Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
  • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
  • C08G69/28—Preparatory processes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/78—Preparation processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
  • B01D53/1487—Removing organic compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
  • B01D53/1493—Selection of liquid materials for use as absorbents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
  • B01J3/006—Processes utilising sub-atmospheric pressure; Apparatus therefor
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/78—Preparation processes
  • C08G63/785—Preparation processes characterised by the apparatus used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
  • C08G64/20—General preparatory processes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
  • C08G64/20—General preparatory processes
  • C08G64/205—General preparatory processes characterised by the apparatus used
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04F—PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
  • F04F5/00—Jet pumps, i.e. devices in which flow is induced by pressure drop caused by velocity of another fluid flow
  • F04F5/54—Installations characterised by use of jet pumps, e.g. combinations of two or more jet pumps of different type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00162—Controlling or regulating processes controlling the pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00245—Avoiding undesirable reactions or side-effects
  • B01J2219/00247—Fouling of the reactor or the process equipment

Definitions

• the invention relates to a method and a device for vacuum generation and separation of volatile compounds in transesterification, esterification and / or polycondensation reactions, in particular in the production of polyesters, polyarylates, polyamides, polysulfones, polyether ketones and polycarbonates, the suction side of the Polycondensation reactor is connected to at least one steam jet vacuum pump with a connected spray condenser.
• polycondensates are widely used in machine and apparatus construction, in electrical engineering, in construction, in the textile industry, in the coating industry and for everyday objects. They are produced either by interfacial condensation or by melt polycondensation using direct polycondensation of dicarboxylic acids and diamines, dialcohols or diphenols or by transesterification of the corresponding acid esters.
• aromatic dihydroxy compounds for example bis (4-hydroxyphenyl) alkanes, in particular bisphenol A with diphenyl carbonate or diarylalkyl- phosphonates transesterified in the presence of catalysts with the elimination of phenol, ofigomerized and then subjected to the polycondensation.
• the transesterification, esterification and / or polycondensation takes place in several reaction stages under increasing vacuum, for example by starting with a slight vacuum of 800 mbar, for the precondensation a vacuum of ⁇ 100 mbar and for the polycondensation in the final stage a vacuum of ⁇ 1 mbar is set at a temperature of 220 to 35O 0 C.
• a vacuum of ⁇ 1 mbar is set at a temperature of 220 to 35O 0 C.
• the polycondensation is usually carried out by reacting one or more monomers with the addition of a catalyst.
• a catalyst for reacting one or more monomers with the addition of a catalyst.
• medium-chain molecules are precondensed in a vacuum at pressures of less than 100 hPa and in the final stage, if longer-chain polymers are already present, pressures of less than 1 hPa and temperatures of up to 350 0 C are necessary.
• the vacuum can be generated in the usual way by means of mechanical pumps, which have surface condensers for separating the condensable constituents, essentially phenols, polyhydric alcohols, minor amounts of other monomers and traces of oligomers, which come out of the reactors and are contained in the vapors. or are connected downstream.
• the disadvantage here is that the vapor volume is very large in accordance with the ideal gas law in high vacuum and the equipment parts, in particular the mechanical vacuum pumps, have to be designed for very large suction volumes.
• the volatile, condensable components cause frequent interruptions in operation at correspondingly low condensation temperatures, on the one hand by covering the surface condensers with liquid and / or solid deposits and on the other hand by the pump and piping system.
• the object of the present invention is therefore to find a process for generating a vacuum and for separating the volatile, condensable constituents of the vapors of a melt-phase polycondensation, in particular the last stage of polycondensation, for example the production of polycarbonate and polyarylate, which compared to the processes of State of the art described leads to a reduction in the vapor volume, and avoids operational disturbances due to monomer and oligomer deposits.
• no waste water contaminated with phenol or oligomers should arise and the agent used as motive steam should also be able to be used in the copolymer production of polyesters from polyhydric phenols, alcohols, amines and polyvalent organic and / or inorganic acid esters.
• at least a first vapor compression is carried out by condensation using steam jets which are operated with steam containing phenol, and a further, second compression is carried out by means of mechanical vacuum pumps in order to increase the energy yield.
• This object is achieved according to the invention by a method for vacuum generation and separation of volatile compounds in polycondensation reactions, in which one or more steam jets, each with an upstream and / or downstream one, on the suction side of a reactor to be evacuated
• Spray condensers are connected, phenol or phenol-containing steam at a pressure of 0.5 hPa to about 1.5 MPa being used as the driving steam and liquid phenol or a phenol-containing liquid being used as the spraying agent.
• at least dihydric phenols, alcohols and / or amines and at least dihydric acids and / or their phenol-containing esters are used in the polycondensation reaction.
• the polycondensation reaction is preferably carried out as a multi-stage melt-phase polycondensation and the reactor to be evacuated is the last or one of the last in the series of polycondensation reactors in which the process is carried out.
• the motive steam used for a steam jet preferably has a pressure in the range from 0.3 hPa to approximately 1.5 MPa. Higher pressures are preferable in terms of energy efficiency. Depending on the dimensioning of the system, it may also be necessary to use a more thermally gentle method, corresponding to a motive steam pressure in the range from 5 hPa to 0.1 MPa.
• Fig. 1 shows an embodiment of the method according to the invention only with steam jets 6, which is particularly advantageous if the product produced and the volatile monomers tend to deposit particularly strong and / or viscous condensates and this through the steam or condensate flow can be transported further.
• one steam jet is usually sufficient per stage, while at low motive steam pressures two steam jets are expediently connected upstream in connection with a spray condenser 7.
• phenol steam 5 can also be between the steam generator and a steam jet to 1 to 100 0 C, preferably superheated to 3 to 25 0 C Ü.
• the vaporous mixture comprising the phenol and other volatile compounds from the polycondensation and oligomers or monomers contained in the vapors leaving the steam jet 6 is passed into a directly connected spray condenser 7, in which phenol 19, which is reprocessed by spraying with liquid condensate 14 and fresh phenol the condensable components are separated.
• the temperature of the spray liquid must be as low as possible. Depending on the purity of the supplied liquid it is advisable to choose a temperature in the range of 10 0 C to 200 ° C, preferably from 40 to 120 ° C.
• the condensate flowing out of the spray condenser 7 is preferably collected in individual receivers (23, 24) and partly circulated as a spray liquid 14 with appropriate temperature control and partly fed to an evaporator 17 for generating the motive steam 5.
• the remaining, excess part of the condensate is discharged from the steam jet spray condenser unit and returned to the phenol evaporator 17 and / or a recovery system 19 within the process. In this way, an accumulation of oligomers, monomers and, for example, phenols in the condensate is avoided.
• the condensates of several spray condensers can be brought together in a collecting tank 23/24 before being divided into partial streams.
• the uncondensed vapor phase when it emerges from the first spray condenser, has a higher pressure than that of the polycondensation steam, depending on the compression ratio of the upstream steam jet (s). reactor.
• the further compression can take place in further analog phenol vapor emitters and / or phenol spray condenser stages or else with mechanical vacuum pumps, as shown in Fig. 2. However, the further compression can also take place initially in one to three further steam jet spray condenser units and then by means of at least one mechanical vacuum pump 26.
• Mechanical vacuum pump is to be understood here to mean, for example, a vacuum blower system, diaphragm pump system and / or a liquid ring pump system 26 with a condenser 13. Condensate from the condensers or pure phenol can be used as the operating liquid for the liquid ring pump. If necessary, heat exchangers and / or additional condensers can be connected. With these further compression stages, the vacuum for the preceding transesterification, esterification and / or polycondensation stages can be generated at the same time.
• multi-stage steam jets and vacuum pumps they can also be used to simultaneously generate the vacuum of a first conversion stage and / or precondensation, partial flows of the condensate from the spray condensers 7, 9, 11, 13 being collected in a separate container 24 and separated in one Evaporators 17 are used to generate the motive steam for the steam jet 6.
• the evaporator 17 can also be operated exclusively with pure phenol with the return of condensate 14.
• the operating pressure of the evaporator is slightly higher - corresponding to the pressure loss in the pipes and fittings - than the desired motive steam pressure. Otherwise, the operation of the evaporator including the usual auxiliary units takes place in the manner described.
• the phenol vapor obtained from the evaporator is divided into a corresponding number of partial streams.
• the evaporator sump is continuously and partially discharged and reused if necessary.
• the monomers, fission products and volatile oligomers carried in the vapors have a significantly higher boiling point than the phenol used and can therefore be concentrated in the evaporator 17.
• the spray liquid has a temperature of 10 to 200 ° C.
• the process in apparatus and pipes can be carried out, which have been heated by at least 2O 0 C hot heating medium.
• the temperature of the heating medium 20 to 125 ° C may, particularly preferably 25 - 100 0 C amount. Due to these low temperatures, the heating system can be designed in a particularly simple manner and can be operated at low cost, for example with warm water.
• the invention also relates to a device for vacuum generation and for the separation of volatile compounds from polycondensation reactions, the reactor to be evacuated being connected on the suction side to one or more steam jets, to which a spray condenser connected upstream and / or downstream is connected, in which phenol or phenol-containing steam at a pressure of 0.5 hPa to about 1.5 MPa can be used as motive steam and liquid phenol or a phenol-containing liquid can be used as a spray.
• a mechanical vacuum pump is also available for generating the vacuum. This mechanical vacuum pump consists of a pump and a condenser.
• the method claimed according to the invention and the associated device allow trouble-free and economically sensible generation of the vacuum for one or more polycondensation reactors in the polyarylate, polycarbonate and polyester copolymer production by the melt process from dihydric phenols, alcohols and / or amines and at least diacids and / or their phenolic esters.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Engineering & Computer Science (AREA)
• General Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Polyesters Or Polycarbonates (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)

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• 2005
  • 2005-04-22 DE DE102005018843A patent/DE102005018843A1/de not_active Withdrawn
• 2006
  • 2006-02-27 JP JP2008506938A patent/JP2008536981A/ja not_active Withdrawn
  • 2006-02-27 KR KR1020077025492A patent/KR20080013882A/ko not_active Ceased
  • 2006-02-27 US US11/918,811 patent/US20090173618A1/en not_active Abandoned
  • 2006-02-27 WO PCT/EP2006/001768 patent/WO2006114149A1/de active Application Filing
  • 2006-02-27 EP EP06707283A patent/EP1871821A1/de not_active Withdrawn
  • 2006-02-27 CN CNA2006800132288A patent/CN101163730A/zh active Pending

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