill, an impact cup and / or a hammer mill. The use of an impact cup or a hammer mill is preferred, especially when the polyurethane foam is introduced into the chemical decomposition device in a frozen state, since this, in particular, embodiment of the third alternative of the invention allows the mechanical comminution of the polyurethane foam, which is preferably carried out, to be at least partially integrated into step (B). In that case, the mechanical comminution of the polyurethane foam in step (A), as described further above, can be limited to a coarse comminution of the polyurethane foam into manageable pieces or can be omitted entirely.

[0110] Apart from the above embodiment involving freezing of the polyurethane foam, the statements made for the first and second alternatives with regard to temperature and pressure also apply correspondingly to the third alternative. In this embodiment of the third alternative, too, the pressure is preferably as described for the first and second alternatives, but the mechanical compression is of course carried out at temperatures below 0° C., in particular down to −20° C.

[0111] As in the second alternative, in the third alternative, it is possible to add the chemical decomposition reagent to the polyurethane foam not only in the chemical decomposition reactor, but also immediately after the second step (i.e. after the degassing operation has ended), i.e. here in the second part of the inlet device. The chemical decomposition reagent added in both cases is in particular at a temperature higher than the first temperature, preferably in the range of 120° C. to 240° C. It is likewise possible to add a catalyst at this early stage (in particular as a solution in the chemical decomposition reagent). If the chemical decomposition reagent is added at an early stage in the second part of the inlet device, the polyurethane foam is preferably wetted with it. The addition of the chemical decomposition reagent at an early stage in the second part of the inlet device does not of course mean that no further chemical decomposition reagent and / or further catalyst is added to the chemical decomposition reactor.

[0112] In this alternative embodiment, the polyurethane foam is conveyed by a conveyor, preferably as closed as possible, in particular a screw conveyor, at a pressure of 100 mbar (abs.) The polyurethane foam is then fed to a device for mechanical comminution under a pressure of 0.1 to 100 MPa, where the majority of the volatile compounds are removed during mechanical comminution by a compression operation in the comminution. The polyurethane foam thus comminuted is conveyed under an inert gas atmosphere to a second part of the inlet device, whereby the cell structure of the polyurethane foam is filled with the inert gas and thus effectively protected against the ingress of other gases. Optionally, the mechanical comminution in step (BI) may replace the mechanical comminution in step (A).

[0113] In a fourth alternative of step (BI) shown in FIG. 4, constituting a second alternative solution, the polyurethane foam is conveyed to a device for mechanical compression 240 arranged in the inlet device during a first step, where the polyurethane foam is compressed in said device for mechanical compression at a pressure of 5 bar during a second step. (abs.) ~200bar (abs.)The polyurethane foam is compressed at a second pressure p2 value in the range of 0.5 - 1.0 bar. The pressure p2 can be determined by a manometer (connected to a capillary tube projecting into the area of ​​the inlet device, where the device for mechanical compression is located). It is preferable, but not essential, to inactivate the polyurethane foam before the mechanical compression. For this reason, after the second step, the pressure should be at least 5 bar. (abs.) which is higher than the pressure preferred for step (B.II) (see further below in this respect). The expansion to the pressure of step (B.II) is preferably carried out when the polyurethane foam treated in step (BI) enters the chemical decomposition reactor. The chemical decomposition reagent 4 can be added in this alternative, for example after passing through the device for mechanical compression (i.e. after the degassing operation has ended) and before entering the chemical decomposition reactor 300 (see further below for further details).

[0114] In this alternative embodiment, the gas removal device 500 is preferably arranged in the inlet device 220. The chemical decomposition reactor 300 may also be arranged with a device 600 for venting reaction gases formed during the chemical decomposition, such as, in particular, carbon dioxide.

[0115] Examples of suitable devices for mechanical compression are extruders (including multi-zone screws, as well as single- and multi-screw extruders), rollers or pistons. Multi-zone screws are extruders whose helices have, for example, different helical winding diameters or inclinations. This facilitates compression.

[0116] As in the second and third alternatives, in the fourth alternative, it is possible to add the chemical decomposition reagent to the polyurethane foam not only in the chemical decomposition reactor, but also immediately after the second step (i.e. after the degassing operation is finished), i.e. here after passing through the device for mechanical compression, but also in the inlet device. The chemical decomposition reagent added in both cases is preferably at a temperature in the range of 120° C. to 240° C., in particular in the range of more than 120° C. to 140° C. However, in contrast to the second and third alternatives, it is preferred not to add any catalyst at this point. If the chemical decomposition reagent is added at an early stage in the inlet device, the polyurethane foam is preferably wetted with it. The addition of the chemical decomposition reagent at an early stage in the inlet device does not of course mean that no further chemical decomposition reagent and / or further catalyst is added to the chemical decomposition reactor.

[0117] As with the other alternatives, the temperature of the second step is preferably in the range of -20°C to 120°C, and corresponds in particular to the first temperature (i.e., no deliberate change in temperature is made when going from the first to the second step). The first temperature is preferably in the range of 0°C to 80°C. This also applies to the second temperature. A lower temperature limit of 16°C (for both steps) has been found to be useful when the compound to be removed is liquid under standard conditions (not excluding significant vapor pressure).

[0118] In the mechanical compression apparatus used in this alternative, the polyurethane foam is compressed and the gases and volatile compounds present within the cell structure of the polyurethane foam are forced out.

[0119] In step (B.II) of the method according to the invention, the cleavage of the urethane bonds is carried out, which is the actual chemical recycling (this does not mean that the reaction cannot be partially initiated in the initial stage of the inlet device, as long as the degassing is complete; see the above explanation for step (BI)). The chemical decomposition is carried out in an inert gas atmosphere, in particular a nitrogen, argon or helium atmosphere. The chemical decomposition reagents used are preferably also saturated without oxygen by inert gas saturation, whether this is added for the first time in the chemical decomposition reactor or at an initial stage of the inlet device).

[0120] Step (B.II) can in principle be carried out by any of the methods known in the specialist field. In particular, a chemical decomposition reactor is partially filled with a chemical decomposition reagent (and catalyst) to carry out the reaction. The polyurethane foam to be converted is introduced into this chemical decomposition reagent "bath". The introduction of the polyurethane foam is possible either above or below the liquid level.

[0121] Preferred configurations of this step are alcoholysis (usually referred to in the literature as glycolysis; see further above at no. 2) and hydroalcoholysis (usually referred to in the literature as hydroglycolysis; see further above at no. 3). Regardless of the specific configuration mode, step (B.II) is carried out in the temperature range of 140°C to 240°C, preferably 160°C to 240°C, more preferably 180°C to 220°C. The pressure in step (B.II) is preferably 960 mbar. (abs.) Over 1.8 bar (abs.) and is in particular equal to ambient pressure (i.e. the reaction in step (B.II) is not particularly pressurized). The pressure in step (B.II) means the pressure prevailing in the gas space of the chemical decomposition reactor.

[0122] If the chemical degradation is carried out as alcoholysis, the chemical degradation reagent (in this case alcohol) is added without adding a significant proportion of water. In this context, without adding a significant proportion of water means that water is not intentionally added in such an amount that it would result in a significant degree of hydroalcohololysis. This does not exclude the introduction of small amounts of water, for example in dissolved form in the alcohol used in step (B.II), which may be introduced by the polyurethane foam or used as a solvent for the catalyst.

[0123] If the chemical degradation is carried out as hydroalcolysis, the chemical degradation reagents used are alcohol and water, in which case these two components may be premixed, but this is not necessary. In particular, it is also possible to first add only the alcohol (and at most a small part of the water), dissolve the polyurethane foam therein, and then add the water (or the remaining water). In hydroalcolysis, it is preferable not to add the entire amount of water used at once, but to add it gradually at a rate at which the water is chemically consumed in the reaction.

[0124] Whether the chemolysis is carried out as alcoholysis or hydroalcohololysis, the chemolysis reagent preferably comprises an alcohol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl glycol, triethylene glycol, glycerol, 2-methylpropane-1,3-diol, or a mixture of two or more of the aforementioned alcohols, with diethylene glycol being particularly preferred.

[0125] Alcoholysis and hydroalcohololysis are preferred, but of course other chemical decomposition methods such as hydrolysis or aminolysis can be used as well.

[0126] Suitable catalysts for step (B.II) are in particular alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal salts of carboxylic acids (in particular acetates), alkaline earth metal salts of carboxylic acids (in particular acetates), Lewis acids (in particular dibutyltin dilaurate, tin octanoate, monobutyltin oxide or tetrabutyl titanate) and / or organic amines (in particular diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undec-7-ene or 1,4-diazabicyclo[2.2.2]octane). The catalyst is added at the latest in the chemical decomposition reactor, alternatively (see explanation above) it may also be added already in advance in the inlet device, in particular dissolved in the chemical decomposition reagent.

[0127] Step (B.II) can be carried out in any reactor known for such purposes in the specialist field. Particularly suitable chemical decomposition reactors are stirred tanks (stirred reactors) and tubular reactors.

[0128] Step (B.II) results in a first product mixture containing unconverted chemolysis reagent (since it was used in a superstoichiometric amount), polyol (originating from the polyol component and / or newly formed as decomposition product in reaction with the chemolysis reagent), and carbamates and / or amines (depending on the chemolysis reagent used). In a preferred embodiment in which the chemolysis is carried out as alcoholysis or hydroalcoholysis, the excess chemolysis reagent comprises at least the alcohol used in the chemolysis, with or without water (if the chemolysis is carried out as hydroalcoholysis). If the chemolysis is carried out as pure alcoholysis, water may additionally be present in small amounts. See explanation above.

[0129] This first product mixture is discharged from the chemical decomposition reactor in step (B.III) and then sent to further work-up (step (C), preferably steps (C) and (D)). The discharge device used for this purpose may be any of the devices known in the specialist field for conveying fluids, in particular pumps.

[0130] Polyol Recovery In step (C) of the process according to the invention, the first product mixture obtained in step (B) is worked up to obtain a polyol. This can be achieved in principle as known in the prior art. Preferably, the first product mixture is first mixed with an organic solvent. Various possible configurations are available for this purpose.

[0131] In one possible configuration of step (C) in the preferred embodiment in which the chemical decomposition is carried out as alcoholysis or hydroalcoholysis, this comprises: (CI) combining the first product mixture obtained in step (B.III) with an organic solvent that is completely immiscible with the alcohol used in step (B), in particular an aliphatic, cycloaliphatic or aromatic hydrocarbon or a mixture of two or more of the aforementioned organic solvents, in particular without prior removal of any water present in the first product mixture, and separating the phases into a first alcohol phase and a first solvent phase; (C.II) working up the first solvent phase to recover the polyol; Includes.

[0132] Step (C.II) includes work-up steps known to those skilled in the art, such as in particular washing and distillation.

[0133] In another possible configuration of step (C) in the preferred embodiment in which the chemical decomposition is carried out as alcoholysis or hydroalcoholysis, this is (CI * ) mixing the first product mixture obtained in step (B.III) with an organic solvent miscible with the alcohol used in step (B), in particular a halogen-substituted aliphatic hydrocarbon, a halogen-substituted cycloaliphatic hydrocarbon, a halogen-substituted aromatic hydrocarbon or a mixture of two or more of the abovementioned organic solvents, optionally followed by removal of the solid components, to obtain a second product mixture; (C.II * ) process (CI *The second product mixture obtained in step (a) is washed with an aqueous wash solution (which partially hydrolyzes any carbonates present in the second product mixture to release amines and alcohols) and the phase is Process (CI * a first solvent phase containing the organic solvent and polyol used in step (a); a first aqueous phase containing water, an alcohol, a carbamate, and an amine; and separating the (C.III * ) working up the first solvent phase to obtain a polyol; Includes.

[0134] Process (C.III * ) also includes work-up steps known to those skilled in the art, such as, inter alia, washing and distillation.

[0135] Extraction of the first product mixture with an organic solvent can of course also be carried out when the chemical decomposition is carried out as a pure hydrolysis.

[0136] Amine Recovery The process according to the invention preferably comprises a step (D) of recovering at least one amine corresponding to the isocyanate of the isocyanate component. The starting point of that part of the work-up is the alcohol phase or the first aqueous phase recovered from the first product mixture in step (C).

[0137] The manner in which step (D) is carried out depends in particular on the manner in which step (B.II) is carried out. If step (B) is carried out as alcoholysis, the first alcoholic or first aqueous phase usually still contains a significant proportion of carbamates which have to be hydrolyzed in step (D). Such hydrolysis is advantageously carried out by means of a catalyst, suitable catalysts being the same as those mentioned above for the chemical decomposition.

[0138] If step (B.II) is carried out as hydroalcohololysis, then at this point in the process carbamates are already no longer present (or at least present in insignificant trace contents) and therefore no separate hydrolysis step is necessary.

[0139] Independently of this, step (D) comprises a work-up step, in particular a distillation, to purify the amine obtained by cleavage of the urethane bonds. Here, it is particularly advantageous to integrate the isolation of the recovered amine from the polyurethane foam into the process for preparing fresh amine, as described in WO 2020 / 260387 and the unpublished international application PCT / EP2021 / 075916.

[0140] The invention will be elucidated in more detail below with reference to examples. EXAMPLES

[0141] Example 1 (first alternative according to the invention): 250 g of polyurethane flakes (flexible foam based on tolylene diisocyanate) were introduced into a flexible polyethylene (PE) bag (30 L), which was closed and connected to a vacuum pump. The vacuum pump was started to increase the pressure in the PE bag to 10 mbar. (abs) The pressure in the PE bag was then reduced to a value below 0.5 wt.%. The interior of the PE bag was then expanded to ambient pressure by adding nitrogen. This operation was repeated two more times. An oxygen probe was then installed at the outlet of the bag. The inerted bag was pressurized and the gas present therein was allowed to flow past the oxygen probe for 1 minute. The oxygen content in the exiting air never exceeded 0.5 wt.%.

[0142] The deactivated foam flakes were then used to carry out glycolysis as follows.

[0143] 250g of diethylene glycol and 2.5g of bismuth tri-neodecanoate were further charged to a 1L three-neck round bottom flask and heated to 200°C. Polyurethane flakes were then added, dissolved and maintained at 200°C for another 3 hours. A constant nitrogen purge was switched on (10NL / hr) during the addition and reaction. After the reaction time the mixture was cooled to room temperature.

[0144] Example 2 (Comparative Experiment): The chemical decomposition of the polyurethane flakes was carried out analogously to Example 1, but without degassing according to the invention. Here too, a nitrogen purge was constantly connected during the metered addition and the reaction.

[0145] In Example 2, a clear blackening of the reaction mixture was observed, whereas the previously degassed polyurethane foam (Example 1) only showed a light brown color, clearly demonstrating the effect of the oxygen present in the polyurethane foam cell structure, which apparently accelerates the oxidation of the tolylenediamine compounds released during glycolysis.

Claims

1. A method for recovering raw materials from a polyurethane foam having a cell structure based on an isocyanate component and a polyol component and containing a component X selected from the group consisting of oxygen, a blowing agent, a disinfectant, and a mixture of two or more of the above, the component X containing at least oxygen, by reacting the polyurethane foam with a chemical decomposition agent, comprising: (A) providing a polyurethane foam in a container; (B) chemically decomposing the polyurethane foam in a chemical decomposition apparatus comprising: (i) an inlet apparatus; (ii) a chemical decomposition reactor connected to the inlet apparatus; (iii) an outlet apparatus connected to the chemical decomposition reactor; and (iv) a gas removal apparatus disposed within the vessel and / or within the inlet apparatus; In addition, chemical decomposition is (B.I) introducing said polyurethane foam from said vessel into said inlet apparatus and thence into said chemical degradation reactor where said polyurethane foam is contacted with said chemical degradation reagents; (α) at ​​least oxygen is fed from the chemical decomposition device to 960 mbar （ａｂｓ．） removing said gaseous form through said gas removal device at a pressure of 0.01 to 0.1 MPa and a temperature of 0.01 to 0.1 MPa; to obtain a degassed polyurethane foam. (B.II) reacting the degassed polyurethane foam with a chemical decomposition reagent in the presence of a catalyst in an inert gas atmosphere in the chemical decomposition reactor to obtain a product mixture; (B.III) discharging the product mixture from the chemical decomposition reactor via the outlet device; followed by working up the product mixture; Contains; (C) recovering the polyol; and (D) optionally recovering an amine corresponding to the isocyanate from the isocyanate component; and A method comprising:

2. Degassing the polyurethane foam in (B.I) (1) In a first step, the polyurethane foam is heated at a first temperature in the range of -20°C to 120°C and 0.1 mbar. （ａｂｓ．） ~100mbar （ａｂｓ．） and exposing the first pressure in the range of (2) In the second step, an inert gas is supplied to the polyurethane foam at a pressure higher than the first pressure, 2.0 bar. （ａｂｓ．） exposing the second pressure to a second pressure equal to or less than The method of claim 1 , wherein the method is carried out by

3. 3. The method according to claim 2, wherein the container and / or the inlet device are provided with an internal flexible lining which collapses in the first step by the establishment of the first pressure, thereby compressing the polyurethane foam, and which expands again in the second step by the supply of the inert gas.

4. the inlet device comprises at least a first locking area having a closable supply device for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, wherein step (B.I) comprises the following steps: (B.I.1.a) closing the removal device of the first locking area, introducing polyurethane foam into the first locking area, and closing the supply device of the first locking area; (B.I.2.a) performing the first step of (B.I) in the first lock region; (B.I.3.a) performing the second step of (B.I) by supplying the inert gas in the first locking zone to obtain a degassed polyurethane foam; (B.I.4.a) transferring the degassed polyurethane foam obtained in (B.I.3.a) to said chemical decomposition reactor; The method of claim 2 , comprising:

5. the inlet device comprises, in addition to the first locking area, a second locking area having a closable feeding device for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, wherein the first portion of polyurethane foam is introduced into the first locking zone in step (B.I.1.a) such that the first portion of degassed polyurethane foam is obtained in step (B.I.3.a), step (B.I) comprising the following steps: (B.I.1.b) closing the removal device of the second locking area, introducing a second portion of the polyurethane foam into the second locking area, and closing the feed device of the second locking area; (B.I.2.b) performing the first step of (B.I) in the second lock region; (B.I.3.b) performing the second step of (B.I) by supplying the inert gas in the second locking zone to obtain a second portion of the degassed polyurethane foam; (B.I.4.b) transferring a second portion of the degassed polyurethane foam to the chemical decomposition reactor; and wherein steps (B.I.1.a) to (B.I.4.a) are combined with steps (B.I.1.b) to (B.I.4.b) to continuously transfer the degassed polyurethane foam to said chemical decomposition reactor.

6. 3. The method according to claim 2, wherein during the first step of (B.I), the polyurethane foam is conveyed through an apparatus for mechanical comminution disposed in a first portion of the inlet device and comminuted, and wherein the second step is carried out such that the polyurethane foam after mechanical comminution is conveyed through a second portion downstream of the first portion of the inlet device into an inert gas atmosphere under the second pressure.

7. Degassing the polyurethane foam in (B.I) (1) In a first step, the polyurethane foam is heated to a first temperature in the range of -20°C to 120°C and 0.1 mbar. （ａｂｓ．） ~960mbar （ａｂｓ．） , especially 100 mbar （ａｂｓ．） ~960mbar （ａｂｓ．） to a device for mechanical compression disposed within said inlet device at a first pressure in the range of wherein the gas removal device is upstream of the device for mechanical compression; (2) In the second step, the polyurethane foam is compressed at 5 bar in the mechanical compression device. （ａｂｓ．） ~200 bar （ａｂｓ．） compressing at a second pressure in the range of The method of claim 1 , wherein the method is carried out by

8. The process according to any one of claims 2 to 7, wherein the second step is carried out at a second temperature in the range of -20°C to 120°C.

9. The component X is mixed at a temperature of 0° C. and a pressure of 1.000 bar. （ａｂｓ．） 9. The method of claim 2, further comprising: at least one component that is liquid at a pressure of at least 1000 psi; and said first temperature is at least 16° C.

10. The method according to claim 1, wherein in step (α), all components of component X or its gaseous decomposition products are removed from the chemical decomposition apparatus.

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