Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J11/00—Recovery or working-up of waste materials
  • C08J11/02—Recovery or working-up of waste materials of solvents, plasticisers or unreacted monomers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/04—Disintegrating plastics, e.g. by milling
  • B29B17/0412—Disintegrating plastics, e.g. by milling to large particles, e.g. beads, granules, flakes, slices
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/02—Preparation of carboxylic acid esters by interreacting ester groups, i.e. transesterification
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/03—Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0203—Separating plastics from plastics
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0217—Mechanical separating techniques; devices therefor
  • B29B2017/0224—Screens, sieves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0217—Mechanical separating techniques; devices therefor
  • B29B2017/0231—Centrifugating, cyclones
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0262—Specific separating techniques using electrical caracteristics
  • B29B2017/0265—Electrostatic separation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0293—Dissolving the materials in gases or liquids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B17/00—Recovery of plastics or other constituents of waste material containing plastics
  • B29B17/02—Separating plastics from other materials
  • B29B2017/0213—Specific separating techniques
  • B29B2017/0293—Dissolving the materials in gases or liquids
  • B29B2017/0296—Dissolving the materials in aqueous alkaline solutions, e.g. NaOH or KOH
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
  • B29K2027/06—PVC, i.e. polyvinylchloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/0005—Condition, form or state of moulded material or of the material to be shaped containing compounding ingredients
  • B29K2105/0038—Plasticisers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
  • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
  • C08J2327/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
  • C08J2327/06—Homopolymers or copolymers of vinyl chloride
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/141—Feedstock
  • Y02P20/143—Feedstock the feedstock being recycled material, e.g. plastics
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

• the invention relates to the field of recycling plastics based on polyvinyl chloride (PVC), in particular a process for extracting and transforming phthalates, plasticizers used in the composition of PVC, by transesterification. More specifically, the invention relates to a process for recovering a dialkylphthalate (DAP) and a reusable target PVC plastic from a PVC load containing at least one phthalate.
• PVC polyvinyl chloride
• DAP dialkylphthalate
• reusable target PVC plastic from a PVC load containing at least one phthalate.
• a plastic is a mixture made up of a basic polymeric material and numerous additives, the whole being capable of being molded or shaped (generally hot and/or under pressure), in order to lead to a semi -product or an object.
• a commonly accepted practice is to name said plastic by the name of the polymer which constitutes it.
• the polyvinyl chloride (PVC) plastic actually corresponds to the combination of the PVC polymer, referred to in the remainder of the description as “PVC resin”, with various additives chosen according to the functionalities required for said plastic.
• Said additives can be organic molecules or macromolecules or inorganic (nano)particles and are used according to the properties they confer on the PVC resin: resistance to heat, light or mechanical stress (stabilizers), flexibility (plasticizers), ease of implementation (lubricants), coloring (dyes/pigments), etc.
• the patents EP0945481, EP1268628 and EP2276801 aim to respectively recycle various PVC-based objects (flexible or rigid pipes, window frames, cables, etc.) and specifically PVC-based objects reinforced with fibers (tarpaulins , floor coverings, etc.) according to a process involving a first step of dissolution in an organic solvent of the PVC resin and soluble additives, followed by a second step of precipitation with water vapor allowing the recovery of resin and most additives.
• phthalates dibutyl phthalate (DBP), dioctyl or diethylhexyl phthalate (DOP or DEHP), benzyl and butyl phthalate (BBP), diisobutyl phthalate (DIBP), dipentyl phthalate (DPP), diisopentyl phthalate, n-pentyl and isopentyl phthalate, dihexyl phthalate, etc.
• DBP dibutyl phthalate
• DIBP diisobutyl phthalate
• DPP dipentyl phthalate
• diisopentyl phthalate diisopentyl phthalate
• n-pentyl and isopentyl phthalate dihexyl phthalate, etc.
• the phthalate plasticizers used today in Europe represent high value-added additives which are not valued as they are when kept in the recycled raw material PVC .
• these are expensive products present in non-negligible proportions in the initial formulations of PVC (several tens of percent) and not making it possible to confer directly on the MPR PVC the ad hoc flexibility properties.
• the addition of "fresh" plasticizers in substantial quantities is then essential for the reusability of the recycled PVC material.
• Patent JP2007092035 discloses another example of possible implementation with dissolution of the PVC resin and at least the phthalate-type additives via the use of a solvent under supercritical conditions and the recovery of said phthalates in this same solvent after "rupture" of said supercritical conditions.
• the elimination or recovery of additives of the phthalate type from a PVC plastic can also be implemented without going through a preliminary step of dissolving said plastic, in particular via a direct extraction of said phthalates from the solid polymer matrix by an organic solvent.
• adequate as is perfectly listed in the publication by Ügdüler et al., 2020, “Challenge and opportunities of solvent-based additive extraction methods for plastic recycling”, Waste Management, 104, 148-182.
• the challenge then lies in optimizing the extraction conditions (nature of the solvent, contact time, temperature, pressure, etc.) to achieve the best possible yields of extracted phthalates.
• this methodology for eliminating phthalates from PVC plastics is frequently used, in particular to detect and analytically quantify these specific additives in said plastics, to our knowledge, no process for regenerating PVC-based objects involves this technique.
• the present invention aims to overcome, at least in part, the problems of the prior art, and aims in particular to provide a process for regenerating PVC-based objects allowing the treatment of any type of PVC load containing phthalates and their transformation into two products of interest likely to be recovered: a specific dialkylphthalate and a recyclable PVC plastic free of phthalates, in particular undesirable phthalates, typically those subject to authorization by the European REACH regulations.
• Another objective of the present invention is to limit, during the recycling of PVC containing phthalates, the number of unit steps conventionally associated with the operations of separation/purification of phthalates, thus making it possible to limit the costs of the process.
• the present invention proposes, according to a first aspect, a process for recovering a dialkylphthalate and a reusable target PVC plastic from a load of PVC containing at least one phthalate, comprising the following steps: a) a solid-liquid extraction of the said PVC filler in the form of particles by bringing the particles of the PVC filler into contact with a solvent comprising at least one alcohol of formula C n H 2n+i OH, n positive integer less than 4 or greater than 8, to produce a liquid phase enriched in said phthalate and a solid phase comprising PVC plastic depleted in said phthalate; b) the chemical transformation of said phthalate of the liquid phase into dialkylphthalate of formula C6H4(COOC n H2 n+i )2 by transesterification by means of said alcohol in order to enrich said liquid phase in said dialkylphthalate; c) a solid-liquid separation between said solid phase and said liquid
• An interest of the present invention lies in the ability of the process, thanks to a chemical transesterification reaction, to transform a mixture of phthalates initially trapped in polymer matrices of various PVC plastic-based objects, regardless of the composition of said mixture ( i.e. whatever the nature and origin of the different phthalates) and despite the possible presence of many other additives, into a single REACH compatible and recoverable phthalate product of the DAP type.
• Obtaining only the specific DAP product from the mixture of phthalates also makes it possible to limit the number of unit steps associated with the separation/purification operations and therefore to limit the costs.
• steps a) and b) are implemented within the same unitary operation.
• steps a) and b) are the subject of two separate unit operations, step a) producing a stream comprising the liquid phase and the solid phase.
• step c) can be carried out between steps a) and b), the flow comprising the liquid phase and said solid phase resulting from step a) being able to be sent to step c) of separation solid-liquid to produce the stream comprising the PVC plastic depleted in said phthalate and a first liquid stream comprising the liquid phase sent to step b).
• the method further comprises an additional step fi) of chemical transformation by transesterification of said unconverted phthalate and/or partially in step b), into dialkylphthalate of formula CeHMCOOC n hb n+i by means of said alcohol, said step fi) being carried out between steps c) and d) by sending said liquid phase obtained at the end of all steps a), b) and c) into a first additional transesterification reactor for producing a second liquid stream enriched in said dialkylphthalate of formula CeHMCOOC n hb n+i , said second liquid stream being sent to step d).
• said solvent is topped up and/or at least part of said second liquid effluent comprising at least said solvent from step d) is recycled in the first additional transesterification reactor.
• said first liquid effluent consists essentially of said dialkylphthalate.
• step d) of liquid-liquid separation also produces a third effluent comprising by-products of alcohol type (AL) obtained during step b) and optionally a fourth comprising phthalate partially converted and/or not converted in step b) and optionally other soluble impurities, said first liquid effluent consisting essentially of said dialkylphthalate and said second effluent consisting essentially of said solvent.
• A alcohol type
• step d) of liquid-liquid separation also produces a third effluent comprising by-products of alcohol type (AL) obtained during step b), said first liquid effluent comprising said dialkylphthalate, partially converted and/or unconverted phthalate in step b) and optionally soluble impurities, said second liquid effluent consisting essentially of said solvent, and the method further comprises a step e) of purifying said first liquid effluent to producing a liquid product consisting essentially of said dialkylphthalate, and a liquid residue comprising said partially converted and/or unconverted phthalate in step b) and optionally said soluble impurities.
• A alcohol type
• the method further comprises an additional step f 2 ) of chemical transformation by transesterification of said unconverted and/or partially converted phthalate in step b), into dialkyl phthalate of formula CeHMCOOC n hb n+i by means of said alcohol, said step f 2 ) being carried out successively at step e) by sending said liquid residue into a second additional transesterification reactor to produce a third liquid stream enriched in said dialkylphthalate of formula CeHUiCOOC n hh n+i , said third liquid stream being returned to step d).
• said solvent is topped up and/or at least part of said second liquid effluent comprising at least said solvent from step d) is recycled in the second additional transesterification reactor.
• the method further comprises the recycling of at least a portion of said liquid residue (17) in step b) and/or in an additional step fi) of chemical transformation by transesterification of said phthalate not converted and/or partially converted in step b), into dialkylphthalate of formula CeHUiCOOC n hh n+i by means of said alcohol, said step fi) being carried out between steps c) and d) by sending said liquid phase obtained to the end of all steps a), b) and c) in a first additional transesterification reactor to produce a second liquid stream enriched in said dialkylphthalate of formula CeHUiCOOC n hh n+i , said second liquid stream being sent to step d).
• the second liquid effluent comprising at least the solvent resulting from stage d) is recycled, at least in part, to stage a) and/or stage b).
• the solid stream comprising the PVC plastic depleted in phthalates is recycled at least in part to step a).
• the alcohol is chosen from the list consisting of methanol, ethanol, n-propanol, /-propanol, and preferably methanol, or from the list consisting of nonanol, linear or branched, decanol, linear or branched, undecanol, linear or branched, dodecanol, linear or branched, and preferably nonanol or decanol.
• the solvent further comprises an organic co-solvent, preferably the organic co-solvent being chosen from an ester derived from said alcohol and having the formula R'COOC n H2n+1, n being identical to n of said alcohol and R' being an alkyl group, preferably comprising between 1 and 3 carbon atoms, and an ether, said organic co-solvent being added to said alcohol so that the mass ratio between said organic co-solvent and said alcohol is between 0.01 and 4.
• an organic co-solvent preferably the organic co-solvent being chosen from an ester derived from said alcohol and having the formula R'COOC n H2n+1, n being identical to n of said alcohol and R' being an alkyl group, preferably comprising between 1 and 3 carbon atoms, and an ether, said organic co-solvent being added to said alcohol so that the mass ratio between said organic co-solvent and said alcohol is between 0.01 and 4.
• the organic co-solvent is selected from the group consisting of methyl acetate, methyl propanoate, and cyclopentyl methyl ether.
• G alcohol is methanol
• the dialkylphthalate is dimethylphthalate
• the solvent preferably comprises methyl propanoate added to methanol so that the mass ratio between the methyl propanoate and the alcohol is comprised between 0.01 and 4.
• the chemical transformation carried out by transesterification in stage b), and optionally in stage fi) and/or f), is carried out by means of a transesterification catalyst, preferably chosen from the list consisting of basic homogeneous catalysts, or inorganic or organic Bronsted acids, or Lewis acids, and heterogeneous catalysts formed by oxides of alkaline earth metals, or carbonates or hydrogen carbonates of alkali and/or alkaline metals -earth, or alkali metals supported on aluminas or zeolites, or zinc oxides and mixtures thereof with other oxides, or ion exchange resins.
• a transesterification catalyst preferably chosen from the list consisting of basic homogeneous catalysts, or inorganic or organic Bronsted acids, or Lewis acids, and heterogeneous catalysts formed by oxides of alkaline earth metals, or carbonates or hydrogen carbonates of alkali and/or alkaline metals -earth, or alkali metals supported on aluminas or
• said at least one phthalate of said PVC filler is a phthalate of molecular formula CH (COORI)(COOR ) whose ester groups are in the position ortho to the benzene nucleus, Ri or R being chosen independently from one of the members of the group consisting of an alkyl chain, linear or branched or cyclic, an alkoxyalkyl chain, linear or branched, or an aryl or alkylaryl chain, R1 and/or R preferably comprising between 1 and 20 carbon atoms, or even between 1 and 15 carbon atoms.
• the target PVC plastic is substantially free of said phthalate, and preferably comprises less than 0.1% by weight in total of phthalates chosen from the list consisting of dibutyl phthalate, dioctyl phthalate or diethylhexyl , benzyl and butyl phthalate, dibutyl phthalate, diisobutyl phthalate, dipentyl phthalate, diisopentyl phthalate, n-pentyl and isopentyl phthalate, dihexyl phthalate, bis(2-methoxyethyl) phthalate, and mixtures thereof.
• phthalates chosen from the list consisting of dibutyl phthalate, dioctyl phthalate or diethylhexyl , benzyl and butyl phthalate, dibutyl phthalate, diisobutyl phthalate, dipentyl phthalate, diisopentyl phthalate, n-pentyl
• step b), and optionally steps f) and/or f), are carried out at a temperature between room temperature and 200° C., preferably between 40° C. and 180° C. °C, at a pressure between atmospheric pressure and 11.0 MPa, preferably between atmospheric pressure and 5.0 MPa, and for a time between 1 minute and 10 hours, preferably between 10 minutes and 4 hours.
• step a) and/or step b), and optionally steps fi) and/or f), are carried out so that the molar ratio between the quantity of alcohol in the solvent and the quantity of said phthalate to be extracted or converted is between 2 and 250, preferably between 4 and 90.
• the present invention relates to a process for recycling a PVC-based object containing at least one phthalate comprising:
• the packaging of said PVC-based object comprising at least one grinding or shredding of said PVC-based object to form a PVC filler in the form of particles;
• the present invention relates to a process for manufacturing a flexible PVC-based object comprising a recycled PVC plastic and/or a dialkylphthalate obtained by the process for recovering a dialkylphthalate and a target PVC plastic reusable according to the invention.
• FIG. 1 is a diagram of the method according to one embodiment of the invention comprising steps a), b), c) and d).
• FIG. 2 is a diagram of the process according to another embodiment comprising stages a), b), c) and d), with in stage d) a separation between the DAP, the solvent, the by-products of alcohol type obtained in step b) and the partially converted and/or unconverted phthalates in step b) optionally mixed with soluble impurities.
• FIG. 3 is a diagram of the process according to the embodiments illustrated in FIG. 1 or in FIG. 2, comprising steps a), b), c), d), and illustrating the implementation of other optional steps transesterification (fi) and recycling of various streams.
• FIG. 4 is a diagram of the process according to another embodiment of the invention comprising steps a), b), c), d) as well as a purification step e) of a first effluent obtained at the step d) comprising the DAP.
• FIG. 5 is a diagram of the process according to the embodiment illustrated in FIG. 4, and illustrating the implementation of other optional steps of transesterification (fi; f ) and recycling of various streams.
• FIG. 6 is a diagram of the process according to a preferred embodiment of the invention, comprising an implementation within the same unitary operation of steps a) and b) (first variant of the process according to the invention), a purification step e) of a first effluent obtained in step d) comprising the DAP and an additional transesterification step f) of the residue resulting from step e).
• FIG. 7 is a diagram of the process according to another embodiment of the invention comprising steps a), b), c), d), in which steps a) and b) are the subject of two unit operations distinct (second variant of the method according to the invention), and in which step c) is carried out between steps a) and b).
• FIG. 8 is a diagram of the process as illustrated in FIG. 7, according to a preferred embodiment comprising a step of purification e) of a first effluent obtained in step d) comprising the DAP and an additional step of transesterification f) of the residue from step e).
• PVC-based object an object, generally for consumption, which comprises, and preferably consists of, at least one PVC plastic.
• polyvinyl chloride plastic also called PVC plastic or simply PVC
• PVC plastic the combination of a PVC polymer, also called PVC resin, with various additives chosen according to the functionalities required for the PVC plastic, themselves chosen according to the targeted applications.
• Said PVC polymer is derived from the radical polymerization of vinyl chloride (VCM), a monomer itself obtained from chlorine and ethylene.
• VCM vinyl chloride
• a monomer itself obtained from chlorine and ethylene.
• four families of PVC resins can be used: 1) suspension PVC resins or PVC-S (polymerization in suspension of VCM), 2) emulsion PVC resins or “paste” PVC (polymerization in emulsion), 3) mass PVC or PVC-M resins (mass polymerization) and 4) overchlorinated PVC or PVC-C resins, obtained by over-chlorination in post-treatment of the preceding resins.
• Said additives entering into the composition of a PVC plastic can be organic molecules or macromolecules or else inorganic (nano)particles and are used according to the properties that they confer on the PVC resin: resistance to heat, to light or mechanical stress (stabilizers), flexibility (plasticizers), ease of processing (lubricants), coloring (dyes/pigments), etc.
• phthalates is meant the group of chemicals formed by the carboxylic diesters of o-phthalic acid. They are composed of a benzene ring and two carboxylic ester groups placed in the ortho position of the benzene ring. They can be described using the following formula: Cheml or also by the formula C 6 H 4 (COORI)(COOR 2 ), where Ri and R 2 are chosen independently from one of the elements of the group consisting of an alkyl, linear, branched or cyclic chain, an alkoxyalkyl chain, linear or branched, or an aryl or alkylaryl chain, said alkyl, alkoxyalkyl, aryl or alkylaryl chain typically possibly comprising between 1 and 20 carbon atoms, or even comprising between 1 and 15 carbon atoms.
• Ri and/or R 2 can be chosen from ethyl, n-butyl, iso-butyl, n-pentyl, iso-pentyl, n-hexyl, n-octyl, n-nonyl, iso-nonyl, n -decyl, isodecyl, methoxyethyl, benzyl.
• Phthalates are commonly used as plasticizers for plastic materials and in particular as plasticizers for plastics of the PVC type, in particular to make them flexible.
• dialkylphthalate denotes the product of molecular formula C 6 H 4 (COOC n H 2n+i ) 2 resulting from the transesterification reaction between at least one plasticizer of the phthalate type (and in particular of formula C 6 H 4 (COORI)(COOR 2 ), as described above) present in PVC-based objects with an alcohol of formula C n hh n+i OH, n ⁇ 4 or n > 8 Dimethylphthalate is an example of DAP.
• the definition of said alcohol of structural formula C n hh n+i OH, n ⁇ 4 or n > 8 can also include its conjugate base of structural formula of C n hh n+i O , with n ⁇ 4 or n>8, the cationic counterion, including metallic in nature, ensuring the electronegativity of said conjugate base being well known to those skilled in the art.
• Said conjugate base is also called the "alcoholate" or "alkoxide" form of said alcohol.
• alcohol-type by-product(s) means the by-product(s) of formula RiOH or R 2 OH resulting from the transesterification reaction between at least one phthalate-type plasticizer present in PVC-based objects with the alcohol of molecular formula C n H 2n+i OH, n ⁇ 4 or n > 8.
• Ri or R 2 are defined identically to Ri and R 2 of phthalates.
• the definition of said by-product of alcohol type of formula RiOH or R 2 OH can also include its conjugate base of molecular formula RiO or R 2 O .
• intermediate alkylphthalate or “partially converted phthalate” means the by-product of molecular formula C6H 4 (COORi)(COOC n H 2n+i ) or C6H 4 (COOR 2 )(COOC n H 2n+ i ) resulting from the incomplete transesterification reaction between at least one plasticizer of the phthalate type (and in particular of formula CeH 4 (COORi)(COOR 2 ), as described above) present in PVC-based objects with a alcohol of structural formula C n H 2n+i OH, n ⁇ 4 or n > 8.
• Ri or R 2 are defined identically to Ri and R 2 of phthalates.
• reusable target PVC plastic means a “phthalate-free PVC”, that is to say the solid comprising at least the PVC resin added with at least one of the additives initially present in the PVC plastic of the filler of PVC treated according to the invention, and from which the phthalates have been extracted and converted into the form of at least one dialkylphthalate according to the invention.
• free of phthalates mean in particular that the solid PVC obtained as product of the process according to the invention contains, in total, less than 0.1% by weight of phthalates subject to authorization by the REACH regulations in Europe (Annex XIV of Regulation (EC) No.
• phthalates chosen from the list consisting of the following phthalates: dibutyl phthalate (DBP), dioctyl or diethylhexyl phthalate (DOP or DEHP), benzyl butyl phthalate (BBP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), dipentyl phthalate (DPP), phthalate diisopentyl, n-pentyl and isopentyl phthalate, dihexyl phthalate, bis(2-methoxyethyl) phthalate, alone or as a mixture.
• DBP dibutyl phthalate
• DIBP diisobutyl phthalate
• DIBP dipentyl phthalate
• DPP dipentyl phthalate
• phthalate diisopentyl dihexyl phthalate
• bis(2-methoxyethyl) phthalate alone or as a mixture.
• the alcohol of molecular formula C n Eh n+i OH, with n ⁇ 4 or n>8, optionally added with at least one organic co-solvent is also referred to as “solvent”.
• n is a positive integer (that is to say strictly greater than zero). According to the invention, n is less than 4 or greater than 8, and preferably less than or equal to 20, or even less than or equal to 15.
• ambient temperature means a temperature typically of 20° C. ⁇ 5° C.
• atmospheric pressure means a pressure of 0.101325 MPa.
• the different ranges of parameters for a given step such as the pressure ranges and the temperature ranges can be used alone or in combination.
• a range of preferred values of pressure can be combined with a range of more preferred values of temperature.
• the process for recovering a DAP and a reusable target PVC plastic from a PVC load containing at least one phthalate comprises, and may consist of, the following steps: a) a solid-liquid extraction of said PVC filler in the form of particles 1 by bringing said PVC filler particles into contact with a solvent 9 comprising at least one alcohol of formula C n f OH, n ⁇ 4 or n > 8, for producing a liquid phase enriched in said phthalate and a solid phase comprising PVC plastic depleted in said phthalate; b) the chemical transformation of said phthalate of said liquid phase into dialkylphthalate of formula CeEMCOOC n Eb n+i by transesterification using said alcohol to enrich said liquid phase in said dialkylphthalate; c) a solid-liquid separation between said solid phase and said liquid phase to produce at least one solid stream comprising the PVC plastic depleted in said phthalate 6 in order to recover said target PVC plastic; d) a
• PVC filler 1 comprising at least one PVC plastic, which necessarily comprises at least one phthalate as described in the present invention.
• Said PVC plastic may comprise at least 0.1% by mass of phthalates, or even at least 1% by mass of phthalates or even at least 5% by mass of phthalates.
• PVC plastics advantageously comprise less than 60% by weight of phthalates, typically less than 30% by weight of phthalates.
• Said PVC filler is advantageously a PVC filler to be recycled of the "production scrap” type, i.e. waste from the production processes of the PVC polymer during its polymerization or from the PVC plastic during its formulation/shaping or PVC-based object during its production, or of the "post-consumer waste” type, i.e. waste generated after consumption by the user of said PVC-based object.
• production scrap i.e. waste from the production processes of the PVC polymer during its polymerization or from the PVC plastic during its formulation/shaping or PVC-based object during its production
• post-consumer waste i.e. waste generated after consumption by the user of said PVC-based object.
• the PVC load to be recycled can come from any existing collection and sorting channels or networks for production scrap and/or post-consumer waste making it possible to isolate a flow based on at least one plastic PVC containing at least one phthalate, in particular the collection and sorting channels or networks specific to plastic waste.
• the PVC load which is typically of the "production offcuts” and/or “post-consumer waste” type, generally comes from the major user application areas of PVC plastic such as, and in a non-exhaustive manner, building and construction, packaging, automotive, electrical and electronic equipment, sports, medical equipment, etc.
• the PVC filler comes from the field of building and construction.
• PVC-based objects are generally used in these areas as profiles (windows, doors, blinds, roller shutter boxes), pipes and fittings, various rigids and bottles, rigid plates and films, flexible films and sheets, tubes and flexible profiles, cables, floor coverings, coated fabrics, etc.
• the PVC-based objects forming the PVC filler comprise at least so-called flexible PVC, that is to say PVC containing additives of the plasticizer type, preferably of the phthalate type, as is the case for example for the following PVC-based objects: flexible films and sheets, flexible tubes and profiles, cables, floor coverings, coated fabrics, etc.
• the PVC filler comprises at least 50% by mass, preferably at least 70% by mass, preferably at least 90% by mass and even more preferably at least 95% by mass of PVC plastic comprising at least one phthalate.
• the PVC filler comprises so-called flexible PVC, that is to say PVC containing additives of the plasticizer type, preferably of the phthalate type. Even more preferably, the PVC filler comprises mainly, or even exclusively, so-called flexible PVC, that is to say PVC containing additives of the plasticizer type, preferably of the phthalate type.
• the PVC filler treated in the process for recovering a DAP and a reusable target PVC plastic according to the invention is in the form of particles.
• the PVC load is in an initial form which is that specific to production scrap or post-consumer waste, in particular in the latter case in the initial form of PVC-based objects, it may undergo, beforehand, a conditioning step comprising at least one grinding or shredding to form a PVC filler in the form of particles.
• the PVC waste can be crushed and/or washed and/or undergo any other conditioning step as described.
• the PVC filler in the form of particles suitable for the process according to the invention.
• the PVC filler can advantageously be in the form of crushed material, possibly washed, the largest dimension of which is less than 20 cm, preferably less than 10 cm, preferably less than 1 cm and even more preferably less than 5mm.
• the PVC filler can also advantageously be in the form of a micronized solid, that is to say in the form of particles preferably having an average size of less than 1 mm, for example between 10 micrometers (pm) and 800 micrometers (pm ).
• the average size advantageously corresponds to the average diameter of the spheres circumscribed by said particles.
• PVC filler in the form of particles, is meant PVC plastic particles typically having an average size, as defined above, of between 10 ⁇ m and 20 cm, for example shredded type particles having an average size of between 1 mm and 20 cm, preferably between 1 mm and 10 cm, more preferably between 1 mm and 1 cm, even more preferably between 1 mm and 5 mm, or particles resulting from micronization (very fine grinding for produce a powder) with an average size of less than 1 mm, preferably between 10 ⁇ m and 800 ⁇ m.
• the PVC filler treated in the process according to the invention is in the form of particles of the ground type, preferably particles of average size between 1 mm and 5 mm, or particles resulting from micronization (very fine to produce a powder) with an average size of less than 1 mm.
• the PVC filler may also include "macroscopic" impurities, such as glass, metal, plastics other than PVC (e.g. PET, etc.), wood, paper, cardboard, mineral elements, etc.
• the PVC filler comprises at most 50% by mass, preferably at most 30% by mass, preferably at most 10% by mass and even more preferably at most 5% by mass of “macroscopic” impurities.
• the PVC filler in the form of particles has a water content less than or equal to 0.3% by mass, and preferably less than or equal to 0.1% by mass.
• the method may comprise a prior step of packaging the PVC filler (not shown in the figures) comprising at least one step of grinding or shredding the PVC filler to form a PVC filler in the form of solid particles as defined above, capable of being sent to stage a) of solid-liquid extraction.
• This preliminary conditioning step may also comprise one or more steps mentioned in the following non-exhaustive list: grinding by micronization, sorting, further sorting, washing, drying, etc.
• the step or steps, as well as their possible frequencies and sequences, involved in the preliminary conditioning step are chosen in particular by the person skilled in the art so as to limit the quantity of macroscopic impurities and to reduce the size of the solid elements initially making up the PVC filler.
• the preliminary conditioning step makes it possible to provide a PVC filler in the form of particles, for example of shredded material, washed, with an average size of less than 5 mm, the macroscopic impurity content of which is preferably at most 10% by mass, and more preferably at most 5% by mass.
• Said PVC filler conditioned beforehand can also be in the form of micronized solid particles, that is to say in the form of particles having an average size of less than 1 mm, for example between 10 ⁇ m and 800 ⁇ m.
• the preliminary step of conditioning the PVC filler preferably comprises at least one step of drying the PVC filler already in the form of solid particles of ad hoc macroscopic size and impurity content, such that said PVC filler contains a residual water content of at most 0.3% by mass and preferably at most 0.1% by mass.
• the method according to the invention comprises a step a) of solid-liquid extraction of the phthalate(s) from the PVC filler in the form of particles 1 by bringing said filler 1 into contact with a solvent 9 comprising an alcohol of molecular formula C n H 2 n +i OH, n ⁇ 4 or n>8, in order to obtain an effluent 2 comprising at least one liquid phase and one solid phase.
• Said liquid phase is then enriched in said phthalate or phthalates, and the solid phase comprises PVC plastic depleted in said phthalate or phthalates.
• n for the alcohol of the solvent (exclusion of C4, C5, C6, C7, C8 alcohols) makes it possible, during step b), to transform, by transesterification using said alcohol, said phthalates into at least least one DAP as defined below, which is not part of the undesirable phthalates such as those subject to authorization by the REACH regulations discussed above.
• said alcohol is an alcohol of molecular formula C n H 2 n +i OH with n > 8, for example chosen from the list consisting of nonanol, linear or branched, decanol, linear or branched , undecanol, linear or branched, dodecanol, linear or branched, and preferably nonanol or decanol.
• said alcohol is an alcohol of molecular formula C n H 2 n +i OH with n > 8 and n less than or equal to 20, or even less than or equal to 15.
• said alcohol of molecular formula C n H 2 n +i OH, n ⁇ 4 or n > 8 can be used according to the invention in its alkoxide form, that is to say in the form of the conjugate base of said alcohol of structural formula C n H 2 n +i O , with n ⁇ 4 or n > 8, the cationic counterion, including of metallic nature, ensuring the electronegativity of said conjugate base being well known to the skilled person.
• Solvent 9 may further comprise an organic co-solvent, added to said alcohol, which aids in the extraction of the phthalate(s) from the PVC filler 1.
• said organic co-solvent may be an ester derived from said alcohol, said ester having the formula R'COOCnEhn +i , n being identical to the n of the alcohol from which the ester is derived (n ⁇ 4 or n > 8, and for example n less than or equal to 20), and R 'being an alkyl group (linear, branched or cyclic, and preferably linear), for example comprising between 1 and 3 carbon atoms, for example 1 or 2 carbon atoms, or said organic co-solvent may be an ether such as, and in a non-exhaustive manner, cyclopentylmethyl ether (CPME), di-n-propyl ether, dioxane, and preferably CPME.
• CPME cyclopentylmethyl ether
• Said organic co-solvent is added to said alcohol so that the mass ratio of co-solvent to alcohol (co-solvent/solvent) is between 0 and 4, preferably between 0.01 and 4, plus preferably between 0.02 and 0.66, and even more preferably between 0.05 and 0.66.
• Said additional organic co-solvent is advantageously chosen, preferably when said alcohol is methanol, from the group consisting of methyl acetate, methyl propanoate, CPM E.
• step a) of solid-liquid extraction of the phthalate(s) from the PVC filler 1 is carried out by bringing said filler 1, in the form of particles, into contact with methanol to which methyl propanoate has been added, preferably such that the mass ratio between the methyl propanoate and the methanol is between 0 and 4, preferably between 0.01 and 4, more preferably between 0.02 and 0.66, and even more preferably between 0.05 and 0.66.
• the DAP produced by the process is dimethylphthalate (DMP).
• Step a) of solid-liquid extraction of the phthalate(s) from the PVC filler 1 is preferably carried out according to the following operating conditions: a temperature between room temperature and 200° C., preferably between 40° C. and 180°C, more preferably between 60°C and 150°C, and even more preferably between 60°C and 145°C, a pressure between atmospheric pressure and 11.0 MPa, preferably between atmospheric pressure and 5.0 MPa, more preferably between atmospheric pressure and 2.0 MPa, a residence time between 1 min and 10 h, preferably between 10 min and 4 h, more preferably between 10 min and 2 hrs.
• a temperature between room temperature and 200° C. preferably between 40° C. and 180°C, more preferably between 60°C and 150°C, and even more preferably between 60°C and 145°C
• a pressure between atmospheric pressure and 11.0 MPa preferably between atmospheric pressure and 5.0 MPa, more preferably between atmospheric pressure and 2.0 MPa
• a residence time between 1 min and 10 h,
• step a) is carried out so that the molar ratio between the amount of alcohol in solvent 9 and the amount of phthalate(s) to be extracted from PVC load 1 is between 2 and 250, preferably between 4 and 90, and even more preferably between 4 and 30.
• the reactor of step a) of the process according to the invention can advantageously be a reactor of the type stirred by a mechanical stirring system and/or by recirculation loop and/or by fluidization, for example a reactor of the batch type or perfectly stirred continuously, or a rotating drum type reactor.
• the PVC filler in the form of particles 1 and the solvent 9 comprising the alcohol, optionally added with at least one organic co-solvent, are advantageously mixed.
• said mixing can be carried out prior to the introduction of the charge and of the solvent into the reactor of step a) of solid-liquid extraction.
• said mixture can be formed in a mixer and can then be introduced into the reactor, the latter being maintained at a desired pressure and temperature.
• the PVC filler in the form of particles 1 and the solvent 9 comprising the alcohol, optionally added with at least one organic co-solvent can be introduced separately in the reactor of step a) of the process according to the invention.
• Said solid PVC charge and the solvent are then preferably injected into the reactor via two separate lines, one allowing the solvent 9 to be injected, and the other the solid PVC charge in the form of particles 1.
• the mixture of the PVC charge and the solvent is formed directly in said reactor.
• said step a) of solid-liquid extraction makes it possible to obtain at least one effluent 2 comprising at least one liquid phase containing at least the extracted phthalates and at least one solid phase containing the depleted PVC plastic made of phthalates, preferably free of phthalates.
• said transesterification reaction is then called methanolysis reaction.
• Step b) of chemical transformation of the phthalate(s) present in the liquid phase at the end of step a) into a DAP of formula CehUiCOOC n hb n+i by transesterification reaction is preferably carried out according to the operating conditions following: a temperature between room temperature and 200°C, preferably between 40°C and 180°C, more preferably between 60°C and 150°C, and even more preferably between 60°C and 145°C, a pressure between atmospheric pressure and 11.0 MPa, preferably between atmospheric pressure and 5.0 MPa, more preferably between atmospheric pressure and 2.0 MPa, a residence time between 1 min and 10 h, preferably between 10 min and 4 h, more preferably between 10 min and 2 h.
• a temperature between room temperature and 200°C preferably between 40°C and 180°C, more preferably between 60°C and 150°C, and even more preferably between 60°C and 145°C
• a pressure between atmospheric pressure and 11.0 MPa preferably between atmospheric pressure and 5.0
• step b) is carried out so that the molar ratio between the quantity of alcohol in solvent 9 and the quantity of phthalates to be converted from the liquid phase containing the phthalate(s) extracted at the end of the step a) is between 2 and 250, preferably between 4 and 90 and even more preferably between 4 and 30.
• step b) The alcohol used to carry out step b) is the same as that used to carry out step a).
• step b) of chemical transformation of the phthalate(s) extracted in step a) into a DAP of formula CehUiCOOC n hb n+i by transesterification reaction is carried out in the presence of a transesterification catalyst, advantageously introduced into the reaction medium.
• the transesterification catalyst thus used is, for example, chosen from catalysts from the following non-exhaustive list, well known to those skilled in the art, and preferably from the list consisting of:
• - homogeneous catalysts such as basic catalysts (sodium or potassium hydroxide, sodium or potassium methoxide, sodium or potassium carbonate, etc.), mineral Bronsted acid catalysts (hydrochloric, sulfuric, phosphoric acids, etc. .), organic Bronsted acid catalysts (methanesulfonic, trifluoromethanesulfonic, trifluoroacetic acids, etc.), Lewis acid catalysts including, in particular, boron (BH3, BF3) and aluminum (AIF3, AICI3) compounds, and organometallic compounds; - heterogeneous catalysts such as alkaline earth metal oxides (CaO, BaO, etc.), carbonates or hydrogen carbonates of alkali metals and/or alkaline earth metals (CaCC>3, etc.), supported alkali metals on aluminas or zeolites, zinc oxides and their mixtures with other oxides (for example zinc oxide and alumina), ion exchange resins (cations or anions), such as for example
• the catalyst used according to the invention is a homogeneous catalyst, in particular a homogeneous catalyst of the basic catalyst type such as sodium methoxide.
• the quantity of catalyst introduced is such that the mass ratio between the catalyst and the phthalate or phthalates to be transformed is between 0.5% and 10% by mass, preferably between 1% and 8% by mass and even more preferably between 1% and 5% by weight.
• the catalyst whether homogeneous or heterogeneous, can be recycled and/or eliminated in the process according to methods well known to those skilled in the art, and is preferably recycled. It can be isolated, to be removed or preferably recycled for the transesterification reaction, in the downstream stages of the process, for example in stage c), in stage d) and/or in stage e), or during any other dedicated step.
• the reactor of step b) of the process according to the invention can advantageously be a reactor of the type stirred by a mechanical stirring system and/or by recirculation loop and/or by fluidization, for example a reactor of the batch type or perfectly stirred continuously, or a rotating drum type reactor.
• said stage b) of transformation of the phthalates makes it possible to obtain at least one effluent comprising at least one liquid phase containing at least the DAP of formula C6H4(COOC n H2 n+i )2 obtained after reaction of transesterification, that is to say the liquid phase formed at the end of step a) and enriched in step b) with DAP.
• Steps a) and b) of the method according to the invention can be implemented within the same unitary operation or else be the subject of two distinct and consecutive unitary operations, the unitary operation of step a) being then always carried out prior to the unitary operation of step b).
• steps a) and b although represented in the form of separate “boxes", can be implemented either within the same unitary operation, or object of two distinct and consecutive unit operations.
• the effluent 2 is present within the same reactor used for example to carry out the two stages a) and b).
• steps a) and b) are the subject of the same unit operation, which this time is represented by the use of a single "box" (a+b).
• steps a) and b) are the subject of two distinct and consecutive unit operations, corresponding to a diagram wherein step c) is performed between steps a) and b), as described below.
• the process according to the invention comprises a step c) of solid-liquid separation between on the one hand the liquid phase containing the phthalate(s) extracted in step a) and/or the DAP of formula C6H4(COOC n H2 n+i )2 obtained after transesterification reaction in step b), and on the other hand the solid phase containing the PVC plastic depleted in phthalates, preferably free of phthalates.
• the physical separation of the liquid phase and the solid phase can advantageously be implemented according to techniques known to those skilled in the art such as, and in a non-exhaustive manner, filtration, centrifugation, electrostatic precipitation or decantation, said techniques being used alone or in combination, in any order.
• This solid-liquid separation step c) therefore makes it possible to produce at least one solid stream (6) comprising the PVC plastic depleted in the phthalate(s) extracted in step a), in order to recover said reusable target PVC plastic.
• Obtaining the reusable target PVC as defined according to the invention may require returning all or part of the solid stream (6) obtained in step c) to step a), according to as many cycles as necessary in order to produce said target PVC plastic.
• said step c) of solid-liquid separation occurs after carrying out steps a) and b).
• This first variant is illustrated in FIGS. 1 to 6.
• the liquid effluent 3 resulting from stage b) is sent to stage c) of solid-liquid separation which leads to the separation between the liquid phase containing at least the DAP obtained after the transesterification reaction in step b), and the solid phase containing the PVC plastic depleted in phthalate(s).
• steps a) and b) are implemented jointly within the same unit operation, this specific implementation leading to a reduction in the number of unit operations necessary to carrying out the process according to the invention and therefore to a limitation of the number of equipment, the quantity of solvent used, the energy involved, etc., and therefore a reduction in costs.
• a preferred example of implementation according to this variant is illustrated in Figure 6.
• stage c) of solid-liquid separation occurs after the performance of stage a) and before the performance of stage b).
• This second variant is in particular illustrated in FIGS. 7 and 8.
• the liquid effluent 2 resulting from stage a) is sent to stage c) of solid-liquid separation which leads to the separation of the phase liquid containing the phthalates extracted from the solid phase containing the PVC depleted in phthalate(s). Consequently for this second variant, steps a) and b) are the subject of two separate unit operations.
• Step c) therefore produces the solid stream 6 comprising the PVC plastic depleted in phthalate(s), and a first liquid stream 18 which contains the phthalate(s) extracted in step a) and which is then sent to step b) for the transformation of said phthalate(s) by transesterification.
• This second variant is particularly suitable in the case where the PVC load to be treated would lead to the formation, during step a), of a solid phase which is not favorable to carrying out the chemical transesterification reaction (in terms of properties chemical or rheological, etc.).
• steps a) and c) according to invention can be consecutively implemented in the same batch reactor having a liquid effluent filtration device 2 allowing several cycles for extracting phthalates from the solid phase and a device for withdrawing at least the solid phase 6 allowing the final recovery of the target PVC plastic.
• step c) can be done by centrifugation of the liquid effluent 2 or 3 comprising the liquid phase containing at least the extracted phthalates and/or the DAP and the solid phase resulting from step a), leading to the separation of said solid 6, and advantageously to the return of all or part of said solid to step a), preferably placed in suspension beforehand, for example by means of an extra solvent 9 (not shown in the figures) , until producing the reusable target PVC plastic.
• the process according to the invention comprises a step d) of liquid-liquid separation making it possible to extract the DAP of formula CehUiCOOC n hb n+i from the liquid phase obtained at the end of the implementation of at least the steps a), b) and c).
• a liquid stream (4, 13) containing said liquid phase advantageously feeds this step d) of liquid-liquid separation which thus makes it possible to produce at least a first liquid effluent comprising the DAP (stream 5 or 14 according to the figures) and a second effluent liquid comprising at least said solvent (stream 7 or 12 according to the figures).
• Step d) of liquid-liquid separation can be carried out according to methods well known to those skilled in the art such as, and in a non-exhaustive manner, distillation, decantation, evaporation, liquid-liquid extraction, etc., performed singly or in combination.
• the operating conditions of this step are determined according to the separation method chosen.
• the first effluent 5 essentially consists of said DAP.
• the second liquid effluent 7, represented for example in FIG. 1 (or as an option in FIG. 3), consists of the residual liquid phase after extraction of the DAP, which contains at least the solvent , that is to say the alcohol optionally added with co-solvent, the alcohol-type by-products (AL), the intermediate alkyl phthalates (API) and the phthalate(s) extracted at the end of step a ) of the process according to the invention possibly unconverted.
• the second liquid effluent 7 can be returned, in whole or in part, preferably totally, to step b) of the process according to the invention.
• step d) produces, in addition of the first effluent 5 consisting essentially of said DAP and of the second effluent 12 consisting essentially of said solvent, a third effluent 10 comprising AL obtained during the transesterification in step b), and a fourth effluent 11 comprising converted phthalate(s) partially (API) and/or not converted in step b) and optionally other soluble impurities.
• the fourth effluent 11 can then be advantageously returned to step b) of the process according to the invention, in particular according to the first and second variants of the process according to the invention, so as to continue the chemical reactions leading to the DAP and thus to improve yield of this product.
• the first liquid effluent 14 comprising the DAP also comprises other compounds such as partially converted phthalate(s) (API) and/or not converted in step b) and optionally soluble impurities.
• API partially converted phthalate
• a step of purification of DAP from the first effluent is necessary.
• step d) of liquid-liquid separation therefore advantageously produces said first liquid effluent 14 of non-pure DAP, a second effluent 12 preferably consisting essentially of said solvent, and preferably a third effluent 10 comprising LAs obtained during the transesterification in step b).
• the isolation of the LAs and of the solvent is made possible in particular depending on the liquid-liquid separation methods chosen, such as, for example, distillation with lateral withdrawal or liquid-liquid extraction.
• the second effluent 12 consists essentially of said solvent thus recovered, the second effluent 12 can then be advantageously returned, in part or in whole, preferably in whole, to step a) and/or to step b) of the method according to the invention, and in particular according to the first and second variants of the method according to the invention.
• the method according to the invention may comprise an optional step e) of purification of the first effluent 14 comprising the DAP resulting from step d) of liquid-liquid separation, to improve its quality and therefore, ultimately, its recovery.
• step e) of purification of the first effluent 14 comprising the DAP resulting from step d) of liquid-liquid separation to improve its quality and therefore, ultimately, its recovery.
• FIGS. 4, 5, 6 and 8 illustrate the implementation of such a purification step e).
• the solvent has advantageously been isolated during the implementation of step d).
• the APIs and optionally the phthalate(s) extracted at the end of step a) of the process according to the invention not converted at the end of step b) may have been isolated during step d ) of the process according to the invention, or alternatively be isolated during the implementation of said step e) of purification.
• the first effluent 14, comprising the DAP, partially converted and/or unconverted phthalate(s) in stage b) and possibly soluble impurities, to this purification stage e) to form a liquid product 16 consisting essentially of said DAP, and a liquid residue 17 comprising the partially converted and/or unconverted phthalate(s) in step b) and optionally the soluble impurities.
• liquid residue 17 thus recovered can then advantageously be returned to step b) of the process according to the invention, in particular according to the first and second variants of the process according to the invention, so as to continue the chemical reactions leading to the DAP, as shown in Figure 4 or Figure 5.
• Purification step e) can advantageously be carried out by methods well known to those skilled in the art, such as precipitation, crystallization, adsorption, optionally followed by filtration or centrifugation.
• Purification step e) can comprise the implementation of several of these methods in parallel or in series.
• the purification step e) can comprise a precipitation and filtration step, followed by an adsorption step, or even comprise an adsorption and filtration step, optionally followed by a step precipitation, or even include a crystallization and filtration step.
• the operating conditions in this step e) are determined according to the purification method chosen.
• step b) of chemical transformation of the phthalate(s) extracted in step a it is possible to carry out, independently of step b) of chemical transformation of the phthalate(s) extracted in step a), a step of additional chemical transformation allowing the transformation of the APIs and/or of the extracted phthalate(s) possibly unconverted at the end of step b).
• the method may thus also comprise an additional step fi), as represented in FIG. 3 or FIG. 5, of chemical transformation by transesterification of the phthalate(s) not converted in step b) and/or of at least one API produced in step b), in DAP of formula CeHMCOOC n hb n+i by means of the solvent comprising the alcohol.
• step fi) is carried out between steps c) and d), and advantageously after step b), by sending the liquid phase 4, advantageously obtained at the end of all the steps a), b) and c), in a first additional transesterification reactor, to produce a second liquid stream 13 enriched in DAP, said second liquid stream 13 being sent to step d).
• step c) is preferably implemented at the end of step b).
• the process can also comprise an additional step f2) of chemical transformation by transesterification of the phthalate(s) not converted in step b) and/or of at least one API produced in step b), or optionally in step fi) optional, in DAP of formula CeHMCOOC n hb n+i by means of the solvent comprising the alcohol, stage f2) being carried out successively at stage e) by sending the liquid residue 17 resulting from stage e) in a second additional transesterification reactor to produce a third liquid stream 15 enriched in said DAP, said third liquid stream 15 being returned to step d).
• step fi) and/or of the additional step f2) of chemical transformation by transesterification can be carried out according to the first variant (step c) of solid-liquid separation carried out after steps a) and b )) or second variant (step c) of solid-liquid separation located between steps a) and b)) of the process according to the invention.
• the process according to the invention comprises a single additional step of chemical transformation by transesterification, and preferably step f2).
• step f) and/or of step f2) is as described for step b) of the method according to the invention.
• the ranges associated with the operating conditions of steps b) and fi) and/or f2) are similar, and the latter are chosen by those skilled in the art so as to promote the production of DAP according to the chemical nature of the stream to be processed as input to said step f) and/or step f2).
• transesterification catalyst 8 as described in step b).
• the transesterification catalyst in step(s) fi) and/or f2) can be identical to or different from that used in step b).
• Said stream sent to stage f) and/or to stage f2) (stream 4 or liquid residue 17) is a liquid phase comprising one or more phthalates extracted in stage a) and optionally partially converted (API) and / or not converted in step b), and optionally soluble impurities, which are then isolated either during the implementation of step d) of liquid-liquid separation of the process according to the invention, or during the implementation of step e) of purification of the process according to the invention if the latter is advantageously implemented.
• step f) and/or step f2 it may be necessary to use an additional supply of solvent comprising the alcohol of molecular formula C n H 2 n +i OH with n ⁇ 4 or n > 8, optionally with the addition of at least one organic co-solvent, this additional solvent supply possibly resulting from a make-up of “fresh” solvent 9 or else from a recycling of the stream 12 of said solvent optionally isolated at the end of step d) of the process according to the invention.
• step e) When purification step e) is implemented, at least part of said liquid residue 17 produced in step e) can be recycled to step fi), as illustrated in FIG. 5, so as to continue the chemical reactions leading to DAP.
• FIGS. 6 and 8 represent preferred embodiments respectively according to the first variant (step c) of solid-liquid separation after carrying out steps a) and b)) and according to the second variant (step c) of solid-liquid separation between steps a) and b)) of the process according to the invention.
• the method comprises an implementation within the same unitary operation of steps a) and b), a step c) solid-liquid separation located after steps a) and b), a liquid-liquid separation step d), a purification step e) of a first effluent 14 obtained in step d) comprising DAP, and advantageously an additional transesterification step f) of residue 17 from step e).
• the charge of PVC in the form of particles 1, optionally conditioned beforehand is introduced into a reactor combining the performance of steps a) and b) respectively of solid-liquid extraction and chemical transformation by transesterification preferably in the presence of a catalyst 8.
• the reactor is also fed with a flow of fresh solvent 9 external to the process comprising at least one alcohol of molecular formula C n h +i OH, with n ⁇ 4 or n>8, preferably methanol, added with a possible co-solvent, preferably methyl propanoate, and optionally with at least a fraction of a stream 12 of solvent isolated in stage d) of liquid- liquid.
• the reaction effluent 3 containing the liquid phase comprising at least the DAP, preferably the DMP, and the solid phase comprising the PVC plastic depleted in phthalates, preferably free of phthalates, is sent to stage c) of solid- liquid, for example using centrifugation, to produce a solid stream 6 comprising said PVC plastic depleted in the extracted phthalate(s) in order to recover said reusable target PVC plastic, and a liquid stream 4 containing at least the DAP, preferably the DMP, and at least the solvent.
• the solid stream 6 can be partly recycled to step a).
• the liquid stream 4 from step c), containing the DAP, the solvent, optionally unconverted or partially converted phthalate(s) (API) and optionally AL, is sent to the liquid-liquid separation step d) which makes it possible to isolate on the one hand the solvent according to a flow 12, but also preferably the AL according to a flow 10, and finally a liquid effluent 14 comprising the DAP, preferably DMP, and optionally phthalate(s) partially and / or unconverted and possibly soluble impurities.
• the liquid effluent 14 is sent to a purification step e), in order to obtain the purified DAP, preferably DMP.
• residue 17 from this purification step e) may still contain unconverted or partially converted phthalate(s) (API)
• an additional step f) of chemical transesterification transformation is preferably carried out.
• the residue 17 is therefore advantageously sent to a second transesterification reactor containing a suitable transesterification catalyst, to carry out the transesterification of the unconverted or partially converted phthalate(s) (API) by means of a solvent 9 comprising the alcohol of molecular formula C n hh n+i OH, with n ⁇ 4 or n > 8, with an optional co-solvent added, preferably methyl propanoate.
• the solvent can be a make-up of fresh solvent or come from the stream 12 recycled at least in part at this stage f).
• This stage f) produces a liquid stream 15 enriched in said DAP, preferably in DMP, returned to stage d) of liquid-liquid separation.
• the method comprises an implementation of steps a) and b) according to two distinct unit operations, with a step c) carried out between steps a) and b), followed by a step d), and also comprises a step e) of purification of a first effluent 14 obtained in step d) comprising the DAP, and an additional step of transesterification f) residue 17 from step e).
• the charge of PVC in the form of particles 1, optionally conditioned beforehand, is introduced into a reactor to carry out step a) of solid-liquid extraction of the phthalate(s) of said PVC filler.
• the reactor is fed with a stream of fresh solvent 9 external to the process comprising at least one alcohol of molecular formula Cnf OH, integer n with n ⁇ 4 or n > 8, preferably methanol, to which is added an optional co-solvent, preferably methyl propanoate, and optionally by a flow 12 of solvent isolated in step d) subsequent liquid-liquid separation.
• the effluent 2 produced in step a) comprises at least one liquid phase containing at least the phthalate(s) extracted from said charge 1 and at least one solid phase containing the PVC plastic depleted in phthalates, preferably free of the extracted phthalates.
• the effluent 2 is sent to a step c) of solid-liquid separation, for example implementing centrifugation, to produce a solid stream 6 comprising said PVC plastic depleted in the phthalate(s), in order to recover said reusable target PVC plastic , and a liquid stream 18 containing at least the phthalate or phthalates extracted in step a) and at least the solvent.
• the liquid stream 18 is then sent to a reactor to perform step b) of chemical transformation of the phthalate(s) extracted by transesterification, preferably in the presence of a catalyst 8.
• the transesterification reactor can also be supplied with a stream of solvent 9 costs external to the process comprising the same alcohol, preferably methanol, added with an optional co-solvent, preferably methyl propanoate, and optionally with at least a fraction of a stream 12 of solvent isolated in step d) liquid-liquid separation.
• the reaction effluent 4 containing the liquid phase comprising at least the DAP, preferably the DMP, the solvent, the unconverted or partially converted phthalate(s) (API), is sent to the liquid-liquid separation stage d) which makes it possible to isolate on the one hand the solvent according to a flow 12, but also the AL according to a flow 10, and finally a liquid effluent 14 comprising the DAP, preferably DMP, and possibly partially phthalate(s) (API) and / or unconverted and possibly soluble impurities.
• the liquid effluent 14 is preferably sent to a purification step e), in order to obtain the purified DAP, preferably the DMP 16.
• the residue 17 from this purification step e) may still contain phthalate(s) unconverted or partially converted (API), an additional stage f) of transesterification chemical transformation is preferably carried out.
• the residue 17 is advantageously sent to a second transesterification reactor preferably containing a suitable transesterification catalyst, to carry out the transesterification of the unconverted or partially converted phthalate(s) (API) by means of a solvent 9 comprising the alcohol of formula crude Cnf OH, with n ⁇ 4 or n > 8, with an optional co-solvent added, preferably methyl propanoate.
• the solvent can be a make-up of fresh solvent or come from the stream 12 recycled at least in part at this stage f).
• This stage f) produces a liquid stream 15 enriched in said DAP, preferably in DMP, returned to stage d) of liquid-liquid separation.
• the present invention also relates to a process for recycling a PVC-based object containing at least one phthalate, said recycling process comprising:
• the packaging of the PVC-based object comprising at least one grinding or shredding of the PVC-based object to form a PVC filler in the form of particles;
• the step of conditioning the PVC-based object can include the various steps detailed above for the prior conditioning of the PVC filler before its introduction in step a).
• the present invention also relates to a method for manufacturing a flexible PVC-based object comprising a recycled PVC plastic and/or a DAP obtained by the method for recovering a DAP and a reusable target PVC plastic described above.
• a manufacturing process typically comprises a step of recovering a DAP and a reusable target PVC plastic from a PVC load, as detailed above, then a step of mixing said reusable target PVC plastic with additives or a step of mixing said recovered DAP with a PVC resin, then a step of shaping said mixture.
• This example illustrates the invention without limiting its scope, and illustrates in particular the extraction of a phthalate contained in a PVC plastic and the conversion of the phthalate into dimethylphthalate in the presence of a catalyst, by methanolysis.
• a PVC plastic filler from PVC-based objects of the "medical tube” type
• DIDP di-decyl phthalate
• 26.5 g of methanol and 17.7 g of methyl propanoate (organic co-solvent) are then added, the methyl propanoate/methanol mass ratio being 0.66 and the methanol/DIDP molar ratio being 84.0, 17 g of catalyst (NaOMe) are then added to the above mixture so that the mass percentage NaOMe/DIDP is 4%.
• the reactor is sealed, purged with nitrogen and then heated to 100° C. with an autogenous pressure of the order of 1.2 MPa and maintained under these conditions for 4 h under stirring at 1000 rpm. .
• the reactor is then cooled.
• the solid obtained was prefractionated by preparative steric exclusion chromatography SEC equipped with dual optical detection (UV/Visible) and refractometry (RI).
• the fractions from the collection were analyzed by high performance liquid chromatography (HPLC) equipped with UV-Visible type optical detection for quantitative purposes.
• HPLC high performance liquid chromatography

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• 2021
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