CN105246943A - Process for workup of mixture obtained in polycondensation processes and plant for performing process - Google Patents
Process for workup of mixture obtained in polycondensation processes and plant for performing process Download PDFInfo
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- CN105246943A CN105246943A CN201480030807.8A CN201480030807A CN105246943A CN 105246943 A CN105246943 A CN 105246943A CN 201480030807 A CN201480030807 A CN 201480030807A CN 105246943 A CN105246943 A CN 105246943A
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- 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
- C08G63/88—Post-polymerisation treatment
- C08G63/90—Purification; Drying
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/06—Flash distillation
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- 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
Abstract
The present invention relates to a process for workup of a mixture obtained in polycondensation processes, comprising at least one diol, monomers, oligomers and/or polymers, comprising the steps of: a) transferring the at least one mixture obtained in a polycondensation reaction, comprising diol, monomers, oligomers and/or polymers, into at least one distillation still (3), b) heating the at least one mixture in the at least one distillation still (3) to the boiling point without reflux of the volatile components of the mixture released during the heating, especially comprising the at least one diol, into the distillation still (3), c) transferring the volatile components of the mixture formed during the heating of the at least one mixture in the at least one distillation still (3), especially comprising the at least one diol, into at least one rectification column (5), and d) further separating the volatile components of the mixture in the at least one rectification column (5), with performance of the heating of the mixture in the at least one distillation still (3) in step b), the transfer of the volatile components of the mixture into the at least one rectification column (5) in step c) and the separation of the volatile components of the mixture in the at least one rectification column (5) in step e) under reduced pressure. The present invention also relates to a plant for performing the process according to the invention.
Description
Technical field
The present invention relates to a kind of method for the treatment of the mixture produced in polycondensation process of preamble according to claim 1 and a kind of equipment for performing described method according to claim 16.
Background technology
Polyester is polymkeric substance or plastics, in addition, polycarbonate, thermoplastic poly terephthalic acid or also have heat cured vibrin belong to polyester.Linear polyester especially manufacture textile fibres, bottle, film, film time or also apply when manufacture meets material.The preparation of polyester is carried out by the reaction (esterification) of carboxylic acid and dibasic alcohol or by the esterification of carboxylicesters and dibasic alcohol and polycondensation subsequently.
As mentioned, poly terephthalic acid (PET) is thermoplastic plastics important in polyester family.The output of whole world PET is greatly about annual 4000 ten thousand tons.The raw material preparing PET is on a large scale that terephthalic acid (Isosorbide-5-Nitrae-benzene dicarboxylic acid) and ethylene glycol are as dibasic alcohol.Sometimes, preparation is also undertaken by the esterification of rutgers and ethylene glycol.Because relate to balanced reaction at this, so and use excessive ethylene glycol, described excessive ethylene glycol again distills out in reaction process, to affect balance aptly.Correspondingly, according to operational conditions and Equipments Setting, monomer, such as carboxylic acid monomer or diester monomer, the oligopolymer of formation and polymkeric substance can be discharged with excessive glycol steam, condensation in suitable condenser and receiving in a reservoir.Not only the oligopolymer of ethylene glycol but also monomer, formation and polymkeric substance be expensive raw material and usually in polycondensation process further process reclaim.Excessive ethylene glycol is also referred to as being ethylene glycol that is contaminated or dirty or rough or that consume.
But when using dimethyl terephthalate (DMT) (DMT) for the preparation of polyester, the ethylene glycol of condensation in reaction process can not purified ground and lead back in polycondensation process, because it contains the methyl alcohol causing interference in polycondensation process.Also for special service condition, such as preparing highly purified and vitreous polyester polymers can need ethylene glycol to reclaim with especially pure form.
Except the oligopolymer of monomer, formation and polymkeric substance, ethylene glycol also comprise water and monomer, oligopolymer with the degradation production of polymkeric substance, such as acetaldehyde (AA) and Jia Ji bis-Evil penta ring (MDO), the oligopolymer of wherein said monomer, formation and polymkeric substance exist with the soluble form of part with solid-state as dibasic alcohol in ethylene glycol.
In known traditional technique, typically via the composition that rectifying separation produces in the reaction mixture of polycondensation.This method can be run continuously or discontinuously.
The water contained in dibasic alcohol (such as ethylene glycol) and so-called degradation production in rectifying also referred to as being low-boiling-point substance.In addition, at dibasic alcohol, such as, also can comprise the dibasic alcohol of the dimerization of certain share in ethylene glycol, such as glycol ether (DEG) is as the ethylene glycol of dimerization, the dibasic alcohol of the dimerization of described share due to higher molecular weight when comparatively high temps as ethylene glycol evaporation and also referred to as high boiling material.According to method steps, ethylene glycol can otherwise as low-boiling-point substance, or to occur as high boiling material.
In the discontinuous operation scheme of rectifying, namely in batch production operation, that be made up of dibasic alcohol, monomer, oligopolymer and polymkeric substance, pending polycondensation mixture to be filled in still kettle and to heat, until low-boiling-point substance to proceed to the rectifying tower connected and finally discharges at the top place of tower.Methyl alcohol is present in the situation in mixture, first distill out methyl alcohol and in a further step except anhydrate and other appended by low-boiling-point substance.After distilling out low-boiling-point substance, there is dibasic alcohol, such as, occur ethylene glycol at the top place of rectifying tower.Then, except remaining dibasic alcohol, such as, outside ethylene glycol, in still kettle, go back residual monomer, the oligopolymer of formation and polymkeric substance.These mixtures can be back in the preparation process of polyester.
In order to obtain pure dibasic alcohol, such as ethylene glycol, distills out dibasic alcohol, especially ethylene glycol from still kettle usually in backflow.Check that the purity of the ethylene glycol distilled out such as is undertaken by refractometer or gas chromatography.At this, the dibasic alcohol of high boiling material such as dimerization, to return in the water collecting basin being retained in still kettle with the form of the oligopolymer of glycol ether, monomer, formation and polymkeric substance and removes in a suitable manner.Foregoing method steps performs by backflow at tower top place, and wherein required additional heat energy is always introduced via the water collecting basin of still kettle.Process described above also can perform in the equipment of continuous operation with multiple tower in succession connected.
This traditional method that the ingredients of a mixture of producing in polycondensation is separated practical application and be known for a long time.Described method has following shortcoming certainly: namely monomer, oligopolymer and polymkeric substance to be present in during whole distillation and rectifying in the still kettle of heating and in whole period thermal load Sum decomposition.At this, realize the different steps of decomposing.In addition, form material, described material strengthens yellow coloring as so-called coupler.The coupler of this share extracts from ethylene glycol and top via tower is transferred in the ethylene glycol of recovery with glycol steam.Therefore, the ethylene glycol by the recovery of traditional rectifying can use as the sub-additive (between 10% to 30%) for fresh glycol when preparing PET or only use for having the PET required compared with inferior quality.Higher additive causes too high jaundice in PET end product, and described jaundice typically illustrates with b* value, makes described end product be no longer commercially acceptable.
In addition, when the residence time of the length at temperature relatively high in still kettle and high glycol concentration, glycol ether is formed with causing enhancing as less desirable side reaction.Thus, in polymer recycled material, (amount of the monomer namely collected in the water collecting basin of still kettle, oligopolymer and polymkeric substance) produces the glycol ether being greater than 2% concentration, and described concentration will be got rid of for different application situation use pet polymer.Therefore, the pet polymer having the diethylene glycol content being greater than 2% is still only limitedly suitable for textile applications.
Correspondingly, there is the demand to following method, described method realizes dibasic alcohol, especially ethylene glycol with form pure does not as far as possible have the degradation production of high share or a recovery of by product, and realizes reclaiming monomer, oligopolymer and/or polymkeric substance in the mixture that produces from large-scale polycondensation process.
Summary of the invention
Therefore, the technical purpose that the present invention is based on is, a kind of method obtaining dibasic alcohol such as ethylene glycol, monomer, oligopolymer and polymkeric substance in mixture produced from polycondensation process is provided, in the process the high boiling material of monomer, oligopolymer and polymkeric substance (twice-laid stuff) and low-boiling-point substance separated from one another in an economical manner and reclaim in the form that this dibasic alcohol can be the purest.In addition, twice-laid stuff directly or after glycolysis should be recovered as the form of raw material use again to make it.Term monomer is always interpreted as monomer below, described monomer and dibasic alcohol when condensation or esterification under react for oligopolymer and polymkeric substance.Correspondingly, monomer can be that dicarboxylic acid such as terephthalic acid or diester are as dimethyl terephthalate (DMT).
According to the present invention, this object by have the feature of claim 1 for the treatment of produce in polycondensation process, the method for the mixture that comprises at least one dibasic alcohol, monomer, oligopolymer and/or polymkeric substance and the equipment for performing described method according to claim 16 realizes.
Therefore, provide a kind of for the treatment of produce in polycondensation process, the method for the mixture that comprises at least one dibasic alcohol, monomer, oligopolymer and/or polymkeric substance, described method comprises the following steps:
A) mixture that at least one produced in polycondensation, that comprise dibasic alcohol, monomer, oligopolymer and/or polymkeric substance transfers at least one, in the distillation receptor of especially still kettle form,
B) at least one distillation receptor, heat at least one mixture until boiling point, and mixture, the volatile share during heating discharged of the mixture that especially comprises at least one dibasic alcohol is not back in distillation receptor,
C) by mixture, the mixture that especially comprises at least one dibasic alcohol at least one distillation receptor, heat at least one mixture during volatile share of being formed transfer at least one rectifying tower, and
D) volatile share of further separating mixture at least one rectifying tower,
Wherein according to step b) at least one distillation receptor in heated mixt, according to step c) volatile share of mixture is transferred at least one rectifying tower and according to steps d) volatile share of separating mixture at least one rectifying tower perform under negative pressure.
Therefore according to present method, heat from the mixture in polycondensation process under negative pressure in distillation receptor, wherein there is the volatile share discharging the mixture be made up of low-boiling-point substance and high boiling material, this volatile share is transferred in rectifying tower at once from distillation receptor, under condition of negative pressure, similarly carries out low-boiling-point substance be separated with the further of volatile share in high boiling material in described rectifying tower.
Preferably from least one distillation receptor, derive mixture, especially comprise the mixture of monomer, oligopolymer and/or polymkeric substance at least one distillation receptor before heating at least one mixture or period the nonvolatile share that produces.
At this, carry out heated mixt in distillation receptor, make to avoid that separated volatile share is common to be back in mixture in distillation receptor.Therefore relate to the so-called disposable evaporation in distillation receptor, in described disposable evaporation all low-boiling-point substances comprise dibasic alcohol, the dibasic alcohol of such as ethylene glycol and the dimerization of certain share, such as glycol ether as high boiling material very fast and in temperature economically with in short time in be separated as so-called PET twice-laid stuff (German is: PET-Rezyklat) with monomer, oligopolymer and polymkeric substance.Thus, reduce PET twice-laid stuff decomposition and and then reduce coupler in the polymer formation and by dibasic alcohol, will be inapparent as ethylene glycol extraction coupler and strongly reduce.
At this, negative pressure used in the method or the pressure of reduction are defined as, and described method is performed under pressure, described pressure under local atmospheric pressure or local normal atmosphere, such as in sea level under 0.1bar or 1000hPa.
Preferably, when the mixture produced in polycondensation process has the glycol content of at least 10%, glycol content, the especially preferred glycol content between 85% to 95% of preferred at least 50%.In addition preferably at least one dibasic alcohol be glycol, especially ethylene glycol time.
Utilize at least one pump (fresh feed pump) at least one mixture can be connect receptor as solution or suspension from least one to be incorporated at least one distillation receptor.At least one mixture introduced or is fed into distillation receptor, such as, can continuously or semi-continuously perform according to other approach application in the distillation receptor of the form of still kettle.
As mentioned, in current polycondensation, preferably produce the polyester that is made up of terephthalic acid (PTA) as acidic component and ethylene glycol as glycol component above.Correspondingly, mixture also comprise water and monomer, the oligopolymer that formed during polycondensation and/or polymkeric substance, especially acetaldehyde, Jia Ji bis-Evil penta ring or also have the degradation production of glycol ether.
In an embodiment of present method, at least one mixture example at least one distillation receptor utilizes heat medium oil or steam heating until boiling point, and the volatile component part wherein such as, be made up of low-boiling-point substance (especially water, acetaldehyde, Jia Ji bis-Evil penta ring) and high boiling material (dibasic alcohol of dibasic alcohol and dimerization, have the ethylene glycol of glycol ether) is distilled out.Steam is transferred directly in rectifying tower, and does not cause in the mixture be back in distillation receptor.
In the water collecting basin of distillation receptor, the correspondingly concentrated nonvolatile component part be made up of the possible residuum of monomer, oligopolymer, polymkeric substance and dibasic alcohol, especially ethylene glycol.The component of the nonvolatile component part in the water collecting basin of distillation receptor can adjust by selecting specific temperature and specific negative pressure.
The nonvolatile component part of collecting in the water collecting basin of distillation receptor of mixture can be suitable by least one pump sucking-off from distillation receptor.This can carry out continuously or discontinuously or semi-continuously.And then, the nonvolatile component part of the sucking-off from distillation receptor of mixture can such as lead back as twice-laid stuff or can flow to glycolysis in polycondensation process.
In another embodiment of present method, volatile share of mixture is especially fractionated into low-boiling-point substance and high boiling material when refluxing at least one rectifying tower.In other words, volatile share is such as separated into water, acetaldehyde and Jia Ji bis-Evil penta ring as the dibasic alcohol of the dimerization of low-boiling-point substance and dibasic alcohol, especially ethylene glycol and certain share, if glycol ether is as high boiling material.
Propose in the variations of present method, discharge and condensation at least one condenser from the top of at least one rectifying tower as low-boiling-point substance isolated volatile share from mixture in rectifying tower, described condenser preferably runs under negative pressure.
The condensation product formed at least one condenser is preferably collected and is divided at least one overhead product and at least one and can be incorporated into backflow in rectifying tower at least one reflux vessel.At this, the ratio of overhead product and backflow is preferably suitable for the purity of the expectation of the low-boiling-point substance at the top place of Deethanizer design and at least one rectifying tower.Especially the overhead product produced when continuous print process control is usually formed by water and other low-boiling-point substances and is no longer again utilized, but it is clean typically to flow to waste water.
As mentioned above, present method performs under negative pressure or vacuum, and this causes the reduction of the boiling point of mixture, and then the heat of mixture meets minimizing or keeps the least possible.For this reason, vacuum or negative pressure are drawn at least one distillation receptor via at least one condenser and at least one rectifying tower by least one vacuum pump.
In the further embodiment of present method, as high boiling material isolated volatile share condensation and collecting in the tower collecting container (Kolonnensumpfbehaelter) in the water collecting basin (Sumpf) of at least one rectifying tower, especially in the distiller of rectifying tower from mixture in rectifying tower.The high boiling material collected in tower water collecting basin is correspondingly eliminated low-boiling-point substance, and wherein said high boiling material is preferably made up of dibasic alcohol and the dibasic alcohol of dimerization, especially ethylene glycol and glycol ether.In the distiller of rectifying tower, the amount of the share of the high boiling material of condensation is followed by the thermal equilibrium in volatile share of the evaporation of mixture and the amount of backflow, volatile share of the evaporation of wherein said mixture has been fed in rectifying tower, and the amount of wherein said backflow is fed in the top of rectifying tower.
In an embodiment of present method, the high boiling material mixture in the water collecting basin of rectifying tower, especially collected in tower collecting container is utilized at least one vaporizer to be evaporated at least in part again and is led back in the water collecting basin of rectifying tower, especially in tower collecting container and lead back in rectifying tower by the high boiling material mixture of evaporator evaporation.Thus, the thermal equilibrium in rectifying tower can be balanced and can improve the rectifying in distiller simultaneously together with the amount of the backflow sent on the top of rectifying tower.
As repeatedly shown, present method can be run continuously or discontinuously.The operation scheme of described method on the one hand with collect in the water collecting basin of rectifying tower, by dibasic alcohol, especially ethylene glycol, relevant with the purity of the high boiling material that the dibasic alcohol of dimerization, especially glycol ether are formed or quality.In addition, process control is determined by the other application target of dibasic alcohol.
Be discussed in more detail below different feasible process control.
In continuous print method, preferably by least one pump, such as the high boiling material condensation product in tower water collecting basin, especially collected in tower collecting container discharged continuously by water collecting basin pump from the water collecting basin of rectifying tower.So, when the continuation use of the dibasic alcohol (ethylene glycol) of the impurity and recovery that only contain trace in the dibasic alcohol collected in tower water collecting basin (such as ethylene glycol) can allow a small amount of impurity, this continuous print operation scheme is especially favourable.
In the operation scheme of the semicontinuous or discontinuous execution of present method, in tower water collecting basin, especially the high boiling material condensation product collected in tower collecting container is not discharged from the water collecting basin of rectifying tower, described high boiling material condensation product is made up of the dibasic alcohol of dibasic alcohol and dimerization, such as, be made up of ethylene glycol and glycol ether.
In the variations of semi-continuous operation scheme, for the time point that tower water collecting basin or tower collecting container are filled by high refuse condensation product, stop and at least one mixture is introduced at least one distillation receptor (such as by turning off at least one fresh feed pump).Correspondingly, the volatile share formed during adding the mixture in thermal distillation receptor transfers to appearance stagnation at least one rectifying tower and volatile share is no longer introduced in rectifying tower.In this case, connecing twice-laid stuff that collect in the water collecting basin of receptor, that comprise monomer, oligopolymer and/polymkeric substance in distillation can by pump, and such as twice-laid stuff pump is discharged from distillation receptor, until distillation receptor is empty.
From now on, after the tower collecting container by high boiling material condensation product packed rectification tower, preferably it is possible that: the heating improving the vaporizer that at least one is connected with tower collecting container, the amount of the high boiling material condensation product evaporated from the tower collecting container of rectifying tower thus increases.
By increasing the amount of the high boiling material condensation product evaporated from tower collecting container, the share being still in the low-boiling-point substance in the top of rectifying tower at this time point is extruded or shifts out from rectifying tower, until discharge pure high boiling material steam, namely pure dibasic alcohol steam (glycol steam) at tower top, wherein said tower collecting container rises in rectifying tower.Liquefy at least one condenser in this so-called " pilot process " at the mixture of the gaseous state of tower top place discharge and as so-called pilot process overhead product collection.The overhead product coming from pilot process can or be dropped, but or also can to flow at least one receiving vessel and again to process.
In another variations of described method, when by high boiling material condensation product packed tower collecting container, also can preferred at least one vaporizer of continuous heating, until only discharge dibasic alcohol (ethylene glycol) and collect at least one overhead condenser as overhead product on the top of rectifying tower.So-called dibasic alcohol overhead product has high purity; Such as form primarily of dibasic alcohol, such as ethylene glycol and only very little have the dibasic alcohol of dimerization, as glycol ether.The dibasic alcohol obtained in this so-called " dibasic alcohol process " can lead back in polycondensation process in order to profit again.
Correspondingly, heating fumigators can continue until the temperature of high boiling material condensation product in water collecting basin at rectifying tower or in tower collecting container rises to (vacuum) boiling temperature of the dibasic alcohol (such as glycol ether) of the dimerization gathered in tower water collecting basin in so-called " dibasic alcohol process ".
Generally may also be considered that, " dibasic alcohol process " continues until the water collecting basin of rectifying tower or tower collecting container are actually empty.This depends primarily on the share of the dibasic alcohol (glycol ether) of the dimerization in high boiling material condensation product.Can discharge by least one pump (water collecting basin pump) at the resistates formed during tower collecting container evaporation high boiling material condensation product and flow to a step in tower collecting container and use, wherein said resistates be especially made up of the dibasic alcohol (such as glycol ether) of dimerization.
If the tower collecting container of rectifying tower becomes empty, so new mixture or can be flowed to the polycondensation of semi-continuous operation scheme below by least one distillation receptor, but or the method can change continuous print operation scheme into when there is no time-consuming transformation.
Equipment for performing method described above comprises following parts:
-at least one distills receptor, described distillation receptor is incorporated into the mixture at least one distillation receptor and the volatile share for separating of mixture at least one heating polycondensation process, described mixture comprises at least one dibasic alcohol, monomer, oligopolymer and/or polymkeric substance
-at least one be connected to distillation receptor downstream rectifying tower, described rectifying tower be used for by mixture distillation receptor in isolated volatile share be separated into low-boiling-point substance and high boiling material,
-at least one condenser, the low-boiling-point substance that described condenser is discharged for the top place being condensate in rectifying tower, and
-at least one vacuum pump, described vacuum pump is used at least one distillation receptor place, applies negative pressure at least one rectifying tower place with at least one condenser place.
In an embodiment of this equipment, at least one vacuum pump is directly connected with at least one condenser, and then can vacuumize at least one distillation receptor via at least one condenser and at least one rectifying tower or take out negative pressure.
In another variations of this equipment, at least one condenser is connected for the reflux vessel holding the condensation product formed within the condenser with at least one.
Also preferred, be provided with at least one at the water collecting basin place of at least one rectifying tower for being contained in water collecting basin container or the tower collecting container of the high boiling material condensation product formed in the distiller of rectifying tower.
In another embodiment of this equipment, at least one water collecting basin container or tower collecting container are connected with at least one vaporizer, make the high boiling material condensation product existed in tower collecting container be directed in vaporizer, in vaporizer heating and the steam formed in vaporizer be directed in tower collecting container and rectifying tower.
Tower collecting container can be formed on single type ground.But generally also can propose, water collecting basin container multi-piece type ground forms, is namely divided into portion's section.
Accompanying drawing explanation
Below, the present invention is elaborated with reference to accompanying drawing appended by embodiment.Accompanying drawing illustrates:
Fig. 1 illustrates according to the schematic overview figure for implementing the equipment according to method of the present invention preferred embodiment.
Embodiment
Fig. 1 illustrates the synoptic chart of the signal of schematic device, and described equipment is suitable for performing according to method of the present invention.
As starting materials, in receiving vessel 1, be collected in the mixture produced in the polycondensation of especially terephthalic acid or dimethyl terephthalate (DMT) and ethylene glycol.By fresh feed pump 2, mixture is fed in still kettle 3 as solution or suspension.According to the purity of the expectation of ethylene glycol to be separated, this charging can semi-continuously or continuously be carried out.
Mixture is heated to boiling point in still kettle 3, and distills out volatile integral part of being made up of low-boiling-point substance and high boiling material and as delivery of steam to rectifying tower 5.As hereafter still set forth, by regulating specific temperature and specific vacuum, draw the concentration ratio of the expectation of ethylene glycol in the water collecting basin of still kettle 3 and the monomer of use, the oligopolymer of formation and polymkeric substance.
The PET twice-laid stuff be made up of monomer, oligopolymer and polymkeric substance obtained in the water collecting basin of still kettle 3 utilizes twice-laid stuff pump 4 discontinuously or continuously sucking-off and can being such as transported in polycondensation plant as feed-in amount in order to proposed application department from still kettle 3.
The steam flowing to rectifying tower 5 from distillation receptor 3 is separated into low-boiling-point substance water, acetaldehyde and Jia Ji bis-Evil penta ring and high boiling material ethylene glycol and glycol ether in rectifying tower 5 when refluxing.
Low-boiling-point substance rises and discharges from tower top as steam in the rectifying portion of rectifying tower 5, and described steam is condensation in condenser 9 under vacuo.
Condensation product flows in reflux vessel 10, and is then divided into overhead product and backflow, and backflow ratio wherein to be used is suitable for the top purity of Deethanizer design and expectation.Usually the overhead product be made up of water and other low-boiling-point substances no longer again utilizes and flows to waste water cleaning device.
Vacuum in still kettle 3 above-mentioned and rectifying tower 5 can be retracted in still kettle 3 via overhead condensation 9 and rectifying tower by vacuum pump 11.Reduce the boiling point of mixture by applying vacuum, and then the thermal load of mixture in still kettle is the least possible.
The condensation and final to know that the mode of low-boiling-point substance is collected in tower collecting container 6 in the distiller of rectifying tower 5 of the share of the high boiling material be made up of ethylene glycol and glycol ether.
Tower collecting container 6 is connected with vaporizer 7.Evaporate the high boiling material condensation product of specified quantitative via vaporizer 7 and be directed in rectifying tower 5 to returning.Therefore, by vaporizer 7, thermal equilibrium can be balanced and can improve the rectifying in distiller simultaneously together with quantity of reflux, and wherein said quantity of reflux does not reoffer on the top of rectifying tower 5.
The application target of the quality of ethylene glycol of collecting in tower collecting container 6 as condensation product and the other of ethylene glycol determines: whether equipment semi-continuously or continuously runs.
If the impurity of the ethylene glycol such as collected in tower collecting container 6 is only a small amount of, and if can allow a small amount of impurity from the other application of the ethylene glycol of tower collecting container 6 recovery, so ethylene glycol can be discharged continuously and carry by water collecting basin pump 8 and further be determined for it from tower collecting container 6.By this way, whole recycled PET twice-laid stuff and all reclaim ethylene glycol run serially from tower collecting container 6 from still kettle 3.Therefore, describe continuous print process and terminate at this.
If but impurity, the especially glycol ether of the ethylene glycol collected in tower collecting container 6 are larger and turn out to be interfering in the further use of the ethylene glycol reclaimed, so described recovery can semi-continuously run.
In semi-continuous operation scheme, as described above, ethylene glycol and glycol ether as high boiling material collecting condensation in tower collecting container 6.But different from continuous print operation scheme, product is not discharged from tower collecting container by water collecting basin pump 8, tower collecting container 6 is thus filled lentamente with high boiling material condensation product.
If tower collecting container 6 is filled by high boiling material condensation product, pending mixture is so stopped to be fed in still kettle 3 and the fresh feed pump 2 that operates is static.Therefore, flow to end from still kettle 3 to the vapour stream rectifying tower 5.Twice-laid stuff in the water collecting basin of still kettle 3 can utilize twice-laid stuff pump 4 to discharge, until still kettle 3 is empty completely.
When only still a small amount of low-boiling-point substance is discharged from reflux vessel 10 as overhead product, be switched on " pilot process ".At this, improve the heating in vaporizer 7, make the ethylene glycol amount of evaporation from tower collecting container 6 increase.The ethylene glycol of evaporation promote the still remaining share be made up of low-boiling-point substance from the tower top of rectifying tower 5 in line go out, until discharge pure ethylene glycol there.
Once temperature on the top of rectifying tower 5 rises to the boiling temperature of ethylene glycol when applying vacuum and ethylene glycol has the purity of expectation, so switch to " EG process ".
The material of pilot process can such as again provide and flow to semi-continuous method in receiving vessel 1.
For " EG process ", improve the heating at vaporizer 7 place, until discharged as overhead product by the ethylene glycol of desired amount when the top of rectifying tower 5 is in default backflow.This " EG process " continues until the water collecting basin temperature in tower collecting container 6 rises on the boiling temperature of glycol ether when applying vacuum, otherwise tower collecting container 6 is empty technically.
The ethylene glycol of recovery like this has high purity and only still has the glycol ether of minute quantity.Described ethylene glycol can forward for again utilizing.
The glycol ether gathered in tower collecting container 6 is discharged by water collecting basin pump 8 and is flowed to further use.
Reference numerals list
1 receiving vessel
2 fresh feed pumps
3 still kettles
4 twice-laid stuff pumps
5 rectifying tower
6 tower collecting containers
7 vaporizers
8 water collecting basin pumps
9 condensers
10 reflux vessel
11 vacuum pumps
Claims (21)
1. for the treatment of produce in polycondensation process, the method for the mixture that comprises at least one dibasic alcohol, monomer, oligopolymer and/or polymkeric substance, described method comprises step:
A) mixture comprising dibasic alcohol, monomer, oligopolymer and/or polymkeric substance at least one produced in polycondensation is transferred at least one distillation receptor (3),
B) at least one distillation receptor (3), mixture described at least one is heated until boiling point, and mixture, the volatile share during heating discharged of the mixture that especially comprises at least one dibasic alcohol is not back in described distillation receptor (3)
C) by mixture, volatile share of being formed during mixture described in heating at least one in the distil container described at least one (3) of the mixture that especially comprises at least one dibasic alcohol transfers at least one rectifying tower (5), and
D) volatile share of described mixture is separated in rectifying tower (5) described at least one further,
Wherein according to step b) described at least one, distill the described mixture of heating in receptor (3), according to step c) volatile share of described mixture is transferred to rectifying tower described at least one (5) neutralization according to steps d) rectifying tower described at least one (5) in be separated described mixture volatile share perform under negative pressure.
2. method according to claim 1, it is characterized in that, from distilling receptor (3) described at least one, from distill described at least one receptor (3) derive described mixture described in heating at least one before mixture or period the nonvolatile share that produces, wherein carry mixture especially to comprise monomer, oligopolymer and/or polymkeric substance.
3. method according to claim 1 and 2, is characterized in that, the described mixture produced in polycondensation process has the glycol content of at least 10%, glycol content, the especially preferred glycol content between 85% to 95% of preferred at least 50%.
4. the method according to any one of the claims, is characterized in that, dibasic alcohol described at least one is glycol, especially ethylene glycol.
5. the method according to any one of the claims, is characterized in that, is separated into low-boiling-point substance and high boiling material in volatile share rectifying tower (5) described at least one of described mixture.
6. the method according to any one of the claims, it is characterized in that, described in described rectifying tower (5) from described mixture isolated volatile share as low-boiling-point substance discharge from the top of rectifying tower described at least one (5) and at least one condenser (9), preferably condensation under negative pressure.
7. method according to claim 6, is characterized in that, the condensation product formed in condenser (9) described at least one receives at least one reflux vessel (10).
8. the method according to claim 6 or 7, is characterized in that, described condensation product is divided at least one overhead product and at least one can be incorporated into backflow in described rectifying tower (5).
9. the method according to any one of the claims, it is characterized in that, negative pressure or vacuum to be drawn into described at least one via condenser described at least one (9) and rectifying tower (5) described at least one by least one vacuum pump (11) distills on receptor (3).
10. the method according to any one of the claims, it is characterized in that, the volatile share as high boiling material be separated from described mixture in described rectifying tower (5) in the distiller of described rectifying tower (5) condensation and described at least one rectifying tower (5) water collecting basin in, especially collect at least one tower collecting container (6).
11. methods according to claim 10, the high boiling material mixture it is characterized in that, again to evaporate at least in part in the described water collecting basin of described rectifying tower (5) by least one vaporizer (7), especially collected in described tower collecting container (6) and the described high boiling material mixture of evaporation lead back in described rectifying tower (5).
12. according to claim 10 to the method according to any one of 11, it is characterized in that, the high boiling material condensation product in the described water collecting basin of described rectifying tower (5), especially collected in described tower collecting container (6) is discharged continuously from the described water collecting basin of described rectifying tower (5), especially by least one pump (8) from described tower collecting container (6).
13. according to claim 10 to the method according to any one of 11, it is characterized in that, the high boiling material condensation product in the described water collecting basin of described rectifying tower (5), especially collected in described tower collecting container (6) is not discharged from the described water collecting basin of described rectifying tower (5), in especially described tower collecting container (6).
14. methods according to claim 13, it is characterized in that, promote the heating of vaporizer described at least one (7), increase from the amount of the high boiling material condensation product of evaporation the described water collecting basin of described rectifying tower (5), in especially described tower collecting container (6) thus.
15. methods according to claim 14, it is characterized in that, vaporizer described at least one (7) heating and continuous is until only discharge dibasic alcohol at the top place of described rectifying tower (5) and receive as in overhead product condenser (9) described at least one.
16. according to claim 14 to the method according to any one of 15, it is characterized in that, the resistates in the described water collecting basin of described rectifying tower (5), especially formed during the described high boiling material condensation product of evaporation in described tower collecting container (6) is discharged by pump described at least one (8).
17. 1 kinds for performing the equipment of the method according to any one of the claims, described equipment comprises:
-at least one distillation receptor (3), described distillation receptor is incorporated into described at least one at least one heating polycondensation process and distills the mixture in receptor (3) and the volatile share for separating of described mixture, described mixture comprises at least one dibasic alcohol, monomer, oligopolymer and/or polymkeric substance
-at least one is connected to the rectifying tower (5) in described distillation receptor (3) downstream, described rectifying tower is used for isolated volatile share in described distillation receptor (3) of described mixture to be separated into low-boiling-point substance and high boiling material
-at least one condenser (9), the low-boiling-point substance that the top place that described condenser is used for being condensate in described rectifying tower (5) discharges, and
-at least one vacuum pump (11), described vacuum pump be used for described at least one, distill receptor (3) place, described at least one rectifying tower (5) place and described at least one condenser (9) place apply negative pressure.
18. equipment according to claim 17, it is characterized in that, vacuum pump described at least one (11) is directly connected with condenser described at least one (9) and described at least one, distills suction in receptor (3) via condenser described at least one (9) and rectifying tower (5) described at least one.
19. equipment according to claim 17 or 18, it is characterized in that, condenser described at least one (9) is connected for the reflux vessel (10) being contained in the described condensation product formed in described condenser (9) with at least one.
20. according to claim 17 to the equipment according to any one of 19, it is characterized in that, described at least one, the described water collecting basin place of rectifying tower (5) is provided with at least one the tower collecting container (6) for being contained in the high boiling material condensation product formed in the distiller of described rectifying tower (5).
21. equipment according to claim 20, it is characterized in that, described at least one, tower collecting container (6) is connected with at least one vaporizer (7), make the described high boiling material condensation product existed in described tower collecting container (6) import in described vaporizer (7), heat in described vaporizer (7) and lead back in described rectifying tower (5) at the middle steam formed of described vaporizer (7).
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102013210180.5 | 2013-05-31 | ||
| DE201310210180 DE102013210180A1 (en) | 2013-05-31 | 2013-05-31 | Process for working up a mixture obtained during polycondensation processes and a plant for carrying out the process |
| PCT/EP2014/060679 WO2014191314A1 (en) | 2013-05-31 | 2014-05-23 | Process for workup of a mixture obtained in polycondensation processes and a plant for performing the process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105246943A true CN105246943A (en) | 2016-01-13 |
Family
ID=51022807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201480030807.8A Pending CN105246943A (en) | 2013-05-31 | 2014-05-23 | Process for workup of mixture obtained in polycondensation processes and plant for performing process |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP3004206A1 (en) |
| CN (1) | CN105246943A (en) |
| DE (1) | DE102013210180A1 (en) |
| WO (1) | WO2014191314A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112321394A (en) * | 2020-11-06 | 2021-02-05 | 艾凡佳德(上海)环保科技有限公司 | Method and equipment for obtaining ethylene glycol and diethylene glycol from recovered liquid |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10358540B2 (en) | 2017-06-09 | 2019-07-23 | GM Global Technology Operations LLC | Process and system for reducing volatile compound emissions from a product |
| CN112830535B (en) * | 2021-01-19 | 2022-05-20 | 烟台东洁环保机械工程有限公司 | Alkali decrement wastewater recovery process for microfiber leather |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1618755A1 (en) * | 1966-02-01 | 1971-07-22 | Du Pont | Methods for cleaning up ethylene glycol |
| WO2006108469A1 (en) * | 2005-04-15 | 2006-10-19 | Lurgi Zimmer Gmbh | Method for treating condensates from polycodensates |
| CN101080438A (en) * | 2004-12-16 | 2007-11-28 | 旭化成化学株式会社 | Industrial evaporation apparatus |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2504258A1 (en) * | 1975-02-01 | 1976-08-05 | Dynamit Nobel Ag | PROCESS AND APPARATUS FOR THE MANUFACTURING OF OLIGOMERIC ALKYLENE TEREPHTHALATES |
| DE10125678B4 (en) * | 2001-05-25 | 2011-04-14 | Lurgi Zimmer Gmbh | Process and apparatus for the production of polyethylene terephthalate |
| DE10346769A1 (en) * | 2003-10-06 | 2005-04-21 | Zimmer Ag | Automatic analyzer and method for monitoring polymer production by mass spectrometry |
| DE102004034708B4 (en) * | 2004-07-17 | 2008-04-10 | Lurgi Zimmer Gmbh | Process for the batch production of polymers by melt condensation |
-
2013
- 2013-05-31 DE DE201310210180 patent/DE102013210180A1/en not_active Ceased
-
2014
- 2014-05-23 CN CN201480030807.8A patent/CN105246943A/en active Pending
- 2014-05-23 EP EP14733530.1A patent/EP3004206A1/en not_active Withdrawn
- 2014-05-23 WO PCT/EP2014/060679 patent/WO2014191314A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1618755A1 (en) * | 1966-02-01 | 1971-07-22 | Du Pont | Methods for cleaning up ethylene glycol |
| CN101080438A (en) * | 2004-12-16 | 2007-11-28 | 旭化成化学株式会社 | Industrial evaporation apparatus |
| WO2006108469A1 (en) * | 2005-04-15 | 2006-10-19 | Lurgi Zimmer Gmbh | Method for treating condensates from polycodensates |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112321394A (en) * | 2020-11-06 | 2021-02-05 | 艾凡佳德(上海)环保科技有限公司 | Method and equipment for obtaining ethylene glycol and diethylene glycol from recovered liquid |
Also Published As
| Publication number | Publication date |
|---|---|
| EP3004206A1 (en) | 2016-04-13 |
| DE102013210180A1 (en) | 2014-12-04 |
| WO2014191314A1 (en) | 2014-12-04 |
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