EP4259686A1 - Procédé de récupération de matières premières à partir de mousses de polyuréthane - Google Patents

Procédé de récupération de matières premières à partir de mousses de polyuréthane

Info

Publication number
EP4259686A1
EP4259686A1 EP21824402.8A EP21824402A EP4259686A1 EP 4259686 A1 EP4259686 A1 EP 4259686A1 EP 21824402 A EP21824402 A EP 21824402A EP 4259686 A1 EP4259686 A1 EP 4259686A1
Authority
EP
European Patent Office
Prior art keywords
polyurethane foam
chemolysis
abs
pressure
degassed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21824402.8A
Other languages
German (de)
English (en)
Inventor
Sebastian Pohl
Friedhelm Steffens
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Covestro Deutschland AG
Original Assignee
Covestro Deutschland AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Covestro Deutschland AG filed Critical Covestro Deutschland AG
Publication of EP4259686A1 publication Critical patent/EP4259686A1/fr
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C08J11/18—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material
    • C08J11/22—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
    • C08J11/26—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing carboxylic acid groups, their anhydrides or esters
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/83—Chemically modified polymers
    • C08G18/831—Chemically modified polymers by oxygen-containing compounds inclusive of carbonic acid halogenides, carboxylic acid halogenides and epoxy halides
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C08J11/16—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with inorganic material
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C08J11/18—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C08J11/18—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material
    • C08J11/22—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
    • C08J11/24—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
    • C08J2375/04—Polyurethanes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

  • the present invention relates to a method for recovering raw materials from a polyurethane foam, comprising step (A), providing a polyurethane foam based on an isocyanate component and a polyol component, the polyurethane foam having a cell structure containing one or more volatile accompanying substances, namely a component X selected from the group consisting of oxygen, a blowing agent, a disinfectant and a mixture of two or more of the aforementioned accompanying substances, where component X comprises at least oxygen, has step (B), the chemolysis of the polyurethane foam with a chemolysis reagent, the polyurethane foam is degassed before being brought into contact with the chemolysis reagent, with at least oxygen, but preferably all the constituents of component X or any gaseous decomposition products formed thereof, at a maximum pressure of 960 mbar (abs.) and a temperature of v at a maximum of 120 °C in gaseous form via a gas removal device from the chemo
  • the raw materials to be recovered primarily include polyols (ie HOR'-OH in the above example).
  • CN 106 279 760 describes the chemolysis of a polyurethane comprising mechanical comminution, reaction with water and an alcohol in an inert gas atmosphere in the presence of antioxidants at 218° C. to 399° C. and a pressure of 50 to 150 kPa for 3 to 5 hours, with a carbodiimide is used as the catalyst.
  • DE 32 32 461 A1 describes a process for the continuous glycolytic splitting of polyurethane plastic waste, in particular polyurethane foam waste, in multi-shaft screw machines by adding optionally preheated diols at splitting temperatures of >250° C. while maintaining at least such a pressure that the polyurethane-diol mixture is in the liquid phase is present, discharge of the glycolyzate mixture after a short residence time of 2 to 30 minutes in the reaction screw and rapid cooling of the glycolyzate mixture.
  • air introduced into the screw machine together with the plastic waste can escape against the conveying direction in front of the feed hopper via a housing bore, to which a slight vacuum is advantageously applied.
  • the application does not disclose that volatile accompanying substances contained in the cell structure of the polyurethane foam, such as in particular oxygen, blowing agents and/or disinfectants, are discharged via the housing bore. With the arrangement described, this is also not to be expected; Rather, it can be assumed that only the air that enters the machine together with the foam waste during the course of the introduction thereof (the air surrounding the foam waste) is actually removed.
  • DE 24 42 387 A1 describes a process for the continuous hydrolytic decomposition of plastic waste, in which waste made from hydrolyzable plastic material is fed into a screw machine together with water and optionally hydrolysis catalysts, where the mixture of water and plastic waste is placed in a reaction zone with intensive mass and heat exchange of the 2nd is exposed to a temperature of 100 to 300 °C at a pressure of 5 to 100 bar for up to 100 minutes and the liquid-gas mixture produced during the hydrolysis is continuously conveyed into a mouthpiece which is firmly connected to the screw machine, from which the gas is a regulator valve which maintains constant screw machine pressure in the die and the liquid exits via a regulator valve which maintains a constant liquid level within the die.
  • the air introduced together with the plastic waste is removed through a housing bore located in front of the feed hopper for the plastic material, seen in the conveying direction, to which a slight vacuum is applied.
  • volatile accompanying substances contained in the cell structure of the polyurethane foam such as in particular oxygen, blowing agents and/or disinfectants, are discharged via the housing bore.
  • the chemolysis reagent here water
  • DE 197 19 084 A1 discloses a process for producing polyols from polyurethane waste, in which foam flakes, ground flexible foam or shredded material are fed into a reactor containing waste from the synthesis of polyesters, which has previously been heated to a temperature above 70°C became.
  • the mixture of polyurethane waste and polyester synthesis waste is further heated and reacted by a controlled, catalytic transesterification reaction at a temperature of 120°C to 250°C.
  • the polyurethane waste is introduced by means of pneumatic conveying through a weak stream of nitrogen. A removal of volatile accompanying substances contained in the cell structure of the polyurethane foam, such as in particular oxygen, blowing agents and/or disinfectants, is not to be expected in this way.
  • DE 10 2004 014165 A1 describes a process for producing polyols from polyurethane waste and a special device for carrying out this process.
  • the pre-comminuted soft foam is metered in from above via a stuffing screw and a constriction ring, with the gases contained in the foam being removed, according to this document.
  • oxygen contained in the cell structure of the polyurethane foam can actually be at least essentially completely removed without the use of reduced pressure before the start of the chemolysis.
  • EP 0 031 538 A2 describes a method and a device for processing polyurethane obtained from waste materials by alcoholysis or acidolysis.
  • the polyurethane is first mechanically comminuted into a starting material and then treated with solvents at a temperature of more than 120 °C. At least at the beginning of the solvent treatment, which leads to the liquefaction of the starting material and is carried out at a reaction temperature of below 200° C., the mechanical comminution of the starting material that is already undergoing chemical degradation is continued.
  • this method results in a shorter treatment time at a lower temperature until the complete solution of the raw material without quality-reducing discoloration occurring or undissolved residues remaining. The dissolution of the starting material naturally takes place with at least partial reaction of the polyurethane bonds.
  • the system for carrying out the process has a mixer fed from storage containers, to which a reactor is connected on the outlet side, in which shearing elements exerting shearing forces and which can be rotated in both directions act on the starting material, which are arranged on a hollow, heatable shaft and controlled by a are surrounded by the reactor shell composed of hollow, heatable sectors.
  • the heat transfer to the mass is improved, so that a uniform temperature distribution and thus a relatively short reaction and dissolving time can be achieved.
  • the application discloses an embodiment in which the initial comminution of the starting material takes place while mixing with a proportion of the polyols later used as a solvent component in a heatable kneading mixer with two counter-rotating shafts with sigma blades.
  • this achieves good pre-wetting of the polyurethane particle surfaces with solvent, releases part of the gases trapped in the polyurethane cell area, reduces the harmful oxygen content, in particular avoids the agglomeration of the polyurethane particles due to the subsequent mechanical stresses in the subsequent reactor zone and improves the dosability and thermal conductivity of the Mass of the starting material increased significantly.
  • the extensive removal of atmospheric oxygen can be effected by subsequent evacuation of the mixture in the same part of the plant and/or by subsequent flushing with protective gas, for example nitrogen, at normal pressure.
  • protective gas for example nitrogen
  • upcycling In addition to the processes mentioned of physical recycling (mechanical crushing of the polyurethane products and admixture in the manufacture of new polyurethane products) and chemical recycling (recovery of polyols and preferably also amines through chemical cleavage of the urethane bonds), so-called "upcycling” should also be mentioned, one thing occupies an intermediate position: With upcycling, as with chemical recycling, a chemical change in the polyurethane takes place, but this does not take place until the raw materials originally used in the synthesis (polyol and amine) are recovered, but rather the aim is to convert the polyurethane to be recycled into another polymer to transfer value product. Thus, DT Sheppard et al.
  • the polyurethane products to be recycled usually also contain various auxiliaries and additives (stabilizers, catalysts and the like) which have to be separated from the actual target products of recycling and disposed of in an economical and environmentally friendly manner.
  • auxiliaries and additives stabilizers, catalysts and the like
  • blowing agents and oxygen both of which are present in the cell structure of the foams.
  • other foreign substances can get into a polyurethane product to be recycled as a result of preparatory steps that precede the actual chemical recycling. For example, it is common to treat reusable polyurethane foams, which come from old mattresses or seating furniture, with disinfectants.
  • the presence of oxygen is also problematic from a safety point of view, since in alcoholysis, for example, work is often carried out above the flash point of the alcohol used.
  • the blowing agents used, such as pentane, are chemically inert, but this is precisely why they accumulate and have to be discharged regularly, resulting in a loss of product (so-called purge).
  • the presence of propellants can also make the exhaust gas load and the processing of the exhaust gas more difficult.
  • Certain common disinfectants such as ethanol, can form carbamates during chemolysis, which may be more difficult to split, releasing the amine, than the carbamates of the actual chemolysis reagent (usually glycol or a glycol derivative). Even if the carbamate cleavage is successful, such alcoholic disinfectants then get into the unreacted chemolysis reagent as contamination during work-up, which can make its recovery more difficult.
  • Other common disinfectants such as hydrogen peroxide or sodium hypochlorite can decompose releasing oxygen. The prior art does not yet offer a satisfactory solution to such problems.
  • one subject of the present invention is therefore a method for recovering raw materials (i.e. polyols and optionally amines) from a polyurethane foam based on an isocyanate component and a polyol component, having a cell structure containing a component X selected from the group consisting of oxygen , a blowing agent, a disinfectant and a mixture of two or more of the above, where component X comprises at least oxygen, by reacting the polyurethane foam with a chemolysis reagent, the method comprising:
  • chemolysis of the polyurethane foam (1) in a chemolysis device comprising (i) an entry device (200), (ii) a chemolysis reactor connected to the entry device (300), (iii) one with the discharge device (400) connected to the chemolysis reactor and (iv) a gas discharge device (500) arranged in the container and/or in the entry device, wherein the chemolysis comprises:
  • At least oxygen i.e. (i) the oxygen contained in component X and (ii) any oxygen formed by decomposition reactions of constituents of component X), but preferably all constituents of component X or any gaseous decomposition products thereof formed, in one pressure of at most 960 mbar (abs) and a temperature of at most 120° C. are discharged in gaseous form via the gas discharge device from the chemolysis device, so that a degassed polyurethane foam (2) is obtained;
  • Processing of the product mixture comprising:
  • a polyurethane foam has a cell structure (also called pore structure) which can be influenced by chemical or procedural parameters during foaming.
  • blowing agents are used which are gaseous under the production conditions of the foaming and lead to the formation of foam cells (also called foam pores) which are connected to one another via so-called webs.
  • foam cells also called foam pores
  • the present invention is concerned with recycling the polyurethane foams prior to initiating chemical recycling, i. H. prior to the first contact of a polyurethane foam to be recycled with a chemolysis reagent, of such volatile accompanying substances.
  • a volatile accompanying substance in this sense, i. H.
  • Tu -20 °C, in particular (namely if the volatile accompanying substances contained in the cell structure are liquid under standard conditions [i.e. at a temperature of 0 °C and a pressure of 1,000 bar(abs)]) 16 °C, and
  • isocyanates includes all isocyanates known to those skilled in the art in connection with polyurethane chemistry, such as in particular tolylene diisocyanate (TDI; can be produced and preferably produced from toluenediamine, TDA), the di- and polyisocyanates of the diphenylmethane series (MDI; can be produced and preferably produced from the di- and polyamines of the diphenylmethane series, MDA),
  • TDI tolylene diisocyanate
  • MDI di- and polyisocyanates of the diphenylmethane series
  • MDA di- and polyamines of the diphenylmethane series
  • 1,5-pentane diisocyanate can be produced and preferably produced from 1,5-pentanediamine, PDA) , 1,6-hexamethylene diisocyanate (HDI; can be produced and preferably produced from
  • 1.6-hexamethylenediamine, HDA isophorone diisocyanate
  • IPDI isophorone diisocyanate
  • XDI xylylene diisocyanate
  • an isocyanate of course also includes embodiments in which two or more different isocyanates (e.g. mixtures of MDI and TDI) were used in the preparation of the polyurethane product, unless expressly stated otherwise, e.g by the formulation "exactly one isocyanate".
  • the entirety of all isocyanates used in the manufacture of the polyurethane product is referred to as the isocyanate component (of the polyurethane product).
  • the isocyanate component includes at least one isocyanate.
  • the entirety of all polyols used in the manufacture of the polyurethane product is referred to as the polyol component (of the polyurethane product).
  • the polyol component includes at least one polyol.
  • polyols includes all polyols known to those skilled in the art in connection with polyurethane chemistry, such as in particular polyether polyols, polyester polyols, polyether ester polyols and polyether carbonate polyols.
  • a polyol also encompasses embodiments in which two or more different polyols were used in the production of the polyurethane product. If, for example, "a polyether polyol” (or “a polyester polyol” etc.) is mentioned below, this terminology naturally also includes embodiments in which two or more different polyether polyols (or two or more different polyester polyols etc.) are used in the production of the Polyurethane product were used.
  • carbamates refer to the urethanes formed by the reaction with the alcohol in step (B).
  • a nitro compound corresponding to an amine designates that nitro compound by reduction of which according to R-NO2+3H2->R-NH2+2H2O the amine can be obtained.
  • the invention is therefore concerned with the recycling of polyurethane foams whose cell structure contains oxygen, (at least) one blowing agent and/or (at least) one (volatile or decomposable to form volatile products) disinfectant, i.e. one, several or all of the volatile accompanying substances mentioned , but oxygen is always present.
  • component X is used in this sense as a collective designation for all volatile accompanying substances present.
  • the method according to the invention removes at least the oxygen present (irrespective of its origin) at least essentially completely. All constituents of component X or gaseous decomposition products thereof are preferably at least essentially completely removed.
  • the invention provides two alternative solutions, as will be explained in more detail below. What they all have in common is that in (B)(1)(a) oxygen, preferably all components of component X or gaseous decomposition products thereof, “gaseous at a maximum pressure of 960 mbapabs and a maximum temperature of 120 °C Colour be taken away”.
  • the first alternative solution is characterized in particular by the fact that the removal of the volatile accompanying substances is essentially effected by a strong pressure reduction followed by a pressure increase.
  • the polyurethane foam is used to carry out the degassing in (B.l)
  • a “degassed polyurethane foam (2)” refers to a polyurethane foam that has been freed from volatile accompanying substances of the type mentioned and saturated with an inert gas.
  • the second alternative solution is characterized in particular by the fact that the volatile accompanying substances are essentially removed by mechanical compression of the polyurethane foam (the volatile accompanying substances are pressed out of the cell structure of the polyurethane foam and into an area of reduced pressure).
  • the polyurethane foam is used to carry out the degassing in (B.l)
  • a “degassed polyurethane foam (2)” refers to a polyurethane foam that has been freed from volatile accompanying substances of the type mentioned and compressed (and is fed in compressed form to the chemolysis carried out in an inert gas atmosphere).
  • FIG. 1 shows a first variant of the method according to the invention using a flexible lining made of, for example, polyethylene (first alternative solution),
  • FIG. 2a, b show a second variant of the method according to the invention
  • FIG. 3 shows a third variant of the method according to the invention
  • FIG. 4 shows a fourth variant of the method according to the invention using a device for mechanical compression (second alternative solution).
  • the container and/or the infeed device is provided internally with a flexible lining which, in the first step, is adjusted by adjusting the first Pressure is contracted and so compresses the polyurethane foam, and is expanded again in the second step by supplying an inert gas to set the second pressure.
  • the flexible lining is a film made of polyethylene, polypropylene, aluminum, polyvinyl chloride, polyetheretherketone, polystyrene, polycarbonate, polyester, Polyethylene terephthalate or a composite of the aforementioned materials.
  • the first and the second step are repeated several times, in particular 2 to 5 times.
  • the second pressure is a maximum of 1.8 bar(abs) and is in particular equal to the ambient pressure.
  • the first temperature is in the range from 0° C. to 80° C., preferably from 16° C. to 80° C
  • the second step is carried out at a second temperature (T2), which is in the range from -20 °C to 120 °C, preferably 0 °C to 80 °C, particularly preferably 16 °C to 80 °C, and in particular corresponds to the first temperature (i.e. there is no specific change in temperature during the transition from the first to the second step).
  • T2 second temperature
  • the entry device has a first lock area (upstream of the chemolysis reactor) having a lockable feed device for the polyurethane foam provided in step (A) and a lockable discharge device for the degassed polyurethane foam, the following steps being run through in step (B1): (BIIa) blocking off the discharge device of the first lock area, introducing polyurethane foam into the first lock area and blocking off the feed device of the first lock area;
  • the entry device has a second lock area in addition to the first lock area, which has a lockable feed device for the in step (A) provided polyurethane foam and a closable discharge device for the degassed polyurethane foam, wherein in step (B.I.I.a) a first subset of the polyurethane foam is introduced into the first lock area, so that in step (B.l.3a) a first subset of the degassed polyurethane foam is obtained, wherein in Step (B.l) the following steps are also run through:
  • the first temperature is in the range from 0°C to 80°C, preferably 16°C to 80°C .
  • the polyurethane foam is only brought into contact with the chemolysis reagent in the chemolysis reactor.
  • the second step is carried out at a second temperature (T2), which is in the range from -20 °C to 120 °C, preferably 0 °C to 80 °C, particularly preferably 16 °C to 80 °C and in particular corresponds to the first temperature (i.e. there is no specific change in temperature during the transition from the first to the second step).
  • T2 second temperature
  • the polyurethane foam is still in the second step first and/or second lock area with chemolysis reagent (optionally already with the catalyst) brought into contact, in particular wetted.
  • the chemolysis reagent has a temperature in the range from 120° C. to 240° C., in particular > 120° C. to 240 °C, on.
  • the second pressure is a maximum of 1.8 bar(abs) and is in particular equal to the ambient pressure.
  • a fifteenth embodiment of the invention which corresponds to a third variant and also belongs to the first alternative solution, during the first step of (Bl) the polyurethane foam is conveyed and crushed by a mechanical crushing device arranged in a first part of the feeding device, the second step is carried out in such a way that the present after the mechanical comminution polyurethane foam by a second, downstream of the first, part of Entry device is promoted in an inert gas atmosphere which is under the second pressure.
  • the polyurethane foam is conveyed in the first and second part of the entry device by means of
  • the device for mechanical comminution comprises a cutting mill, a knife mill, an impact crusher and/or a hammer mill.
  • the device for mechanical comminution comprises an impact crusher and/or a hammer mill, the first temperature being in the range from ⁇ 0°C to -20°C.
  • the first temperature is in the range from 0 °C to 80 °C, preferably 16 °C to 80°C
  • the polyurethane foam is only brought into contact with chemolysis reagent in the chemolysis reactor.
  • the second step is carried out at a second temperature (T2), which is in the range from -20 °C to 120 °C, preferably 0 °C to 80 °C, particularly preferably 16 °C to 80 °C, and in particular the first temperature (ie there is no intentional change in temperature during the transition from the first to the second step).
  • T2 second temperature
  • a twenty-third embodiment of the invention which is a special configuration of the fifteenth embodiment and can be combined with all other embodiments of the third variant, provided these are not limited to the addition of the chemolysis reagent only in the chemolysis reactor, the polyurethane foam is still in the second step second part of the entry device with chemolysis reagent (optionally already with the catalyst) brought into contact, in particular wetted.
  • the chemolysis reagent has a temperature in the range from 120 °C to 240 °C, in particular >120 °C to 240 °C, when brought into contact with the polyurethane foam in the second part of the entry device C, on.
  • the second pressure is a maximum of 1.8 bar(abs) and is in particular equal to the ambient pressure.
  • the gas discharge device is arranged in the entry device.
  • the device for mechanical compression comprises an extruder (also including multi-zone screws and single and multi-screw extruders), a roller or a flask.
  • the polyurethane foam is still in the entry device with the Chemolysis reagent brought into contact, especially wetted.
  • the chemolysis reagent when brought into contact with the polyurethane foam in the feed device a temperature in the range from 120 °C to 240 °C.
  • the first temperature is in the range from 0°C to 80°C, preferably 16°C to 80°C .
  • the second step is carried out at a second temperature (T2), which is in the range from -20 °C to 120 °C, preferably 0 °C to 80 °C, particularly preferably 16 °C to 80 °C, and in particular corresponds to the first temperature (i.e. there is no specific change in temperature during the transition from the first to the second step).
  • T2 second temperature
  • step (B.ll) is carried out at a temperature in the range from 140° C. to 240° C., preferably from 160° C. to 240° C., particularly preferably 180 °C to 220 °C.
  • step (B.II) is carried out at a pressure in the range from >960 mbar(abs) to 1.8 bar(abs), in particular at ambient pressure. carried out.
  • component X contains at least one component which, under standard conditions (i.e. at a temperature of 0° C. and a pressure of 1,000 bar(abs)) is liquid, the first temperature being at least 16°C.
  • the blowing agent comprises (in particular is) pentane, a chlorofluorocarbon, dichloromethane or a mixture of two or more of the aforementioned blowing agents; and includes (particularly is) the disinfectant hydrogen peroxide, chlorine dioxide,
  • Formaldehyde peracetic acid, an alkali metal hypochlorite (especially sodium hypochlorite), ethanol, isopropanol, 1-propanol or a mixture of two or more of the aforementioned disinfectants.
  • alkali metal hypochlorite especially sodium hypochlorite
  • ethanol isopropanol, 1-propanol or a mixture of two or more of the aforementioned disinfectants.
  • the isocyanate component contains an isocyanate selected from tolylene diisocyanate (TDI), the di- and polyisocyanates of the diphenylmethane series (MDI), 1,5-pentane diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI) or a mixture of two or more of the aforementioned isocyanates.
  • TDI tolylene diisocyanate
  • MDI diphenylmethane series
  • PDI 1,5-pentane diisocyanate
  • HDI 1,6-hexamethylene diisocyanate
  • IPDI isophorone diisocyanate
  • XDI xylylene diisocyanate
  • Particular preference is given to polyurethane foams which, with regard to the isocyanate component, are based on a mixture of TDI and MDI.
  • the polyol component contains a polyol selected from a polyether polyol, a polyester polyol, a polyether ester polyol, a polyether carbonate polyol or a mixture of two or more of the aforementioned polyols.
  • the polyol component preferably contains a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., does not contain any other polyols other than polyether polyols; however, a mixture of two or more different polyether polyols is encompassed and does not depart from the scope of this embodiment).
  • the isocyanate component contains toluylene diisocyanate (TDI) and di- and polyisocyanates of the diphenylmethane series (MDI) (in particular only TDI), and the polyol component contains a polyether polyol (and is in particular a polyether polyol, i.e. it does not contain any other polyols different from polyether polyols, but a mixture of two or more different polyether polyols is included and does not go beyond the scope of this embodiment).
  • TDI toluylene diisocyanate
  • MDI di- and polyisocyanates of the diphenylmethane series
  • the chemolysis reagent comprises an alcohol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl glycol, triethylene glycol, glycerol, 2-methyl-1,3-propanediol or one Mixture of two or more of the aforesaid alcohols.
  • the chemolysis reagent comprises water.
  • the catalyst is selected from an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal salt of a carboxylic acid (especially an acetate), an alkaline earth metal salt of a carboxylic acid (especially an acetate), a Lewis acid (especially dibutyltin dilaurate, tin octoate, monobutyltin oxide or tetrabutyl titanate) and/or an organic amine (especially diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undec- 7-ene or 1,4-diazabicyclo[2.2.2]octane).
  • the chemolysis reagent has a temperature in the range from 120° C. to 240° C., in particular >120° C. to 240° C., when brought into contact with the polyurethane foam .
  • step (A) of the method according to the invention the polyurethane foam to be chemically recycled is provided.
  • this can be any type of polyurethane foam; in particular, both flexible foams and rigid foams are suitable, with flexible foams (for example from old mattresses, upholstered furniture or car seats) being preferred.
  • polyurethane foams are produced using a blowing agent. Apart from water-blown foams (in which carbon dioxide is released by hydrolysis in situ), pentane is a particularly common blowing agent nowadays. When recycling old polyurethane foams, it is conceivable that chlorofluorocarbons, which were previously used as blowing agents, were also used. Another conceivable blowing agent is dichloromethane.
  • polyurethane foams which, with regard to the isocyanate component, are based on an isocyanate selected from tolylene diisocyanate (TDI), the di- and polyisocyanates of the diphenylmethane series (MDI), 1,5-pentane diisocyanate (PDI), 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI) or mixtures of two or more of the aforementioned isocyanates.
  • TDI tolylene diisocyanate
  • MDI diphenylmethane series
  • PDI 1,5-pentane diisocyanate
  • HDI 1,6-hexamethylene diisocyanate
  • IPDI isophorone diisocyanate
  • XDI xylylene diisocyanate
  • Particular preference is given to polyurethane foams which, with regard to the isocyanate component, are
  • polyurethane foams which are based on a polyol selected from a polyether polyol, a polyester polyol, a polyether ester polyol, a polyether carbonate polyol or a mixture of two or more of the aforementioned polyols.
  • the polyol component preferably contains a polyether polyol. More preferably, the polyol component is a polyether polyol (i.e., does not contain any other polyols other than polyether polyols; however, a mixture of two or more different polyether polyols is encompassed and does not depart from the scope of this embodiment).
  • the polyurethane foam is very particularly preferably a foam whose isocyanate component contains toluylene diisocyanate (TDI) and di- and polyisocyanates of the diphenylmethane series (MDI), in particular only TDI, and whose polyol component contains a polyether polyol (and is in particular a polyether polyol i.e. does not contain any other polyols other than polyether polyols, although a mixture of two or more different polyether polyols is included and does not go beyond the scope of this embodiment.)
  • TDI toluylene diisocyanate
  • MDI di- and polyisocyanates of the diphenylmethane series
  • Step (A) preferably already comprises preparatory steps for the cleavage of the urethane bonds in step (B.II).
  • this involves mechanical comminution of the polyurethane foams.
  • Such preparatory steps are known to those skilled in the art; reference is made, for example, to the literature cited in [1].
  • it can be advantageous to "freeze" it before mechanical shredding to facilitate the shredding process.
  • the polyurethane foam can be treated with (aqueous or alcoholic) disinfectants.
  • disinfectants are preferably hydrogen peroxide, chlorine dioxide, formaldehyde, alkali metal hypochlorites (in particular sodium hypochlorite) and/or peracetic acid (aqueous disinfectants) or ethanol, isopropanol and/or 1-propanol (alcoholic disinfectants).
  • the compounds contained in the cell structure can also include those which are liquid under standard conditions, ie at a temperature of 0° C. and a pressure of 1,000 bar(abs). In this case, it is preferable to select a value of 16° C. as the minimum value for the first temperature.
  • the foam thus prepared is finally transferred to the container (reference number 100 in the figures) connected to the feeding device.
  • This container can be a conventional container known in the art, such as solid silos or containers.
  • the prepared foam is filled into suitable transport vehicles, such as silo vehicles, for onward transport.
  • suitable transport vehicles such as silo vehicles
  • the prepared foam can also be compressed for onward transport in order to achieve a higher mass-to-volume ratio.
  • the foam is then filled into the container at the site of the chemolysis reactor.
  • connect the transport vehicle used directly to the infeed device in which case the transport vehicle is to be regarded as a container within the meaning of the terminology of the present invention.
  • Step (B) of the method according to the invention includes the chemolysis of the polyurethane foam provided in step (A). This step is performed in a chemolysis device, the
  • Step (iv) has at least one gas discharge device (reference number 500 in the figures) for discharging the compounds contained in the cell structure.
  • Step (B) comprises the sub-steps (B.l), the introduction of the polyurethane foam from the container into the entry device and from there into the chemolysis reactor, the polyurethane foam being degassed before it is brought into contact with the chemolysis reagent by
  • the polyurethane foam is degassed, i. H. the volatile accompanying substances present in the cell structure are removed from the cells and/or the webs of the cell structure of the polyurethane foam and discharged via the at least one gas discharge device (500).
  • the volatile accompanying substances present in the cell structure are removed from the cells and/or the webs of the cell structure of the polyurethane foam and discharged via the at least one gas discharge device (500).
  • step (B.l) belonging to the first alternative solution and shown in FIG. 1, the container (100 in FIG. 1) and/or the feeder (not shown in FIG. 1, but also possible) is provided internally with a flexible liner (600) which in the first step is adjusted by adjusting the first pressure (p1) is contracted to a value in the range from 0.1 mbar(abs) to 100 mbar(abs) and thus compresses the polyurethane foam, and in the second step, by supplying an inert gas (3) to set the second pressure (p2 ) is extended again.
  • the second pressure is preferably a maximum of 1.8 bar (abs.) and corresponds in particular to ambient pressure (i.e. in the second step, the pressure is reduced to ambient pressure).
  • M here and in the other figures stands for motor and designates a motor-driven device, in this case a device for opening and closing the entrance to and exit from the container (100).
  • FIG. 1 the filling of the container (100) with polyurethane foam (1) is shown on the left.
  • the valve in the lower area of the container (110), the connection to the inlet device (200) and the gas discharge device (500; valve 510 in the "closed” position) are closed.
  • FIG. 1 shows the implementation of the first step.
  • the filling opening of the container (100), the valve 110 and the connection to the entry device (200) are closed.
  • a vacuum (valve 510 in the “open” position) is applied via the gas discharge device (500) and the pressure inside the flexible lining (600) is reduced to p1.
  • FIG. 1 shows the second step or the conveying of the degassed polyurethane foam (2) into the feed device (200) that follows the second step.
  • the pressure inside the flexible lining is increased to p2 by adding an inert gas (3) through the valve 110, which is now open.
  • the degassed polyurethane foam (2) is conveyed to the entry device (200) (or simply falls down into it due to the force of gravity).
  • Both the first and the second step are preferably carried out at a temperature in the range from 0°C to 80°C. If the compounds to be removed are liquids under standard conditions (which does not exclude the possibility that a significant vapor pressure may be present), a lower temperature limit of 16 °C has proven useful. It has proven advantageous to repeat the first and the second step several times, in particular 2 to 5 times, before the polyurethane foam degassed in this way is fed to the reaction of step (B.II).
  • the flexible lining used in this variant is preferably a film made of polyethylene, polypropylene, aluminum, polyvinyl chloride, polyether ether ketone, polystyrene, polycarbonate, polyester, polyethylene terephthalate or a composite of the aforementioned materials.
  • the flexible lining contracts and compresses the polyurethane foam.
  • volatile accompanying substances are pressed out of the cell structure of the foam and discharged via the gas discharge device.
  • an inert gas in particular nitrogen, argon or helium
  • the degassed polyurethane foam can be conveyed to the chemolysis reactor by vibration, mechanically or pneumatically or simply by gravity.
  • the chemolysis reagent and the catalyst are only added after the polyurethane foam has left the area of the chemolysis reactor provided with the flexible lining; in particular, the chemolysis reagent and the catalyst are only added in the chemolysis reactor.
  • the chemolysis reagent is preferably added at a temperature which is in particular higher than the first temperature and is preferably in the range from 120°C to 240°C.
  • step (B1) which also belongs to the first alternative solution and which is shown in FIG. 2a, b is shown graphically, the entry device has a first lock area (121) (upstream of the chemolysis reactor), having a lockable feed device for the polyurethane foam (1) provided in step (A) and a lockable discharge device for the degassed polyurethane foam (2) , where in step (Bl) the following steps are run through: (BII.a) blocking off the discharge device of the first lock area, introducing polyurethane foam into the first lock area and blocking off the feed device of the first lock area;
  • first lock area In the simplest configuration of this embodiment, there is only one lock area; the wording "first lock area” therefore does not imply the inevitable presence of several lock areas.
  • the entry device has, in addition to the first lock area, a second lock area, which has a lockable feed device for the polyurethane foam provided in step (A) and a lockable discharge device for the degassed polyurethane foam, wherein in step (B.I.I.a ) a first subset of the polyurethane foam is introduced into the first lock area, with the following steps also being run through in step (B.l):
  • steps (B.I.I.a) to (B.l.4.a) are matched to steps (B.I.I.b) to (B.l.4.b) in such a way that continuously degassed polyurethane foam (2) is transferred to the chemolysis reactor.
  • FIG. 2a shows a lock (220) with a first (221) and a second lock area (222).
  • the second lock area (222) is constructed like the first; this is no longer shown in detail in the figure. Access to the second lock area (222) is closed. Polyurethane foam (1) is being filled into the first lock area (221). The first lock area (221) is closed towards the bottom (i.e. towards the chemolysis reactor). After completion of the filling process, as shown in the right half of FIG. 2a, the entrance to the first lock area (221) is closed.
  • the valve (510) associated with the gas discharge device (500) is opened and the pressure p1 is set by reducing the pressure (first step).
  • polyurethane foam (1) can be introduced into the second lock area (222).
  • the valve 510 is closed and the pressure p2 is set by adding an inert gas (3) through the valve 210 (left half of FIG. 2b).
  • Chemolysis reagent can also be supplied through the valve 210 .
  • the valves 210 and 510 are closed and the polyurethane foam (2), which has now been degassed and possibly wetted with chemolysis reagent, can be conveyed on to the chemolysis reactor (right half of FIG. 2b).
  • the chemolysis reagent can be added to the polyurethane foam not only in the chemolysis reactor, but also immediately after the second step (ie after the end of the degassing process), ie in the first and/or second lock area.
  • the added chemolysis reagent has a temperature which is in particular higher than the first temperature and is preferably in the range from 120.degree. C. to 240.degree. It is also possible to add the catalyst at this point (in particular as a solution in the chemolysis reagent).
  • the Polyurethane foam preferably wetted with this.
  • the addition of chemolysis reagent in the first and/or second lock area naturally does not preclude the addition of further chemolysis reagent and/or further catalyst in the chemolysis reactor.
  • the polyurethane foam can be introduced into the first or second lock area by vibration, mechanically or pneumatically.
  • the lock area fills with the polyurethane foam and is then closed. Vacuum is applied and the exhaust air valve is then closed again.
  • volatile compounds are sucked out of the cell structure of the foam and discharged via the gas discharge device.
  • the second pressure has been set by supplying an inert gas (in particular nitrogen, argon or helium)
  • the degassed polyurethane foam can be conveyed to the chemolysis reactor. Again, this can be done by vibration, mechanically or pneumatically, or simply as a result of gravity.
  • the apparent density of the polyurethane foam increases, as a result of which it can easily fall down into the reactor.
  • mixing of the polyurethane foam into chemolysis reagent already present in the chemolysis reactor is facilitated if the cell structure of the polyurethane foam already contains chemolysis reagent.
  • step (B.l) which also belongs to the first alternative solution and which is shown in FIG. 3 is shown graphically, the polyurethane foam is during the first step of (B.l) with adjustment of the first pressure (p1) to a value in the said range of 0.1 mbar (abs.) To 100 mbar (abs) by a in a first Part of the entry device (201) arranged device for mechanical comminution (230) and comminuted there, the second step being carried out in such a way that the polyurethane foam (11) present after the mechanical comminution is passed through a second part of the entry device ( 202) in an inert gas atmosphere (particularly in a nitrogen, argon or helium atmosphere) which is under the second pressure.
  • This promotion can take place by means of (at least) a screw shaft, (at least) a piston, (at least) a conveyor belt, vibration and/or gravity.
  • the device for mechanical comminution (230) can be, for example, a cutting mill, a knife mill, an impact crusher and/or a hammer mill.
  • the use of an impact crusher or a hammer mill is particularly preferred when the polyurethane foam is introduced into the chemolysis device in a frozen state becomes.
  • this embodiment of the third variant of the present invention makes it possible to include the mechanical comminution of the polyurethane foam, which is preferably to be carried out, at least partially in step (B).
  • the above-described mechanical comminution of the polyurethane foam in step (A) can be limited to coarse comminution of the polyurethane foam into pieces of manageable size, or can even be omitted entirely.
  • the first and second variants also applies correspondingly to the third variant with regard to the temperatures and pressures.
  • the pressures are also preferred in this embodiment of the third variant as described for the first and second variant, but the mechanical compression naturally takes place at a temperature below 0°C, in particular at temperatures of down to -20°C.
  • the chemolysis reagent can also be used in the third variant not only in the chemolysis reactor, but also immediately after the second step (i.e. after the end of the degassing process), i. H. are still given here in the second part of the entry device to the polyurethane foam.
  • the added chemolysis reagent has a temperature which is in particular higher than the first temperature and is preferably in the range from 120.degree. C. to 240.degree. It is also possible to add the catalyst at this point (in particular as a solution in the chemolysis reagent). If the chemolysis reagent is already added in the second part of the feed device, the polyurethane foam is preferably wetted with it.
  • the addition of chemolysis reagent in the second part of the feed device naturally does not preclude the addition of further chemolysis reagent and/or further catalyst in the chemolysis reactor.
  • the polyurethane foam is conveyed via a - preferably sealed as possible - conveyor, in particular a screw conveyor, to the device for mechanical comminution, which is under a maximum pressure of 100 mbar (abs), with volatile compounds largely being released during the mechanical comminution Compression processes are removed during shredding.
  • a mechanical comminution in step (B1) can optionally replace a mechanical comminution in step (A).
  • step (B1) which represents the second alternative solution and which is shown in FIG. 4, the polyurethane foam is conveyed during the first step to a mechanical compression device (240) arranged in the infeed device, wherein in the second step the polyurethane foam is transported in this mechanical compression device at a value for the second pressure p2 in the range of 5 bar(abs) to 200 bar(abs) is compressed.
  • the pressure p2 can be determined by means of a manometer (connected to a capillary protruding into the area of the feeding device where the device for mechanical compression is arranged). Making the polyurethane foam inert prior to mechanical compression is preferred, but not essential.
  • the pressure is at least S hares.), which is higher than the pressure preferred for step (B.II) (see the explanations further below).
  • the expansion to the pressure of step (B.II) preferably takes place when the polyurethane foam treated in step (B1) enters the chemolysis reactor.
  • chemolysis reagent (4) can be added, for example, after passing through the device for mechanical compression (ie after the end of the degassing process) and before entry into the chemolysis reactor (300) (see further below for further details).
  • the gas discharge device (500) is preferably arranged in the entry device (200).
  • a device (600) for discharging reaction gases formed during the chemolysis, such as in particular carbon dioxide, can be arranged in the chemolysis reactor (300).
  • a suitable device for mechanical compression is, for example, an extruder (also including multi-zone screws and single- and multi-screw extruders), a roller or a piston.
  • Multi-zone screws are extruders whose spiral has, for example, different diameters or pitches of the spiral windings. This promotes compression.
  • the chemolysis reagent can also be used in the fourth variant not only in the chemolysis reactor, but also immediately after the second step (i.e. after the end of the degassing process), ie here still in the entry device, but after passing through the device for the mechanical Compression to be given to the polyurethane foam.
  • the chemolysis reagent added has a temperature which is preferably in the range from 120.degree. C. to 240.degree. C., in particular in the range >120.degree. C. to 140.degree.
  • the polyurethane foam is preferably wetted with it.
  • the additions of chemolysis reagent of course, already in the entry device does not rule out that further chemolysis reagent and/or further catalyst is added in the chemolysis reactor.
  • the temperature for the second step is preferably in the range from -20 °C to 120 °C and corresponds in particular to the first temperature (i.e. there is no deliberate change in temperature during the transition 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. If the compounds to be removed are liquids under standard conditions (which does not preclude a significant vapor pressure), a lower temperature limit of 16 °C (in both steps) has proven useful.
  • the polyurethane foam is compressed, as a result of which gases and volatile compounds present in the cell structure of the polyurethane foam are forced out.
  • step (B.ll) of the method according to the invention the actual chemical recycling, the cleavage of the urethane bonds, takes place (which does not rule out that the reaction can already begin in part in the entry device, provided that the degassing is complete; see the above explanations Step (B.l)).
  • the chemolysis is carried out in an inert gas atmosphere (particularly in a nitrogen, argon or helium atmosphere).
  • the chemolysis reagent used is preferably also saturated after being freed of oxygen by inert gas saturation (regardless of whether this is added for the first time in the chemolysis reactor or already in the feed device).
  • step (B.ll) can be carried out by any method known in the art.
  • the chemolysis reactor in particular is partially filled with chemolysis reagent (and catalyst).
  • the polyurethane foam to be converted is introduced into this "bath" of chemolysis reagent.
  • the polyurethane foam can be fed in both above and below the liquid level.
  • step (B.II) is preferably carried out at a temperature in the range from 140° C. to 240° C., preferably from 160° C. to 240° C., particularly preferably from 180° C. to 220° C.
  • the pressure in step (B.II) is preferably >960 mbar(abs) to 1.8 bar(abs) and is in particular equal to ambient pressure (ie the reaction in step (B.II) is carried out). in particular operated without pressure).
  • the pressure in step (B.II) means the pressure prevailing in the gas space of the chemolysis reactor.
  • the addition of the chemolysis reagent occurs without the addition of significant amounts of water.
  • the chemolysis reagent in this case an alcohol
  • without the addition of significant amounts of water means that water is not deliberately added in such quantities that would bring about hydroalcoholysis to a significant extent. This does not rule out the entry of small amounts of water, which may be contained dissolved in the alcohol used in step (B.II), are introduced via the polyurethane foam or can be used as a solvent for the catalyst.
  • chemolysis is carried out as hydroalcoholysis
  • an alcohol and water are used as the chemolysis reagent, and these two components can, but do not have to, be premixed.
  • the chemolysis reagent preferably contains an alcohol selected from ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, methyl glycol, triethylene glycol, glycerol, 2-methyl-1,3-propanediol or a mixture of two or more of the aforementioned alcohols.
  • Diethylene glycol is particularly preferred.
  • a particularly suitable catalyst for step (B.II) is an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal salt of a carboxylic acid (especially an acetate), an alkaline earth metal salt of a carboxylic acid (especially an acetate), a Lewis acid (especially dibutyltin dilaurate, tin octoate, monobutyl tin oxide or tetrabutyl titanate) and/or an organic amine (especially diethanolamine, 1,1,3,3-tetramethylguanidine, 1,8-diazabicyclo(5.4.0)undec-7-ene or 1,4-diazabicyclo[2.2 .2]octane).
  • a Lewis acid especially dibutyltin dilaurate, tin octoate, monobutyl tin oxide or tetrabutyl titanate
  • organic amine especially diethanolamine, 1,1,3,3-tetramethylguan
  • Step (B.II) can be carried out in any reactor known in the art for such a purpose.
  • Stirred tanks (stirred reactors) and tubular reactors are particularly suitable as chemolysis reactors.
  • Step (B.ll) provides a first product mixture which contains unreacted chemolysis reagent (because it is used superstoichiometrically), polyols (originating from the polyol component and/or newly formed as degradation products during the reaction with the chemolysis reagent) and (depending on the chemolysis reagent used) carbamates and /or contains amines.
  • the excess chemolysis reagent comprises at least the alcohol used in the chemolysis and optionally (when the chemolysis is carried out as a hydroalcoholysis) water pure alcoholysis may be present in small amounts; see the explanations above.
  • This first product mixture is discharged from the chemolysis reactor in step (B.III) and then fed to further work-up (step (C), preferably step (C) and step (D)).
  • step (C) preferably step (C) and step (D)
  • a discharge device to be used for this purpose all devices known in the art for fluid delivery, such as in particular pumps, can be used.
  • step (C) of the process according to the invention the first product mixture obtained in step (B) is worked up to obtain the polyols.
  • this work-up can be carried out as known from the prior art.
  • An organic solvent is preferably first added to the first product mixture.
  • Various possible configurations are available for this:
  • step (C) in the preferred embodiments, with the chemolysis being carried out as an alcoholysis or hydroalcoholysis, this comprises the steps:
  • step (Cl) Mixing the first product mixture obtained in step (B.III), in particular without prior separation of any water present in the first product mixture, with an organic solvent which is not completely miscible with the alcohol used in step (B) (in particular a aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, or a mixture of two or more of the foregoing organic solvent) and phase separation into a first alcohol phase and a first solvent phase;
  • an organic solvent which is not completely miscible with the alcohol used in step (B) (in particular a aliphatic hydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, or a mixture of two or more of the foregoing organic solvent) and phase separation into a first alcohol phase and a first solvent phase;
  • Step (C.II) comprises work-up steps known to those skilled in the art, such as washing and distillation in particular.
  • step (C) in the preferred embodiments, with the chemolysis being carried out as an alcoholysis or hydroalcoholysis, this comprises the steps:
  • step (C.l*) mixing the first product mixture obtained in step (B.III) with an organic solvent which is miscible with the alcohol used in step (B) (in particular a halogen-substituted aliphatic hydrocarbon, a halogen-substituted alicyclic hydrocarbon, a Halogen-substituted aromatic hydrocarbon or a mixture of two or more of the aforesaid organic solvents), optionally followed by a separation of solid components to give a second product mixture;
  • an organic solvent which is miscible with the alcohol used in step (B) in particular a halogen-substituted aliphatic hydrocarbon, a halogen-substituted alicyclic hydrocarbon, a Halogen-substituted aromatic hydrocarbon or a mixture of two or more of the aforesaid organic solvents
  • step (C.ll*) Washing of the second product mixture obtained in step (C.l*) with an aqueous washing liquid (whereby any carbamates present in the second product mixture are partially hydrolyzed with release of amines and alcohol) and phase separation into a first solvent phase containing in step (C.l *) organic solvents and polyols used, and a first aqueous phase containing water, alcohol, carbamates and amines;
  • Step (C.III*) in turn comprises work-up steps known to those skilled in the art, such as, in particular, washing and distillation.
  • An extraction of the first product mixture with an organic solvent can of course also be carried out when carrying out the chemolysis as a pure hydrolysis.
  • the process according to the invention preferably comprises a step (D) for obtaining at least one amine which corresponds to an isocyanate of the isocyanate component.
  • the starting point for this part of the work-up is the alcohol phase or first aqueous phase obtained from the first product mixture in step (C).
  • step (D) depends in particular on the way in which step (B.II) is carried out. If step (B) is carried out as an alcoholysis, the first alcohol phase or the first aqueous phase will regularly still contain substantial proportions of carbamates which have to be hydrolyzed in step (D). Such a hydrolysis is advantageously carried out catalytically, with the same catalysts as described above being suitable for the chemolysis.
  • step (B.II) is carried out as a hydroalcoholysis, then at this point in the process there are no longer any carbamates present (or at most in insignificant trace amounts), so that a separate hydrolysis step can be dispensed with.
  • step (D) comprises work-up steps, such as in particular a distillation, in order to purify the amine obtained by cleaving the urethane bonds. It is particularly advantageous here to integrate the insulation of amines recovered from a polyurethane foam into a process for producing new amines, as described in WO 2020/260387 A1 and the as yet unpublished patent application PCT/EP2021/075916.
  • Example 1 (according to the invention, first variant):
  • Example 2 the reaction mixture was clearly black, while the previously degassed polyurethane foam (Example 1) was only slightly brown. This clearly shows the influence of the oxygen contained in the cell structure of the polyurethane foam through significantly increased oxidation of the toluenediamine compounds released during glycolysis.

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  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé de récupération de matières premières à partir d'une mousse de polyuréthane, comprenant l'étape (A), la fourniture d'une mousse de polyuréthane à base d'un constituant isocyanate et d'un constituant polyol, la mousse de polyuréthane comprenant une structure cellulaire contenant une ou plusieurs substances d'accompagnement volatiles, à savoir un constituant X sélectionné dans le groupe constitué de l'oxygène, d'un agent d'expansion, d'un agent désinfectant et d'un mélange de deux ou plusieurs de ceux ci-dessus, le constituant X comprenant au moins de l'oxygène, l'étape (B), la chimiolyse de la mousse de polyuréthane avec un réactif de chimiolyse, la mousse de polyuréthane étant dégazée avant d'être mise en contact avec le réactif de chimiolyse, au moins l'oxygène, mais préférablement tous les constituants du constituant X ou n'importe lesquels de ses produits de dégradation gazeuse qui ont été formés sont retirés de l'appareil de chimiolyse sous la forme gazeuse par l'intermédiaire d'un dispositif d'élimination de gaz à une pression non supérieure à 960 mbar(abs.) et une température non supérieure à 120 °C, afin d'obtenir une mousse de polyuréthane dégazée, suivi de la réaction de la mousse de polyuréthane dégazée avec le réactif de chimiolyse en la présence d'un catalyseur sous une atmosphère de gaz inerte et la préparation du mélange de produits obtenu par la chimiolyse, l'étape (C), l'obtention d'au moins un polyol, et éventuellement l'étape (D), l'obtention d'au moins une amine correspondant à un isocyanate du constituant isocyanate.
EP21824402.8A 2020-12-14 2021-12-13 Procédé de récupération de matières premières à partir de mousses de polyuréthane Pending EP4259686A1 (fr)

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EP20213874 2020-12-14
EP21203752 2021-10-20
PCT/EP2021/085405 WO2022128871A1 (fr) 2020-12-14 2021-12-13 Procédé de récupération de matières premières à partir de mousses de polyuréthane

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WO2023241927A1 (fr) * 2022-06-14 2023-12-21 Basf Se Procédé de récupération de matières premières à partir d'un matériau de polyuréthane
EP4345094A1 (fr) 2022-09-30 2024-04-03 Covestro Deutschland AG Procédé de production de phosgène avec recyclage du dioxyde de carbone issu du recyclage de matière de valeur

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2442387C3 (de) 1974-09-04 1981-09-10 Bayer Ag, 5090 Leverkusen Verfahren zur kontinuierlichen hydrolytischen Aufspaltung von hydrolysierbaren Kunststoffabfällen
DE2951617C2 (de) 1979-12-21 1985-08-14 Wilhelm Prof. Dr.-Ing. 5100 Aachen Schütz Verfahren und Anlage zur Aufbereitung von Polyurethan
DE3232461A1 (de) 1982-09-01 1984-03-01 Bayer Ag, 5090 Leverkusen Verfahren zum kontinuierlichen glykolytischen hochtemperatur-abbau von polyurethankunstoffabfaellen in schneckenmaschinen
DE19719084A1 (de) 1997-04-30 1998-11-05 Gerhard Prof Dr Behrendt Verfahren zur Herstellung von Polyolen aus Polyurethanabfällen und durch dieses Verfahren erhältliches Polyol
DE10313150A1 (de) 2003-03-17 2004-09-30 Behrendt, Gerhard, Prof. Dr. Verfahren und Vorrichtung zur Herstellung von Recyclat-Polyolen aus Polyurethanen
CN106279760A (zh) 2016-08-12 2017-01-04 成都威迪斯达科技有限公司 一种废旧聚氨酯的回收处理工艺
CN113993928A (zh) 2019-06-27 2022-01-28 科思创德国股份有限公司 从聚氨酯产品中回收原材料的方法

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