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 step of preparing a polyurethane foam based on an isocyanate component and a polyol component, wherein the polyurethane foam has a cell structure containing one or more volatile ancillary 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 ancillary substances, and component X contains at least oxygen; and a step of chemically decomposing the polyurethane foam with a chemical decomposition reagent, wherein the polyurethane foam is degassed before contact with the chemical decomposition reagent, and at least oxygen, preferably all components of component X, or any gaseous decomposition products that may be formed, are degassed to 960 mbar (abs.) The present invention relates to a method for recovering raw materials from polyurethane foam, comprising the steps of: (B) removing the gaseous material from a chemical decomposition apparatus via a gas removal device at the following pressure and temperature of 120°C or less to obtain degassed polyurethane foam; subsequently reacting the degassed polyurethane foam with a chemical decomposition reagent in an inert gas atmosphere in the presence of a catalyst, and post-treating the mixture of products obtained by chemical decomposition; (C) recovering at least one polyol; and optionally (D) recovering at least one amine corresponding to the isocyanate component of the isocyanate. [Background technology]

[0002] Polyurethane foam has a variety of applications in industry and daily life. Polyurethane foam is typically divided into rigid foam (e.g., used as insulation) and flexible foam (e.g., used in the manufacture of cushioned furniture). Despite these differences, the basic polyurethane structure is common to all polyurethane foams, and this is formed by the polyaddition reaction of a polyfunctional isocyanate and a polyol. For example, in the case of polyurethane based on diisocyanate O=C=NRN=C=O and diol 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 follows.

[0003] The great economic success of polyurethane foam has generated a large amount of polyurethane waste (e.g., from old mattresses or chairs (seated furniture)), which needs to be used rationally. The easiest technically feasible reuse method is incineration, where the heat of combustion released is used in other processes, such as industrial processes. However, this method does not complete the raw material loop. Another reuse method is called "physical recycling," in which polyurethane waste is mechanically crushed and used in the manufacture of new products. Because this recycling method has clear limitations, attempts to recover the raw materials that form the basis of polyurethane production by re-cleaving the polyurethane bonds (called "chemical recycling") will not be abandoned. These raw materials to be recovered mainly consist of polyols (i.e., HO-R'-OH in the above example). In addition, it is also possible to recover amines by hydrolytic cleavage of the urethane bonds (i.e., H2N-R-NH2 in the above example), which can be phosgenated after post-treatment to form isocyanates (forming O=C=NRN=C=O in the above example).

[0004] Various chemical recycling approaches have been developed to date. The four most important can be summarized as follows: 1. Hydrolysis of urethane, in which amines and polyols are recovered through reaction with water, and carbon dioxide is formed. 2. Glycolysis of urethane by reaction with alcohol. The polyol incorporated in the urethane group is replaced by the alcohol used and released. This process is generally referred to as transesterification (more precisely transurethanization) in the literature. Regardless of the exact nature of the alcohol used, this method of chemical recycling is called glycolysis in the literature, which is actually a term applicable only to glycols. Therefore, in the present invention, the term alcoholysis is generally used. Hydrolysis may be carried out following glycolysis. When hydrolysis is carried out in the presence of the glycolysis mixture that has not yet changed, 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 glycolysis and hydrolysis processes proceed in parallel. 4. Acid decomposition 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 Non-Patent Document 1.

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

[0007] Patent Document 2 describes a method for continuous glycol decomposition and cleavage of polyurethane polymer waste, particularly polyurethane foam waste, in a multi-screw machine by adding an optionally preheated diol at a cleavage temperature exceeding 250°C while maintaining at least a pressure such that the polyurethane-diol mixture is in the liquid phase, discharging the glycol decomposition product mixture after a short residence time of 2 to 30 minutes in the reaction screw, and rapidly cooling the glycol decomposition product mixture. In a preferred embodiment, the air introduced into the screw machine with the polymer waste can escape through a hole in the housing upstream of the introduction funnel opposite to the conveying direction, where the pressure is advantageously slightly reduced. Patent Document 2 does not disclose that volatile incidental substances present in the cellular structure of the polyurethane foam, such as oxygen, blowing agents, and / or disinfectants, are removed through the hole in the housing. Furthermore, this is not expected in the described configuration; instead, it is actually expected that only the air entering the machine with the foam waste during the introduction process (air surrounding the foam waste) will be removed.

[0008] Patent Document 3 describes a method for the continuous hydrolytic cleavage of polymer waste, in which waste of a hydrolyzable polymer material is introduced into a screw machine together with water and optionally a hydrolysis catalyst, where the mixture of water and polymer waste is exposed in a reaction zone with intense mass and heat transfer at a pressure of 5 bar to 100 bar and a temperature of 100 °C to 300 °C for 2 minutes to 100 minutes. The liquid-gas mixture formed during hydrolysis is continuously conveyed to a die fixedly connected to the screw machine, from which gas escapes through a control valve that keeps the screw machine pressure in the die constant, and liquid escapes through a control valve that keeps the liquid level in the die constant. In a preferred embodiment, the air introduced together with the polymer waste is removed through holes in the housing located upstream of the polymer material introduction funnel in the conveying direction, where a slight vacuum is applied. Patent Document 3 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 expected with essentially just a slight vacuum and compression of the foam after the addition of the chemical decomposition reagent (here water). Instead, here, as in the case of Patent Document 2, it is necessary to assume that only the air that enters this machine together with the polymer waste (the air surrounding the polymer waste) is removed during the introduction process.

[0009] Patent Document 4 discloses a method for producing polyols from polyurethane waste, in which foam flakes, shredded soft foam or shredded material are introduced into a reactor containing waste from the synthesis of polyester previously heated to a temperature above 70 °C. The mixture of polyurethane waste and waste from polyester synthesis is further heated and converted by a controlled catalytic transesterification reaction at a temperature of 120 °C to 250 °C. In a preferred embodiment, the polyurethane waste is introduced by pneumatic transport with a gentle nitrogen stream. The 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 expected with this method.

[0010] Patent Document 5 describes a method for producing polyols from polyurethane waste and a specific apparatus for carrying out the method. In this case, according to Patent Document 5, pre-crushed soft foam is metered in from above via a tightening screw and a throttling ring while removing gases present in the foam. However, it is doubtful whether the oxygen present in the cellular structure of the polyurethane foam can be removed at least essentially completely without applying reduced pressure before the start of chemical decomposition. This is even more true for any accompanying substances that may be present in the cellular structure of the polyurethane foam, such as blowing agents or disinfectants (which may be in liquid form), which boil at significantly higher levels than oxygen, potentially impairing recycling.

[0011] Patent document 6 describes a method and apparatus for treating polyurethane obtained from waste by alcohol decomposition or acid decomposition. This involves first mechanically grinding the polyurethane to obtain a starting material, and then treating it with a solvent at a temperature above 120°C. At a minimum, the mechanical grinding of the already chemically decomposed starting material is continued at the start of the solvent treatment, which is carried out at a reaction temperature below 200°C, resulting in liquefaction of the starting material. According to the description in Patent document 6, this method results in a lower temperature and shorter processing time without causing discoloration that impairs quality or leaving undissolved residue until the starting material is completely dissolved. The starting material is, of course, dissolved by at least a partial reaction of the polyurethane bonds.

[0012] The apparatus for carrying out this method has a mixer that receives a supply from a reservoir vessel, connected to a reactor at the outlet side, and in the reactor, shear elements that exert shear force and can rotate in both directions act on the starting material, these shear elements are arranged on a hollow, heatable shaft and surrounded by a reactor shell consisting of hollow, heatable sectors. This reactor improves heat transfer to the material so that a uniform temperature distribution, and consequently a relatively short reaction time and dissolution time, can be achieved. Patent Document 6 discloses an embodiment in which the starting material is pre-pulverized while being mixed with a proportion of polyol to be used later as a solvent component in a heatable kneading mixer having two co-rotating shafts having sigma blades. According to Patent Document 6, this achieves good pre-wetting of the surface of the polyurethane particles with the solvent, releases some of the gas trapped in the polyurethane cell region, reduces the harmful oxygen content, avoids aggregation of polyurethane particles as a result of subsequent mechanical stress in the downstream reaction zone in particular, and decisively increases the metric and thermal conductivity of the starting material. Substantial removal of atmospheric oxygen can be achieved, according to Patent Document 6, by subsequent exhaust of the mixture from the same part of the equipment and / or subsequent purging with a protective gas at standard pressure, such as nitrogen. However, it should be noted here that the presence of solvents (= chemical decomposition reagents) that wet the polyurethane hinders effective degassing.

[0013] In addition to the processes of physical recycling (mechanical pulverization of polyurethane products and addition in the manufacture of new polyurethane products) and chemical recycling (recovery of polyols, preferably amines, by chemical cleavage of urethane bonds) mentioned above, it is also necessary to mention "upcycling," which occupies an intermediate position. In the case of upcycling, as in the case of chemical recycling, a chemical change occurs in the polyurethane, but it does not go as far as recovering the raw materials (polyols and amines) that were originally used in the synthesis. Rather, it aims to convert the reused polyurethane into a different useful polymer product. For example, DT Sheppard et al., in Non-Patent Literature 2, describe treating a cross-linked polyurethane foam with dibutyltin dilaurate in dichloromethane, and then mechanically processing the thus treated foam in a twin-screw mixer or twin-screw extruder while removing air to obtain a film or fiber.

[0014] Of the polyurethane recycling processes documented in the literature, only a few are sustainably carried out on an industrial scale, and many have not even reached a pilot scale (Non-Patent Literature 1). Given the growing general environmental awareness and the increasing effort to make industrial processes as sustainable as possible, it is clear that polyurethane product recycling is far from mature from a technical and economic standpoint. Opportunities for physical recycling are clearly very limited. Upcycling can pave the way for viable reuse of polyurethane products and is effective in this respect, but it cannot close the raw material cycle. Only chemical recycling offers a possibility if the used polyols, preferably with additional amines, can be recovered and used to manufacture new polyurethane products of equivalent quality to the original polyurethane product. In this regard, there are challenges, particularly regarding the purity of the recovered products. When reused in the manufacture of polyurethane foam, for example, to avoid adverse effects on foaming properties, it is necessary to recover polyols that are as free of amine impurities as possible. If the goal is further recovery of amines, these must also be obtained with maximum purity. Furthermore, economical recycling processes must ensure that the reagents used (e.g., used alcohol) can be recovered and reused (i.e., recycled) as completely as possible.

[0015] Recycled polyurethane products typically still contain various auxiliary agents and additives (stabilizers, catalysts, etc.), which must be separated from the actual recycled product and disposed of in an economically viable and environmentally friendly manner. In the case of polyurethane foam, particular attention should be paid to the foaming agents and oxygen present within the foam's cellular structure. In addition to these auxiliary agents and additives present for manufacturing-related reasons, preparatory processes preceding actual chemical recycling may introduce further foreign substances into the recycled polyurethane product. For example, it is common to treat recycled polyurethane foam derived from old mattresses or chairs (seating furniture) with disinfectants. These foreign substances may impair the chemical recycling and / or subsequent use of the recovered raw materials in new manufacturing processes.

[0016] Oxygen can trigger oxidation reactions, particularly of amines. From a safety standpoint, the presence of oxygen is problematic, especially considering the operating temperatures that exceed the flash point of the alcohol used in alcohol decomposition. While foaming agents such as pentane are chemically inert, they accumulate for this specific reason, requiring periodic purging, which results in product loss. The presence of foaming agents can also increase the off-gas load, making off-gas post-treatment difficult. Certain commonly used disinfectants, such as ethanol, can form carbamates during chemical decomposition, some of which are more difficult to cleave and release amines than the carbamates of the actual decomposition reagents (usually glycols or glycol derivatives). Even if carbamate cleavage is successful, such alcoholic disinfectants can contaminate unconverted decomposition reagents as impurities during post-treatment, complicating their recovery. Other commonly used disinfectants, such as hydrogen peroxide or sodium hypochlorite, can decompose and release oxygen. Conventional technology has yet to provide satisfactory solutions to these problems. [Prior art documents] [Patent Documents]

[0017] [Patent Document 1] Chinese Patent Application Publication No. 106279760 [Patent Document 2] German Patent Application Publication No. 3232461 [Patent Document 3] German Patent Application Publication No. 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) [Overview of the project] [Problems that the invention aims to solve]

[0019] Therefore, further improvements are needed in the field of chemical recycling of polyurethane foam. In particular, it is desirable to remove as much as possible from the polyurethane foam before the actual chemical recycling begins, to the extent that it does not interfere with subsequent processes. [Means for solving the problem]

[0020] Therefore, considering the requirements outlined, the present invention relates to a method for recovering raw materials (i.e., polyols and optionally amines) from a polyurethane foam having a cell structure based on an isocyanate component and a polyol component, and comprising a component X selected from the group consisting of oxygen, a foaming agent, a disinfectant, and a mixture of two or more of the above, wherein component X contains at least oxygen, by reacting the polyurethane foam with a chemical decomposition reagent. (A) Prepare polyurethane foam 1 in container 100, (B) A chemical decomposition apparatus comprising (i) an inlet device 200, (ii) a chemical decomposition reactor 300 connected to the inlet device, (iii) an outlet device 400 connected to the chemical decomposition reactor, and (iv) a gas removal device 500 located inside the container and / or inside the inlet device, wherein the polyurethane foam 1 is to be chemically decomposed, Furthermore, chemical decomposition is (BI) The polyurethane foam is introduced from the container into the inlet device, and from there into the chemical decomposition reactor, and before the polyurethane foam comes into contact with the chemical decomposition reagent, (α) At least oxygen (i.e., (i) oxygen present in component X, and (ii) any oxygen formed by the decomposition reaction of the components of component X), preferably all components of component X or any of its gaseous decomposition products, from a chemical decomposition apparatus at 960 mbar (abs.) The gaseous gas is removed via a gas removal device at the following pressures and temperatures below 120°C. The process involves degassing to obtain degassed polyurethane foam 2. (B.II) In the chemical decomposition reactor 300, the degassed polyurethane foam 2 is reacted with the chemical decomposition reagent 4 in the presence of a catalyst under an inert gas atmosphere to obtain a product mixture. (B.III) Discharge the product mixture from the chemical decomposition reactor 300 through the outlet device 400, and then, Post-treatment of the product mixture, Includes; (C) Recovering (at least) the polyol (from the polyol component obtained by chemical decomposition or its decomposition products), (D) Optionally, recover an amine corresponding to (at least) the isocyanate from the isocyanate component, This provides a method that includes [something].

[0021] Surprisingly, it has been found that removing the volatile byproducts defined by component X according to the present invention before initially contacting the polyurethane foam with the chemical decomposition reagent results in particularly careful depletion of such byproducts, thereby overcoming or at least minimizing the problems outlined above. Oxygen, in particular, whether present from the outset or formed in situ as a result of the decomposition of disinfectants such as hydrogen peroxide or sodium hypochlorite, is successfully removed by the method of the present invention, especially avoiding the oxidation reaction of amines. This is because a feature of the method of the present invention is that it can successfully remove not only byproducts present on the surface or in an attached form, but also by volatile byproducts present within the cellular structure of the polyurethane foam.

[0022] This is because, as is known to those skilled in the art, polyurethane foam has a cellular structure (also called a pore structure) that can be influenced by chemical or chemical engineering parameters in the foaming process. In the manufacture of polyurethane foam, a foaming agent is used, which is gaseous under the foaming manufacturing conditions, resulting in the formation of foam cells (also called foam pores) connected to one another via lamellae. Reused polyurethane is usually volatile and contains ancillary substances that potentially interfere with chemical decomposition, which may be present not only in the cells (i.e., cavities) but also in the lamellae (for example, if disinfectants are filled into the lamellae).

[0023] Therefore, the present invention relates to removing volatile accompanying substances from a polyurethane foam before the start of chemical recycling, i.e., before first contacting the polyurethane foam to be recycled with a chemical decomposition reagent. The volatile accompanying substances in this context, i.e., component X, are understood to mean oxygen, a blowing agent, a disinfectant, or a mixture of two or more of the above in the context of the present invention, and particularly when the volatile accompanying substances (i.e., component X or its constituents) are gaseous in at least a partial region of the pressure range and temperature range defined by the lower pressure p U , upper pressure p O , lower temperature T U and upper temperature T O , or decompose to form gaseous decomposition products, p U = 0.1 mbar (abs.) , p O = 960 mbar (abs.) , T U = -2° C, particularly (i.e., when the volatile accompanying substances present in the cell structure are liquid under standard conditions (i.e., a temperature of 0° C and a pressure of 1,000 bar (abs.) ), 16° C, and, T O = 120° C.

[0024] The pressures p U and p O can be determined by a conventional manometer. This, of course, also applies to the pressures p1 and p2 described further below. Although it may be described linguistically simply as "volatile accompanying substances", the presence of further compounds not included in the definition of component X in the context of the present invention is not excluded, and it is understood that recycling such a polyurethane foam by the method according to the present invention is not outside the scope of the present invention.

[0025] The conditions mentioned are met for oxygen. This is also true for blowing agents (e.g., pentane) commonly used in the manufacture of polyurethane foam. Furthermore, most conventional disinfectants can be converted into gaseous or gaseous decomposition products under the conditions mentioned, allowing unwanted substances to be removed via gas removal equipment. Examples of decomposable volatile by-products include hydrogen peroxide and sodium hypochlorite, both of which tend to decompose and form oxygen in particular, and can therefore be removed as "gaseous decomposition products" via gas removal equipment.

[0026] In the terminology of the present invention, the term isocyanate encompasses all isocyanates known to those skilled in the art in connection with polyurethane chemistry, for example, particularly tolylene diisocyanate (TDI; can be prepared from tolylenediamine (TDA), and is preferably prepared), diphenylmethane-based diisocyanates and polyisocyanates (MDI; can be prepared from diphenylmethane-based diamines and polyamines (MDA), and is preferably prepared), pentane 1,5-diisocyanate (PDI; can be prepared from pentane-1,5-diamine (PDA), and is preferably prepared), hexamethylene 1,6-diisocyanate (HDI; can be prepared from hexamethylene-1,6-diamine (HDA), and is preferably prepared), isophorone diisocyanate (IPDI; can be prepared from isophorone diamine (IPDA), and is preferably prepared), and xylylene diisocyanate (XDI; can be prepared from xylylenediamine (XDA), and is preferably prepared). The term "isocyanate" naturally includes embodiments in which two or more different isocyanates (e.g., a mixture of MDI and TDI) are used in the manufacture of polyurethane products, unless otherwise explicitly stated, for example, by the expression "exactly one isocyanate." All isocyanates used in the manufacture of polyurethane products are collectively referred to as the isocyanate component (of the polyurethane product). The isocyanate component contains at least one isocyanate. Similarly, all polyols used in the manufacture of polyurethane products are collectively referred to as the polyol component (of the polyurethane product). The polyol component contains at least one polyol.

[0027] In the terminology of this invention, the term "polyol" encompasses all polyols known to those skilled in the art in relation to polyurethane chemistry, such as polyether polyols, polyester polyols, polyether ester polyols, and polyether carbonate polyols. The expression "polyol" also naturally encompasses embodiments in which two or more different polyols are used in the manufacture of polyurethane products. Therefore, when referring to, for example, "polyether polyol" (or "polyester polyol," etc.), this term naturally encompasses embodiments in which two or more different polyether polyols (or two or more different polyester polyols, etc.) are used in the manufacture of polyurethane products.

[0028] In the technical terminology of this invention, "carbamate" refers to the urethane formed by the reaction with alcohol in step (B).

[0029] An amine corresponding to an isocyanate is an amine that can be phosgenated to produce an isocyanate: R-NH2 + COCl2 → RN=C=O + 2HCl. Similarly, a nitro compound corresponding to an amine is a nitro compound that can be reduced to produce an amine: R-NO2 + 3H2 → R-NH2 + 2H2O.

[0030] All pressure values ​​are for absolute pressure, indicated by adding the suffix "abs." to the unit of pressure (for example, "mbar"). (abs.) )]

[0031] Therefore, the present invention relates to the recycling of polyurethane foam in which oxygen is always present, but the cell structure contains oxygen, (at least) a foaming agent, and / or (at least) a (volatile) disinfectant (or one that can decompose to form volatile products), i.e., one, two or more or all of the volatile incidental substances mentioned. In the terminology of the present invention, the expression "component X" is used as a collective term for all volatile incidental substances present in this context.

[0032] The method according to the present invention removes at least present oxygen (of any origin) at least essentially completely. Preferably, all components of component X or its gaseous decomposition products are removed at least essentially completely. In this regard, the present invention provides two alternative solutions, which are described in detail below. What they all have in common is that in (B)(I)(α), oxygen, preferably all components of component X or its gaseous decomposition products, is removed at "960 mbar (abs.) The requirement is that the substances are removed in gaseous form at the following pressures and temperatures below 120°C. This means that not only the oxygen present, but preferably the foaming agents and disinfectants, if present (it is not essential that all of the volatile incidental substances mentioned be present; for example, disinfection of polyurethane foam is not required in all cases), are removed from the polyurethane foam, at least essentially completely, before the actual chemical decomposition reaction begins.

[0033] A special feature of the first alternative solution is that the removal of volatile byproducts is essentially achieved by a significant pressure drop followed by a pressure increase. For this purpose, polyurethane foam is degassed in (BI), (1) In the first step, 0.1 mbar at a first temperature T1 in the range of -20°C to 120°C. (abs.) ~100mbar (abs.) Expose to a first pressure p1 in the range (wherein in particular, the first pressure is adjusted to a first temperature such that all components of component X to be removed in (B)(I)(α), which do not exist in gaseous form in any case, such as oxygen, are converted to the gas phase or decompose to form gaseous products), Also, (2) In the second step, by supplying an inert gas, the pressure is increased to 2.0 bar, which is greater than the first pressure. (abs.) The subject is exposed to a second pressure p2, which is as follows:

[0034] Therefore, in this context, "degassed polyurethane foam 2" refers to polyurethane foam from which the specified type of volatile by-products has been removed and which has been saturated with an inert gas.

[0035] A special feature of the second alternative solution is that the removal of volatile adjuncts is essentially achieved by the mechanical compression of the polyurethane foam (the volatile adjuncts are pushed out of the cellular structure of the polyurethane foam and drawn into the reduced pressure region). For this purpose, the polyurethane foam is subjected to degassing in (BI), (1) In the first step, a first temperature T1 in the range of -20℃ to 120℃ and 0.1 mbar (abs.) ~960mbar (abs.) , especially 100mbar (abs.) ~960mbar (abs.) At a first pressure p1 in the range, the material is transported to a mechanical compression device located within the inlet device (where, in particular, the first pressure is adjusted to a first temperature so that in either case, all components of component X to be removed in (B)(I)(α), which are not gaseous like oxygen, are converted to the gas phase or decompose to form gaseous products, and the gas removal device is located upstream of the mechanical compression device), Also, (2) In the second step, 5 bar in a mechanical compression device. (abs.) ~200 bar (abs.) The volatile components are compressed at a second pressure p2 within the specified range (this pushes them out of the cell structure, drawing them into the region of the upstream inlet device for mechanical compression, where they are subsequently removed via a gas removal device).

[0036] Therefore, in this context, “degassed polyurethane foam 2” refers to polyurethane foam from which specified types of volatile incidental substances have been removed and which has been compressed (sent in a compressed form for chemical decomposition carried out in an inert gas atmosphere).

[0037] The attached diagrams illustrate specific methods for implementing these two alternative solutions. [Brief explanation of the drawing]

[0038] [Figure 1] This figure shows a first alternative example (first alternative solution) of the method according to the present invention, for example, using a flexible polyethylene lining. [Figure 2a] This figure shows a second alternative example (first alternative solution) of the method according to the present invention using a locking system. [Figure 2b] This figure shows a second alternative example (first alternative solution) of the method according to the present invention using a locking system. [Figure 3] This figure shows a third alternative example (first alternative solution) of the method according to the present invention using a mechanical grinding apparatus. [Figure 4] This figure shows a fourth alternative example (second alternative solution) of the method according to the present invention using a mechanical compression device. [Modes for carrying out the invention]

[0039] Herein, we will outline various possible embodiments of the present invention.

[0040] In a first embodiment of the present invention corresponding to and forming part of the first alternative solution, an internal flexible lining is provided in the container and / or inlet device, which compresses polyurethane foam by collapsing in a first step by establishing a first pressure, and then expands again in a second step by supplying an inert gas that establishes a second pressure.

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

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

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

[0044] In a fifth embodiment of the present invention, which is a specific configuration of the first embodiment and can be combined with all other embodiments of the first alternative example, 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 can be combined with all other embodiments of the first alternative example, the second step is performed 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 in particular corresponds to the first temperature (i.e., no specific temperature change is made when transitioning from the first step to the second step).

[0046] In a seventh embodiment of the present invention, corresponding to the second alternative example and similarly forming part of the first alternative solution, the inlet device has a first lock region (upstream of the chemical decomposition reactor) having a closable feeder for the polyurethane foam prepared in process (A) and a closable removal device for the degassed polyurethane foam, Here, the process (BI) is as follows: (BI1.a) A step of closing the removal device for the first lock area, introducing polyurethane foam into the first lock area, and closing the supply device for the first lock area, (BI2.a) A step of performing the first step of (BI) in the first lock area, (BI3.a) A step of obtaining degassed polyurethane foam by supplying an inert gas in the first lock region to perform the second step of (BI), The process involves transferring the degassed polyurethane foam obtained in (BI4.a)(BI3.a) to a chemical decomposition reactor, Includes.

[0047] In an eighth embodiment of the present invention, which is a specific configuration of the seventh embodiment and can be combined with all other embodiments of the second alternative example, the inlet device has a second locking area having, in addition to a first locking area, a closable feeder for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, Here, the first portion of the polyurethane foam is introduced into the first lock region in step (BI1.a) so that the first portion of the degassed polyurethane foam is obtained in step (BI3.a), and step (BI) is the following step: (BI1.b) A step of closing the removal device for the second lock area, introducing the second portion of polyurethane foam into the second lock area, and closing the supply device for the second lock area, (BI2.b) A process in which the first step of (BI) is performed in the second lock area, (BI3.b) A second step of (BI) is performed by supplying an inert gas in the second lock region to obtain a second portion of the degassed polyurethane foam, (BI4.b) A step of transferring the second portion of the degassed polyurethane foam to a chemical decomposition reactor, The process also includes steps (BI1.a) to (BI4.a) combined with steps (BI1.b) to (BI4.b), and the degassed polyurethane foam is continuously transferred to a chemical decomposition reactor.

[0048] In a ninth embodiment of the present invention, which is a specific configuration of the seventh embodiment and can be combined with all other embodiments of the second alternative example, 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 can be combined with all other embodiments of the second alternative example, the polyurethane foam is first brought into contact with a chemical decomposition reagent in a chemical decomposition reactor.

[0050] In an eleventh embodiment of the present invention, which is a specific configuration of the seventh embodiment and can be combined with all other embodiments of the second alternative example, the second step is performed 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 in particular corresponds to the first temperature (i.e., no specific temperature change is made when transitioning from the first step to the second step).

[0051] In a twelfth embodiment of the present invention, which is a specific configuration of the seventh embodiment and can be combined with all other embodiments of the second alternative example, the polyurethane foam is in contact with the chemical decomposition reagent (optionally already with the catalyst) in the first and / or second lock regions after the second step, and is particularly wet.

[0052] In the thirteenth embodiment of the present invention, which is a specific configuration of the twelfth embodiment, the chemical decomposition reagents that come into contact with the polyurethane foam in the first lock region and / or second lock region are at a temperature in the range of 120°C to 240°C, particularly above 120°C to 240°C.

[0053] In a 14th embodiment of the present invention, which is a specific configuration of the seventh embodiment and can be combined with all other embodiments of the second alternative example, the second pressure is 1.8 bar. (abs.) The following applies, and is particularly equal to ambient pressure.

[0054] In a 15th embodiment of the present invention, corresponding to a third alternative example and similarly forming part of the first alternative solution, the polyurethane foam is conveyed and crushed during a first step of (BI) through a mechanical crushing device located in a first part of the inlet device, where the second step is carried out such that the mechanically crushed polyurethane foam is conveyed into an inert gas atmosphere under a second pressure through a second part downstream of the first part of the inlet device.

[0055] In a 16th embodiment of the present invention, which is a specific configuration of the 15th embodiment and can be combined with all other embodiments of the third alternative example, the transport of polyurethane foam in the first and second parts of the inlet device is as follows: (at least) screw shaft, (at least) piston, (At least) conveyor belts, Vibration, and / or, It is carried out by gravity.

[0056] In a specific configuration of the 15th embodiment, and in combination with all other embodiments of the third alternative example, in an 18th embodiment of the present invention, the apparatus for mechanical grinding includes a cutting mill, a knife mill, an impact cup and / or a hammer mill.

[0057] In the 19th embodiment of the present invention, which is a specific configuration of the 18th embodiment, the apparatus for mechanical grinding 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 20th embodiment of the present invention, which is a specific configuration of the 15th embodiment and can be combined with all other embodiments of the third alternative example except the 19th embodiment, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0059] In a 21st embodiment of the present invention, which is a specific configuration of the 15th embodiment and can be combined with all other embodiments of the third alternative example, the polyurethane foam is first brought into contact 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 can be combined with all other embodiments of the third alternative example, the second step is performed 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 in particular corresponds to the first temperature (i.e., no specific temperature change is made when transitioning from the first step to the second step).

[0061] In a 23rd embodiment of the present invention, which is a specific configuration of the 15th embodiment and can be combined with all other embodiments of the third alternative example, the polyurethane foam is in contact with the chemical decomposition reagent (optionally already with the catalyst) and is particularly wetted in the second part of the inlet device after the second step.

[0062] In the 24th embodiment of the present invention, which is a specific configuration of the 23rd embodiment, the chemical decomposition reagent that comes into contact with the polyurethane foam in the second part of the inlet device is at a temperature in the range of 120°C to 240°C, particularly above 120°C to 240°C.

[0063] In a 25th embodiment of the present invention, which is a specific configuration of the 15th embodiment and can be combined with all other embodiments of the third alternative example, the second pressure is 1.8 bar. (abs.) The following applies, and is particularly equal to ambient pressure.

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

[0065] In a 27th embodiment of the present invention, which is a specific configuration of the 26th embodiment and can be combined with all other embodiments of the 4th alternative example, the apparatus for mechanical compression includes an extruder (including multi-zone screw, as well as single-screw and multi-screw extruders), rollers, or pistons.

[0066] In a 28th embodiment of the present invention, which is a specific configuration of the 26th embodiment and can be combined with all other embodiments of the 4th alternative example, the polyurethane foam is in contact with the chemical decomposition reagent in the inlet device and is particularly wet even after passing through the device for mechanical compression (i.e., after the second step).

[0067] In the 29th embodiment of the present invention, which is a specific configuration of the 28th embodiment, the chemical decomposition reagent that comes into contact with the polyurethane foam in the inlet device is at a temperature in the range of 120°C to 240°C.

[0068] In a 30th embodiment of the present invention, which is a specific configuration of the 26th embodiment and can be combined with all other embodiments of the 4th alternative example, the first temperature is in the range of 0°C to 80°C, preferably 16°C to 80°C.

[0069] In a 31st embodiment of the present invention, which is a specific configuration of the 26th embodiment and can be combined with all other embodiments of the 4th alternative example, the second step is performed 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 in particular corresponds to the first temperature (i.e., no specific temperature change is made when transitioning from the first step to the second step).

[0070] In a 32nd embodiment of the present invention, which can be combined with all four alternative embodiments, step (B.II) is carried out in a temperature range of 140°C to 240°C, preferably 160°C to 240°C, and more preferably 180°C to 220°C.

[0071] In a 33rd embodiment of the present invention, which can be combined with all four alternative embodiments, step (B.II) is performed at 960 mbar (abs.) Super ~1.8 bar (abs.) This is done at pressures within a certain range, especially ambient pressure.

[0072] In a 34th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, component X is defined as being under standard conditions (i.e., a temperature of 0°C and 1,000 bar) (abs.) It contains at least one component that is liquid (at a pressure of ), wherein the first temperature is at least 16°C.

[0073] In a 35th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, The blowing agent comprises pentane, hydrochlorofluorocarbon, dichloromethane, or a mixture of two or more of the above-mentioned blowing agents (in particular these), The disinfectant comprises hydrogen peroxide, chlorine dioxide, formaldehyde, peracetic acid, alkali metal hypochlorite (especially sodium hypochlorite), ethanol, isopropanol, 1-propanol, or a mixture of two or more of the above disinfectants (especially these).

[0074] In a 36th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, the isocyanate component includes an isocyanate selected from tolylene diisocyanate (TDI), diphenylmethane-based diisocyanates and polyisocyanates (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 above-mentioned isocyanates. With respect to the isocyanate component, polyurethane foams based on a mixture of TDI and MDI are particularly preferred. With respect to the isocyanate component, polyurethane products based solely on TDI are very particularly preferred.

[0075] In a 37th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, the polyol component contains a polyol selected from polyether polyols, polyester polyols, polyether ester polyols, polyether carbonate polyols, or mixtures of two or more of the polyols described above. The polyol component is preferably a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., does not contain any polyols other than polyether polyols; however, mixtures of two or more different polyether polyols are included and do not fall outside the scope of this embodiment).

[0076] In the 38th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, the isocyanate component comprises tolylene diisocyanate (TDI), as well as diphenylmethane-based diisocyanates and polyisocyanates (MDI) (TDI in particular), and the polyol component comprises a polyether polyol (in particular a polyether polyol, i.e., not containing any further polyols other than polyether polyols, but including a mixture of two or more different polyether polyols, which does not depart from the scope of this embodiment).

[0077] In a 39th embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, the chemical decomposition 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 alcohols described above.

[0078] The 39 In a 40th embodiment of the present invention, which is a specific configuration of the embodiments, the chemical decomposition reagent includes water.

[0079] In a 41st embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, 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 octanoate, monobutyltin oxide or tetrabutyl titanate), and / or organic amines (especially diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undeca-7-ene or 1,4-diazabicyclo[2.2.2]octane).

[0080] In a 42nd embodiment of the present invention, which can be combined with all embodiments of all four alternative examples, the chemical decomposition reagent in contact with the polyurethane foam is at a temperature in the range of 120°C to 240°C, particularly above 120°C to 240°C.

[0081] The embodiments and further conceivable embodiments briefly outlined above will be described in more detail below. Unless otherwise stated or clearly indicated in 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 prepared.

[0083] Polyurethane foam can be of any type in principle, with both flexible and rigid foams being particularly useful, and flexible foam (e.g., from used mattresses, furniture cushioning, or car seats) being preferred. Such polyurethane foam is manufactured using a blowing agent. Apart from water-foamed foam (in which case it hydrolyzes in place and releases carbon dioxide), pentane is a commonly used blowing agent. In the recycling of used polyurethane foam, hydrochlorofluorocarbons, which were previously commonly used as blowing agents, may be used. Another possible blowing agent is dichloromethane.

[0084] In addition, with respect to the isocyanate component, polyurethane foams based on isocyanates selected from tolylene diisocyanate (TDI), diphenylmethane-based diisocyanates and polyisocyanates (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 above-mentioned isocyanates are preferred. With respect to the isocyanate component, polyurethane foams based on a mixture of TDI and MDI are particularly preferred. With respect to the isocyanate component, polyurethane products based solely on TDI are very particularly preferred.

[0085] Regarding the polyol component, polyurethane foam based on a polyol selected from the group consisting of polyether polyols, polyester polyols, polyether ester polyols, polyether carbonate polyols, or mixtures of two or more of the above-mentioned polyols is preferred. The polyol component is preferably a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., it does not contain any polyols other than polyether polyols; however, mixtures of two or more different polyether polyols are included and do not fall outside the scope of this embodiment).

[0086] Most preferably, the polyurethane foam is a foam in which the isocyanate component contains tolylene diisocyanate (TDI), as well as diphenylmethane-based diisocyanates and polyisocyanates (MDI), particularly TDI only, and the polyol component contains a polyether polyol (particularly a polyether polyol, i.e., not containing any further polyols other than polyether polyols, but including a mixture of two or more different polyether polyols, which does not deviate from the scope of this embodiment).

[0087] Preferably, step (A) already includes a preparatory step for breaking the urethane bonds in step (B.II). This is in particular the mechanical grinding of the polyurethane foam. Such preparatory steps are known to those skilled in the art. See, for example, Non-Patent Document 1. Depending on the properties of the polyurethane foam, it may be advantageous to "freeze" the polyurethane foam before mechanical grinding to facilitate the grinding operation.

[0088] Before, during, or after mechanical grinding, 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 performing such disinfection, compounds present within the cell structure should be treated under standard conditions, i.e., a temperature of 0°C and 1,000 bar. (abs.) This also includes substances that are liquid at a given pressure. In this case, it is preferable to select a value of 16°C as the minimum first temperature.

[0089] The foam thus prepared is then transferred to a container (reference numeral 100 in the figure) connected to an inlet device. This container may include a conventional container known in the art, such as a silo or container for solids.

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

[0091] Chemical decomposition of polyurethane foam Step (B) of the method according to the present invention includes the chemical decomposition of the polyurethane foam prepared in step (A). This step is (i) Inlet device (reference numeral 200 in the figure) (ii) A chemical decomposition reactor connected to the inlet device (reference numeral 300 in the figure), (iii) An outlet device connected to the chemical decomposition reactor (reference numeral 400 in the figure), (iv) At least one gas removal device (reference numeral 500 in the figure) for removing compounds present within the cell structure, This is carried out in a chemical decomposition apparatus having the following features.

[0092] Process (B) is a sub-process of the following: (BI) introducing polyurethane foam from the container into the inlet device, and from there into the chemical decomposition reactor, where before contacting the polyurethane foam with the chemical decomposition reagent, (α) At least oxygen (i.e., (i) oxygen present in component X, and (ii) any oxygen formed by the decomposition reaction of the components of component X), preferably all components of component X or its gaseous decomposition products, from a chemical decomposition apparatus at 960 mbar (abs.) The gaseous gas is removed via a gas removal device at the following pressures and temperatures below 120°C. The process includes: (B.II) degassing the polyurethane foam to obtain a degassed polyurethane foam; (B.III) reacting the degassed polyurethane foam with a chemical decomposition reagent in an inert gas atmosphere in the presence of a catalyst in a chemical decomposition reactor 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 the process (BI), the polyurethane foam is degassed, meaning that volatile incidental substances present within the cell structure are removed from the cells and / or lamellae of the polyurethane foam's cell structure and discharged through at least one gas outlet device 500. There are various ways to achieve this.

[0094] Forming part of the first alternative solution, in the first alternative example of the process (BI) shown in Figure 1, the container (100 in Figure 1) and / or inlet device (not shown in Figure 1, but similarly possible) are subjected to a first pressure p1 of 0.1 mbar in the first process. (abs.) ~100mbar (abs.) An internal flexible lining 600 is provided which is compressed by adjusting to a value within a certain range, thereby compressing the polyurethane foam, and then expanded again by supplying an inert gas 3 in a second step to establish a second pressure p2. The second pressure is preferably 1.8 bar. (abs.) The following applies, particularly in response to ambient pressure (i.e., the second step involves expansion to ambient pressure). In this case and in other drawings, "M" represents a motor, meaning a motor-driven device, in this example a device that opens and closes the inlet and outlet of container 100.

[0095] The left side of Figure 1 shows the filling of container 100 with polyurethane foam 1. The valve 110 in the lower region of the container, the connection to the inlet device 200, and the gas removal device (500; valve 510 is 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 container 100, the valve 110, and the connection to the inlet device 200 are closed. The pressure is reduced using the gas removal device 500 (valve 510 is in the "open" position) to reduce the pressure inside the flexible lining 600 to p1.

[0097] The right side of Figure 1 shows the second step and the subsequent transport of the degassed polyurethane foam 2 to the inlet device 200. In the second step, the pressure inside the flexible lining is increased to p2 by adding inert gas 3 through the valve 110, which is opened at this point. After the connection to the inlet device is opened, the degassed polyurethane foam 2 is transported to the inlet device 200 (i.e., simply falls into it under gravity).

[0098] Preferably, in the first alternative example, no intentional change in temperature is made when transitioning from the first step to the second step, and the step temperature is 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. When the compound to be removed is a liquid under standard conditions (this does not mean that a significant vapor pressure cannot exist), a lower limit temperature of 16°C has been found to be useful. It has been found to be advantageous to repeat the first and second steps particularly 2 to 5 times before the degassed polyurethane foam is sent to the reaction in step (B.II).

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

[0100] The pressure in the first process is up to 100 mbar. (abs.)By reducing the pressure to a certain level, the flexible lining is crushed and the polyurethane foam is compressed. This pushes volatile adjuncts out of the foam's cellular structure and discharges them through a gas removal device. After establishing a second pressure by supplying an inert gas (particularly nitrogen, argon, or helium), the degassed polyurethane foam can be transported to the decomposition reactor by vibration, mechanically, pneumatically, or simply by gravity. In this alternative, the decomposition reagents and catalysts are added only after the polyurethane foam has left the area of ​​the decomposition reactor with the flexible lining. In particular, the decomposition reagents and catalysts are added only to the decomposition reactor. Preferably, the decomposition reagents are added at a temperature higher than the first temperature, preferably in the range of 120°C to 240°C.

[0101] Similarly, forming part of the first alternative solution, in the second alternative example of process (BI) shown in Figures 2a and 2b, the inlet device has a first locking region 121 (upstream of the chemical decomposition reactor) having a closable feeder for polyurethane foam 1 prepared in process (A) and a closable removal device for degassed polyurethane foam 2, Here, the process (BI) is as follows: (BI1.a) A step of closing the removal device for the first lock area, introducing polyurethane foam into the first lock area, and closing the supply device for the first lock area, (BI2.a) In the first lock region, the first pressure is 0.1 mbar (abs.) ~100mbar (abs.) The first step of (BI) is to adjust the value to the specified range, (BI3.a) In the first lock region, the second pressure is increased to over p1 ~ 2.0 bar by supplying an inert gas. (abs.) The second step (BI) is performed by adjusting the value to the specified range to obtain degassed polyurethane foam, The process involves transferring the degassed polyurethane foam obtained in (BI4.a)(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 mean that the existence of multiple lock regions is required.

[0103] However, using at least two locking regions and operating them alternately expands the options for continuously transferring the polyurethane foam to the chemical decomposition reactor. In this embodiment of a second alternative example of the present invention, the inlet device has a second locking region in addition to the first locking region, which has a closable feeder for the polyurethane foam prepared in step (A) and a closable removal device for the degassed polyurethane foam, Here, the first portion of the polyurethane foam is introduced into the first lock area in process (BI1.a), and process (BI) is the following process: (BI1.b) A step of closing the removal device for the second lock area, introducing the second portion of polyurethane foam into the second lock area, and closing the supply device for the second lock area, (BI2.b) In the second lock region, the first pressure is 0.1 mbar (abs.) ~100mbar (abs.) The first step of (BI) is to adjust the value to the specified range, (BI3.b) In the second lock region, the second pressure is increased to over p1 ~ 2.0 bar by supplying an inert gas. (abs.) The second step (BI) is performed by adjusting the value to the specified range to obtain the second portion of the degassed polyurethane foam, (BI4.b) A step of transferring the second portion of the degassed polyurethane foam to a chemical decomposition reactor, The process also includes steps (BI1.a) to (BI4.a) combined with steps (BI1.b) to (BI4.b), and the degassed polyurethane foam 2 is continuously transferred to the chemical decomposition reactor.

[0104] The left half of Figure 2a shows a lock 220 having a first lock region 221 and a second lock region 222. The second lock region 222 has the same configuration as the first lock region, which is not specifically shown in the figure. Access to the second lock region 222 is closed. Polyurethane foam 1 is being introduced into the first lock region 221. The first lock region 221 is closed downwards (i.e., toward the chemical decomposition reactor). After the filling operation is complete, the inlet to the first lock region 221 is closed, as shown in the right half of Figure 2a. Valve 510 attached to the gas removal device 500 is opened, and pressure p1 is established by a pressure drop (first step). In parallel, polyurethane foam 1 can be introduced into the second lock region 222. When pressure p1 is reached in the first lock region 221, valve 510 is closed, and pressure p2 is established by the addition of inert gas 3 through valve 210 (left half of Figure 2b). The chemical decomposition reagent can also be supplied via valve 210. When pressure p2 is reached, valves 210 and 510 are closed, and at this point degassing occurs, allowing the polyurethane foam 2, optionally moistened with the chemical decomposition reagent, to be further transported to the chemical decomposition reactor (right half of Figure 2b).

[0105] Regarding temperature and pressure, the description above for the first alternative also applies to the second alternative.

[0106] In this alternative example, 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 is completed), i.e., within the first and / or second locked regions. In either case, the added chemical decomposition reagent is at a temperature higher than the first temperature, preferably in the range of 120°C to 240°C. It is also possible to add a catalyst at this initial stage (especially as a solution in the chemical decomposition reagent). When the chemical decomposition reagent is added in the initial stages of the first and / or second locked regions, the polyurethane foam is preferably wetted with it. The addition of the chemical decomposition reagent in the initial stages of the first and / or second locked regions does not, of course, mean that further chemical decomposition reagents and / or further catalysts cannot be added to the chemical decomposition reactor.

[0107] In this alternative example, 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 vacuum, the air outlet valve is closed again. The pressure in the first step is up to 100 mbar. (abs.) By reducing the pressure to a certain level, volatile components are drawn out of the foam's cell structure and discharged through a gas outlet device. After a second pressure is established by supplying an inert gas (particularly nitrogen, argon, or helium), the degassed polyurethane foam can be transported to the chemical decomposition reactor. This can be achieved, in this case as well, by vibration, mechanically, by pneumatically, or simply as a result of gravity. If the polyurethane foam is brought into contact with the chemical decomposition reagent in the initial stages of the first or second locking region, the apparent density of the polyurethane foam increases, and as a result 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] Similarly, forming part of the first alternative solution, in the third alternative example of process (BI) shown in Figure 3, the polyurethane foam is subjected to a first pressure p1 of 0.1 mbar during the first process of (BI). (abs.) ~100mbar (abs.) The second step is performed such that, by adjusting to a value within a specified range, the polyurethane foam 11 is conveyed and crushed through a mechanical crushing device 230 located in the first part 201 of the inlet device, in which case the mechanically crushed polyurethane foam 11 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 (particularly a nitrogen, argon, or helium atmosphere). This conveying can be carried out by (at least) a screw shaft, (at least) a piston, (at least) a conveyor belt, vibration, and / or gravity.

[0109] The mechanical grinding apparatus 230 may be, for example, a cutting mill, a knife mill, an impact cup, and / or a hammer mill. The use of an impact cup or hammer mill is particularly preferred when introducing the polyurethane foam into the chemical decomposition apparatus in a frozen state. This is because this particular embodiment of the third alternative example of the present invention allows for at least partially incorporating the preferred mechanical grinding of the polyurethane foam into step (B). In that case, the mechanical grinding of the polyurethane foam in step (A), as further described above, may be limited to coarse grinding of the polyurethane foam into pieces of a manageable size, or may be omitted entirely.

[0110] Apart from the above embodiments involving the freezing of polyurethane foam, the descriptions of temperature and pressure given for the first and second alternatives also apply to the third alternative. In this embodiment of the third alternative, the pressure is preferably as described for the first and second alternatives, but the mechanical compression is naturally carried out at a temperature lower than 0°C, particularly down to -20°C.

[0111] Similar to the second alternative example, in the third alternative example, the chemical decomposition reagent can be added to the polyurethane foam not only within the chemical decomposition reactor but also immediately after the second step (i.e., after the degassing operation is completed), i.e., in this case, within the second part of the inlet device. In either case, the chemical decomposition reagent to be added is at a temperature higher than the first temperature, preferably in the range of 120°C to 240°C. It is also possible to add a catalyst at this initial stage (especially as a solution in the chemical decomposition reagent). When the chemical decomposition reagent is added in the initial stage of the second part of the inlet device, the polyurethane foam is preferably moistened with it. The addition of the chemical decomposition reagent in the initial stage of the second part of the inlet device does not, of course, mean that further chemical decomposition reagents and / or further catalysts cannot be added to the chemical decomposition reactor.

[0112] In an alternative example, polyurethane foam is transported by a conveyor, preferably one that is as enclosed as possible, especially a screw conveyor, at a rate of 100 mbar. (abs.) The polyurethane foam is then led to a mechanical grinding apparatus under the following pressure, where most of the volatile compounds are removed by the compression operation during the grinding process. The thus-ground polyurethane foam is then transported to a second section of the inlet apparatus under an inert gas atmosphere, thereby filling the cellular structure of the polyurethane foam with inert gas and effectively protecting it from the intrusion of other gases. In some cases, the mechanical grinding in process (BI) may be replaced with the mechanical grinding in process (A).

[0113] A second alternative solution is formed, and in the fourth alternative example of the process (BI) shown in Figure 4, the polyurethane foam is transported during the first process to a mechanical compression device 240 located in the inlet device, where the polyurethane foam is compressed to 5 bar in the mechanical compression device during the second process. (abs.) ~200 bar (abs.)It is compressed to a second pressure p2 value within the range. The pressure p2 can be determined by a manometer (connected to a capillary tube protruding into the area of ​​the inlet device where the mechanical compression device is located). It is preferable, but not essential, to inactivate the polyurethane foam before mechanical compression. Therefore, after the second step, the pressure is at least 5 bar. (abs.) This pressure is higher than the preferred pressure for process (B.II) (see further explanation below). The pressure increase for process (B.II) is preferably carried out when the polyurethane foam processed in process (BI) enters the chemical decomposition reactor. In this alternative example, the chemical decomposition reagent 4 can be added, for example, after passing through the mechanical compression apparatus (i.e., after the degassing operation is completed) and before entering the chemical decomposition reactor 300 (see further details below).

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

[0115] Examples of suitable mechanical compression apparatus include extruders (including multi-zone screw extruders, as well as single-screw and multi-screw extruders), rollers, or pistons. A multi-zone screw extruder is an extruder in which the helix has, for example, different diameters or inclinations of helical windings. This facilitates compression.

[0116] Similar to the second and third alternatives, in the fourth 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 is completed), i.e., after passing through the mechanical compression apparatus, but also in the inlet apparatus. In all cases, the chemical decomposition reagent to be added is preferably at a temperature in the range of 120°C to 240°C, particularly above 120°C to 140°C. However, in contrast to the second and third alternatives, it is preferable not to add any catalyst at this point. If the chemical decomposition reagent is added in the initial stage of the inlet apparatus, the polyurethane foam is preferably moistened with it. Adding the chemical decomposition reagent in the initial stage of the inlet apparatus does not, of course, mean that further chemical decomposition reagents and / or further catalysts will not be added to the chemical decomposition reactor.

[0117] As with other alternatives, the temperature of the second step is preferably in the range of -20°C to 120°C, and in particular corresponds to the first temperature (i.e., no intentional change in temperature is made when transitioning 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. When the compound to be removed is a liquid under standard conditions (not excluding significant vapor pressure), a lower limit temperature of 16°C has been found to be useful (in both steps).

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

[0119] In step (B.II) of the method according to the present invention, the actual chemical recycling of urethane bonds is performed (this does not mean that the reaction cannot be partially initiated in the initial stages of the inlet device, provided that degassing is complete; see the above description of step (BI)). Chemical decomposition is carried out in an inert gas atmosphere (particularly nitrogen, argon, or helium atmosphere). The chemical decomposition reagents used are preferably oxygenated by inert gas saturation. withoutThis is also the state (regardless of whether it is added for the first time in the chemical decomposition reactor or in the initial stages of the inlet equipment).

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

[0121] The preferred configuration of this process is alcohol decomposition (usually referred to as glycol decomposition in the literature; see further section 2 above) and hydroalcoholysis (usually referred to as hydroglycol decomposition in the literature; see further section 3 above). Regardless of the specific configuration, process (B.II) is carried out in a temperature range of 140°C to 240°C, preferably 160°C to 240°C, and more preferably 180°C to 220°C. The pressure in process (B.II) is preferably 960 mbar. (abs.) Super ~1.8 bar (abs.) This pressure is, in particular, equal to the ambient pressure (i.e., the reaction in process (B.II) is not particularly pressurized). The pressure in process (B.II) refers to the dominant pressure in the gas space of the chemical decomposition reactor.

[0122] When chemical decomposition is carried out as alcohol decomposition, the chemical decomposition reagent (in this case, alcohol) is added without adding a substantial proportion of water. In this regard, not adding a substantial proportion of water means not intentionally adding an amount of water that would result in a substantial degree of hydrolytic alcohol decomposition. This does not exclude the introduction of small amounts of water, which may be introduced by polyurethane foam in a form dissolved in the alcohol used in process (B.II), or which may be used as a catalyst solvent.

[0123] When chemical decomposition is carried out as hydrolytic alcohol decomposition, the chemical decomposition reagents used are alcohol and water. In this case, these two components may be mixed beforehand, but this is not necessary. In particular, it is also possible to add only alcohol (and much or a small amount of water) first, dissolve the polyurethane foam in it, and then add the water (or the remaining water). In hydrolytic alcohol decomposition, it is preferable to add the water gradually at the rate at which it is chemically consumed in the reaction, rather than adding the entire amount of water at once.

[0124] Whether the chemical decomposition is carried out as alcohol decomposition or as hydrolytic alcohol decomposition, the chemical decomposition reagent preferably contains 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 above alcohols. Diethylene glycol is particularly preferred.

[0125] Alcohol decomposition and hydrolysis of alcohol are preferred, but naturally, other chemical decomposition methods such as hydrolysis or aminolysis can also be used.

[0126] Suitable catalysts for step (B.II) are, in particular, 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 octanoate, monobutyltin oxide, or tetrabutyl titanate), and / or organic amines (especially diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undeca-7-ene, or 1,4-diazabicyclo[2.2.2]octane). The catalyst is added at the latest in the chemical decomposition reactor, or alternatively (see above description), it may be added beforehand in the inlet apparatus, particularly dissolved in the chemical decomposition reagent.

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

[0128] Step (B.II) yields a first product mixture containing unconverted chemilysis reagent (because it was used in hyperstoichiometric amounts), a polyol (derived from the polyol component and / or newly formed as a decomposition product in reaction with the chemilysis reagent), and a carbamate and / or amine (depending on the chemilysis reagent used). In preferred embodiments where the chemilysis is carried out as alcohol decomposition or hydrolysis of alcohol, the excess chemilysis reagent may contain at least the alcohol used for chemilysis and may or may not contain water (when chemilysis is carried out as hydrolysis of alcohol). When chemilysis is carried out as pure alcohol decomposition, a small amount of water may be additionally present. See the above description.

[0129] This first product mixture, after being discharged from the chemical decomposition reactor in step (B.III), is sent for further post-treatment (step (C), preferably steps (C) and (D)). The discharge device used for this purpose may be any device known in the field for fluid transport, particularly pumps.

[0130] Polyol recovery In step (C) of the method according to the present invention, the first product mixture obtained in step (B) is post-treated to obtain a polyol. This post-treatment 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 a possible configuration of step (C) in a preferred embodiment in which the chemical decomposition is carried out as alcohol decomposition or hydrolysis of alcohol, this is: (CI) The first product mixture obtained in step (B.III) is combined with an organic solvent that is completely immiscible with the alcohol used in step (B) (particularly aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, or a mixture of two or more of the above organic solvents), without removing any water present in the first product mixture beforehand, and the phase is separated into a first alcohol phase and a first solvent phase. (C.II) A step of recovering the polyol by post-treatment of the first solvent phase, Includes.

[0132] Process (C.II) includes post-treatment steps known to those skilled in the art, particularly washing and distillation.

[0133] In a preferred embodiment in which the chemical decomposition is carried out as alcohol decomposition or hydrolysis of alcohol, in another possible configuration of step (C), this is: (CI * The first product mixture obtained in step (B.III) is mixed with an organic solvent miscible with the alcohol used in step (B) (particularly halogen-substituted aliphatic hydrocarbons, halogen-substituted alicyclic hydrocarbons, halogen-substituted aromatic hydrocarbons, or a mixture of two or more of the above-mentioned organic solvents), and the solid components are optionally subsequently removed to obtain a second product mixture. (C.II * ) process (CI * The second product mixture obtained in ) is washed with an aqueous washing solution (which partially hydrolyzes any carbonate present in the second product mixture to release amines and alcohols), and the phase is, Process (CI * A first solvent phase containing an organic solvent and polyol used in ) A first aqueous phase containing water, alcohol, carbamate and amine, The process of separating into, (C.III * ) A step of post-treating the first solvent phase to obtain a polyol, Includes.

[0134] Process (C.III *) also includes post-treatment steps known to those skilled in the art, such as 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 performed as pure hydrolysis.

[0136] Amine recovery The method according to the present invention preferably includes a step (D) of recovering at least one amine corresponding to the isocyanate of the isocyanate component. The starting point for that part of the post-treatment is the alcohol phase or the first aqueous phase recovered from the first product mixture in step (C).

[0137] The method of carrying out step (D) is determined in particular by the method of carrying out step (B.II). When step (B) is carried out as alcohol decomposition, the first alcohol phase or the first aqueous phase usually contains a considerable proportion of carbamates that still need to be hydrolyzed in step (D). Such hydrolysis is preferably carried out by a catalyst, and suitable catalysts are the same as those described above for chemical decomposition.

[0138] If step (B.II) is performed as hydrolysis of alcohol, then carbamates are no longer present at this point in the process (or at least present in trace amounts that are not problematic), and therefore another hydrolysis step is unnecessary.

[0139] Unrelated to this, step (D) includes post-treatment steps, particularly distillation, to purify the amine obtained by cleaving the urethane bonds. Here, it is particularly advantageous to incorporate the isolation of the recovered amine from the polyurethane foam into the process of preparing the new amine, as described in International Publication No. 2020 / 260387 and the unpublished International Application PCT / EP2021 / 075916.

[0140] The present invention will be described in more detail below with reference to examples. [Examples]

[0141] Example 1 (First alternative example according to the present invention): 250g of polyurethane flakes (a tolylene diisocyanate-based flexible foam) was placed in a 30L flexible polyethylene (PE) bag, which was then closed and connected to a vacuum pump. The vacuum pump was started to increase the pressure inside the PE bag to 10 mbar. (abs) The pressure was reduced to less than 0.5% by weight. Next, nitrogen was added to expand the inside of the PE bag to ambient pressure. This operation was repeated two more times. Then, an oxygen probe was placed at the bag's outlet. The deactivated bag was pressurized, and the gas present inside was passed through the oxygen probe for one minute. The oxygen content in the exhaust air never exceeded 0.5% by weight.

[0142] Next, glycol decomposition was performed using inactivated foam flakes as follows.

[0143] 250 g of diethylene glycol and 2.5 g of bismuth trineodecanoate were further packed into a 1 L three-necked round-bottom flask and heated to 200°C. Subsequently, polyurethane flakes were added and dissolved, and the mixture was maintained at 200°C for a further 3 hours. A constant nitrogen purge was switched on (10 NL / hour) 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 polyurethane flakes was carried out in the same manner as in Example 1, but degassing according to the present invention was not performed. Here as well, a nitrogen purge was kept connected at all times during metering, addition, and reaction.

[0145] In Example 2, a clear blackening of the reaction mixture was observed, while the polyurethane foam that had been degassed earlier (Example 1) only showed a pale brown color. This clearly demonstrates the effect of oxygen present in the cell structure of the polyurethane foam, which significantly accelerates the oxidation of the tolylenediamine compound released during glycol decomposition.

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 foaming agent, a disinfectant, and a mixture of two or more of the above, wherein component X contains at least oxygen, by reacting the polyurethane foam with a chemical decomposition reagent, (A) Prepare polyurethane foam inside the container, (B) A chemical decomposition apparatus comprising (i) an inlet device, (ii) a chemical decomposition reactor connected to the inlet device, (iii) an outlet device connected to the chemical decomposition reactor, and (iv) a gas removal device disposed in the container and / or the inlet device, wherein the polyurethane foam is to be chemically decomposed, Furthermore, chemical decomposition is (B.I) The polyurethane foam is introduced from the container into the inlet device, and from there into the chemical decomposition reactor, before the polyurethane foam is brought into contact with the chemical decomposition reagent, (α) At least oxygen from the chemical decomposition apparatus to 960 mbar （ａｂｓ．） The gas is removed in gaseous form via the gas removal device at the following pressure and temperature of 120°C or lower. To degasse and obtain degassed polyurethane foam, (B.II) In the chemical decomposition reactor, the degassed polyurethane foam is reacted with a chemical decomposition reagent in the presence of a catalyst in an inert gas atmosphere to obtain a product mixture. (B.III) Discharging the product mixture from the chemical decomposition reactor through the outlet device, followed by, Post-treatment of the aforementioned product mixture, including; (C) To recover the polyol, (D) Optionally, recover the amine corresponding to the isocyanate from the isocyanate component, Methods that include...

2. (B.I) The degassing of the polyurethane foam is (1) In the first step, the polyurethane foam is heated to 0.1 mbar at a first temperature in the range of -20°C to 120°C. （ａｂｓ．） ~100mbar （ａｂｓ．） Exposure to a first pressure within the range, (2) In the second step, by supplying an inert gas, the polyurethane foam is subjected to a pressure greater than the first pressure, 2.0 bar. （ａｂｓ．） Being exposed to the following second pressure, The method according to claim 1, performed by...

3. The method according to claim 2, wherein an internal flexible lining is provided in the container and / or the inlet device, which compresses the polyurethane foam by collapsing in the first step by establishing the first pressure, and expands again in the second step by supplying the inert gas.

4. The inlet device has at least a first locking area having a closable supply device for the polyurethane foam prepared in process (A) and a closable removal device for the degassed polyurethane foam, Here, process (B.I) is the following process: (B.I.1.a) A step of closing the removal device for the first lock area, introducing polyurethane foam into the first lock area, and closing the supply device for the first lock area, (B.I.2.a) A step of performing the first step of (B.I) in the first lock area, (B.I.3.a) A step of performing the second step of (B.I.) by supplying the inert gas in the first lock region to obtain a degassed polyurethane foam, The process involves transferring the degassed polyurethane foam obtained in (B.I.4.a) and (B.I.3.a) to the chemical decomposition reactor, The method according to claim 2, including the method described in claim 2.

5. The inlet device has, in addition to the first locking region, a second locking region having a closable supply device for the polyurethane foam prepared in process (A) and a closable removal device for the degassed polyurethane foam. Here, the first portion of the polyurethane foam is introduced into the first lock region in step (B.I.1.a) so that the first portion of the degassed polyurethane foam is obtained in step (B.I.3.a), and step (B.I.) is the following step: (B.I.1.b) A step of closing the removal device for the second lock area, introducing the second portion of the polyurethane foam into the second lock area, and closing the supply device for the second lock area, (B.I.2.b) A step of performing the first step of (B.I) in the second lock area, (B.I.3.b) The second step of (B.I.) is performed by supplying the inert gas in the second lock region to obtain the second portion of the degassed polyurethane foam, (B.I.4.b) A step of transferring the second portion of the degassed polyurethane foam to the chemical decomposition reactor, The method according to claim 4, further comprising steps (B.I.1.a) to (B.I.4.a) combined with steps (B.I.1.b) to (B.I.4.b), wherein the degassed polyurethane foam is continuously transferred to the chemical decomposition reactor.

6. The method according to claim 2, wherein the polyurethane foam is transported and crushed during the first step of (B.I) through a mechanical crushing device located in the first part of the inlet device, the second step being carried out such that the mechanically crushed polyurethane foam is transported into an inert gas atmosphere under a second pressure through a second part downstream of the first part of the inlet device.

7. (B.I) The degassing of the polyurethane foam is (1) In the 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．） ~960 mbar （ａｂｓ．） , especially 100 mbar （ａｂｓ．） ~960 mbar （ａｂｓ．） To convey to a mechanical compression device located within the inlet device at a first pressure within the range of, Furthermore, the gas removal device is located upstream of the mechanical compression device; (2) In the second step, the polyurethane foam is compressed at a second pressure in the range of 5 bar （ａｂｓ．） to 200 bar （ａｂｓ．） in the apparatus for mechanical compression; The method according to claim 1, performed by...

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

9. The aforementioned component X is at a temperature of 0°C and 1,000 bar （ａｂｓ．） The method according to any one of claims 2 to 8, comprising at least one component that is liquid at a pressure, and wherein the first temperature is at least 16°C.

10. The method according to any one of claims 1 to 9, 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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