Method and arrangement for recycling a polyurethane (PU) foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material

Abstract

The invention is directed to a method and arrangement for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material in a process, the process comprising the steps of: - mechanically pre-processing the PU material to provide a PU particulate material, - feeding the PU particulate material into a reactor arrangement, and - chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU material. According to the invention - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and - the reactor arrangement comprises at least one reactor. According to the invention therein chemically processing of the PU particulate material comprises the steps of: - feeding the PU flexible-particulate material into a reactor of the reactor arrangement and chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor to provide a PU slurry material, wherein the alcoholysis is effected using a diol, and - chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

Description

[0001] BASF SE

[0002] Carl-Bosch-StraBe 38, 67056 Ludwigshafen am Rhein

[0003] Germany

[0004] Method and arrangement for recycling a polyurethane (PU) foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material

[0005] The present invention is directed to a method and arrangement for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU from said PU material in a process. The present invention also leads to a PU slurry material.

[0006] Said process of recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material comprises the steps of:

[0007] - mechanically pre-processing the PU material to provide a PU particulate material,

[0008] - feeding the PU particulate material into a reactor arrangement, and - chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam.

[0009]

[0010] Therein

[0011] - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and

[0012] - the reactor arrangement comprises at least one reactor.

[0013] In the arrangement for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU foam from said PU material in a process arrangement, the process arrangement comprises:

[0014] - a pre-processing arrangement for mechanically pre-processing the PU material to provide a PU particulate material,

[0015] - a feeding arrangement feeding the PU particulate material into a reactor arrangement, and

[0016] - a chemical processing arrangement for chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam, wherein

[0017] - the PU particulate material is provided from the pre-processing arrangement as a PU flexible-particulate material, and

[0018] - the reactor arrangement of the chemically processing comprises at least one reactor.

[0019] Currently, in the field of polyurethane (PU) material recycling, in particular PU foam material, innovative alternatives are being developed and deployed that are categorized as chemical recycling (vs. only mechanical recycling).

[0020] Chemical recycling will take a plastic resin back to its base state - for instance in the case of polystyrene foam (PS foam), back to a styrene monomer, or in the case of polyurethane foam (PU foam) back to the raw materials pf aromatic diisocyanates (e.g. TDI, MDI) and polyol. TDI is typically used to make flexible polyurethane foam for furniture, bedding, carpet underlay and other products. MDI is primarily used to make rigid polyurethane foams used as insulation for homes, but may also be present in flexible foam formulations. An example of typical preprocessing steps for foam recycling, in particular for polystyrene foams, are sum-

[0021]

[0022] marized in the website https: / / www.recyclefoam.org / about-foam-recycling (Available as received on 06-06-2024 at Internetsite of Foodservice Packaging Institute (FPI)).

[0023] Foam residues are either placed in the same container as other recyclables or are taken to a dedicated drop-off center. From there, the recyclables are delivered to a sorting facility or material recovery facility (MRF) where the foam is either separated from other recyclables (mechanically or manually) or are kept separated from the other recyclables. The foam pieces are delivered to a grinder or shredder from where they are transferred to a densifier or a press, where the loose foam elements are compacted for storage or transportation to the recycling facility. Another example of the steps of a pre-processing method for a polystyrene foam mix can be found in the website https: / / www.homeforfoam.com / recy-cling.

[0024] In a mechanical recycling process, the foam pieces or elements are typically mixed with a binding agent and the mixture is steamed and pressed, for instance in a cylindrical press, a process with is antibacterial and actives the binding agent. After the pressed cylinder has dried, it can be peeled to a desired thickness. The rolls are ultimately cut to size into a recycled foam product, for instance as fall absorbing plates or sound or heat isolating material.

[0025] Polyurethane is one of the most important materials of the wide-ranging and diverse family of polymers and plastics. It can be solid or have an open cellular structure. In this case it is referred to as foam. Foams, in turn, can be flexible or rigid. Polyurethane is typically manu-factured by reacting raw materials of polyols and diisocyanates, both products derived from crude oil. A series of additives are then added to produce high-quality PU foam products. The nature of the additives depends on the application the foam will be used for, which include, among others, bedding, furniture, and automotive.

[0026] In the case of flexible PU-foam, the main application for mechanical recycling is re-bounded foams, e.g. for carpet underlays. Mainly post industrial waste, rather than post costumer waste, flex foams are shredded, and the single pieces are

[0027]

[0028] glued together with a PU-adhesive and pressed to form a carpet underlay. Mechanical recycling processes are described, for instance, in documents US 5,290,818 A, US 6,136,870 A or US 9,410,026 B1.

[0029] The brochure “The end-of-life of flexible polyurethane foam from mattresses and furniture. An overview of regulatory drivers, recycling technologies and remaining challenges” issued by the European Association of Flexible Polyurethane Foam Block Manufacturers (https: / / europur.org / wp-content / uploads / 2022 / 04 / EoL-Bro-chure-2021-EUROPUR.pdf), August 2021, in particular in Part II, addresses the evolution of recycling technologies, namely mechanical recycling, chemical recycling and thermochemical recycling.

[0030] The scientific publication by M. Grdadolnik et al. titled Insight into Chemical Recycling of Flexible Polyurethane Foams by Acidolysis, ACS Sustainable Chem. Eng. 2022, 10, 3, 1323-1332 describes an exemplary chemical recycling process for polyurethane foams. Other examples of chemical recycling processes are disclosed, for instance in documents DE 102016 122275 A1, DE 102013 106364 A1 , WO 2021 / 023889 A1 , and US 2022 / 0251328 A1 .

[0031] A typical chemolysis process for chemical recycling of PU foam in general is basically DE 43 16389 A1 and as described in detail in US 2008 / 0132591 A1 and US 5,908, 894.

[0032] WO 2023 / 083968 A1 relates to a method for recovering raw materials -generally- from polyurethane products, said method having a chemolysis process. The chemolysis process is characterized in that the polyurethane products are reacted with (i) an aminic chemolysis reagent selected from (a) a primary or secondary organic amine, (b) an amino alcohol with a primary or secondary amino group, or (c) a mixture of (a) and (b) and (ii) water in the presence of (iii) a catalyst at a temperature ranging from 100 °C to 195 °C and at a pressure ranging from 900 mbar (abs) to 2000 mbar (abs), wherein the mass ratio of aminic chemolysis reagent and water to the polyurethane product ranges from 0.5 to 2.5, and the mass of the water ranges from 3.0% to 22% of the mass of the aminic chemolysis reagent.

[0033]

[0034] DE 10 2020 129636 A1 relates to a metering screw arrangement for the metered introduction of polyurethane in general into a reactor within a continuous process, in particular into a reactor for recycling polyurethane, having a metering screw, which has a screw spiral, and a housing for receiving the metering screw, the housing having an inlet and an outlet for discharging the polyurethane into the reactor. According to the continuous process of DE 10 2020 129636 A1 , it is proposed that the metering screw arrangement is set up to compress the polyurethane, wherein a degree of compression based on the volume of the polyurethane when introduced into the metering screw arrangement compared to the volume of the polyurethane when leaving the metering screw arrangement is 1.1 :1 to 7:1 , in particular 1.2:1 to 5:1 .

[0035] In a contemporary concept, feeding of PU into a main reactor is of specific interest only for supporting a continuous procedure of PU recycling like in DE 103 13 150 A1 . Therein the mixing of the components, the mechanical comminution of the polyurethane and the chemical reaction are carried out in a single-shaft or multi-shaft mixing / kneading reactor in which the agitator shafts rotate essentially horizontally, intensively mix the liquid and solid reactants by means of suitable kneading elements or blades and transport them essentially in a plug-flow-like manner through one or more processing zones in the direction of the discharge.

[0036] Therein an apparatus for the continuously operating process consists, for example, of the following elements: 1 . metering devices for the reaction components (polyurethane waste, one or more glycols, one or more aliphatic amines, oligoester condensate from polyester production), 2. a reactor with an inlet zone, a feed zone, and a feed zone for the reaction components (polyurethane waste, one or more glycols, one or more aliphatic amines, oligoester condensate from polyester production). A reactor with feed zone, comminution, dissolution and mixing zone, main and optionally post-reaction zone and discharge zone, 3. optionally an integrated device for distillation under reduced pressure, 4. a discharge and optionally filtration device (for separating foreign bodies such as sand, metal parts, etc.) for the product, 5. a heating unit, 6. a control unit.

[0037] Therein, the metering devices are adapted to the properties of the components to be conveyed. For example, in a preferred embodiment, a tearing screw and a

[0038]

[0039] tamping screw can be mounted on the reactor for the comminution and conveying of flexible polyurethane foam. In a preferred embodiment, the compressed flexible foam is fed below the filling level of the liquid reaction material in the reactor chamber in the axial or tangential region in the area of the downward movement of the kneading and agitating elements of the reactor shaft in the operating state.

[0040] However, it turns out that a step-by-step chemolysis process for chemical recycling of PU material, in particular PU foam material, is more promising than a continuous procedure; thus, the restraints in conveying and feeding as indicated above are mood for a step-by-step chemolysis process for chemical recycling of PU foam.

[0041] In KR10-2023-0110849 a “one-step-process” for producing regenerated polyol from waste polyurethane is described and also a method for producing regenerated polyurethane containing the same. The “one-step-process” relates to a method for producing a recycled polyol from waste polyurethane, comprising the step of: subjecting waste polyurethane to a glycolysis reaction to regenerate a polyol, and using a polyol, which is a raw material of the waste polyurethane, as a depolymerization agent in the glycolysis reaction. Accordingly, the method for producing a recycled polyol from waste polyurethane comprises the step of introducing a long-chain polyol, which is an initial raw material of polyurethane foam, into a glycolysis depolymerization agent and recycling it through the glycolysis method. Thereby a one-phase product is created. Also thereby the process by omitting the separation step is simplified and the deterioration of physical properties of the foam that occurs when using polyols such as diethylene glycol or dipropylene glycol in the past is prevented.

[0042] In WO 2022 / 128871 A1 a developed process for recovering raw materials from a polyurethane foam is described. The developed process comprises in a step (A), the providing of a polyurethane foam based on an isocyanate component and a polyol component, wherein the polyurethane foam comprises 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

[0043]

[0044] a mixture of two or more of the above, wherein component X comprises at least oxygen; and ina step (B), the chemolysis of the polyurethane foam with a chemolysis reagent. Wherein the polyurethane foam is degassed before being contacted with the chemolysis reagent, wherein at least oxygen, but preferably all constituents of component X or any gaseous breakdown products thereof that have formed are removed from the chemolysis apparatus in gaseous form via a gas removal.

[0045] This approach of degassing is one aspect, but not sufficiently elaborated with regard to a total overall typical chemolysis process for PU recycling.

[0046] A promising approach is described in WO 2023 / 078802 A1 which provides a new method for recycling of polyurethane, in particular polyurethane foam, via solvolysis.

[0047] The method includes a pre-treatment method of the polyurethane, wherein it is converted into a polyurethane dispersion. The inventors surprisingly found out, that the problems of the present invention can be solved by a process composing the steps

[0048] a. Providing a polyurethane material, preferably a polyurethane foam material, b. Preparing a dispersion from the polyurethane material,

[0049] c. Solvolysis of the polyurethane dispersion, preferably carried out as alcoholysis, aminolysis, amonolysis, hydrolysis or acidolysis, of the dispersion,

[0050] if the polyurethane to be dispersed has an average particle size of 0.1 to 12 mm, and if the polyurethane content in the dispersion after step b. and / or the dispersion used for step c. is in a range of from 4 to 20 % by weight.

[0051] The high surface polyurethane powder of WO 2023 / 078802 A1 is converted to a dispersion before being subjected to solvolysis. Preparing the dispersion can be done under mild conditions, for example at ambient pressure and temperature, thus, it does not have any respectively it does have only very low negative impact on the external surface of the polyurethane powder The resulting polyurethane dispersion of the invention can be dosed precisely into a reactor and avoids the above discussed problems with dry polyurethane powders, which floated on the

[0052]

[0053] reaction solution. Beside of the precise dosing, a very efficient and fast mixing of the polyurethane dispersion with the reaction mixture is possible. In summary, that process therefore leads to short reaction time, high yields of polyol and allows very efficient and precise feeding of polyurethane into a reactor.

[0054] To obtain a particular stable polyurethane dispersion in view of segregation and / or wetting of the particles, in WO 2023 / 078802 A1 it is preferred that the polyurethane powder is to be dispersed, i.e. dispersed as mentioned therein in step b2. In the described process particles have an average particle size of preferably 0,2 to 4 mm more preferred 0,5 to 2 mm. Dispersions obtained from such polyurethane particles have shown to be storage stable over a long period of time even if, after the long period of time, segregation takes place, in particular in dispersion made from the polyurethane particles obtained after step b1 as mentioned therein, i.e. those with the fully open structure; the particles were found to be still very well wetted. Preferably therein a liquid or a mixture of a liquid and other components, which is / are used as reactant and / or solvent in the solvolysis step c. or a solvolysis reaction product of step c, such as recycling polyol, is used as dispersing medium in step b. respectively b2. More preferred the liquid or a mixture of the liquid and other components is selected from the group consisting of water, organic solvents, preferably selected from the group consisting of polyol, recycling polyol, glycol, glycerin, toluene diamine and mixtures thereof, a mixture comprising a base and water and / or a base and an organic solvent as defined before, preferably an aqueous solution of a base, more preferred an aqueous solution comprising a base as defined further below and water.

[0055] This approach aims for mild conditions, for example at ambient pressure and temperature, thus, it aims to preserve the high surface polyurethane powder and does not have any respectively it does have only very low negative impact on the external surface of the polyurethane powder. Examples for mild conditions of dispersing are preparation of an aqueous dispersion, preparation of a dispersion in aqueous potassium carbonate solution, preparation of a dispersion in aqueous potassium carbonate solution, preparation of a dispersion in aqueous potassium carbonate solution by means of recirculation, hydrolysis of polyurethane snow dispersion.

[0056]

[0057] However, even this available new pre-processing method of WO 2023 / 078802 A1 which includes a very efficient pre-treatment method of the polyurethane, wherein it is converted into a polyurethane dispersion has disadvantages, as it starts from using powders. This is often not feasible and also alternatives of a powder seem more prosperous as a starting base for typical chemolysis process for chemical recycling of PU foam. Further, dispersed PU powder from a pre-treatment as an educt has limitations in supporting the chemolysis process for PU recycling.

[0058] In the document US 2021 / 0017354 A1 (as mentioned in said WO 2023 / 078802 A1) a process for PU recycling starting with an acidolysis followed by a glycolysis is described to improve efficiency of the chemical recycling. Shredded PU having a size of 2x2x2 cm was added to an acidolysis mixture comprising polyethertriol, phthalic acid, maleic acid, acrylic acid and a radical starter until a reaction mixture comprising 40 % by weight PU was obtained. The process of US 2021 / 0017354 A1 still is inefficient because of the number of process steps and reactants needed. The high PU content causes that the wetted PU cannot be pumped like liquids or dispersions as well as that mixture comprises a low amount of heat transfer medium. As consequence long reaction times, e.g. more than 3 hours in the examples of US 2021 / 0017354 A1, are needed. Another consequence was incomplete conversion of the PU leading to insufficient productivity of the process.

[0059] It seems that a pre-processing method for the PU as such is promising, still however, up to date, suggestions are conflicting with either the structure of available PU particulate starting material and / or with the needs of the follow-up chemolysis process for PU recycling, respectively also the mechanical aspects of feeding and conveying to the main reactor related therewith. Thus, an approach of a chemolysis process for PU recycling with a pre-treatment for the PU is still to be improved, wherein the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material. Also a developed process with more than one step in the chemolysis process for recovering raw materials has the potential to improve product quality.

[0060]

[0061] It is therefore an object of the present invention to provide a method and apparatus for a pre-treatment method of the polyurethane, wherein it is converted into a Pll educt of improved kind before the chemolysis process for chemical recycling of PU flexible-particulate material. It is therefore a more specific object of the present invention to provide a method and apparatus for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU foam from said PU material in a process as mentioned in the introduction and wherein the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material. Further it should be intended in the mechanically pre-processing of the PU material that it is converted into a PU educt of improved kind before the chemolysis process for chemical recycling of the PU material, i.e. to provide a PU educt of improved kind for the chemically processing of the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam.

[0062] According to a first aspect of the present invention, the object is achieved by the method of claim 1.

[0063] The invention in the first aspect is directed to a method of recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material in a process.

[0064] Said process comprises the steps of:

[0065] - mechanically pre-processing the PU material to provide a PU particulate material,

[0066] - feeding the PU particulate material into a reactor arrangement, and

[0067] - chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU material.

[0068] In said process

[0069] - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and

[0070] - the reactor arrangement comprises at least one reactor.

[0071]

[0072] Therein according to the invention the chemically processing of the PU particulate material comprises the steps of:

[0073] - feeding the PU flexible-particulate material into a reactor of the reactor arrangement and chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor to provide a PU slurry material, wherein the alcoholysis is effected using a diol, and

[0074] - chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0075] According to a second aspect of the present invention, the object is achieved by a PU slurry material of claim 14, received from chemically pre-processing a PU flexible-particulate material by alcoholysis in a reactor to provide the PU slurry material in a method of the concept of the invention.

[0076] According to a third aspect of the present invention, the object is achieved by the arrangement of claim 15.

[0077] The arrangement is adapted for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU foam from said PU material in a process arrangement. In particular therein the arrangement is adapted to execute the method of the invention. The invention starts from the process arrangement comprising:

[0078] - a pre-processing arrangement for mechanically pre-processing the PU material to provide a PU particulate material,

[0079] - a feeding arrangement for feeding the PU foam particulate material into a reactor arrangement, and

[0080] - a chemical processing arrangement for chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam.

[0081]

[0082] In said arrangement the PU particulate material is provided from the pre-processing arrangement as a PU flexible-particulate material, and according to the invention the reactor arrangement of the chemically processing comprises at least one reactor.

[0083] According to the invention, further:

[0084] a reactor of the at least one reactor is adapted for chemically pre-processing the PU flexible-particulate material by alcoholysis to provide a PU slurry material, wherein the alcoholysis is effected with a diol,

[0085] - wherein a reactor of the at least one reactor is adapted for chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0086] The invention starts from the consideration that a problem is related with the result of a mechanical preparation of PU flexible-particulate material in mechanically pre-processing the PU material when an efficient follow-up pre-processing and chemolysis process is of interest.

[0087] Namely, in particular, particulate PU material in the form of PU flexible-particulate material has a very low density, i.e. a density of 20-40 kg / m3. Thus comminuted PU flexible-particulate material is provided preferably in flakes and of low bulk density; advantageously of a flake size with dimensions of below 80mm and / or a bulk density of 15-25 kg / m3or the like.

[0088] Thus the invention recognized that large volumes are required e.g. for storage tanks and bunkers. Subsequently, a problem arises when the required material quantity (in particular mass) must be fed into a reaction vessel of a reactor arrangement, as a very large and thus uneconomical reactor volume is required when the PU flexible-particulate material would be preset to the reactor arrangement.

[0089] The invention starts from the consideration that in particular it turns out that a problem is related with the reactor of solvolysis, which is usually designed as a

[0090]

[0091] pressurised reactor. Metering and / or dosing than has to be carried out with a corresponding overpressure into the reactor if the volume reduction is to take place through the solvolysis as a hydro-glycolysis and the ongoing hydro-glycolysis in the pressurised reactor itself.

[0092] This would generally require the use of a complicated shear- or pressure apparatus (extruder / compounder). The use of an extruder however has not only an economical disadvantage but also a lot of technical challenges.

[0093] According to the invention it is advantageous related with the above aspects, when the feeding arrangement has a first feeding device for feeding the Pll foam flexible-particulate material into the at least one reactor of the reactor arrangement.

[0094] The invention and its developments thus provide a new flexible polyurethane foam recycling process and also has a high economic advantage. Feeding and dosing the PU flexible-particulate material to the first reactor is less complicated and can be improved in various aspects related to the specific demands of alcoholysis in the reactor arrangement, in particular in a first reactor, namely a nonpressurized reactor, of the reactor arrangement or in one reactor operated in a first state, namely a non-pressurized state.

[0095] This is in particular true in that the process does not require an extremely large and thus expensive pressure reactor or expensive shearing equipment; shearing equipment’s like an extruder for feeding / dosing under pressure is avoided. Respectively volume and energy consumption in the process is reduced.

[0096] Therein, the at least one reactor of the reactor arrangement is adapted for an improved chemically pre-processing of the PU flexible-particulate material by alcoholysis to provide a PU slurry material.

[0097] The solvolysis in the chemical processing of the PU slurry material is also adaptable for an improved hydro-glycolysis effected with diethyleneglycole (DEG) as a

[0098]

[0099] first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0100] In the following, developments and definitions to the method of the first aspect of the invention will be described.

[0101] Preferably, the PU material is a PU foam material, the PU particulate material is a PU foam particulate material, and the PU flexible-particulate material is a PU foam flexible-particulate material. PU-f lexible particulate material is also referred to as PU flakes.

[0102] In a preferred development, the alcoholysis is a glycolysis that is effected with di-ethyleneglycole (DEG) as a solvent of the glycolysis.

[0103] Preferably the solvolysis in the step of chemically processing the PU slurry material is effected in the presence of a catalyst agent, in particular a catalyst agent comprising an amine corresponding to the isocyanate component of the PU material.

[0104] Preferably for chemically pre-processing the PU flexible-particulate material by alcoholysis to provide a PU slurry material, wherein the alcoholysis is effected with a diol, the alcoholysis, in particular glycolysis, is carried out without catalyst agent. Preferably, the solvolysis in the step of chemically processing the PU slurry material is effected in the presence a catalyst agent, in particular a catalyst agent comprising an amine corresponding to the isocyanate component of the PU material. Preferably, the catalyst agent comprises the amine corresponding to the isocyanate component of the PU material, such as, for example, toluenediamine (TDA).

[0105] In a particular preferred development, the alcoholysis is a glycolysis. Additionally or alternatively, it is preferred that the alcoholysis, in particular the glycolysis, in the step of chemically pre-processing the PU flexible-particulate material is effected using the diol as a solvent for the alcoholysis, in particular a first solvent of the solvolysis. Preferably therein the diol is in form of a diol agent, the diol agent

[0106]

[0107] comprising the diol in form of a, in particular polymeric, polyol or re-polyol as a solvent for the alcoholysis. The first solvent of the solvolysis, in particular the diol in form of a diethyleneglycole (DEG), is used as a solvent for the alcoholysis and the first solvent of the solvolysis.

[0108] Preferably the reactor arrangement comprises a number of reactors, wherein the at least one reactor is one reactor or a multitude of reactors. In a preferred development the reactor arrangement comprises the reactor as one reactor or the reactor arrangement comprises the reactor as one of a number of reactors, in particular wherein the reactor arrangement comprises at least a first reactor and a second reactor.

[0109] In a preferred development in the reactor arrangement the reactor is one reactor wherein the one reactor is operated in the alcoholysis, in particular in the glycolysis, in a non-pressurized operation condition and is operated in the solvolysis in a pressurized operation condition.

[0110] In particular therein the reactor arrangement comprises the at least one reactor as a single reactor. Thus the one reactor can be single reactor; this includes only one reactor in the meaning of a single reactor, wherein no further reactor is used. The chemical pre-processing is performed first, for obtaining a slurry material, in the reactor and then the same reactor is used for the subsequent chemical processing.

[0111] However, preferably the reactor arrangement comprises at least one reactor or more reactors of same kind, which are each operated on an alternating mode but in a parallel operation. In a development two pressurized reactors are provided, which are then operated in an alternating A / B mode. This means that both reactors are operated "open" and "closed" and the time factor remains the same as when using an "open" and "closed" reactor. The use of two separate units -each of the same kind of reactor- has the advantage that there is sufficient time for dosing by the pneumatic air conveyor as this is the time-limiting step.

[0112]

[0113] ln an alternative preferred development the reactor arrangement comprises at least a first reactor and a second reactor, in particular wherein the reactor arrangement comprises at least a first reactor and a separate second reactor wherein the operation is set in a continuous sequential throughflow of initially the first reactor for the glycolysis reaction and thereafter the second reactor for the hydro-glycolysis reaction. Generally therein the first reactor is operated in the alcoholysis, in particular in the glycolysis, in a non-pressurized operation condition and is operated in the solvolysis in a pressurized operation condition.

[0114] In particular in the aforementioned preferred development

[0115] - the PU flexible-particulate material is fed into the first reactor of the reactor arrangement for chemically pre-processing the PU flexible-particulate material and providing the PU slurry material; and

[0116] - the PU slurry material is fed into the second reactor of the reactor arrangement for chemically processing the PU slurry material in the solvolysis.

[0117] Thus in a particular preferred development, the reactor arrangement comprises a first reactor and a second reactor, which is connected to the first reactor. In this particular development, the PU flexible-particulate material is fed into the first reactor of the reactor arrangement for chemically pre-processing the PU flexibleparticulate material and providing the PU slurry material; and the PU slurry material is then fed into the second reactor of the reactor arrangement for chemically processing the PU slurry material in the solvolysis.

[0118] Feeding the PU slurry material from the first reactor into the second reactor is also less complicated and can be improved in various aspects related to the specific demands of the solvolysis as a hydro-glycolysis in the second reactor. Feeding the PU flexible-particulate material into the first reactor of the reactor arrangement is less complicated, as the alcoholysis, or preferably, the glycolysis in the first reactor needs no pressurizing.

[0119] Preferably the feeding of the PU slurry material into the second reactor comprises:

[0120]

[0121] - conveying the PU slurry material from the first reactor by a conveying arrangement, in particular by a conveying arrangement comprising a piping system, - dosing the PU slurry material in the piping system to the second reactor, in particular by a dosing arrangement comprising feeding and / or dosing pump.

[0122] Further the metering and / or dosing of the PU flexible-particulate material can be improved and has less restrictions as compared to feeding to a pressurized reactor; thus metering and / or dosing of the PU flexible-particulate material into the first reactor can be improved in various aspects related to the specific demands of the low density and dimensions of the PU flexible-particulate material as such and also the alcoholyis, or, preferably, the glycolysis.

[0123] The glycolysis is, in effect, a transesterification reaction between the ester part of the urethane group of the PU material and the hydroxyl groups of a glycolytic agent to produce mixed structure polyols comprising the original glycols and isocyanate.

[0124] Preferably the chemically pre-processing of the PU particulate material, or the PU foam particulate material, is a glycolysis with diethyleneglycole (DEG) as the only solvent of the glycolysis. More particularly basically the glycolysis is carried out without aqueous agent. Additionally or alternatively the glycolysis is carried out without catalyst agent.

[0125] In other words the glycolysis in the chemical pre-processing of the PU flexibleparticulate material, for instance in the first reactor, as a first reaction, is mainly a glycolysis and only the second reaction in the second reactor is a hydro-glycolysis, wherein water is added in the second reactor. Preferably the hydro-glycolysis is carried out in the presence of an amine corresponding to the isocyanate component of the PU material (e.g., TDA) as catalyst. Preferably only the second reactor is a pressure reactor.

[0126] However, in some cases, water that is incorporated or accumulated in the PU material, for instance in the PU foam cells of PU foam material is also introduced into the glycolysis by the PU material dosage. Although this is not considered an

[0127]

[0128] intentional addition of water as required for the hydro-glycolysis of the chemical processing of the PU slurry material this effect can advantageously be taken into account with the hydro-glycolysis of the chemical processing.

[0129] Adding diethyleneglycole (DEG) in the chemical pre-processing step has the advantage that this component is part of the chemical recipe for the solvolysis in the subsequent chemical processing step that involves the solvolysis.

[0130] Additionally, or alternatively, the chemical pre-processing of the PU particulate material is a glycolysis with other glycols, polyethers or polyethylenglycols (PEG), preferably with a molar mass from in a range from 1 to 10000 g / mol, in addition to, or in alternative to, diethyleneglycole (DEG) as the solvent of the glycolysis. In particular the chemical pre-processing may include low molecular weight polyalkylene diols, diethyleneglycol, triethyleneglycol, tetraethyleneglycol, pentaethyleneglycol or mixtures thereof, preferably in the molecular weight range from 180 to 800, such as, for example, monoethyleneglycole (MEG) or triethy-leneglycole (TEG) as the solvent of the glycolysis. Thus, other glycols are possible as solvent, e.g., monoethyleneglycole (MEG) or triethyleneglycole (TEG), but not necessarily feasible for the chemical processing step involving the solvolysis, which is effected with DEG as a first solvent.

[0131] Preferably the solvolysis is a hydro-glycolysis, wherein water as the second solvent in the second reactor. In particular therein the second reactor has a pressurized vessel reactor. Optionally a catalyst agent is added in the second reactor. The catalyst agent comprises an amine corresponding to the isocyanate component of the PU material.

[0132] The materials obtained from the solvolysis in the reactor arrangement, i.e. the raw materials for the fabrication of recycled PU foam, preferably comprise an amine corresponding to the isocyanate component of the PU material (e.g., TDA) and / or polyol. In particular the raw materials obtained by chemically processing the PU slurry material comprise aromatic diisocyanates (e.g. TDI, MDI) and polyol.

[0133]

[0134] Even further advantageous developments of the invention are found in the dependent claims and indicate in detail advantageous possibilities to realize the concept described above within the scope of the object as well as with regard to further advantages.

[0135] In a particular preferred development it is advantageous that

[0136] - the reactor arrangement, in particular a first reactor, is adapted to have the PU particulate material being chemically pre-processed by alcoholysis, or glycolysis, at atmospheric pressure, in particular without a pressure control, and / or

[0137] - the reactor arrangement, in particular a second reactor of the reactor arrangement that is connected to the first reactor, is adapted to have the PU slurry material being chemically processed by solvolysis as a hydro-glycolysis at raised pressure above atmospheric pressure, in particular with a pressure control.

[0138] In a particular preferred further development it is advantageous that

[0139] - the reactor arrangement, in particular a first reactor arrangement, comprises one or more stirred reactor vessel for chemically pre-processing the PU flexibleparticulate material and / or the reactor arrangement, in particular a second reactor arrangement connected to the first reactor arrangement, comprises one or more pressure tight reactor vessel, and / or

[0140] - the reactor arrangement, in particular the first reactor arrangement, comprises a e first reactor vessel of first raised temperature and the reactor arrangement, in particular the second reactor arrangement comprises a second reactor vessel of second raised temperature.

[0141] Preferably, the dosing is carried out under inert gas (e.g., N2) and the exhaust gas is then optionally subjected in whole or in part to exhaust gas treatment (e.g. adsorption by means of activated carbon or combustion).

[0142] Preferably a conversion of the PU flexible foam mass in an upstream stirred tank is preferred that carries out a pure alcoholysis, e.g., a glycolysis with DEG. An extra catalyst is not necessarily added to this step. More particular the pure alcohol-yis, e.g., a glycolysis with DEG, can be carried out without presence of a catalyst.

[0143]

[0144] Preferably the glycolysis is carried out without catalyst agent. This glycolysis destroys the macroscopic structure of the PU flakes and therefore reduces / mini-mizes the volume of the PU flakes. Temperatures of at least in the range of 180°C to 240°C are required in this step. Ideally, the slurry also has the temperature of the subsequent reaction (preferably at or around T=200°C). As an example a dissolution reaction of PU flex foam to slurry in the first reactor is preferred with a slurry production at atmospheric pressure reaction temperature of T = 200°C.

[0145] In a particular preferred further development it is advantageous that the PU particulate material is a PU flexible-particulate material of low bulk density, in particular in the form of PU foam flakes. In particular the PU flexible-particulate material is in the form of PU flakes of low bulk density.

[0146] Additionally or alternatively the PU slurry material is received from alcoholysis (or glycolysis)-educt-ratios of between 70 wt% (weight %) and 86 wt% of PU (foam) particulate material and between 14 wt% and 30wt% of DEG, wherein the alcoholysis (glycolysis)-educt-ratios sum up to 100%. In particular a ratio of 79-80 wt% of PU particulate material and 20-21 % of DEG is preferred.

[0147] As an example still a quite high concentration (e.g. as a limit from a test) can be achieved with 1200g foam in 200g DEG (i.e. 85.7 % foam, 14.3% DEG). However advantageously an amount of foam and DEG is set according to a preferred recipe and slurry properties. Preferably a good pumpability of the slurry still at high viscosity of the slurry is to be achieved. A particular preferred example provides for a slurry concentration resulting from: 78.6 % of PU foam and 21.4% of DEG.

[0148] In a particular preferred further development it is advantageous that the PU slurry material has a viscosity q in a range between 250 and 350 mPa*s, in particular in a range between 280 and 320 mPa*s, in particular in a range between 295 and 305 mPa*s, preferably a viscosity q of approximately 300 mPa*s, when measured or otherwise determined at a temperature T of 200°C.

[0149]

[0150] In a particular preferred further development it is advantageous that the pre-processing temperature of pre-processing the PU particulate material (e.g. PU foam particulate material) by alcoholyis or glycolysis, preferably in the first reactor of the reactor arrangement when separate reactors are present, to provide the PU slurry material is the same or at least near to the processing temperature of processing of the PU slurry material in a solvolysis. The solvolysis is carried out for instance in the second reactor or in a second processing step carried out it the first reactor when only one reactor is present.

[0151] In particular the reaction temperature of pre-processing the PU foam particulate material by glycolysis in the first reactor to provide the PU slurry material is in a range of a reaction temperature between 140 °C and 230 °C, in particular in a range between 180 °C to 220 °C, in particular in a range between 195 °C and 205 °C, preferably at a reaction temperature of at least 200 °C. To provide the raw materials for the fabrication of recycled PU foam, therein the solvolysis is a hydro-glycolysis reaction. In particular therein the reaction temperature of preprocessing the PU foam particulate material by alcoholysis or glycolysis to provide the PU slurry material more preferably is in a range between 170 and 230 °C, in particular in a range between 180 and 220 °C, in particular in a range between 195 and 205 °C.

[0152] As an example, a pre-reaction temperature of above 180 °C is preferably needed, in particular preferred at about 200 °C; still a maximum temperature of 230 °C is sufficient and above that not needed or even detrimental.

[0153] In a particular preferred further development it is advantageous that a volume reduction ration of PU foam particulate material to PU slurry material is in a range between 15 and 50, in particular in a range between 25 and 30. As an example a volume reduction from e.g. a volume of 60L of foam flakes to 2kg of PU slurry material at a volume of about 2L can be achieved.

[0154] In a particular preferred further development it is advantageous that the feeding of PU in the form of particulate material, in particular PU foam in the form of par-

[0155]

[0156] ticulate material, into the reactor arrangement or the first reactor of the reactor arrangement comprises:

[0157] - conveying the PU particulate material, in particular PU foam particulate material from a bunker by a conveying arrangement, in particular by a conveying arrangement comprising a conveyer belt and / or a pneumatic conveying apparatus;

[0158] - dosing the PU foam particulate material from the conveying arrangement to the reactor arrangement (or to the first reactor, when more reactors are provided), in particular by a dosing arrangement comprising rotary feeder and / or a stuffing screw.

[0159] In a particular preferred further development it is advantageous that for feeding the PU particulate material (e.g. PU foam particulate material or PU foam flakes) into the reactor arrangement or into the first reactor when more reactors are provided) is fed by means of dosing device, in particular wherein the dosing device is adapted for feeding, in particular force-feeding, the PU particulate material into the reactor arrangement or into the first reactor through a vapor barrier.

[0160] In a particular preferred further development it is advantageous that the method further comprises applying pressure to the PU foam flexible-particulate material to degas gaseous content and / or to separate water from the PU foam flexibleparticulate material. The pressure can be applied via e.g. a rotary valve, rotatory feeder and / or a stuffing screw.

[0161] As an example it is preferred to force-feed the PU foam flexible-particulate material into the reactor with a stuffing unit, rotary valve, rotatory feeder and / or a stuffing screw or the like suitable vapor barrier. A stuffing unit e.g. can be adapted as a conical screw. A stuffing unit, respectively the conical screw can be adapted to compress the PU foam flexible-particulate material to a suitable extent such that the PU foam flexible-particulate material is degassed by the compression.

[0162] Thereby e.g. it is advantageously achieved that air at least partially is pressed out of the bulk of the PU foam flexible-particulate material and a bit out of its cells. This has the advantage that less oxygen is in the chemically processing, respec-

[0163]

[0164] tively in the glycolysis reaction. Thus, unwanted side reactions are diminished respectively unwanted or even detrimental results from side reactions are avoided. Thus, preferably by said pressurizing device it is possible to at least partially degas the PU foam flexible-particulate material, in particular to degas air and / or oxygen (O2) from the PU foam flexible-particulate material by compression. Preferably this also allows to apply a preferred reaction gas to the chemically processing by re-expansion of the PU foam flexible-particulate material to introduce a “reaction gas” other than air and / or oxygen (O2).

[0165] A degassing prcess takes place in the conical or stuffing screw, where the foam is pressed and reduced in volume so that the air contained in the pores must escape. Excess water can also escape. However this is not a particular advantage as it cannot be drawn off in the apparatus. Thus, PU foam material that is so heavily loaded with water that it can be "squeezed out" is preferably sorted out in a sorting step and not reach the stuffing screw.

[0166] The vapor barrier preferably comprises a component that actively blows inert gas (e.g., N2 or argon) into a passageway and tends to direct the gas flow downwards. This can partially prevent rising gases from rising upwards into the stuffing screw or cyclone. Rising gases are a nuisance, as they lead to sticking and more problematic handling of the PU foam flakes. However, the PU foam flakes can easily fall down into the reactor and are not affected by the "vapor barrier" and are not compressed.

[0167] It turns out that in a particular preferred further development it is advantageous that a pressurizing device adapted to apply pressure to the PU foam particulate material is adapted to compress the PU foam particulate material in range of more than 1 :7, in particular more than 1 :10.

[0168] It turns out that in a particular preferred further development it is advantageous that the feeding the PU slurry material into a second reactor comprises:

[0169] - conveying the PU slurry material from the first reactor by a conveying arrangement, in particular by a conveying arrangement comprising a piping system,

[0170]

[0171] - dosing the PU slurry material in the piping system to the second reactor, in particular by a dosing arrangement comprising feeding and / or dosing pump.

[0172] The resulting mass of the slurry of the -insofar preliminary- alcoholysis or glycolysis from chemical pre-processing step (e.g., in the first reactor) can subsequently be conveyed / pumped into the second reactor, in particular into a pressure vessel of the second reactor. A suitable pump can be applied for that purpose when using two vessels (of a first and second reactor).

[0173] Preferably even a subsequent hydrolysis (residual glycolysis) can be carried out to fully remonomerize the flexible polyurethane foam.

[0174] In the following, developments and definitions to the method and apparatus of the invention will be described related to the mechanically pre-processing the PU material, such as PU foam material, to provide a PU particulate material.

[0175] The invention starts from a foam mix including one or more PU pieces, such as PU foam pieces, which can be the whole PU foam part of articles such as mattresses, vehicle seats, upholstered chairs or sofas, or portions thereof, and that corresponds to the starting material.

[0176] In a particular preferred further development it is advantageous that the step of mechanically pre-processing the PU material, or PU foam material, to provide a PU particulate material, or PU foam particulate material, comprises shredding selected PU pieces (for instance foam pieces of a target foam material) to result in shredded PU elements, or PU foam elements, with an average dimension in the range of 100 to 500 mm, and preferably with a relatively small standard deviation.

[0177] In a particular preferred further development it is advantageous that the step of mechanically pre-processing the PU flexible-particulate material comprises milling selected PU elements to result in milled PU particulate material with a maximum dimension smaller than 120 mm, preferably smaller than 90 mm, even more

[0178]

[0179] preferably smaller than 70 mm, wherein the milled Pll particulate material constitute said PU flexible-particulate material, in particular constitute PU foam flakes of low bulk density.

[0180] Related with the second aspect of the invention, in a development, the arrangement preferably comprises the mechanically pre-processing arrangement of the PU material adapted to provide a PU particulate material and comprises:

[0181] - a shredding arrangement adapted for shredding selected PU pieces to result in shredded PU elements with an average dimension in the range of 100 to 500 mm, and preferably a relatively low standard deviation, and / or

[0182] - a milling arrangement adapted for milling selected PU elements to result in milled PU particulate material with a maximum dimension smaller than 120 mm, preferably smaller than 90 mm, even more preferably smaller than 70 mm, wherein the milled PU foam particulate material constitute said PU foam flexibleparticulate material, in particular constitute PU foam flakes of low bulk density.

[0183] This being said, preferably the PU particulate material has a minimum dimension clearly exceeding 5 mm, preferably exceeding 10 mm.

[0184] The PU foam particulate material can be constituted by milling or other types of comminuting. The comminuted PU foam particulate material constitute said PU foam flexible-particulate material, in particular constitute PU foam flakes of low bulk density.

[0185] In the context of the present invention the polyurethane (PU) material in general may be provided in any form; in particular however, the polyurethane (PU) material is be considered as some kind of foam material. A foam material in this case is a solid foam material with closed-cell structure (with discrete gas pockets, each completely surrounded by the solid material) or open-cell structure (where gas pockets connect to each other).

[0186] In the context of the present invention the shredded foam elements, respectively target foam elements, in particular are regarded to mean “shredded PU foam ele-

[0187]

[0188] merits”. Shredded PU foam elements embrace generally a “comminuted polyurethane or polyisocyanurate foam or the like foam material”. Preferably this means the material is obtained from a foam, and the comminuted polyurethane or polyisocyanurate is for example used in shredded form, i.e. in the form of granules, flakes, as an agglomerate, or as a powder.

[0189] The polyurethane or polyisocyanurate foams can be comminuted by conventional methods, for example by shredding, e.g. in a rotation mill or rotary mill at room temperature, to a particle size of ordinarily less than 500 mm, for example to a particle size in the range of from 10 to 500 mm, preferably to a particle size of less than 20 mm, or ground, e.g. by known cold grinding processes. Additionally or alternatively, the milling unit is configured to provide milled target foam flakes maximum dimension smaller than 120 mm preferably smaller than 90 mm even more preferable smaller than 70 mm.

[0190] The mechanically pre-processing arrangement of the second aspect of the invention thus shares the advantages of the method for pre-processing a foam mix of the first aspect, or of any of its developments. The mechanically pre-processing arrangement, is suitable for pre-processing a foam mix following a method according to the first aspect, in particular for feeding a reactor of a recycling process for recovering raw materials.

[0191] In a development, the arrangement is confined within a single plant or building arrangement, and the first transporting unit and / or the second transporting unit comprise a conveying system, such as a conveyor belt or a sucking and / or blowing unit, to transport the corresponding selected target foam pieces and / or the selected target foam elements to the shredding unit and / or to the milling unit. In an alternative development, the pre-processing arrangement is distributed in two or more different location and the first transporting unit and / or the second transporting unit include a road-based transporting unit (e.g., a truck), a rail-based transporting unit (e.g., a train), an air-based transporting unit (e.g., a cargo plane) and / or a sea-based transporting unit (e.g., a container ship).

[0192]

[0193] Further the properties of the polyurethane or polyisocyan urate foams -in this particular case of the invention the properties of PU foam flexible-particulate material- might vary in broad ranges. Preferably for said PU foam flexible-particulate material, polyurethane foams are used in the process and arrangement of the present invention. According to a further embodiment, the present invention is also directed to the process and arrangement as disclosed above, wherein the polyurethane foams are selected from the group consisting of polyisocyanate derived polyurethane foams.

[0194] The polyurethane or polyisocyanurate foams used in the present invention are preferably obtained from items produced from polyurethane foams at a time after use for the purpose for which they were manufactured or polyurethane foam waste from production processes.

[0195] Herein, the term “polyurethane foam waste” includes end-of-life polyurethane foams and production rejects of PU foams or waste generated through further processing of PU foams. In this context, the term “spent polyurethane foam” denotes an item produced from a polyurethane foam at a time when it has already been used for the purpose for which it was manufactured. “Production rejects of polyurethane foams" denotes polyurethane foam waste occurring in production processes of PU foams.

[0196] Generally, polyurethane foams are produced by a reaction between a polyisocyanate component and a polyol component. Typically, further materials, in particular additives, such as flame retardants (e.g. phosphorous-based), polymerization catalysts (e.g. tertiary amines), fillers and surfactants as siloxanes can be added in the production process of the polymers.

[0197] The properties of a polyurethane foam are influenced by the chemistry of polyisocyanate and polyol components used and the recipe applied in polymerization. For example, the starting materials may influence the crosslinking density of the polymers in a three-dimensional network. Rigid polyurethane are typically obtained from monomers with a comparably low molecular weight and high functionality creating a highly crosslinked, dense network.

[0198]

[0199] Industrially and consequently in large quantities, especially methylenedi (phenylisocyanate) (MDI) or its polymeric forms or toluene 2,4 and 2,6-diisocyanate (TDI) are used as polyisocyanate components for the production of PU rigid foams and PU flexible foams. For a representative composition of these PU foams, see for example US 9,023,907 B2, WO 2015 / 121057 A1 and WO 2013 / 139781 A1.

[0200] Organic polyisocyanates that can be used in the preparation of polyurethanes are any of the known organic di- and polyisocyanates, preferably aromatic polyfunctional isocyanates.

[0201] Suitable polyisocyanate components used for the production of the polyurethanes or polyisocyanurates comprise any of the polyisocyanates known for the production of polyurethanes or polyisocyanurates. These comprise the aliphatic, cycloaliphatic, and aromatic difunctional or poly-functional isocyanates known from the prior art, and also any desired mixtures thereof. Examples are diphenylmethane 2, 2’-, 2,4’-, and 4,4’-diisocyanate, the mixtures of monomeric diphenylmethane diisocyanates with diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), isophorone diisocyanate (IPDI) and its oligomers, toluene 2,4- and 2,6-diisocyanate (TDI), and mixtures of these, tetramethylene diisocyanate and its oligomers, hexa-methylene diisocyanate (HDI) and its oligomers, naphthylene diisocyanate (NDI), and mixtures thereof.

[0202] Preferably, toluene 2,4- and / or 2,6-diisocynate (TDI) or a mixture thereof, monomeric diphenyl-methane diisocyanates, and / or diphenylmethane diisocyanate homologs having a larger number of rings (polymer MDI), and mixtures of these. Other possible isocyanates are mentioned by way of example in "Kunststoffhand-buch [Plastics handbook], volume 7, Polyurethane [Polyure-thanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.2 and 3.3.2.

[0203] The organic di- and polyisocyanates may be used individually or in the form of mixtures.

[0204] Common polyols used in huge quantities are, e.g., selected from the group consisting of polyether polyols, polyester polyols, polyetherester polyols and mixtures thereof. Polyetherols are by way of example produced from epoxides, for example propylene oxide and / or ethylene oxide, or from tetrahydrofuran with starter

[0205]

[0206] compounds exhibiting hydrogen-activity, for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example sucrose, sorbitol or mannitol, with use of a catalyst. Basic catalysts and double-metal cyanide catalysts, as described by way of example in WO 2006 / 034800 A1 , EP 0090444 A1 or WO 2005 / 090440 A1 , can be used for this purpose.

[0207] Polyesterols are by way of example produced from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals, and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are mentioned byway of example in "Kunststoffhandbuch [Plastics hand-book], volume 7, Polyurethane [Polyurethanes]", Carl Hanser Verlag, 3rd edition 1993, chapter 3.1.In the following, developments of the arrangement of the second aspect will be disclosed.

[0208] Foam, also referred to as foamed plastic, is a synthetic resin converted into a spongelike mass with a closed-cell or open-cell structure, either of which may be flexible or rigid. Foam is used for a variety of products, including cushioning materials, air filters, furniture, toys, thermal insulation, sponges, plastic boats, panels for buildings, lightweight beams, etc. Under appropriate conditions almost every thermosetting or thermoplastic resin can be converted into a foam. Plastics that are commonly foamed include vinyls, polystyrene, polyethylene, phenolics, silicones, cellulose acetate and urethanes, such as polyurethane (PU). PU foams is typically used in the fabrication of mattresses and upholstery. Different types of PU foams include, for instance, standard PU foam, high resilience (HR) PU foam, viscoelastic PU foam, etc. Depending on foam parameters such as the density or chemical compositions, PU foams are available as, for example, and non-restric-tively, charcoal foam, dry fast foam, high density foam, lux foam (evlon foam), latex-rubber foam, rebond foam, etc , which are all open-cell Polyurethane foams.

[0209] A PU foam may contain a type of additive and / or impurity of the sample foam piece or the sample foam element, in particular a type of additive selected from a

[0210]

[0211] group consisting of water, inorganic fillers, flame retardants, styrenes (in particular styrene acrylonitrile), silicon stabilizers, crosslinker, chain extenders, monools, antioxidants, defoamers, catalysts and dyes.

[0212] The above mentioned SAN content of the introduction generally may embrace content of “graft polyols” often also termed polymer polyols. Polymer polyols mean dispersions of polymers, mostly styrene acrylonitrile (SAN) copolymers, in particular stabilized by the co-polymerization of macromers in a polyether polyol matrix. The graft polyols used for the preparation of polyurethane foams usually have a hydroxy value in the range from 15 to 120 mg KOH / g. They may be present in the polyurethane foams in an amount of up to 25 wt.%.

[0213] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0214] The embodiments of the invention are described in the following on the basis of the drawing in comparison with the state of the art, which is also partly illustrated. The latter is not necessarily intended to represent the embodiments to scale. The drawing is, where useful for explanation, shown in schematized and / or slightly distorted form. With regard to additions to the teaching immediately recognizable from the drawing, reference is made to the relevant prior art. It should be kept in mind that numerous modifications and changes can be made to the form and detail of an embodiment without deviating from the general concept of the invention. The features of the invention disclosed in the description, in the drawing and in the claims may be essential for a further development of the invention, either individually or in any combination. In addition, all combinations of at least two of the features disclosed in the description, drawing and / or claims fall within the scope of the invention.

[0215] The general concept of the invention is not limited to the exact form or detail of the preferred embodiments shown and described below or to a subject matter, which would be limited in comparison to the subject matter as claimed in the claims.

[0216]

[0217] For specified design ranges, values within specified limits of the ranges are also disclosed as limit values and thus are arbitrarily applicable and claimable.

[0218] The following drawing shows in:

[0219] FIG. 1 , FIG. 2 each an exemplary method, wherein a basic flow diagram is shown in FIG. 1 and a scheme is shown in FIG. 2, each depicting the main steps of recycling a polyurethane (PU) foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material in a process of a preferred embodiment, the process comprising a mechanical part and a chemical part;

[0220] FIG. 3 a detailed flow diagram of the mechanical part of the exemplary method of the preferred embodiment of FIG. 1 with FIG. 2;

[0221] FIG. 4 in view (A) the mechanical and chemical part of the exemplary method of the preferred embodiment of FIG. 1 with FIG. 2 and a basic flow diagram, and in view (B) a detail of the flow diagram of the mechanical part with an exemplary apparatus of the preferred embodiment of FIG. 3, and a feeding arrangement in view (C) of the preferred embodiment of FIG. 3, namely a preferred embodiment of a first feeding device for feeding the PU foam flexible-particulate material into a reactor of the reactor arrangement;

[0222] FIG. 5 in view (A) the mechanical and chemical part of the exemplary method of the preferred embodiment as already shown in FIG. 4 view (A), and in view (B1 ) and view (B2) a detail of the flow diagram of the mechanical part with an exemplary apparatus, of the preferred embodiment of FIG. 1 with FIG. 2; namely a preferred embodiment of a first reactor arrangement in view (B1 ) and a preferred embodiment of a second reactor arrangement in view (B2);

[0223] FIG. 6 a detailed flow diagram of an example of the method of recycling a polyurethane (PU) foam material to recover raw materials for the

[0224]

[0225] fabrication of recycled PU foam from said PU foam material in a chemical part of the process of a preferred embodiment based on FIG. 1 with FIG. 3.

[0226] FIG. 1 depicts schematically and exemplary in principle an improved concept of a method 100 of recycling a polyurethane (PU) material, exemplarily and in a nonlimiting manner, in the form of PU foam material, to recover raw materials for the fabrication of recycled PU foam from said PU material in a process of a preferred embodiment.

[0227] According to the concept of the method 100 the instant embodiment is adapted to apply for recycling a polyurethane (PU) foam material provided from the mechanically pre-processing in step S1 as a PU foam flexible-particulate material. This part of the overall process is also referred to as the mechanical part 300. A PU foam flexible particle of the PU flexible-particulate material can be understood as compressible particle of an irregular form. The PU foam flexible particle is only partially elastic but mostly plastic and as such compressible.

[0228] The PU foam flexible-particulate material is provided to a reactor arrangement by dosing and feeding said PU foam flexible-particulate material in step S12 to a reactor arrangement.

[0229] In step S2, the chemically processing of the PU-foam particulate material is effected. This part of the overall process is also referred to as the chemical part 400.

[0230] The reactor arrangement adapted for the chemically processing of the PU-foam particulate material (as shown and described with FIG. 3 to FIG. 6) may comprise a first and a second reactor of a number of reactors - also in an alternative the reactor arrangement; may comprise basically one reactor wherein the one reactor can be operated in a first and a second reactor state of a number of reactors states, (so to say in a sense consist of a single reactor)

[0231]

[0232] As will become clear the chemically processing of the PU-foam particulate material provides for a combination of a glycolysis and hydro-glycolysis in the chemical processing of the PU foam particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam.

[0233] The concept of the method 100 in the chemical part 400 proposes a chemical pre-processing of the PU foam flexible-particulate material by glycolysis followed by a chemically processing a PU slurry material as received from the glycolysis in the follow-up hydro-glycolysis.

[0234] This chemical part 400 will be described in detail with regard to FIG. 4 to FIG. 6 of the below embodiment in detail and in combination with a particular preferred approach of feeding the respective reactor of the reactor arrangement for chemically processing the PU material.

[0235] FIG. 2 shows a schematic block diagram of a pre-processing arrangement 200 in accordance with an embodiment of the invention in compliance with the method fog FIG. 1. The arrangements 200 can be configured e.g. as pre-processing arrangement for pre-processing a mattress mix as a foam mix.

[0236] The pre-processing arrangement 200 is suitable for pre-processing a foam mix 202 for feeding a reactor arrangement 250 of a recycling process for recovering raw materials. The reactor arrangement 250 is exemplarily for a chemical reactor arrangement comprising one reactor or a multitude of reactors for chemically recycling PU foam.

[0237] The pre-processing arrangement 200 comprises a target foam selection unit 204, configured to select, from the foam mix 202, target foam pieces 206 e.g. comprising one or more foam pieces 206A, 206B. Said target foam pieces 206 comprise target foam material 207 that is suitable for the reactor arrangement 250. The target foam selection unit 204 may comprise a determination unit 205 with a suitable processing unit 209. The target foam selection unit 204 is configured to perform an analysis step to select proper target foam pieces 206A, 206B. If the analysis step is not indicative of the target foam material 207, however, the sample foam

[0238]

[0239] piece 203 is not selected and is removed from the pre-processing arrangement 200.

[0240] Preferably, the analysis is indicative of a type of foam, in particular of a type of polyurethane foam of the sample foam piece 203 or the selected target foam piece 206 respectively. Additionally or alternatively it is indicative of a type of additive of the sample foam piece 203 or the selected target foam piece 206 respectively, in particular indicative of one or more additives, selected from a group consisting of water, inorganic fillers, flame retardants, styrenes (in particular styrene acrylonitrile), silicon stabilizers, crosslinker, chain extenders, monools, antioxidants, defoamers, catalysts and dyes. Additionally, or alternatively, the analysis is indicative of the presence of an impurity or contamination, such as unacceptable dirt, dust, or microbial or fungal layers.

[0241] The pre-processing arrangement 200 further comprises a transporting unit 208 that is configured receive the selected target foam pieces 206 and to transport the selected target foam pieces 206 to a shredding unit 210, wherein the shredding unit 210 is configured to shred the selected target foam pieces 206 to form shredded foam elements 212 for feeding to the reactor.

[0242] The pre-processing arrangement 200 in accordance with the embodiment of the invention is suitable for pre-processing a foam mix 202, for example a flexible foam mix, in particular a polyurethane (PU) mix for feeding a reactor arrangement 250 of a recycling process. The latter is in this embodiment a chemical recycling process for recovering raw materials 252. Raw materials 252 obtained comprise an isocyanate component of the PU material complementary amine and / or polyol, in particular the raw materials obtained by chemically processing the PU slurry material comprise aromatic diisocyanates (e.g. TDI, MDI) and polyol.

[0243] The raw materials to be recovered are typically TDA and polyols in the case of TDI-based PU foam. In the case of a MDI-based PU foam or a TDI / MDI mixed foam, then MDA is also obtained. Typically, in the recycling process, the amine is converted back to the corresponding isocyanate in a downstream step, generally after a dedicated reprocessing and purification chain.

[0244]

[0245] The selected target foam pieces 206 which have been selected -e.g. based on its content of target foam material 207- are then transported by a first transporting unit 208 that is configured to receive the selected target foam pieces 206 and to transport the selected target foam pieces 206 to a shredding unit 210. The transporting unit 208 of FIG. 2 is exemplarily configured as a conveyor belt. The shredding unit 210 is configured to shred the selected target foam pieces 206 to form shredded foam elements 212.

[0246] The shredding unit 210 may for instance comprise a cylindrical chamber with a cylindrical rotating element co-axially arranged inside the chamber to rotate along the common longitudinal axis. The rotating element has cutting and / or gripping elements distributed along its surface. The inner wall of the cylindrical chamber may also comprise cutting and / or gripping elements. A gap between the inner wall of the chamber and the rotating element allows the introduced foam piece to move. When engaged by the cutting or gripping elements, the foam pieces are cut or tore. A filtering mesh allows those shredded pieces with a predetermined size to exit the shredding unit 210. These are referred to as foam elements 212.

[0247] Also a milling unit 220 can be configured to mill the selected target foam elements 206 to form target foam flakes 222 that are suitable, both in size and in composition, to be fed to the reactor 250.

[0248] The milling unit and the shredding unit can be based on a similar technology, although the average size of the target foam flakes is smaller than the average size of the shredded foam elements. Preferably, the milled target foam flakes have a maximum dimension smaller than 120 mm preferably smaller than 90 mm even more preferable smaller than 70 mm. Preferably the PU particulate material has a minimum dimension clearly exceeding 5 mm, preferably exceeding 10 mm.

[0249] The PU foam particulate material, presently as form target foam flakes 222, can be constituted by milling or other types of comminuting. The comminuted PU foam particulate material constitute said PU foam flexible-particulate material, in particular constitute PU foam flakes of low bulk density.

[0250]

[0251] FIG. 3 shows a flow diagram of an exemplary method 100 for pre-processing a foam mix that includes a method for selecting target foam pieces that comprise target foam material in accordance with a first embodiment of the invention. The following discussion will also make reference to the features of exemplary preprocessing arrangements that are shown in FIG. 4 and FIG. 5 and described below with more detail. The method related with the mechanical part 300 is adapted for selecting target foam pieces and thus forms a first step S1 of the method 100 for pre-processing the foam mix as indicated above.

[0252] The invention thus is directed to a method and apparatus of recycling a polyurethane (PU) material to recover raw materials 252 for the fabrication of recycled PU material from said PU material in a process, the process comprising the steps of the mechanical part 300, which is part of the overall process:

[0253] - mechanically pre-processing the PU material to provide a PU particulate material,

[0254] - feeding the PU particulate material into a reactor arrangement. Therein the PU foam flexible-particulate material is provided to a reactor arrangement 250 by dosing and feeding said PU foam flexible-particulate material to a reactor arrangement as indicated in step S12 as referenced above.

[0255] The invention is directed to a method and apparatus of recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material in a process, the process comprising the steps of:

[0256] - mechanically pre-processing 300 the PU material to provide a PU particulate material,

[0257] - feeding the PU particulate material into a reactor arrangement.

[0258] Turning to FIG. 3 at first in general it should be understood that generally in a selecting step 301 a collection and packing of end of life PU products (“EoL PU Products”) and the like PU waste material usually comprises some kind of decentralized and / or organized collection of said PU waste material and followed by a transport step to external sites of collection and packing, like off-site or decentral sites. As follow-up external or off-site fractioning of the PU waste material usually implies a complex sequence of steps of sorting and packing. .In the end a good

[0259]

[0260] fraction of PU foam materials are provided to a pressing and baling step, so that the good fraction of worthy PU foam material is provided.

[0261] After a transport step 302 from external sites of collection and packing, like offsite or decentral sites, to the core site further recycling can take place as is shown there below. It is to be understood that transport steps to the packing sites and from the packing sites to recycling plant sites can comprise any kind of transport units like by way of vehicles or conveying of any kind. To and from various different facilities of collection and packing and recycling transport units like by road train or any kind of conveying by belt, shuttles or the like is useful.

[0262] Whereas the recycling of PU foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material in the process is to be understood as a combination of block-step S1 of a mechanical part 300, dosing step S12 and block-step S2 of a chemical part 400 with respective reactor assembly, the advancing collection and packing of the original PU waste material in terms of this recycling process as described hereinbefore is not considered as being part of the recycling process as such.

[0263] As mentioned in the introduction in general two categories of polyurethane recycling approaches are known in order to recycle from a polyurethane foam material raw materials wherein the raw materials are of use for the fabrication of recycled PU foam from said polyurethane (PU) foam material in the process. The two categories can be generally addressed as a mechanical recycling process and a chemical recycling process; both with the aim to generate the recycled PU foam for further use in a new product.

[0264] In general in a mechanical PU recycling process PU foam material is comminuted or milled, possibly granulated to provide PU foam particulate material. Binding agents as well as fresh PU to be mixed with said PU foam particulate material. With applying heat and / or pressure the new PU material can be generated as recycled PU foam to be further used in new products having a comparingly high portion of recycled PU material.

[0265]

[0266] Further referring to FIG. 3 a general overall scheme is depicted as a flow diagram to exemplary describe a preferred method and apparatus of recycling a polyurethane (PU) foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material in a process of a preferred embodiment.

[0267] The overall method of recycling in the process starts with a mechanically pre-processing 300 of the PU foam material to provide a PU foam flexible-particulate material as is shown in the block-step S1 of FIG. 1. The mechanically pre-processing 300 of the PU foam material provides a PU foam flexible-particulate material which is provided to the chemical processing of the in a reactor arrangement as is shown in block-step S2 of FIG. 1 , respectively shown in detail in step 305 of FIG. 3.

[0268] The PU foam flexible-particulate material is provided in a shredding step 303 followed by an optional fractionating and / or bunker storing in step 304.

[0269] After a conveying step 306 at an interface (dosing also referred to as metering) dosing of the PU foam flexible-particulate material is performed in dosing step 307. The dosing step 307 is adapted to both, the educt properties of the mechanical pre-processing, i.e. the PU foam flexible-particulate material and also the margins and conditions of the chemical processing of said PU foam flexible-particulate material in said reactor assembly of block-step S2.

[0270] In the preferred embodiment of a method of recycling a polyurethane (PU) foam material to recover raw materials for the fabrication of recycled PU foam from said PU foam material in a process shown in FIG. 1 the mechanical pre-processing 300 of the PU foam material of good fraction as shown in block-step S1 provides that the PU foam material of good fraction arrives to provide the good fraction PU foam material to the mechanical pre-processing.

[0271] Comminuting steps may comprise a sequence of on-site process steps, with conveying 302, with shredding 303 and fractionating 304. In the conveying step 302 a good fraction of PU foam material is conveyed, for instance by belt conveying

[0272]

[0273] or pneumatic conveying, to a shredding arrangement. The shredding arrangement can have various shredding units and also can be applied in a circle such that conveying 302, shredding 303 and fractionating 304 can be applied in a circle to apply shredding units of different kinds in order to comminute the Pll foam material to a PU foam particulate material of proper particulate size. In the instant embodiment the PU foam particulate material results from a first step of comminuting by shredding and a first step of comminuting by milling; thereby the PU foam material is comminuted at first to a rather coarse particulate material, and then thereafter, the a rather coarse particulate material is milled to a finer particulate material.

[0274] In the instant preferred embodiment a two-step comminuting process has been found to be useful in the mechanically pre-processing the PU foam material to provide a PU foam particulate material. In a first shredding step coarse PU foam particulate material of coarser grains of 100 to 500 mm size can be provided. A good fraction of in that sense the coarser grains of PU foam particulate material can be provided to a second shredding step to provide from the coarse grain PU foam particulate material a fine grain PU foam particulate material with grains of below 100 mm. Once the follow-up fractionating step finds this fine size grains of PU foam particulate material as useful said fine grain PU foam particulate material of good fraction is stored in a bunker in step 304.

[0275] It has been found that by applying a useful and advantageous, e.g. two-step, shredding in a preferred embodiment a PU foam particulate material of flexible kind is provided which means that the particulates of the PU foam particulate material are flexible and kind of flakes rather than a powder, i.e. at least the PU foam flexible-particulate material has a low bulk density and a comparably high surface which is in particular the case for PU foam particulate material in the form of PU foam flakes. It has been found that PU foam flakes have a good combination of low bulk density of 15-25 kg / mA3 on the one hand and a relatively large surface, still with a maximum dimension smaller than 120 mm, preferably smaller than 90 mm, even more preferably smaller than 70 mm, wherein the milled PU foam particulate material constitute said PU foam flexible-particulate material, in particular constitute said PU foam flakes of low bulk density. This combination establishes

[0276]

[0277] PU foam flakes as having good properties for being provided to a follow-up chemically processing 400 as is shown block-step S2 of FIG. 1.

[0278] In particular in the present preferred embodiment of process the step of mechanically processing 300 the PU foam material to provide a PU foam flexible particulate material comprises shredding 303 said selected target foam pieces to result in shredded in PU foam elements with a maximum dimension in the range of 100 to 500 mm. Further the step of mechanically processing the PU foam material to provide a PU foam particulate material, namely particulate PU foam flakes as described above, comprises milling selected target PU foam elements to result in milled target PU foam flakes with a maximum dimensions smaller than 120 mm preferably smaller than 90 mm, even more preferably smaller than 70 mm. The milled target PU foam flakes constituted that flex PU foam particulate material of low bulk density.

[0279] The embodiment follows the concept of the invention to use PU foam particulate material in the form of a PU foam flexible-particulate material of low bulk density, in particular in the form of PU foam flakes.

[0280] Whereas these advantages overweigh still it should be noted that on the other hand said flex particulate PU foam material in the form of PU foam flakes has quite a low density of between 30 to 40 kg / m3and thus comminuted a flexible PU foam as described above in flakes of a size of below 80mm and bulk density of 15 to 25 kg / m3necessarily require quite a large volume in said step of bunker or tank storing.

[0281] Further, a dosing step S1 .2, 307 to provide the PU foam flakes to the reactor assembly is demanding as the chemically processing of the PU foam flexible particulate material in said reactor arrangements for recovering the raw materials for the fabrication of recycled PU foam demands to the best of contemporary understanding some sort of hydro-glycolysis at raised temperature above room at temperature and raised pressure above atmospheric pressure.

[0282]

[0283] As exemplified in FIG. 3 a problem arises when the required foam quantity (mass) of a batch must be fed into a reaction vessel that has a much smaller volume than the material to be fed; this is of particular relevance for said PU foam flexible-particulate material in the instant preferred embodiment. In a standard approach a very large and thus uneconomical reactor volume would be required when the PU foam flexible-particulate material would be preset to the reactor.

[0284] Even more, in a standard approach a pressurized reactor would have to be used; then the dosing S12, 307 further would have to be carried out with force-feeding 308 at a corresponding overpressure into the reactor if the volume reduction is to take place through the ongoing hydro-glycolysis in the reactor itself. This would require the use of a complicated shear- or pressure apparatus (extruder / com-pounder). The use of an extruder has not only an economic disadvantage but also a lot of technical challenges.

[0285] The instant invention is directed to a batch process. Expected batch size is some hundreds of kiloggrams (kg) to tons of foam (given an estimated assumption that 1 ton (1t) corresponds to a volume of 50mA3 for an estimated assumption of density at 20kg / mA3 for the foam).

[0286] The invention is directed to a method and apparatus of recycling a polyurethane (PU) material to recover raw materials 252 for the fabrication of recycled PU material from said PU material in a process, the process further comprising the steps of the chemical part 400:

[0287] - chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU material.

[0288] Unlike that “solely mechanical” category of recycling further a chemical PU recycling process is known wherein three basic approaches of chemical processes are known: acidolysis, glycolysis and hydrolysis.

[0289] In the following and as described below in a preferred embodiment of FIG. 4 to FIG. 6 the inventive concept of recycling a polyurethane (PU) material based on

[0290]

[0291] the exemplary case of PU foam material, to recover raw materials for the fabrication of recycled PU foam from said PU material proposes a new process combining a mechanical part 300 and a chemical part 400.

[0292] According to the invention

[0293] - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and

[0294] - the reactor arrangement comprises at least one reactor, wherein chemically processing of the PU particulate material comprises the steps of: - feeding the PU flexible-particulate material into a reactor of the reactor arrangement and chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor to provide a PU slurry material, wherein the alcoholysis is effected using a diol, and

[0295] - chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0296] Turning to FIG. 4A and FIG. 5A as mentioned above, the concept is adapted to apply for recycling a polyurethane (PU) foam material provided from the mechanically pre-processing 300 as a PU foam flexible-particulate material. The mechanical pre-processing 300 is shown in more detail in FIG 4B. A Force-feeding device FF is shown in FIG. 4C for use in the force-feeding step 308.

[0297] The chemically processing 400 of the PU-foam particulate material provides for a combination of a glycolysis and hydro-glycolysis in the chemical processing of the PU foam particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam.

[0298] Turning to FIG. 5 the reactor arrangement of the chemically processing respectively for a pre-reacting comprises a first reactor R1 for the glycolysis reaction and for a pressure reaction comprises a second reactor R2 for the hydro-glycolysis reaction. The first and second reactor R1 , R2 in this preferred embodiment - as shown in FIG. 5 view (B1)- are described and shown with a respective first

[0299]

[0300] vessel separate from a respective second vessel. The first reactor R1 is in a first state for a stirred pre-reaction and the second reactor R2 is in a second state for a pressure reaction with set conditions of temperature T and pressure p as parameters. The first and second reactor are understood to be constituted by different and separate first vessel separate from a respective second vessel as shown in FIG.5 view (B1), wherein the operation is set in a continuous sequential throughflow of initially the first reactor R1 for the glycolysis reaction and thereafter the second reactor for the hydro-glycolysis reaction.

[0301] Still nevertheless it is to be understood, that in another embodiment one or combined vessel -as shown and referenced with “one reactor” R in FIG.5 view (B2)- of so-to-say one reactor R, can be used. Also the embodiment of view (B2) in FIG. 5 is adapted to provide for both the -still separate- glycolysis and hydroglycolysis reaction in the chemical processing of the PU foam particulate material in the so-to-say one reactor R. The one reactor R is in a first state S1 for a stirred pre-reaction and then the same reactor R is in a second state S2 for a pressure reaction with set conditions of temperature T and pressure p as parameters.

[0302] In another embodiment the one reactor R can be single reactor. In the particular embodiment of view (B2) in FIG. 5, that includes only one reactor R in the meaning of a single reactor. The chemical pre-processing is performed first, for obtaining a slurry material, in the reactor R and then the same reactor R is used for the subsequent chemical processing.

[0303] However, preferably the reactor arrangement comprises at least one reactor or more reactors of same kind, which are each operated on an alternating mode but in a parallel operation as seen in FIG. 5 view (B2). In a developed processing of the embodiment shown in FIG. 5 view (B2)e- two pressurized reactors R are provided, which are then operated in an alternating A / B mode. This means that both reactors R are operated "open" and "closed" and the time factor remains the same as when using an "open" and "closed" reactor. The use of two separate units -each of the same kind of reactor R- has the advantage that there is sufficient time for dosing by the pneumatic air conveyor as this is the time-limiting step.

[0304]

[0305] ln the particular embodiment of view (B1 ) in FIG. 5 that comprises two reactors R1 , R2, the chemical pre-processing step is performed in the first reactor R1 and the chemical processing step is performed in the second reactor R2. It has been shown for the instant concept of the invention that further advantages result from the lower volume for the second reactor R2 of view (B1) or the one reactor R in a second state S2 of view (B2) -also referred to as the pressure reaction-.

[0306] For one batch with an amount of 1 ton (t) (or approximately a volume of 50mA3) of PU foam flexible-particulate material a huge reactor would be needed as indicated above. Thus it is expensive and difficult to provide a sufficient heat transport and poses a challenge also for mass transport. In fact, when the foam is prefilled and the appropriate amount of DEG and water is added and hydro-gly-colized this would result in a poor mass transport. The reason is that at those conditions only the foam that comes into contact with both DEG and water can react.

[0307] Thus, the concept of the invention now provides for a volume reduction ratio at least of some significant amount in view of the process to transfer the foam flakes to the PU slurry material; the ratio is preferably in a range of between 15 and 50, in particular between 25 and 30, however may also have some other significant amount upon transferring the foam flakes to the PU slurry material. The volume reduction ratio is given between the foam flakes provided in relation to the PU slurry material resulting in a smaller pressure reactor. This allows for lower overall reaction time, as the dissolution can take place during another reaction.

[0308] In general, in particular by further providing raised temperatures and pressure to a PU material, -in chemical processing a PU educt material- the PU chains of the PU educt material are changed; respectively they are dissolved or even decomposed for the provision of raw materials. The raw materials comprise at least polyols, optionally also an amine corresponding to the isocyanate component of the PU material, such as, for example, TDA, used to generate the original PU foam material. This also includes MDI, HDI IPDI foams. Thereby originally products of similar kind as the original products can be produced by the recycled PU foam materials.

[0309]

[0310] For good order it is to be recognized that the instant description is meant to be rather abstract and in principle.

[0311] In particular it is to be understood that the pure reactor arrangement and the interconnection of foam dosing and chemical reaction - glycolysis and hydro-glycol-ysis- as is mentioned and described herein lead to the final raw materials with the original product properties of polyol and TDA upon applying further refinement of art. A person skilled in the art will note that further refinement is useful and will be able to apply such refinement from his general knowledge.

[0312] Further, the exemplary reactions mentioned as such (of course) naturally yield a mixture containing TDA and polyol and only after the reaction and a complex processing chain takes place, e.g. via centrifugation / filtration / distillation / ion exchanger, after which the polyol and / or TDA is isolated in such a form that it is suitable for new use in foam production. The TDA must also be converted into the isocyanate TDI before it can be used for new foaming.

[0313] Still also, the chemical processing of the PU foam particulate material in generally is subject to a comparable higher energy input, however, processing can be simplified. Also the products thereof are of advantage for the total recycling process of PU foam materials to recover said raw materials for the fabrication of recycled PU foam from said PU foam material in the process.

[0314] Consequently the concept of the invention proposes to provide the chemically processing 400 of block-step S2 of FIG. 1 as shown in FIG. 4 view (A) and FIG. 5 view (A). The concept proposes a chemical processing, of the PU foam flexible particulate material in the reactor arrangement in a two-step processing in a reactor assembly; namely providing a chemically pre-processing in step S21 of FIG. 4 view (A) and FIG. 5 view (A) for pre-reacting of the PU-foam particulate material and followed-up by a main chemically processing in step S22 of FIG. 4 view (A) and FIG. 5 view (A) adapted for using the educts from the pre-processing for pressure reacting.

[0315]

[0316] As shown in FIG. 4 view (A) and FIG. 5 view (A) the processing step S21 -as a pre-reaction- of the chemically processing of the PU foam flexible particulate material starts from an educt provided with the dosing step S12 of first kind S12a. The resulting PU slurry material of processing step S21 is the starting educt for the second step of main chemically processing S22, which is in particular provided with the dosing step S12 of second kind S12b. Generally the dosing step S12 can be understood s a combination with a useful dosing step of first kind S12a and preferably a dosing step of second kind S12b as will be clear from FIG.

[0317] 5 view (B1) in detail.

[0318] Consequently, as shown in FIG. 4 view (A) and FIG. 5 view (A), the concept of the invention proposes to provide an advantageous dosing step S12 related at least with dosing step of first kind S12a of FIG. 4 view (B) and view (C) with dosing. In a first embodiment the dosing step of first kind S12a comprises that the PU foam flexible-particulate material is force-feed FF into a first reactor R1. Also, in an varied second embodiment the dosing step of first kind S12a comprises that the PU foam flexible-particulate material is force-feed FF into a reactor R in a first state S1.

[0319] In case of the first embodiment the dosing step S12 also is related with a dosing step of second kind S12b as shown in FIG. 5 view (B1) in detail; therein dosing may further comprise that the PU slurry material is pumped PP into the second reactor R2.

[0320] As shown in FIG. 4 view (B), before processing the PU foam flexible-particulate material in step S12, the embodiment of the invention proposes to store the PU foam flexible-particulate material of low bulk density, in particular in the form of PU foam flakes, in a bunker or the like - this has been illustrated with step S13 in Fig. 4 view (B).

[0321] For feeding the PU foam flexible-particulate material into the reactor arrangement at first the PU foam flexible-particulate material is force-feed into the first reactor R1 as shown in FIG. 5 view (B1 ) or a reactor R in a first state S1 as shown in FIG. 5 view (B2).-

[0322]

[0323] As shown in FIG. 4 view (B) this approach, before such processing, comprises conveying C the PU foam flexible-particulate material from the bunker S13 by a conveying arrangement, in particular by a conveying arrangement comprising a conveyer belt and / or a pneumatic conveying apparatus like a pneumatic conveying system P. The feeding to the first vessel / pre-reactor can be done with a pneumatic conveying system, a rotary valve and a suitable vapor barrier.

[0324] Further the PU foam flexible-particulate material then is force-feed FF from the conveying arrangement to the first reactor R1 as shown in FIG. 5 view (B1) or a reactor R in a first state S1 as shown in FIG. 5 view (B2).

[0325] In this embodiment force-feeding is accomplished by a combination of a rotary feeder RF and / or a stuffing screw SS. As an example it is preferred to force-feed the PU foam flexible-particulate material into the first reactor R1 or the reactor R with a stuffing unit, rotary valve, rotatory feeder RF and / or a stuffing screw SS or the like suitable vapor barrier VB. A stuffing unit e.g. can be adapted as a conical screw. A stuffing unit, respectively the conical screw can be adapted to compress the PU foam flexible-particulate material to a suitable extent such that the PU foam flexible-particulate material is degassed by the compression. Similarly a rotary valve or a rotatory feeder can be designed.

[0326] For feeding the PU foam particulate material into the first reactor R1 or reactor R in a first state S1. The reactor R1 , R (S1) is fed by means of a dosing device, wherein the dosing device is adapted for force-feeding FF, the PU foam particulate material into the first reactor R1 or the reactor R in a first state S1 through a vapor barrier VB.

[0327] As depicted in a non-limiting preferred example of FIG. 4 view (C) the arrangement comprises a pressurizing device adapted to mechanically apply pressure to the PU foam particulate material to degas gaseous content and / or to separate water from the PU foam particulate material.

[0328] The pressurizing device is adapted to apply pressure to the PU foam particulate material to compress the PU foam particulate material in range of more than 1 :7,

[0329]

[0330] in particular more than 1 :1O. Thereby e.g. it is advantageously achieved that air at least partially is pressed out of the bulk of the PU foam flexible-particulate material and a bit out of its cells. This has the advantage that less oxygen is in the chemically processing, respectively in the glycolysis reaction. Thus, unwanted side reactions are diminished respectively unwanted or even detrimental results from side reactions are avoided. Thus, preferably by said pressurizing device it is possible to at least partially degas the PU foam flexible-particulate material, in particular to degas air and / or oxygen 02 from the PU foam flexible-particulate material by compression. Preferably this also allows to apply a preferred reaction gas to the chemically processing by re-expansion of the PU foam flexible-particulate material to introduce a “reaction gas” other than air and / or oxygen 02. To avoid additional entry of oxygen from the foam flakes into the pre-reactive glycolysis by the atmospheric oxygen inside its pores, it is in particular possible to force-feed the foam into the first reactor R1 or the reactor R in first state S1 with a stuffing unit (conical screw) and to degas it by compression as shown in FIG. 4 view (C).

[0331] The problem of dosing under pressure is thus circumvented, as the upstream pre-reactor can be run in a quasi-pressureless state. The introduction of the foam flakes into this pre-reactor and / or slurry vessel can be realized in various ways:

[0332] 1. The feeding to the first vessel / pre-reactor R1 or reactor in a first state S1 can be done with a pneumatic conveying system, a rotary valve and a suitable vapor barrier.

[0333] 2. As depicted in FIG. 4C in a preferred embodiment to avoid additional entry of oxygen from the foam flakes into the pre-reactive glycolysis by the atmospheric oxygen inside its pores, it is also possible to force-feed the foam into the reactor R1 , R (S1 ) with a stuffing unit (conical screw) and to degas it by compression. The foam thus falls into the reaction mixture at least partially degassed (deoxygenized).

[0334] It is also conceivable that the upstream first reactor R1 or a reactor R in a first state S1 is initially operated in an open mode as described above and after that

[0335]

[0336] the dosing step proceeds to transfer the material to a second reactor R2 or a reactor R in a second state S2; in particular in a closed state (pressure vessel) in which all openings and lids of a reactor R2, R(S) are closed.

[0337] Preferably -in a developed processing of the embodiment shown in FIG. 5 view (B2)- two pressurized reactors R are provided, which are then operated in an alternating A / B mode. This means that both reactors R are operated "open" and "closed" and the time factor remains the same as when using an "open" and "closed" reactor. The use of two separate units -each of the same kind of reactor R- has the advantage that there is sufficient time for dosing by the pneumatic air conveyor as this is the time-limiting step (whereas this advantage also holds for the embodiment shown in FIG. 5 view (B1)).

[0338] This configuration of FIG. 5 view (B2) (compared to the configuration of the embodiment shown in FIG. 5 view (B1) with a first reactor R1 for the pre-processing step connected to a second reactor R2 for the processing step) also presents the advantage, that the PU slurry material does not have to be pumped between the two reactors R and therefore cannot cause blockages in the pump or pipes. The slurry is thus converted into the monomers and only then pumped into the next downstream unit. The reaction discharge is significantly less viscous and easier to pump.

[0339] The chemical pre-processing method of the first aspect is adapted with feeding PU foam flakes to a reactor of a chemical recycling process, in particular with feeding PU-containing foam flakes to a reactor for recovering the isocyanate component of the PU material complementary amine (e.g., TDA) and polyol as raw materials for the fabrication of recycled PU foam. The process comprises the steps of feeding the PU foam particulate material into the reactor arrangement and chemically pre-processing the PU foam particulate material by alcoholysis (e.g., glycolysis) to provide a PU slurry material, wherein, preferably, the alcoholysis is a glycolysis effected with diethyleneglycole (DEG) as a solvent of the glycolysis.

[0340]

[0341] The glycolysis is, in effect, a transesterification reaction between the ester part of the urethane group of the PLJ foam material and the hydroxyl groups of a glycolytic agent to produce mixed structure polyols comprising the original glycols and isocyanate. The chemically pre-processing of the PU foam particulate material is a glycolysis with diethyleneglycole (DEG) as the only solvent of the glycolysis, in particular basically without aqueous agent and / or without catalyst agent. The chemically pre-processing of the PU foam particulate material can be a glycolysis with other glycols in addition or in alternative to diethyleneglycole (DEG) as the solvent of the glycolysis, in particular with monoethyleneglycole (MEG) or triethy-leneglycole (TEG) as the solvent of the glycolysis.

[0342] The instant concept as shown in the exemplary embodiment of FIG. 5 view (B1) and FIG. 5 view (B2) provides a transesterification of the PU flexible foam mass in an upstream stirred tank that carries out a pure glycolysis with DEG. An extra catalyst is not necessarily added to this step; i.e. the pure glycolysis with DEG can be carried out without the presence of a catalyst. This glycolysis destroys the macroscopic structure of the foam flakes and therefore reduces / minimizes the volume of the foam flakes. Temperatures of at least 180 °C - 240 °C are required in this step. Ideally, the slurry also has the temperature of the subsequent reaction, which temperature is around 200°C.

[0343] Thus, the first reactor R1 in the embodiment of FIG. 5 view (B1) or the reactor R in a first state S1 in the embodiment of FIG. 5 view (B2) is adapted to have the PU foam flexible-particulate material being chemically pre-processed, preferably by glycolysis at atmospheric pressure, in particular without a pressure control. In particular in the embodiment of FIG. 5 view (B1) the first reactor R1 has one or more stirred reactor vessels and / or the second reactor R2 has one or more pressure tight reactor vessels; as shown in FIG. 5B view (B1) each reactor R1 , R2 has a separate vessel.

[0344] By this concept of the embodiment of FIG. 5 view (B2) a better decoupling of pneumatic conveyor and reactor is achieved. The use of two separate units for the first and second reactor R1 , R2 has the advantage that there is sufficient time for dosing by the pneumatic air conveyor as this is the time-limiting step.

[0345]

[0346] Further advantages at least are related in that:

[0347] - it is possible to (partially) degas (air / O2) the foam by compression; the foam thus falls into the reaction mixture of the first reactor R1 at least partially degassed (deoxygenized);

[0348] - possibly a re-expansion in “reaction gas” is allowed for;

[0349] - a volume reduction of foam in pre-reactor R1 is achieved;

[0350] - a dissolution or other reaction of foam to slurry in the first reactor R1 is at least in part achieved;

[0351] - a volume reduction ration (R_p / s) of PU foam flexible-particulate material to PU slurry material is in a range between 15 and 50, in particular between 25 and 30. E.g. a volume reduction from 60L of foam flakes (about 2kg in weight) to an estimated volume of slurry at 2L is possible. A slurry production is possible initially or steadily at atmospheric pressure and reaction temperature of already T = 200°C; - it is also conceivable that the upstream reactor is initially operated in an open mode as described above and after the dosing step is transferred to a closed state (pressure vessel) in which all openings and lids are closed;

[0352] - a stuffing screw is preferred but still optional for the process;

[0353] - an advantage of a stuffing screw or other compressing feeding means is that generally it is possible to press air at least partially out of the bulk foam and a bit out of its cells; thus less oxygen is transported into the main reaction and as a consequence this supports to lower side reactions and / or diminish unwanted side products.

[0354] For the embodiment of FIG. 5 view (B1) the pre-processing temperature T Pre-Reaction of pre-processing the PU foam particulate material by glycolysis in the first reactor R1 to provide the PU slurry material is preferably the same or at least near to the processing temperature T Reaction of processing of the PU slurry material in main processing by a solvolysis in the second reactor R2 to provide the raw materials, wherein the solvolysis is a hydro-glycolysis reaction. In particular wherein the reaction temperature T Pre-Reaction of pre-processing the PU foam particulate material by alcoholysis or glycolysis to provide the PU slurry material is in a range of a reaction temperature T Pre-Reaction between 170 and 230 °C, in particular in a range between 180 and 220 °C, in particular in a range

[0355]

[0356] between 195 °C and 205 °C, preferably at a reaction temperature T Pre-Reac-tion of at least 180 °C or of at least 200 °C. In principle the above parameters also hold for the embodiment of FIG. 5 view (B2).

[0357] The process comprises -only in a subsequent second step- the main chemical reaction; this comprises feeding the PU slurry material into a second reactor of the reactor arrangement. The resulting mass (PU slurry material) of the preliminary glycolysis can subsequently be conveyed / pumped into the pressure vessel with a suitable pump when using two vessels and a subsequent hydrolysis (residual glycolysis) can be carried out to fully remonomerize the flexible polyurethane foam.

[0358] In particular for the embodiment of FIG. 5 view (B1 ), the dosing S12 in step of second kind S12b provides dosing in that the PU slurry material is pumped PP into the second reactor R2 by a conveying arrangement comprising a piping system and dosing the PU slurry material in the piping system to the second reactor, in particular by a dosing arrangement comprising feeding and / or dosing pump.

[0359] The process -for both of the embodiments of FIG. 5 view (B1 ) and view (B2)- then further comprises chemically processing the PU slurry material in a solvolysis (respectively in the second reactor R2 or a in the reactor R of second state S2) to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with diethyleneglycole (DEG) as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis. Preferably, hydro-glycolysis is carried out in the presence of a catalyst agent comprising an amine corresponding to the isocyanate component of the PU material, in this particular case toluenediamine (TDA).

[0360] The raw materials obtained from the chemical processing step in the reactor arrangement preferably comprise TDA and / or polyol.

[0361] The solvolysis in the preferred embodiment is a hydro-glycolysis, as a catalyst the amine corresponding to the isocyanate component of the PU material (e.g,

[0362]

[0363] TDA) is added to the reactor arrangement and water is added to the reactor arrangement. Preferably the reactor arrangement is in a pressurized state (pressure reactor). During the chemical processing step, the reactor arrangement (or the second reactor thereof) is adapted to have the PU slurry material being chemically processed by solvolysis as a hydro-glycolysis at raised pressure above atmospheric pressure, in particular with pressure control.

[0364] A viscosity q of the PU slurry material in the first reactor R1 varies in a comparably wide range even following a small derivation in the ratios of PU foam flexible particulate material on the one hand and DEG on the other hand. Still nevertheless it has also been found that the viscosity q provides only a small window of viscosity range to be preferred from the processing point of view. This holds for the embodiment of FIG. 5 view (B1) wherein the PU slurry material is provided by chemically pre-processing the PU foam flexible-particulate material by glycolysis in the first reactor R1 to provide a PU slurry material from the first reactor. This holds for the embodiment of FIG. 5 view (B2) wherein the PU slurry material is provided by chemically pre-processing the PU foam flexible-particulate material by glycolysis in the reactor R in a first state S1 to provide a PU slurry material from the reactor R,

[0365] Therein the glycolysis is effected with diethyleneglycole (DEG) as a solvent of the glycolysis.

[0366] With reference to FIG. 6 , it has been found that a range of viscosity q for pumping the PU slurry material has advantages in the range as outline according to FIG. 6 in the preferred temperature range around 200°C. A limit range of preferred viscosity is related at the reaction temperature of or around 200 °C.

[0367] Therefrom it can be retrieved that the PU slurry material preferably should have a viscosity of q in a range between 250 and 350 mPa*s, in particular in a range between 280 and 320 mPa*s, in particular in a range between 295 and 305 mPa*s, preferably a viscosity value q of approximately 300 mPa*s, when measured at a temperature T of approximately 200°C.

[0368]

[0369] Thus the ratios of PU foam flexible particulate material and DEG should be provided for the pre-processing step preferably as indicated in the following, i.e. broadly preferred is a slurry mixture for the PU slurry material of 70-86 wt% of PU foam flexible particulate material and, respectively, more than 14-30 wt% of DEG wherein the said glycolysis-educt-ratios sum up to 100%.

[0370] Currently, in a preferred example, contents of 78.6 % of PU foam flexible-particulate material and 21.4 % DEG is suggested as being preferred for a viscosity of = -300 mPa*s at T_Reaction= 200°C.

[0371] The preferred example depicted in FIG. 6 show that in a preferred example advantages in the above concept result from the current slurry concentration. The amount of foam and DEG is set for preferred slurry-properties and / or pumpability at comparingly high (but not too high) viscosity.

[0372] High concentrations of PU foam flexible-particulate material hinder pumpability of the slurry and result in longer residence times for dissolution in pre-reactor R1 or reactor R of first state S1. It is shown by comparative example that an upper boarder is provided preferably with 85% content of PU foam flexible particulate material provided to a PU slurry material. The high concentration in limit would at most be accepted at a content of 85.7 % of foam and 14.3% of DEG. Thus, this preferably has to be observed for feeding the PU flexible-particulate material into a reactor R1 , R of the reactor arrangement.

[0373] Low-viscosity media are generally easier to pump. However, the composition depends on the recipe required to break down the foam, resulting in a ratio of approximately 21 wt% DEG to approximately 79 wt% of PU foam. This is a compromise between maximizing the yield and pumpability. A higher yield (i.e. higher ratio of “PU foam to DEG” or generally a higher ratio of PU foam to alcohols (diols) or virgin polyols and repolyols) also means that more valuable product (e.g., polyol and isocyanate) is achieved in the reaction per batch; still also a more difficult pumpability (higher viscosity) and too long "dissolving time" of the foam flakes may be implied therewith to provide the PU slurry material.

[0374]

[0375] If the “PU foam to DEG ratio” is chosen too low, a PU slurry material can be produced more quickly, but the yield per batch decreases. On the other hand in a comparative example it has been found that already at a content of PU foam flexible particulate material of 85.7% the viscosity is too high and thus pumpability could be questionable.

[0376] Thus, the preferred content of PU foam flexible particulate material to provide the PU slurry material from the glycolysis reaction in reactor R1 or reactor R should stay within at least the range of 76% and 82%, preferably stay in a range of between 77% to 79%.

[0377] It should be noted that it is more preferred -in that or a broader range- that the content of PU foam flexible particulate material is preferably chosen in rather lower amount than in a higher amount in that range. The reason is that the higher the content of PU foam flexible particulate material is in the slurry the higher the viscosity of the slurry will be and thus the more pumpability possibly will be questioned.

[0378] Chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor R1 , R is adapted to provide a favorable PU slurry material, wherein the alcoholysis is effected using a diol. For chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor R1 , R to provide a favorable PU slurry material the ratios of PU foam flexible particulate material and al-coholes (dioles), in particular virgin polyole and repolyole, should be provided for said pre-processing step.

[0379] Example - the conditions should preferably be set as indicated in the following:

[0380] A slurry mixture for the PU slurry is broadly preferred as a material of 50-90 wt% of PU foam flexible particulate material and, respectively, more than 10-50 wt% of alcohols (dioles), in particular virgin polyole and repolyole, wherein the said gly-colysis-educt-ratios sum up to 100%.

[0381]

[0382] ln a preferred example contents of 40-50 % of PU foam flexible-particulate material and 50-60 % virgin polyole and repolyole is suggested as being preferred for a viscosity of q= -300 mPa*s at T_Reaction= 200°C.

[0383] The amount of foam and alcohole (Diole), in particular virgin polyole and repolyole, is set according to receive favorable slurry-properties and / or a preferred pumpability at comparingly high but not too high viscosity. As outlined above high concentrations of PU foam flexible-particulate material hinder pumpability of the slurry and result in longer residence times for dissolution in pre-reactor R1. Low-viscosity media are generally easier to pump. However, the composition depends on the required recipe to break down the foam.

[0384] In summary, the PU slurry material preferably is received from glycolysis-educt-ratios of less than 80% PU foam flexible-particulate material and more than 20% DEG, wherein the glycolysis-educt-ratios sum up to 100%, in particular wherein the PU foam particulate material forms a glycolysis-educt-ratio of between 77% to 79%.

[0385] Preferably the PU slurry material is received from glycolysis-educt-ratios of not more than 82% PU foam flexible-particulate material and not less than 18% DEG, wherein the glycolysis-educt-ratios sum up to 100%. Preferably the PU slurry material is received from glycolysis-educt-ratios of not less than 76% PU foam flexible-particulate material and not more than 24% DEG, wherein the glycolysis-educt-ratios sum up to 100%.

[0386] Turning to the preferred example of a method as shown with the process flow diagram in FIG. 6 in detail a summary of a best mode example of the process is shown.

[0387] The flow chart shows a preferred example of a dosing step D1 followed by a chemical part of the chemically processing. The chemical part comprises a first chemical part of the chemically processing in the first reactor R1 (or a reactor R in a first state S1) with process steps G1 , G2 and G3 and a second chemical part

[0388]

[0389] of chemically processing in a second reactor R2 (or the said reactor R in a second state S2) with process steps H1 and H2.

[0390] As has been explained with the preferred example of processing of FIG. 4 view B a first step of dosing S12a is shown, namely with a stuffing screw SS or the like force-feeding device FF for PU foam flexible particulate material being force-feeded to the first the reactor R1 or a reactor in a first state S1.

[0391] In the first reactor R1 or a reactor in a first state S1 the chemically pre-processing as a pure glycolysis is executed with the preferred viscosity and temperature preferences as indicated in step G1 , G2. The solvent for glycolysis preferably is DEG as indicated in step G3.1 , whereas other solvents are also possible in addition thereto as preferably indicated in step G3.2.

[0392] In a second part the slurry is fed to the second reactor R2 by a pressure pump PP or the like liquid conveying means; this has been addressed with the second dosing step S12b in FIG. 5 view (B1 ) and view (B2).

[0393] The second reactor R2 as shown in FIG. 5 view (B1 ) is a pressure reactor for executing a hydro-glycolysis as indicated in step H2. Therein the volume of the pressure reactor R2 can be designed within the practicable margins as the volume reduction of the PU foam flexible particulate material is provided due to the pre-processing of the slurry in the first reactor R1. In another embodiment of FIG.

[0394] 5 view (B2) the reactor R can be set from a first state S1 to another pressurized state S2 for executing a hydro-glycolysis as indicated in step H2.

[0395] In summary, the invention is directed to a method of recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material in a process, the process comprising the steps of:

[0396] - mechanically pre-processing the PU material to provide a PU particulate material,

[0397] - feeding the PU particulate material into a reactor arrangement, and

[0398] - chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU material.

[0399]

[0400] Therein

[0401] - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and

[0402] - the reactor arrangement comprises at least one reactor.

[0403] According to the invention chemically processing of the PU particulate material comprises the steps of:

[0404] - feeding the PU flexible-particulate material into a reactor of the reactor arrangement and chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor to provide a PU slurry material, wherein the alcoholysis is effected using a diol, and

[0405] - chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0406] Accordingly in the arrangement for recycling a polyurethane (PU) material - the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and

[0407] - the reactor arrangement comprises at least one reactor.

[0408] According in the invention therein

[0409] - a reactor of the at least one reactor is adapted for chemically pre-processing the PU flexible-particulate material by alcoholysis to provide a PU slurry material, wherein the alcoholysis is effected with a diol,

[0410] - wherein a reactor of the at least onereactor is adapted for chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

[0411] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

[0412]

[0413] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0414] A single unit or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different de-pendent claims does not indicate that a combination of these measures cannot be used to advantage.

[0415] Any reference signs in the claims should not be construed as limiting the scope.

[0416]

[0417] Reference list

[0418] SS stuffing screw

[0419] PP pressure pump

[0420] FF Force-feeding device

[0421] R1 first reactor

[0422] R2 second reactor

[0423] S0.1 - S0.4, SO collection steps

[0424] S1.1 - S1.3, S1 mechanical pre-processing

[0425] S12, S12a, S12b dosing steps

[0426] S2, S21 , S22 chemical processing

[0427] D1 process step of mechanical pre-processing G1, G2, G3 process steps of glycolysis

[0428] H1, H2 process steps of hydro-glycolysis

Claims

CLAIMS1. Method of recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU material from said PU material in a process, the process comprising the steps of:- mechanically pre-processing the PU material to provide a PU particulate material,- feeding the PU particulate material into a reactor arrangement, and- chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU material, wherein- the PU particulate material is provided from the mechanically pre-processing as a PU flexible-particulate material, and- the reactor arrangement comprises at least one reactor, wherein chemically processing of the PU particulate material comprises the steps of:- feeding the PU flexible-particulate material into a reactor of the reactor arrangement and chemically pre-processing the PU flexible-particulate material by alcoholysis in the reactor to provide a PU slurry material, wherein the alcoholysis is effected using a diol, and- chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

2. Method of claim 1 , characterized in that the solvolysis in the step of chemically processing the PU slurry material is effected in the presence of a catalyst agent, in particular a catalyst agent comprising an amine corresponding to the isocyanate component of the PU material.

3. Method of claim 1 or 2, characterized in that the alcoholysis is a glycolysis, and / or- the alcoholysis, in particular the glycolysis, in the step of chemically pre-processing the PU flexible-particulate material is effected using the diol, wherein the diol is in form of a diol agent, the diol agent comprising the diol in form of a, in particular polymeric, polyol or re-polyol as a solvent for the alcoholysis and the first solvent of the solvolysis, in particular the diol in form of a diethyleneglycole (DEG) is used as a solvent for the alcoholysis and the first solvent of the solvolysis.

4. Method as claimed in one of the preceding claims, wherein the reactor arrangement comprises a number of reactors, wherein the at least one reactor is one reactor or a multitude of reactors, wherein- in the reactor arrangement the reactor is one reactor wherein the one reactor (R) is operated in the alcoholysis, in particular in the glycolysis, in a non-pressur-ized operation condition and the one reactor (R) is operated in the solvolysis in a pressurized operation condition, in particular wherein the reactor arrangement comprises the at least one reactor as a single reactor, or- the reactor arrangement comprises the at least one reactor as one of a number of reactors, wherein the reactor arrangement comprises at least a first reactor (R1) and a second reactor (R2), wherein- the first reactor (R1) is operated in the alcoholysis, in particular in the glycolysis, in a non-pressurized operation condition and the second reactor (R2) is operated in the solvolysis in a pressurized operation condition, and / or- the PU flexible-particulate material is fed into the first reactor (R1) of the reactor arrangement for chemically pre-processing the PU flexible-particulate material and providing the PU slurry material; and- the PU slurry material is fed into the second reactor (R2) of the reactor arrangement for chemically processing the PU slurry material in the solvolysis.

5. Method as claimed in one of the preceding claims, characterized in that the feeding of the PU slurry material into the second reactor comprises:- conveying the PU slurry material from the first reactor by a conveying arrangement, in particular by a conveying arrangement comprising a piping system,- dosing the PU slurry material in the piping system to the second reactor, in particular by a dosing arrangement comprising feeding and / or dosing pump.

6. Method as claimed in one of the preceding claims, characterized in that - the chemically pre-processing of the PU particulate material is a glycolysis with diethyleneglycole (DEG) as the only added solvent of the glycolysis, in particular basically without aqueous agent and / or without catalyst agent, orthe chemically pre-processing of the PU particulate material is a glycolysis that includes in addition or in alternative to diethyleneglycole (DEG) as the solvent of the glycolysis, low molecular weight polyalkylene diols, diethyleneglycol, triethyleneglycol, tetraethyleneglycol, pentaethyleneglycol or mixtures thereof, preferably in the molecular weight range from 180 to 800, in particular in eluding monoethyleneglycole (MEG) and / or triethyleneglycole (TEG).

7. Method as claimed in one of the preceding claims, characterized in that the raw materials obtained by chemically processing the PU slurry material comprise an isocyanate component of the PU material complementary amine and / or polyol, in particular the raw materials obtained by chemically processing the PU slurry material comprise aromatic diisocyanates (e.g. TDI, MDI) and polyol.

8. Method as claimed in one of the preceding claims characterized in that the solvolysis of the chemically processing of the PU slurry is a hydro-glycolysis, wherein the isocyanate component of the PU material complementary amine as the catalyst agent and water as the second solvent are added in the reactor arrangement, in particular wherein the reactor arrangement has a pressurized vessel reactor for the hydro-glycolysis.

9. Method as claimed in one of the preceding claims, characterized in that - the reactor arrangement, in particular a first reactor, is adapted to have the PU flexible-particulate material being chemically pre-processed by alcoholysis, preferably by glycolysis, at atmospheric pressure, in particular without a pressure control, and / or- the reactor arrangement, in particular a second reactor different from the first reactor, is adapted to have the PU slurry material being chemically processed bysolvolysis as a hydro-glycolysis at raised pressure above atmospheric pressure, in particular with a pressure control.

10. Method as claimed in one of the preceding claims, characterized in that - the reactor arrangement comprises one or more stirred reactor vessels for chemically pre-processing the PU flexible-particulate material and / or one or more pressure tight reactor vessel for chemically processing the PU slurry material, and / or- the reactor arrangement comprises a first reactor vessel of first raised temperature and a second reactor vessel of second raised temperature.

11. Method as claimed in one of the preceding claims, characterized in that - the PU flexible-particulate material is in the form of PU flakes of low bulk density, and / or- the PU slurry material is received from alcoholysis-educt-ratios of between 70 wt% and 86 wt% of PU flexible-particulate material and between 14 wt% and 30 wt% of DEG, in particular approximately 79 wt% PU flexible-particulate material and 21 wt% of DEG, wherein the weight percentages of the alcoholysis-educt-ra-tios sum up to 100 %.

12. Method as claimed in one of the preceding claims, characterized in that - the PU slurry material has a viscosity (q) in a range between 250 to 350 mPa*s, in particular in a range between 280 to 320 mPa*s, in particular in a range between 295 to 305 mPa*s, preferably a viscosity (q) of 300 mPa*s, measured at a temperature (T) of 200°C,and / or- the pre-processing temperature (T Pre-Reaction) of pre-processing the PU foam particulate material by glycolysis in the first reactor (R1) to provide the PU slurry material is the same or at least near to the processing temperature (T_Re-action) of processing of the PU slurry material in a solvolysis in the second reactor (R2) to provide the raw materials, wherein the solvolysis is a hydro-glycolysis reaction, and / or wherein- the reaction temperature (T Pre-Reaction) of pre-processing the PU foam par-ticulate material by glycolysis in the first reactor (R1) to provide the PU slurry material is in a range of a reaction temperature (T Pre-Reaction) between 140 °C and 230 °C, in particular in a range between 180 °C to 220 °C, in particular in a range between 195 °C and 205 °C, preferably at a reaction temperature (T_Pre-Reaction) of at least 200 °C.

13. Method as claimed in one of the preceding claims, characterized in that the feeding of the PU particulate material into the reactor arrangement comprises: - conveying the PU particulate material from a bunker by a conveying arrangement, in particular by a conveying arrangement comprising a conveyer belt and / or a pneumatic conveying apparatus- dosing the PU particulate material from the conveying arrangement to the first reactor, in particular by a dosing arrangement comprising rotary feeder and / or a stuffing screw,in particular wherein for feeding the PU particulate material into the reactor arrangement, the at least one reactor is fed by means of a dosing device, in particular wherein the dosing device is adapted for feeding, in particular force-feeding, the PU particulate material into a the reactor through a vapor barrier, and / or- further comprising applying pressure to the PU flexible-particulate material to degas gaseous content and / or to separate water from the PU flexible-particulate material, and / ora pressurizing device adapted to apply pressure to the PU particulate material is adapted to compress the PU particulate material in range of more than 1 :7, in particular more than 1 :10.

14. PU slurry material received from chemically pre-processing a PU flexibleparticulate material by alcoholysis in a reactor to provide the PU slurry material in a method of any of the preceding claims.

15. Arrangement for recycling a polyurethane (PU) material to recover raw materials for the fabrication of recycled PU foam from said PU material in a process arrangement, in particular wherein the arrangement is adapted to execute the method as claimed in one of the preceding claims, the process arrangementcomprising:- a pre-processing arrangement for mechanically pre-processing the PU material to provide a PU particulate material,- a feeding arrangement for feeding the PU foam particulate material into a reactor arrangement, and- a chemical processing arrangement for chemically processing the PU particulate material in the reactor arrangement for recovering the raw materials for the fabrication of recycled PU foam, wherein- the PU particulate material is provided from the pre-processing arrangement as a PU flexible-particulate material, and- the reactor arrangement of the chemically processing comprises at least one reactor, andwherein a reactor of the at least one reactor is adapted for chemically pre-processing the PU flexible-particulate material by alcoholysis to provide a PU slurry material, wherein the alcoholysis is effected with a diol,- wherein a reactor of the at least onereactor is adapted for chemically processing the PU slurry material in a solvolysis to provide the raw materials, wherein the solvolysis is a hydro-glycolysis effected with the diol as a first solvent of the solvolysis, an aqueous agent as a second solvent of the solvolysis.

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