CN1332714A

CN1332714A - Method for purifying and producing high-purity aromatic polycarboxylic acid and derivatives thereof

Info

Publication number: CN1332714A
Application number: CN99813645A
Authority: CN
Inventors: 文森特·T·D·林
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-11-24
Filing date: 1999-11-19
Publication date: 2002-01-23
Anticipated expiration: 2019-11-19
Also published as: WO2000031014A8; EP1131276A1; WO2000031014A1; KR20010101068A; JP2003510247A; EP1131276A4; CN1264798C; KR100642625B1

Abstract

The present invention provides a process for the solvent extraction purification of aromatic polycarboxylic acids or derivatives thereof, having a purity which meets or exceeds the polymerization grade specifications. The process comprises dissolving a crude aromatic polycarboxylic acid or a derivative thereof (e.g., methyl ester) in a basic compound, removing impurities and an excess of the basic compound, and also removing residual basic compound when recovering the product. This purification process not only removes impurities from the crude acid or derivative thereof, but also simultaneously removes residual base compounds from the final product that contaminate the product. The salt in the percolated cake is converted to the product by acid substitution, pyrolysis, or electrolysis. The process uses an alkaline extraction solvent to extract the alkaline compounds and impurities from the salt. Then, the residual alkali compounds in the recovered product are removed by leaching, stripping, electromagnetic wave thermal agitation, or pyrolysis evaporation. The purification process eliminates the need for crystallizers and equipment for drying and gas delivery. Finally, combining this purification process with the oxidation and solvent recovery of the currently known technology, one can reduce the two current process steps for the production of aromatic polycarboxylic acids or derivatives to one, thereby significantly reducing the production costs.

Description

The purifying of high purity aromatic polycarboxylic acids and derivative thereof and manufacture method

Invention scope

This invention is relevant high purity aromatic polycarboxylic acids and derivative thereof, particularly relevant for the method that improves purifying and manufacturing high purity aromatic polycarboxylic acids or derivatives thereof (for example ester).

Background of invention

Aromatic polycarboxylic acids is to be made by alkyl corresponding on the oxidizing aromatic compounds, these sour examples have: the purified terephthalic acid (Pure Terephthalic Acid, PTA), m-phthalic acid (IsophthalicAcid, IPA), trimellitic acid (Trimellitic Acid, TMA), 2, the 6-naphthalene dicarboxylic acids (2,6-Naphthalene Dicarboxylic Acid, 2,6-NDA), 2, the 7-naphthalene dicarboxylic acids (2,7-NDA) etc.Because of PTA is most typical method, so it will be used to explain orally the present invention.Yet purifying of the present invention and manufacture method are also applicable to all aromatic polycarboxylic acids and derivative thereof.

The main production method of PTA be with the thick terephthalic acid of the following step production (CrudeTerephthalic Acid, CTA).

1) oxidation: p-Xylol (PX) and air are that catalyzer and acetic acid are that the solvent oxidation reaction forms terephthalic acid with cobalt-manganese-bromine in the liquid phase of 150-230 ℃ and 150-425 psia.

2) crystallization: the effluent of oxidation reactor is precipitated out terephthalic acid via the crystallization under the decompression desuperheat of 3 to 5 big crystallizers from mother liquor.

3) filter: thick acid is separated from mother liquor via centrifugal/filtration.The Recycling Mother Solution of handling or being untreated is to oxidation step.

4) drying: dry up thick acid with rare gas element, and the entrained acetic acid of this rare gas element is reclaimed by scrubber then.Dried thick terephthalic acid is delivered to warehouse by air push, therefore needs a large amount of nitrogen or air separation equipment.

5) solvent and catalyst recovery: solvent and catalyzer can reclaim via many diverse ways.

The CTA that contains about 0.5% impurity via hydrogenation to make the 4-that contains about 25PPM PTA to the benzoic polymerization grade of toluic acid and 0-50PPM to acidic group phenyl aldehyde (4-CBA), 150PPM.Be similar to above-mentioned CTA technology, also must pass through similar crystallization, filtration, the recovery of exsiccant programstep again via the PTA behind the hydrogenation purifying.Therefore, the impurity of reactor effluent about 0.5% is removed, is purified to the product of about 0.025% impurity, at present the step of the following costliness of arts demand:

1) processing step of two cover crystallizations, centrifugal/filtration, drying and gas delivery.

2) come purifying with the method for the chemical reaction of costliness.Except the equipment cost of the hydrogenation unit of costliness, because of operating in high pressure-temperature and using the catalyzer of precious metal also to need the production cost of great number.

3) the crystallization residence time of quite growing.CTA needs 3-5 approximately, and PTA needs 5 big crystallizers so that product is reclaimed in mother liquor approximately.In addition, because the bromine and the acetic acid environment of highly corrosive, some crystallizer must use expensive corrosion resistant material, for example the equipment of titanium lining.

4) step procedure of drying and gas delivery is to make end product.

5), but still contain 0.01% the impurity of having an appointment though product conforms with the specification of polymerization grade.

Make trevira, film and molded resin and must use highly purified PTA and derivative thereof.Why terephthalic acid is difficult to purifying, mainly is because low, high boiling point of its solubleness in most solvents and product have similar rerum natura and voltinism to impurity.

The method of another kind of purifying is to remove impurity with solvent extraction.It is that cost is lower that solvent extraction attracts part, and this method can trace back to nineteen fifty-three (United States Patent (USP) 2,664,440), or may be more early.Early stage solvent of being advised and unstable, can with product produce reaction, toxic, maybe CTA can't be purified to desired degree.Thereafter, Iwane (United States Patent (USP) 5,344,969) and Hirowatari (United States Patent (USP) 5,565,609) disclose the more method of solvent stability of using.Below will summarize these methods.

1) the thick acid of dissolving: aromatic polycarboxylic acids and many alkali cpds can form salt, and this salt dissolves in many dissolution solvents, such as the water or the alcohol that heat up.

2) remove impurity: some impurity can separate via handling before the solution easily, as come the adsorption coloring agent with activated carbon.But the approaching impurity of character and acid then must cool off at least 30 ℃, separates from mother liquor with crystallization mode.

3) product reclaims: Hirowatari, or in the presence of ethylene glycol, contacts steam and thermal degradation with this concentrated solution pre-treatment solution thermal degradation by thermal treatment.Iwane then precipitates salt and washs it, then by thermal degradation, or adds a kind of sour substituted solvent with the product acid in the replacement salt, and changes it product of purifying into.Iwane is also by directly adding to sour substituted solvent in the solution to reclaim product.

Iwane and Hirowatari all use only nitrogenous for heteroatomic amine compound, for example aliphatic, alicyclic, aromatic series or heterocyclic amine.Iwane is that dissolution solvent comes the autoxidizable thick NDA in purifying source with alcohol.Hirowatari then is dissolution solvent with water, and the vibrin of aromatic dicarboxilic acid from hydrolysis reclaimed.Because of impurities only is additive and tinting material, it can be easily reclaimed by activated carbon and separates, so this method is not with the salt of Crystallization Separation purifying.Therefore, this method is only applicable to the highly purified PTA of purifying (it contains the additive and the tinting material of separate easily), does not contain the thick aromatic dicarboxilic acid that is difficult to isolating oxidation impurities and be suitable for purifying.

As for pyrolysis, Iwane is added in paraffinic hydrocarbons, alkylbenzene, alkylnaphthalene or the alkyl biphenyl salt and heating, and does not use steam to heat.But will residuing in the product, selected high boiling solvent becomes another kind of pollutent.Hirowatari is then with pre-treatment solution heating and reflux decomposing amine salt, or after concentrating this solution with distillation method, contacts with decomposition again with steam and removes this amine compound.Ethylene glycol mainly is in order to the lifting reflux temperature, will increase the residual quantity of alkali cpd in the product but reflux, and the also necessary water that evaporates above 50% of distillation method, so needs a large amount of energy.

Iwane can with 97.2% 2, the 6-NDA purity improvement degree to about 99.8%, Hirowatari then can reclaim purity and be about 99.9% PTA from the vibrin of hydrolysis.Iwane utilize its method only in the future the purity of the autoreactor effluent thick NDA that is lower than CTA be purified to the degree that approaches CTA.Though above two methods all can improve degree of purity of production, but still can't reach the specification (＞99.98%) of polymerization grade PTA.

Another method is Lee (No. the 5767311st, a United States Patent (USP)), and it directly is dissolved in CTA in 140-190 ℃ the N-Methyl pyrrolidone (NMP), and does not use dissolution solvent.This solution makes it crystalline deposit after being cooled to 5-50 ℃.Filter and wash this throw out so that PTA reaches the polymerization grade.Yet use the experiment of this method to show, still have considerable salt pollution product.The formation of this pollution may be that PTA and NMP can form salt because it fails to understand in this method.Lee thinks that the throw out of solution is PTA, but in fact it still is a salt.During washing, salt is washed solvent, as methyl alcohol or water, changes into product.But still having a large amount of salt not transformed, is all salt can't be converted into product because washing is only arranged.The method of this dissolving and solvent recuperation is very expensive.If compare with amine compound or morpholine, the expensive about 2-3 of NMP price times, and need to use 3-5 amount doubly dissolve thick acid.And the solvent boiling point height, a large amount of energy recovery of essential cost.In addition, Lee thinks that mistakenly CTA dissolves in the water-free morpholine solution.No matter solution temperature is how, unless the water existence, its solubleness is little of negligible.Even morpholine can dissolve CTA, its end product will not be PTA but salt, because methyl alcohol can't change into PTA with the throw out of alkylbenzyldimethylasaltsum saltsum.Later on the difference of NMP and alkylbenzyldimethylasaltsum saltsum will be discussed more at large, and the present invention will bring into play its advantage.The present invention will use new crystallization method and cleaning solvent to improve the quality of this method product.

Even above-mentioned so many advantages are arranged, but still find no the commercial exploitation of solvent extraction purifying.One of them main problem be since residue in the end product the however, residual base compound but contravariant become a kind of pollutent.All propose that the organo-alkali compound that uses all contains nitrogen, and it will cause color and some other problems when making polyester, there is no prior art at present and disclose this problem, and how to remove this alkali cpd in product.

Xln comprises residual solution usually when crystallization.Use some known crystallization method, it may comprise the residual alkali lye more than 0.1%, and its degree is very near the foreign matter content among the CTA.In order to be applicable to the manufacturing polyester, the residual alkali compound must remove to several degree that is about 1,000,000, and it is near the PTA impurity levels.Therefore, known solvent extraction technology can be removed the impurity in the thick acid, but makes residual alkali compound polluted in product, makes it can't be applicable to the manufacturing polyester.

All known methods all do not attempt removing residual alkali from end product.The Iwane teaching is used sour solvent, and the Hirowatari teaching makes water come alkali cpd in the washing filter end product cake, and Lee then teaching uses NMP, p-Xylol, acetone, methyl ethyl ketone or methyl alcohol to take the washing and filtering cake.Use the water of 100: 1 ratios to wash and with 10 hours experiment of this filter cake leaching, the purified product that is produced still contains a large amount of alkali cpds.Show thus,, just be difficult to be removed again in case alkali cpd is contained in the product xln.Because known references do not discuss this problem, or for being familiar with known to this skill person but still treat with solution.

In the known solvent extraction purification process, all express or impliedly teaching replace hydrogenation unit with solvent extraction, and use CTA to be charging, having only Lee is exception.He thinks that the direct filtration reactor effluent is the CTA of recyclable a large amount by mistake, and does not need to use crystallizer or other method.But direct filtration, most CTA still is present in the mother liquor of reactor effluent, and it needs quite long residence time with deposit C TA.Present technology use 3-5 big crystallizer reclaim CTA have its because of.The present invention advises using flash evaporation and evaporates to reduce residence time.

Itself also needs crystallization, filtration, drying and gas delivery the solvent extraction purification process.So known solvent extraction purification technique also needs two cover processing steps to produce PTA.Therefore, the solvent extraction method of all known purifying aromatic polycarboxylic acids all has following shortcoming:

1) contains the residual alkali compound in crystal, and pollute end product.

2) need the equipment of two cover crystallizations, centrifugal/filtration, drying and gas delivery.

3) still contain tangible detectable impurity in the end product.

4) need quite long residence time to come crystallization, therefore need several big crystallizers.

5) need drying and gas delivery to make end product.

Therefore, a few project of the present invention is designated as:

1) provides a cover solvent extraction purification process, removing the impurity in the thick acid, thereby meet or surpass the specification of aromatic polycarboxylic acids polymerization grade.

2) alkalization of removing in the end product is closed, and makes trevira, film, molded resin so that it is applicable to, or the application of others.

3) provide the method for the aromatic polycarboxylic acids of making the polymerization grade, and only need a cover processing step, thereby reduce investment and production cost in fact.

4) reduce the number of crystallizer, or even fully need not.

5) produce the aromatic polycarboxylic acids that can be directly used in the manufacturing polyester, and need not use the step procedure of drying and gas delivery.

The disclosed solvent extraction method of this invention is very unexpected and find that surprisingly it can remove impurity the degree that can't measure to present standard HPLC institute, so further advantage will be more obvious then.

Summary of the invention

The invention provides the solvent extraction purification process of aromatic polycarboxylic acids or derivatives thereof, its purity can satisfy or surpass the specification of polymerization grade.This method comprises also removes the residual alkali compound when thick aromatic polycarboxylic acids or derivatives thereof (as methyl esters) is dissolved in the alkali cpd, removes impurity and excessive alkali cpd and reclaims product.This purification process is not only removed impurity from thick sour or derivatives thereof, also remove simultaneously the residual alkali compound of pollution products in end product.Salt in the filter cake is to be converted into product with acid replacement, pyrolysis or electrolysis mode.This method uses the alkali extraction solvent to extract alkali cpd and impurity from salt.Then, the residual alkali compound in this recovery product is removed in the mode of leaching, stripping, hertzian wave thermal agitation or pyrolysis evaporation.This purification process can exempt to use the equipment of crystallizer and drying and gas delivery.At last, oxidation and the solvent recuperation of this purification process with present known technology combined, the two cover processing steps of producing aromatic polycarboxylic acids or derivative at present can be kept to a cover, thereby significantly reduce production costs.

Detailed Description Of The Invention

The invention provides the solvent extraction purification process of a cover aromatic polycarboxylic acids or derivatives thereof, its purity can satisfy or above the polymerization grade.This method is applicable to any poly carboxylic acid, for example PTA, IPA, TMA, 2,6-NDA, 2,7-NDA etc.This method also is suitable for this sour derivative, comprises ester, as terephthalic acid dimethyl ester (DMT), 2, the 6-naphthalene diformic acid dimethyl ester (2,6-NDC), the polyester of hydrolysis etc.This method comprises thick aromatic polycarboxylic acids or derivatives thereof is dissolved in the alkali cpd; Remove impurity and excessive alkali cpd; And when making purified product, remove the residual alkali compound.Preferred alkali cpd is the alkali that contains aerobic and nitrogen heteroatom, as morpholine or NMP, and other alkali cpd discussed in more detail below.Salt in the filter cake can replace solvent, pyrolysis or electrolytic method by acid and transform back product.

Except removing the impurity from thick sour or derivatives thereof, this method uses the alkali extraction solvent to extract alkali cpd and impurity and reclaim product from salt.The residual alkali compound that reclaims in the product can further be removed by leaching (leaching), stripping (stripping), hertzian wave thermal agitation (thermalagitating with electromagnetic waves) or evaporation pyrolysis (evaporation withthermal decomposition).Residual alkali cpd is not an impurity, but a kind of pollutent of introducing by purge process.This purification process can avoid using the equipment of crystallizer and drying or gas delivery, thereby reduces cost.At last, this purification process will be in conjunction with traditional oxidation and solvent-extracted technology (it all uses two cover purifying process steps), and only uses a cover processing step to produce aromatic polycarboxylic acids.

The xln of the aromatic polycarboxylic acids that solvent extraction is purified can be via being adsorbed in plane of crystal; Be retained in crack, crack or agglomerating gathering; And be contained in the fluid bag, and contain alkali cpd and other employed solvent.Alkali cpd in the crystal not necessarily is in a liquid state, and may form solid-state salt with crystallinic acid.The solvent that washing or pyrolysis only may be removed a part of absorption or be held back is contained in fusibility and is the solvent in about 300-425 ℃ the product crystal but can't remove those.It is very difficult these however, residual base compounds being removed in the product crystallization.

Known technology uses rare gas element to go bad to cause the product variable color to avoid the alkali oxide compound, but this can only hide the problem that the alkali cpd existence is caused.Standard HPLC analytical procedure is energy measurement impurity and can't measure the alkali cpd of non-aromatic only; The product color measurement method also can't detect alkali cpd, except that involuntary the alkali cpd oxidation is existed to show it.A kind of method of simple detection however, residual base compound is to make the long-time heat of end product be oxidized to non-white color, with present its colourity of color measurement method amount, and with by the PTA of hydrogenation purifying relatively.

Be not excessive alkali cpd in the salt of purifying with carboxylic acid functional bonded alkali cpd.Only from salt, remove excessive alkali cpd and can not avoid contact alkali cpd when reclaiming product fully, because alkali cpd is still a composition of salt.Therefore, need remove with other method and be contained in the residual alkali compound that reclaims in the product crystallization, and this method is extremely difficult and non-obvious.

The present invention finds that the alkali extraction solvent can and reclaim extraction alkali cpd and impurity the product from salt.Suitable alkali extraction solvent is any unazotized compound, and maybe salt can be changed into product acid to target crystalline solubleness is low; To alkali cpd and impurity solubleness height; And be easy to separate, or need not separate with product.But this kind solvent hydroxyl, carbonyl, ether, ketone, ester or other functional group.

Unless other bright stating, described solvent extraction method is under predetermined pressure, put to the temperature of maximum boiling point in solution solidifies and carry out, and the preferred temperature of using is to maximum boiling point from temperature of cooling water.Working pressure is not specially limited; Can be 0 to 100 bar absolute pressure, and be preferably 0.001 to 5 bar absolute pressure.

The purification process of removing impurity and residual alkali compound comprises the following step.

Dissolve thick acid or derivative

Thick aromatic polycarboxylic acids or derivatives thereof and alkali cpd form salt and dissolve.If this salt can be dissolved in the dissolution solvent, thereby then this solvating agent can be used to increase solubleness reduction dissolving cost.Otherwise then do not use solvating agent.This also comprises that some thick acid or derivative can be dissolved in alkali cpd but the salifiable rare example of shape not.

Thick aromatic polycarboxylic acids or derivatives thereof can be from any source of containing any impurity.It can be from oxidation reactor, and the centre of many technologies or final product stream are for example made DMT or 2, the intermediate product of 6-naphthalene diformic acid dimethyl ester (NDC), the polyester of hydrolysis etc.Alkali cpd comprises and contains oxygen and oxygen-free alkali cpd.Oxygen containing alkali cpd comprises any aerobic and nitrogen of containing as heteroatomic alkali cpd, for example morpholinium compound, amide compound, mineral alkali etc.Oxygen-free alkali cpd then comprises amine compound and ammonia.Alkali cpd comprises aliphatic series, alicyclic, aromatic series and heterocyclic compound.The usage quantity of alkali cpd is every mole of carboxyl or replace the 0.5-100 mole of carboxyl functional group in the aromatic polycarboxylic acids or derivatives thereof, and usual amounts is the 1-2 mole of every mole of carboxyl functional group in the thick aromatic polycarboxylic acids.Dissolution solvent comprises water, alcohol, ether, ketone and ester etc.The consumption of dissolution solvent can be the 0-100 mole of every mole of carboxyl functional group in the thick aromatic polycarboxylic acids, is the 1-10 mole than usual amounts.

Known technology all uses the traditional heating method that energy is delivered to salt ion via solvent molecule and makes it overcome gravitation to dissolve thick acid.The present invention also can use electromagnetic thermal agitation method to dissolve thick acid or ester except using the traditional heating method.The thermal agitation of ion under hertzian wave is different from traditional heating or microwave heating.Hertzian wave provides thermal agitation to solvent molecule and salt ion simultaneously.Yet salt ion receives bigger stirring energy than solvent molecule, makes ion heat other molecule, and is different from traditional heating method.So electromagnetic thermal agitation method has tangible characteristic, such as, solubleness, solvent evaporation and crystalline polamer.For example dissolve, but also may be returned original acid or ester molecule by pyrolysis quickly, and different solubleness is arranged owing to salt ion receives more energy; Owing to higher evaporation of vapours has crystalline rate preferably; Because of energetic ion may return product acid or ester with the salt pyrolysis of a part, and different precipitation mechanism is arranged.Its main advantage is effectively to save the dissolving energy and time.Less dissolution time then can reduce degrading solvent or react with impurity.

Iwane and Hirowatari use oxygen-free amine compound, and Lee then uses pyrrolidone, alicyclic amide compound, and it has carbonyl and amine functional group characteristic.Other preferably contains the oxonium base compound is the morpholinium compound with ether and amine functional group characteristic.Contain oxygen and oxygen-free organo-alkali compound in basicity, specific inductivity, moment of dipole, or visibly different characteristic is all arranged with the water absorbability aspect of dissolution solvent.The present invention will utilize these characteristics and advantage that alkali cpd and impurity are removed from end product.

Oxygen containing salt is called alkali salt, and oxygen-free salt is called conventional salt.Most conventional salt can be dissolved in many solvents, as water and alcohol.The salt that contains ether will be called as the ether alkali salt, and big multipotency is dissolved in water, but manyly can not be dissolved in other solvent, as alcohol.The salt that contains carbonyl will be called as the carbonyl alkali salt, be not dissolved in solvating agent more, comprise water and alcohol.The alkali extraction solvent maybe can be reduced into salt product acid for salt solubility is hanged down, and to alkali cpd and the high solvent of impurity solubleness, thereby be used for purification of salts and product.The key that the present invention finds the carbonyl alkali salt a little less than.Therefore more described salt is reduced into product, and alkali cpd is removed from product, but difficult formation of this salt and dissolving cost are more expensive, the ether alkali salt is then opposite.Therefore, alkali cpd is that impurity is separated in thick acid, and the alkali extraction solvent then separates with impurity alkali cpd in purification of salts and end product.

More particularly, aromatic polycarboxylic acids for contain one or more condensed ring those, wherein two or more carboxylic acid groups can be on any position of aromatic ring or condensed ring, and any hydrogen all can be replaced by any other functional group.The poly carboxylic acid example that contains an aromatic ring includes but not limited to that terephthalic acid, m-phthalic acid, phthalic acid (orthophthalic acid), trimellitic acid, benzene connect tricarboxylic acid (hemimellitic acid), trimesic acid (trimesic acid), pyromellitic acid (pyromellitic acid) and mellic acid (mellitic acid).Contain two aromatic ring poly carboxylic acid examples and include but not limited to 2,6-naphthalene dicarboxylic acids, 2,7-naphthalene dicarboxylic acids, 1,7-naphthalene dicarboxylic acids, 1,8-naphthalene dicarboxylic acids, 2,3,6-naphthalene tricarboxylic acid, 1,4,5,8-naphthalene tetracarboxylic acid and 2,3,6,7-naphthalene tetracarboxylic acid.The poly carboxylic acid example that contains three aromatic rings includes but not limited to 2,6-anthracene dicarboxylic acid, 2,7-anthracene dicarboxylic acid, 2,8-anthracene dicarboxylic acid, 2,9-anthracene dicarboxylic acid, 1,9-anthracene dicarboxylic acid, 2,3,6-anthracene tricarboxylic acid, 1,4,5,8-anthracene tetracarboxylic acid and 2,3,6,7-anthracene tetracarboxylic acid.Aromatic polycarboxylic acids also comprises the aromatic polycarboxylic acids with any mixed, for example, 2,6-naphthalene dicarboxylic acids and 2, the mixture of 7-naphthalene dicarboxylic acids.

As for alkali cpd, the nitrogen-atoms on the alkali cpd can have trivalent or pentavalent.This alkali cpd comprises the heteroatoms of all why not co-located in office and the combination of carbon atom; and saturated or unsaturated compound with one or more hydrogen atoms; hydrogen atom can be replaced by alkyl, aryl or acyl group, or the ammonium salt that comes out of all these compound derivings.If this alkali cpd is solid-state or gaseous state under normal conditions, then can use its aqueous solution.Alkali cpd also comprises the mixture of any ratio.Mineral alkali can be sodium hydroxide, potassium hydroxide etc.

Morpholine kind compound comprises morpholine, N-methylmorpholine, N-ethylmorpholine, N-propyl group morpholine, N-sec.-propyl morpholine, N-methylmorpholine oxide compound, N-phenyl-morpholine, 4-morpholine propionitrile, 1-morpholine-1-tetrahydrobenzene etc.Other alkali cpd that contains ether functional group also is included in the single heterogeneous ring compound with 3 to 8 atoms of nitrogenous and Sauerstoffatom in the ring, and it comprises oxa-azocine class (oxazocines), oxa-azepines class (oxazepines), oxazine Lei, oxazole class, isoxazole, oxygen diazete (oxadiazetes), oxaza propylene class (oxazirines) etc.

Amide compound comprises the acid amides of aliphatic series, for example dimethyl formamide, N,N-DIMETHYLACETAMIDE, ethanamide, ethanamide etc.Alicyclic acid amides comprises pyrrolidone, N-Methyl pyrrolidone, N-ethyl-pyrrolidone, N-alkyl-2-Pyrrolidone, N-mercaptoalkyl-2-Pyrrolidone, N-mercaptoethyl-2-Pyrrolidone, N-alkyl-2-thiopyrrolidone, N-methyl-2-thiopyrrolidone, N-hydroxyalkyl-2-Pyrrolidone and N-hydroxyethyl-2-Pyrrolidone, lactan etc.Aramid comprises phenyl-acetamides, phenylene terephthalamide (phenylene terephthalamide) etc.

Aliphatic amine comprises methylamine, dimethylamine, Trimethylamine 99, ethamine, diethylamine, triethylamine, Tri N-Propyl Amine, di-n-propylamine, Tri-n-Propylamine, Isopropylamine, Diisopropylamine, tri-isopropyl amine, quadrol, N-methyl ethylenediamine, N, N-dimethyl-ethylenediamine, N, N '-diethyl ethylenediamine, N, N '-dimethyl-ethylenediamine, N, N, N '-trimethylammonium quadrol, N, N, N ', N '-Tetramethyl Ethylene Diamine, 1,2-diaminopropanes, 1,3-diaminopropanes, monoethanolamine, diethanolamine, trolamine, N,N-DIMETHYLACETAMIDE, dimethyl formamide etc.Cycloaliphatic amines comprises methyl cyclohexylamine, N-methylcyclohexylamine, N, N-dimethylcyclohexylamine, ethyl cyclohexylamine, N-ethyl cyclohexylamine, N, N-diethyl cyclohexylamine, sec.-propyl hexahydroaniline, N-sec.-propyl hexahydroaniline, N, N-di-isopropyl hexahydroaniline, ethylenimine, propylidene imines etc.Aromatic amine comprises N, accelerine, N, N-Diethyl Aniline, N, N-dibutyl aniline, N, N-dimethyl methyl aniline, N, N-diethyl Tolylamine etc.Heterocyclic amine comprises pyridine, piperidines, N-methyl piperidine, N-crassitude etc.

Alkali cpd commonly used is morpholine, NMP, Trimethylamine 99, triethylamine (triethyalamine) or trolamine.

Alcohols comprises aliphatic monohydric alcohol, such as methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, isopropylcarbinol, sec-butyl alcohol, the trimethyl carbinol, Pentyl alcohol, primary isoamyl alcohol, sec.-amyl alcohol, tertiary amyl alcohol, neopentyl alcohol, hexanol, enanthol, octanol, nonyl alcohol and decyl alcohol; Alicyclic monohydroxy-alcohol such as cyclopentanol and hexalin etc.; Aliphatic straight chain dibasic alcohol such as ethylene glycol, glycol ether, propylene glycol, butyleneglycol and pentanediol; Alicyclic dibasic alcohol is as 1, and 2-encircles pentanediol, 1, and 3-encircles pentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol; With aliphatic polyol such as glycerol and tetramethylolmethane etc.Be preferably and have 3 carbon atoms or 3 aliphatic monohydric alcohol or 4 carbon atoms or 4 aliphatic diols that carbon atom is following that carbon atom is following.Alcohol can be the mixture of the above-mentioned various alcohol of any ratio.Preferred alcohol is methyl alcohol, ethanol or aklylene glycol.

Ether comprises dme, diamyl ether, diethyl ether, isopropyl ether, n-butyl ether, n-hexyl ether, chloro dme, methyl-phenoxide, two methyl-phenoxides, oxyethane, diox, trioxane, furans, tetrahydrofuran (THF), methyl-tetrahydrofuran (THF), tetrahydropyrans, methyl-tetrahydropyrans etc.Ketone comprise acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, Methyl amyl ketone, methylacetone, 2-methyl-cyclopentanone, cyclopentanone, pimelinketone etc. other.Ester comprises Ethylene Glycol Methyl ether, Diethylene Glycol methyl ether, glycol ethyl ether, Diethylene Glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, ethylene glycol phenyl methyl ether, glycol ether, triglycol, alkyl formate, alkyl acetate, alkyl propionates, barkite, lactic acid alkyl ester, carbonic ether, benzoic ether etc.

Remove impurity and excess base compound

This step is removed impurity by pre-treatment, precipitation, separation and washing and filtering cake.Present known technology is teaching, can remove impurity by solution pre-treatment and crystallisation by cooling.In addition, the present invention will provide novel method to remove impurity and the excess base compound in the washing after-filtration cake.

The purpose of solution pre-treatment is to remove easily from the isolating impurity of solution, for example with activated carbon adsorption tinting material or additive, the undissolvable impurity of filtration, flow out or wipe impurity of drift etc. off.The method of separating these impurity is widely known by the people, and the present invention will be not limited to arbitrary specific method.If do not have this type of impurity in the thick acid, then do not need the solution pre-treatment.

The crystalline purpose is to remove difficult separation and rerum natura and voltinism and all very approaching impurity of product.Under certain temperature and solution composition, the solubleness of impurity salt be not low than product salt be exactly height.Therefore by the variation of solution temperature and/or composition, the impurity with low solubility earlier precipitation and with other separating substances.Precipitated product salt then can separate with the impurity of those high-dissolvabilities in mother liquor.

Known technology uses type of cooling crystallization with separating impurity at present, and salt is to separate with general method, as filtration or centrifugal.Because the very long residence time of needs makes the crystal growth in the mother liquor, so need several very big crystallizers.Other mode is control solution composition and cooling, to reduce required residence time.After thick acid is dissolved fully and before crystallization,,, remove the solvent of predetermined amount, so that cooled slurries still have the mother liquor of q.s with separating impurity as evaporation or distillation by general method., this method needs quite long crystallization residence time though reducing.This dual mode all attempt keeping as much as possible impurity in mother liquor to separate with purification of salts.

Known technology uses alkali cpd to take washing and filtering salt usually at present, because solvating agent can dissolve salt at once.Because the viscosity height of salt is so detersive efficiency is very low.In addition, this method will make salt contain more alkali cpd, thereby increase the content of alkali cpd in the end product.Other known technology then teaching uses aliphatic hydrocrbon or aromatic hydrocarbons to do cleaning solvent.This method just replaces intracrystalline solvent with cleaning solvent simply, there is no the ability of any extraction, and its residue may pollute end product.

The present invention uses the alkali extraction solvent to remove excessive alkali cpd and impurity in salt.This new method comprises with the alkali extraction solvent to be washed with leaching, has following crystal salt, exists precipitated product acid down, salt directly to extract in the alkali extraction solvent in the alkali extraction solvent, salinization crystallization again, and alkali salt replaces.

Most alkali extraction solvent can not transform back salt acid, but then can change in order to washing carbonyl alkali salt as if this solvent.But mix with alkali cpd if will transform the alkali extraction solvent of salt, then can reduce salt and transform.For example, take washing and filtering salt, then can reduce the conversion of salt widely with 50% methyl alcohol and NMP mixed solvent.The present invention wishes to keep the washing cake in the form of salt as far as possible.

More particularly, the alkali extraction solvent can be water, hydrogen peroxide, alcohol, ether, phenol, ketone, ester etc.Alcohol, ether, ketone and ester had before been defined.The alkali extraction solvent can use separately, or is the mixture of two or more solvent with any mixed, and this solvent can use with liquid state or steam state form.Preferred alkali extraction solvent is water, methyl alcohol, ethanol, aklylene glycol, acetone, tetrahydrofuran (THF) or tetrahydropyrans.Though the crystallization of this step is the salt of purifying, therefore getting rid of solvating agent is the alkali extraction solvent.But the crystallization of next step is a product acid or derivatives thereof, and then solvating agent can comprise used alkali extraction solvent.

The color of most of impurity salts is non-white, and excessive alkali cpd all has the smell of ammonia.With the filter cake of washing of alkali extraction solvent or leaching, its color and smell compare to by other cleaning solvent, as alkali cpd or the washed salt of hydrocarbon polymer significant improvement are arranged all.According to the definition, leaching and be different from the washing and filtering cake (the chemical industry handbook of Perry ' s, the 6th edition, 19-48).Washing is widely known by the people with the method for leaching, and the present invention is not limited to use arbitrary ad hoc approach.

After thick acid is dissolved fully, also can add the alkali extraction solvent to solution.In the crystallisation process, the existence of alkali extraction solvent can reduce the alkali cpd that is contained in the crystallization, simultaneously also can be from salt extracting impurities and alkali.In addition, the alkali extraction solvent exists in solution and also may change crystalline mechanism, such as shape, size and speed.For example, add the crystallite size that methyl alcohol, acetone or tetrahydrofuran (THF) can change shape and increase NMP-PTA salt.

In the solution that the alkali extraction solvent exists, add acid and replace the precipitable pure products acid of solvent.And the existence of alkali extraction solvent can be from throw out extracting impurities and alkali cpd.The present invention finds, for the carbonyl alkali salt, water can be the alkali extraction solvent but also can be that acid replaces solvent, because of it can directly be settled out product acid in saturated solution, but other alkali extraction solvent, as methyl alcohol, precipitable salt in some solution composition scope.Yet 4-CBA and NMP salt solubleness in water is hanged down 10 times approximately than methyl alcohol.Compare with the prior art that transforms salt with washing, precipitated product acid in the solution that the alkali extraction solvent exists, the salt that can better control precipitated product by controlled temperature, stirring, composition and residence time transforms and crystallite size.Known technology replaces solvent with acid and directly adds solution with precipitated product, and does not use the alkali extraction solvent.Because of most of impurity will be with the product coprecipitation, and reduce product purity.

If most or whole solvents is removed in solution by evaporation or flash evaporation, is then obtained solid salt or slurry.Because of impurity can not evaporate under normal operating condition, it will stay in salt entirely.At present known technology is all avoided this kind situation, and in solution crystallization so that impurity is stayed in isolating mother liquor.Yet the present invention is very unexpected and find that surprisingly from then on the alkali extraction solvent can plant in the salt directly extracting impurities and excessive alkali cpd.Like this then can exempt the requirement of crystallization residence time.Its product organic efficiency then depends on the solubleness of salt in the alkali extraction solvent, and solvating agent stays the amount in slurry.Different with the crystallization of prior art, this direct crystallization from salt extraction does not need cooling solution to come crystallization.Before adding the alkali extraction solvent, the mother liquor in the slurry can be separated or do not separate.Solution after the extraction is to separate with salt with general isolating method.

If throw out is dissolved in solvating agent or alkali cpd again, and the recrystallize one or many, can reach with present standard HPLC can't measure the degree of impurity, maybe the thick acid that contains higher impurity can be purified to the specification that conforms with the polymerization grade.Therefore, the salinization crystallization comprises crystal salt from thick acid dissoluting liquid again; Separate washing and dissolved salt again; Recrystallize salt from solution; Separate and washing salt with general method.Preferably, before crystallization, salt is dissolved fully.If the washing cake is crystallization or to transform salt with meeting be that the alkali extraction solvent of acid washs under hertzian wave, then may contain product acid.Acid in the washing cake can separate from salt, or does not separate, or dissolves with alkali cpd again.Arbitrary crystallization method of discussion that the front is carried all can be used for crystallization and precipitation, but preferably directly extracts the method for crystallization and recrystallize with salt.If precipitated product under the alkali extraction solvent then is preferred for last crystallisation step.The number of times of recrystallize there is no special restriction, preferred 1-2 time.

Aforesaid method can use different types of alkali extraction solvent in different step to remove impurity.Alkali extraction solvent consumption can be the 0.1-100 mole of every mole of carboxyl functional group, preferred 1-10 mole.Methyl alcohol or ethanol are the preferred bases extraction solvents of ether alkali salt, and aklylene glycol, acetone, tetrahydrofuran (THF) or tetrahydropyrans then are the preferred bases extraction solvents of carbonyl alkali salt.

Saline and alkaline replacement is to replace alkali in the salt to improve the method for the product rate of recovery by another kind of alkali.As previously mentioned, the carbonyl alkali salt is higher than difficult formation and dissolving cost, but easy recovery and cost recovery are lower.For example, make NMP-PTA salt and make the expensive several times of morpholine-PTA salt, but it can be reclaimed by more cheap water.The present invention finds that the alkali cpd of salt can be replaced by another high boiling alkali cpd, so ether alkali salt or conventional salt can be converted into the carbonyl alkali salt.Therefore, make and to make purification of salts with the alkali cpd of less expensive, convert thereof into another kind of easily the recovery and the lower salt of cost recovery then.With the salt that is converted with replace alkali and mix, mixing also can add or not with solvating agent.With traditional heating or hertzian wave mode, use the method for general solution separating then,, substituted alkali cpd and/or solvating agent are isolated from solution as evaporation or distillation.This substituted salt can be under existence of alkali extraction solvent or non-existent situation, and cooling is precipitated out, or is directly extracted and got by salt.Solvating agent, for example water can reclaim then in order to dissolve unconverted salt, or continue conversion in a series of step.Saline and alkaline replacement also is included under the situation of another alkali cpd existence, changes the crystallization of salt, as shape or size.The consumption that replaces alkali can be the 0.1-100 mole of every mole of carboxyl functional group, preferably with the 1-10 mole.

Except being that sour alkali extraction solvent comes the washing and filtering cake with not transforming salt, the also available salt that can transform takes the washing and filtering cake for the alkali extraction solvent of acid or with the sour solvent that replaces.This can be considered to merge to wash with next step will discuss the step of sour method of substitution, and it also is the employed method of Lee.Yet washing has only very little controlled on the conversion of salt and product characteristics.The method preferably of it is considered herein that is before filtration the product Acid precipitation of purifying to be come out, or precipitate and isolate purification of salts, with next step method of being discussed salt is converted into product acid then because the two to the conversion of salt, in product extracting impurities and alkali cpd, and product particulate size, all have controlled preferably.Concerning some alkali salt, the size of salt particle can influence product particulate size, and the big I of salt particle by spraying drying, regulate composition, residence time, temperature, stirring or other is controlled.

Therefore, the method for removing impurity comprise solution pre-treatment, crystallisation by cooling, solution composition control and crystallisation by cooling, in the alkali extraction solvent exist deposited salt down, in the alkali extraction solvent have down that precipitated product, salt directly extract, salinization crystallization again, alkali salt replace, with the washing of alkali extraction solvent, might make up with leaching of alkali extraction solvent or aforesaid method.Except removing the impurity from thick sour or derivatives thereof, this step is also removed the excess base compound with the alkali cpd residual quantity in the end product that reduces following step manufacturing from filter cake.

Make purified product and remove the residual alkali compound simultaneously

The purpose of this step is to reclaim product by salt, if contain the salt of enough amounts in the filter cake, and/or removes the residual alkali compound before making end product.The method that is reclaimed product by purification of salts comprises sour replacement, pyrolysis or electrolysis.Be preferable over extraction solvent and have recovery product down.Because of solution composition, temperature, stirring and residence time all can influence product coating of particles and size, these factors should cooperate the extraction of alkali and impurity to reach best situation.

Acid replaces

For salt is converted into product, adds acid and replace solvent with the product acid in replacement and the deposited salt.Salt can mix with the alkali extraction solvent earlier.Method is to dissolve ether alkali salt or conventional salt before acid replaces solvent fully in solvating agent adding preferably, and preferred solvating agent is water, methyl alcohol, ethanol, aklylene glycol or its mixture.The carbonyl alkali salt is insoluble to most solvents, and water is preferably acid replacement solvent of this salt.Method is to add entry in the presence of alkali extraction solvent such as methyl alcohol, ethanol, acetone, tetrahydrofuran (THF) or tetrahydropyrans preferably.The acid replacement can be in hertzian wave operation down.Acid in the presence of the alkali extraction solvent replaces can reduce the residual alkali compound that reclaims in the product and the packet content of impurity.

It can be aliphatic carboxylic acid, mineral acid, water etc. that acid replaces solvent.Aliphatic carboxylic acid can be formic acid, acetic acid, propionic acid, butyric acid, hydroxacetic acid, lactic acid, oxysuccinic acid, tartrate, mesotartaric acid, citric acid, monochloroacetic acid, the acid of monobromo acetic acid, a nitroacid acid, trifluoracetic acid and Tricholroacetic Acid; And mineral acid can be nitric acid, hydrochloric acid, hydrogen bromide, hydrogen iodide, sulfuric acid, phosphoric acid and perchloric acid.As discussed, water or alkali extraction solvent can be the acid replacement solvents of carbonyl alkali salt.It can be the above-mentioned acid mixture with any ratio that acid replaces solvent, or with solvating agent or alkali extraction solvent mixture with any ratio, and ratio that should acid is greater than 1% weight.It is aliphatic carboxylic acid that the preferred acid of ether alkali salt or conventional salt replaces solvent, and acetic acid most preferably.The carbonyl alkali salt then is best with water.The consumption that acid replaces solvent is the 0.5-100 mole of every moles of carboxylic acids functional group in the aromatic polycarboxylic acids.Common consumption is more more slightly than the mole number of carboxylic acid functional.Pyrolysis

Heat is added to purification of salts, in 50-350 ℃ temperature range, the alkali cpd in can thermolysis salt.Salt also can mix with the alkali extraction solvent with desirable boiling point, and this boiling point can pressure controlling.Preferred alkali extract compounds is water, steam or alcohol.Heat can apply by hot tranfer system, such as heat exchange pattern, or directly contacts with thermal medium.

Except above-mentioned traditional heating means, salt also can be in thermal degradation under the hertzian wave.Preferable methods is with salt and alkali extraction solvent, and as water, steam or alcohol etc., with any mixed, and solvent solubilized salt or acid replace salt, and can absorb hertzian wave to assist the decomposition of salt.These molecules of electromagnetism wave energy thermal agitation and with them from can't absorbing electromagnetic product Crystallization Separation, solution thereby the product that is become to have transformed by pyrolysis and the mixture of unconverted salt.If in a suitable scope, solution then can be decomposed by hertzian wave constantly with solvent strength and temperature maintenance.Also can add the alkali extraction solvent in the step of continuous row makes it to continue to decompose to this mixture.Unconverted salt also dissolves in the solvating agent and separates with product, and filtrate can be recycled, or continues pyrolysis filtrate with a succession of step by hertzian wave.Therefore, this method can be used in partial or continuous mode.Compare with traditional method, less energy and treatment time are used in the hertzian wave pyrolysis.For example, compare with the traditional method that needs 2-12 hour residence time, this method only needs 0.04-0.6 hour.In addition, thermal agitation mode from inside to outside can reduce and comprise the chance of alkali cpd in crystal.

The alkali cpd that decomposes can separate in product with general common method, absorbs or transports out of with rare gas element, steam or solvating agent etc. as evaporation, vacsorb, distillation, absorption agent.

For the carbonyl alkali salt, method is that salt directly contact with steam or is the alkali extraction solvent with water or with steam preferably, by the sour again replacement salt of hertzian wave interaction energy pyrolysis simultaneously.In in such cases, the product granular size will be decided by the salt particle size that is easier to control.In addition, be that solvent comes pyrolysis salt residue and evaporating solvent then can avoid using step procedure such as filtration, drying and gaseous transfer with the aklylene glycol, this will discuss it in the back.

Electrolysis

Galvanize by purification of salts and be dissolved in the alkali extraction solvent and in the solution that forms, negative electrode will attract base cations and anode will attract acid anion.If institute's electric current of executing is enough big, product acid can precipitate around anode.Other method is acid to be replaced solvent or heat be added near this electrode to precipitate this product acid, with electric field base cations is separated to reduce product acid being contained in chance in the alkali cpd simultaneously.Designing electrode with present common method disturbs to reduce around the ionic of other electrode.This electrolytic process is similar to the metallic element electrolysis manufacturing process of having known at present, but the present invention is not limited to arbitrary ad hoc approach.The employed magnitude of current is also without particular limitation, and it depends on the electric field of ideal productive rate and isolating ions.Use not can with ionic reaction and can pass into solution in and the material of pollution products, maybe can be with the material of ion deposition on electrode as electrode.Preferred alkali extraction solvent is the mixture of methyl alcohol, ethanol, aklylene glycol or these solvents.

Reclaim product and can use method commonly used at present to separate, its filter cake can use alkali extraction solvent, acid to replace solvent, or washs with the solvent mixture of any blending ratio.Some reclaims product if use the following step then can not need to separate and be directly used in polymerization.

Known technology is only removed the residual alkali compound or is made salt be converted into product with mode of washing at present, and it is not enough to the alkali cpd in the end product is removed to desirable degree.These end products contain quite high however, residual base compound former because still contain too many alkali cpd in the cake that has washed, when product reclaims in crystallization extraction residual alkali compound, will contain the direct pyrolysis of solution of high-alkali compound concentration, alkali cpd will be back in the pyrolysis solution or will replace as acid that solvent is used to transform salt and residual a lot of unconverted salt is medium in product with washing soln.

On the other hand, the present invention will be as far as possible removes the unnecessary alkali cpd in desalting, and reclaims in the product extraction residual alkali compound certainly to reduce residual quantity.Yet, because alkali cpd is a composition of salt, so when reclaiming product, can't avoid contacting alkali fully.Therefore, these can only reduce, and remove the residual alkali compound in the product fully but can't reclaim certainly.The more foregoing alkali step of removing can not done, but will increase the amount of residual alkali compound.Because the residual alkali compound is difficult to remove, so should in each step, reduce the content of alkali cpd as far as possible.

Below will provide the present invention to remove the novel method that reclaims residual alkali compound in the product, and make it can be applicable to the manufacturing polyester.This novel method comprises leaching, stripping, with the combination of hertzian wave thermal agitation, evaporation pyrolysis or said procedure.

With the alkali extraction solvent predetermined amount and in the time leaching reclaim product, but leaching number of times one or many.The method of residual solvent is widely known by the people in leaching or the stripping filter cake, and the present invention is not limited to arbitrary ad hoc approach.But leaching or stripping only can be removed those part alkali cpds that is adsorbed or holds back, and are contained in intracrystalline alkali cpd and can't remove those.

The hertzian wave thermal agitation can impose on hertzian wave in the mixture that reclaims product or itself and alkali extraction solvent.This method is similar to the method for hertzian wave pyrolysis salt, but its emphasis is the residual alkali compound that is contained in the recovery product removing.Hertzian wave does not have effect to the product crystal, but can cause that residual alkali cpd and solvent thermal stir and generate heat, and is adsorbed on the surface or is contained in intracrystalline basic ion and solvent is separated in crystal and make.The alkali cpd that decomposes and other solvent then separate with gas, liquid adsorption or by crystal alkali extraction solvent leaching on every side.The alkali extraction solvent can be continuously or the batch-wise mode add to assist the decomposition of salt residue.This method can be removed residual alkali compound and while desciccate.

The evaporation pyrolysis is the evaporation of residual solvent, as water or acetic acid, and pyrolysis residual alkali compound, its service temperature can be 50-350 ℃, preferred 90-210 ℃.Reclaim product and monomer, as aklylene glycol mix or with mix (size of this oligomer chain is the 1-100 elementary cell) by product acid with the oligomer (oligomer) of this monomer polymerization gained or mix with alkali extraction solvent (as the water of intensification).High boiling aklylene glycol or oligomer be in order to the pyrolysis salt residue and in solution the evaporation residue solvent.In addition, aklylene glycol is the tectonic element of polyester, and therefore this solution or filter cake can remove the step of drying and gas delivery from directly in order to produce polyester.If polyester equipment and purifier apparatus be not or not same place, then this method can be carried out at arbitrary place.Preferably heat to avoid introducing other composition with heat transfer or hertzian wave thermal agitation.The residual solvent that is evaporated is then removed with vacuum take-off or other proper method.The consumption of aklylene glycol is required amount during polymerization preferably, so that the solution after handling can be directly in order to make polyester.This step also can be applicable to existing manufacture method, thereby undried end product is mixed the step of removing drying and gas delivery from aklylene glycol.Solution with this method gained is different from the pyrolysis solution that above-mentioned product reclaims, because of it contains quite high alkali cpd and other solvent, so inapplicable to make polyester.

Be used for product recovery, washing, leaching, stripping, hertzian wave thermal agitation or the not necessarily same kind of evaporation pyrolytic alkali extraction solvent.The consumption of alkali extraction solvent is also without particular limitation, the normally every moles of carboxylic acids 0.5-1000 of functional group mole.

If do not remove the residual alkali compound, if desired, also can come drying to remove residual solution, or come dry with aforesaid hertzian wave with slumpability gas commonly used at present with aklylene glycol evaporation pyrolysis.

Solvent-extracted purification process can operate under air, steam, rare gas element (as nitrogen, argon, helium) or the reducing gas (as hydrogen or the lower appropriate hydrocarbon gas of molecular weight).This method can be in batches, semi-batch or successive.

Recycle can improve product and reclaim and the solvent service efficiency.For example, filtrate can be circulated to previous step or in order to washing or leaching, to reduce the solvent demand and to measure and improve product and reclaim.The filtrate of recycle can be handled or not handle.Filtrate can be handled with any appropriate means, as distillation, filtration, centrifugal, sedimentation, evaporation, cool off, add solvent or above any combination.Recycle is widely known by the people with the method for improvement efficient, and the present invention is not limited to arbitrary ad hoc approach.

The product purity of above-mentioned purification process gained is very unexpected and surprisingly find and can't measure impurity with present standard HPLC measuring method.Compare single hundred times approximately with the product purity of prior art.The color of product high bake can reach present standard, and it shows that alkali cpd removes to gratifying degree.The PTA of low impurity can provide many advantages: increase polymerizable molecular amount, the stronger thinner fiber of production, the oxygen permeability that reduces bottle, increase spinning rotating speed to increase output, to reach many still undiscovered advantages.

Can provide a cover to reduce the novel method of quite a lot of investment and production cost in conjunction with the oxidation of above-mentioned purification process and present known technology and solvent and catalyst recovery method.This method can be applied to produce all aromatic polycarboxylic acids, and this aromatic polycarboxylic acids is produced by the corresponding alkyl of oxidation, such as PTA, IPA, TMA, 2,6-NDA, 2,7-NDA etc.PTA is most typical example, and it will be used to illustrate this novel method.

The two cover processing steps that this bound energy will be produced high purity aromatic polycarboxylic acids at present are kept to a cover, and this mainly is following properties and the advantage of giving full play in the new purification process of the present invention.

1) except being the charging with CTA, new purification process also can directly need not use present known technology separation of C TA as charging with reactor effluent.This effluent contains for example composition such as catalyzer (comprising catalyst promoting agent) and acetic acid, and these compositions can separate in the process of above-mentioned purification process.So can allow at present employed two cover processing steps are kept to a cover with remarkable reduction investment and production cost.

2) at present technology must be considered following factors, as viscosity, granular size, product reclaim and crystal impure etc., and above-mentioned salt directly the crystallization method of extraction can not consider these factors.In addition, the alkali extraction solvent also can be in order to regulate the slurry viscosity of separating and transmitting.

3) new purification process can be removed more impurity by present method for hydrogenation.This makes oxidation reactor to operate under more economic condition, as lower hydrocarbon combustion rate and catalyst consumption rate etc.

4) new purification process can not need crystallizer to come crystallization.

5) new purification process can use aklylene glycol to evaporate pyrolysis, to avoid the step of drying and gas delivery.

6) new purification process uses physical separation method rather than chemical reaction method to remove impurity, so the investment of purifying and production cost are all lower.

7) new purification process can be produced than more highly purified product at present.This provides a lot of aforesaid potential advantages.

The present invention brings into play these collaborative mutually advantage and non-obvious features, and so that the combination of not advised before the cover to be provided, it can reduce considerable investment and production cost.New combining method comprises oxidation, the thick acid of dissolving, removes impurity and alkali cpd from purification of salts, also remove the residual alkali compound simultaneously and reclaim solvent and catalyzer when salt reclaims product.The step procedure of this technology is described below:

Oxidation

This step is produced aromatic polycarboxylic acids with alkyl oxidation corresponding on the aromatic compound.The oxidation of this aromatic polycarboxylic acids was studied widely in past 50 years, and the present invention can use any previous method, and is not limited to arbitrary ad hoc approach.

The method that Middle Ages, company was developed is the method for oxidation of present widespread use, and it is mixing and circulation that solvent is assisted slurry with acetic acid; With heavy metal,, be catalyzer as cobalt and manganese; With bromated compound is promotor.Reaction conditions is normally at 175-230 ℃ and 1500-3000kPa.

Charging can comprise the pump around circuit thing, and it can contain catalyzer, reactor solvent or from the intermediate product of the following step, as dissolve thick acid and alkali cpd, by removing impurity and alkali cpd, and solvent and catalyst recovery etc. in the purification of salts.

Dissolve thick acid or derivative

Thick aromatic polycarboxylic acids or derivatives thereof is dissolved in description in front in the alkali cpd.Before also once mentioned, new purification process can be thick sour charging with the CTA of reactor effluent or present method.Therefore, many selections are arranged to prepare thick acid at these two kinds between extreme.For example, if with the slurry after the reactor effluent flash evaporation as thick sour, then reactor solvent and catalyzer will come across in the filtrate of solvent extraction purification process simultaneously with impurity, it reclaims in the recycling step of solvent and catalyzer then.Other selection is the method that adopts known technology institute teaching, the solvent of reactor and catalyzer are separated in thick acid, and method such as the flash evaporation of known technology institute teaching, evaporation, heating/cooling, crystallization, filtration, centrifugal clarifier, distillation, classification tower, hydraulic cyclone, cyclonic separator, sedimentation, replaced mother liquor, film permeation or make arbitrary intermediate steps of CTA method at present with water.Isolating mother liquor can be back to reactor or deliver to solvent and the step of catalyst recovery.The present invention is not limited to arbitrary ad hoc approach and comes the separate reactor effluent.But preferable methods is the most of mother liquor in the evaporation flash evaporation reactor effluent, and the pump around circuit sub-fraction contains the certainly thick sour isolating mother liquor of catalyzer.Evaporation also can be in hertzian wave operation down.This method can not used under the crystallizer mode, reclaims most thick acid from reactor effluent.

May originating in addition of thick acid is from handling or untreated backflow filtrate, or from the step of solvent and catalyst recovery.

Remove impurity and excessive alkali cpd

The front has described how to remove impurity.As previously mentioned, the number that can reduce required crystallizer with crystallisation by cooling is formed in control, and the direct extractive crystallization rule of salt can exempt to use crystallizer.

Handle or untreated filtrate is capable of circulation is back to other step, or deliver to the step of solvent and catalyst recovery.Partly impurity must be removed from this step avoiding continuing accumulation, and this can carry out in any suitable method.Wherein an example will be for containing the filtrate evaporation of a large amount of impurity, and its bottoms then are back to reactor, or with the method that product reclaims, before refluxing, impurity salt are changed into impurity.

Also remove the residual alkali compound when making purified product simultaneously

The front had been described this step.If use aklylene glycol to remove the residual alkali compound, then can not need present drying or gas delivery step with the evaporation pyrolysis.

Compare with the granular size of present PTA method gained, generally less with the product particle that sour substitution technique was reclaimed, but more even.If remove the residual alkali compound with aklylene glycol, the mixture after then handling can be directly used in makes PET.Yet, if necessary, can dissolve again and recrystallize to adjust the loose density of PTA.This can be realized by present known several different methods.PTA loose density behind the recrystallize not only can be the same with at present commercially available PTA, and purity can be higher and comprise still less impurity.

Solvent and catalyst recovery

Except using present currently known methods to reclaim reactor solvent, water, the catalyzer, this step also reclaims alkali cpd, alkali extraction solvent, acid and replaces solvent (if it is used to reclaim product and is different from reactor solvent) and solvating agent (be used and be different from water as it).In addition, also may contain residual impurity and product from the pump around circuit filtrate of some purification steps.

Be not that all the components all must be recycled to original purity.Some composition can reclaim with mixture.For example, in the step of the thick acid of dissolving, can use the mixture of alkali cpd and solvating agent.Moreover, if comprising number acid, this mixture replaces solvent, it also there is no tangible influence to purification efficiency.

In all solvents, some solvent may form azeotropic mixture.If reclaim product with sour method of substitution, then alkali cpd and acid replacement solvent may form ionogen.Yet, the method that is used to separate these compositions is widely known by the people, as distillation, filtration, centrifugal, sedimentation, evaporation, pyrolysis, cooling, film permeation, replace, replace, add another material to destroy azeotropic mixture etc. with stronger acid with stronger alkali.The present invention also can use hertzian wave in evaporation, distillation and pyrolysis etc.

Conclusion

Therefore, purification process of the present invention is not only removed the impurity in the thick aromatic polycarboxylic acids or derivatives thereof, also provide the method for removing in order to the alkali cpd of purifying simultaneously, otherwise it can pollute this end product.The invention solves over unresolved or unknown problem, it is pratical and feasible that it becomes solvent-extracted purification process.

New purification process has reduced the quantity that is used for the crystalline crystallizer, or fully need not.Can remove the step of required drying of present technology and gas delivery from aklylene glycol separating residual alkali cpd.

Compare with present known technology, new purification process can be produced the product that can't measure the purity of foreign matter content with standard HPLC method, and it improves nearly 100 times.High purity provides many potential advantages, for example can be in order to make stronger thinner new fiber, to improve weaving speed productive rate, minimizing oxygen permeability new purposes and many other still undiscovered advantages so that the PET bottle to be provided to increase the PET fiber.

The present invention gives full play to some special characteristics and the advantage that new purification process is found, and combines with the present oxidation and the method for solvent and catalyst recovery, two present cover method stepss can be kept to a cover.The bound energy of not mentioned before this reduces the investment and the production cost of high purity aromatic polycarboxylic acids in a large number.

Except aromatic polycarboxylic acids, this purification process can be in order to any organic acid or derivatives thereof that contains close rerum natura and voltinism impurity of purifying.These derivatives can contain the acid functional group of any number; Acidic group is replaced by other functional group; Acidic group is at different positions; Or acidic group in same position but its hydrogen replaced by other functional group, as methyl etc.

Therefore, scope of the present invention should with appended claim and legally equivalent determine, rather than decide by the specific embodiment of being narrated.Below will illustrate the present invention.

Reference example

Table 1 is depicted as thick terephthalic acid (CTA) foreign matter content that the PTA method used in the experiment is produced:

Table 1	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 1	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	??2436	?1097	????515

Wherein ppmw represent 1,000,000 of weight/.

Comparing embodiment 1

Table 2 is depicted as and will has the traditional hydrogenation purification process purifying of the CTA of same composition with prior art with table 1, obtains the PTA product of foreign matter content as shown in table 2:

Table 2	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 2	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	????15	Detection less than	????141

Similarly, table 3 is depicted as the foreign matter content by the PTA product of other source gained:

Table 3	??4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 3	??4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	????25	????52	????150

The foreign matter content of this purified product is the terephthalic acid of typical commercial polymerization grade.

Comparing embodiment 2 (remove impurity but do not eliminate the lixiviating compound)

The described CTA sample of 150 gram tables 1 is mixed with 198 gram morpholines and 180 gram water.This solution is heated to 100 ℃ CTA is dissolved fully, be cooled to room temperature then and make it precipitation.Filter slurry to separate with mother liquor, then with morpholine washing and filtering cake to obtain the 196 wet cakes that restrain.The solid that will reclaim mixes with 84 gram water and 22 gram morpholines then.And with this solution temperature rise to 110 ℃ with the evaporation 57ml condensation products, then this solution is cooled to room temperature make it the precipitation.Then, with morpholine washing and filtering cake with obtain 145 the gram pure salt.Then this salt is mixed with 235 gram acetic acid and 14 gram water and make the PTA precipitation.Thereupon with about 600 gram water washing filter cake, will wet then cake in baking oven in about 275 ℃ dry 4 hours down, to obtain the dried PTA of 40 grams.Table 4 is the result of HPLC analysing impurity, but the B value of color measuring filter cake is 6.5, than about 4 times of standard value 1.6 height.This shows the morpholine that contains significant quantity in the PTA.

Table 4	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 4	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	Detection less than	Detection less than	Detection less than

Comparing embodiment 3 (by direct interpolation acetic acid with precipitated product)

With the described CTA sample of 3 gram tables 1 at room temperature be dissolved in fully contain 5.010 the gram triethylamines and 9.047 the gram methanol solutions in.Add 7.570 gram acetic acid then with precipitated crystal, filter then and drying, obtain the terephthalic acid of 2.179 grams.HPLC analyzes and shows that this acid contains impurity as shown in table 5.

Table 5	??4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 5	??4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	??2471	??844	????471

Embodiment 1 (from the sedimentary direct extractive crystallization process of leaching)

The described CTA sample of 40 gram tables 1 is mixed with 52 gram morpholines and 48 gram water.Solution is heated to 110 ℃ of condensation products with dissolving CTA and the about 29ml of evaporation, is cooled to room temperature thereupon and makes it precipitation.With the wet cake that obtains 55 grams after methanol wash and the leaching filter cake.Should restrain methanol mixed for wet cake and 30, the acetic acid that add 85 grams then are to solution, with the precipitation terephthalic acid.Be somebody's turn to do wet cake with about 35 gram methanol wash then,, obtain the wet cakes of one 31.5 grams again with 35 gram methyl alcohol leachings 3 times.Wet cake gets the dried cakes of 24 grams after 4 hours in about 250 ℃ of dryings in baking oven.The B-value of this cake is 2.73, and it still is higher than standard value, and HPLC analyzes and shows that this PTA contains the impurity in the table 6.

Table 6	??4-CBA	Phenylformic acid	Paratolunitrile
Table 6	??4-CBA	Phenylformic acid	Paratolunitrile	PTA(ppmw)	??20.8	Detection less than	Detection less than

Embodiment 2 (by evaporating the pyrolytic crystallization process of salinization again)

The CTA sample that 925 grams are as described in Table 1 mixes with 1103 gram morpholines and 1205 gram water.Solution is heated to 110 ℃ of also condensation products of the about 404ml of evaporation, and is stopping before the crystallization rapidly.Solution is cooled to room temperature thereupon and leaves standstill 4 hours with precipitated crystal.Add 250 gram ethanol with the dilution slurry, and with obtaining 1455 salt that restrain after about 750 gram washing with alcohol and the leaching filter cake.The salt of getting 1005 grams is dissolved in 465 gram water.Solution is heated to 109 ℃, and crystallization rapidly behind the condensation product of the about 280ml of evaporation.With 650 these salt of gram ethanol leaching, and, obtain the 702 pure salt that restrain with 250 gram washing with alcohol filter cake.The salt of 35 grams is dissolved in 40 gram water and the 40 gram ethanol, and the acetic acid of 60 grams is added in the solution to precipitate this product crystallization.Then with the wet cakes that obtain 27.5 grams after the water washings of about 200 grams and the leaching filter cake 3 times.Then the EG with 130 grams mixes.This solution is heated to 150-160 ℃ under normal pressure, up to there not being the condensation brown liquid to isolate from solution.Hydrothermal solution is filtered at once, to obtain the wet cake of 15.4 grams after 300 gram water washings and the leaching.The wet cake that is placed on the sorbent material was heated 20 minutes with moderate power in microwave oven, in baking oven, obtain the dried cakes of 11.6 grams then after 4 hours in about 250 ℃ of dryings.The B-value of this cake is 1.58, its conformance with standard value, and HPLC analyzes and shows that this PTA contains the impurity shown in the table 7.

Table 7	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 7	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	Detection less than	Detection less than	Detection less than

Embodiment 3 (condition of analogue reactor effluent and leaching)

150 grams CTA sample as described in Table 1 is at room temperature mixed with the solution that composition is similar to the constituent of reactor effluent flash evaporation.This solution contains 202 gram morpholines, 191 gram water, 29 grams, 48% Hydrogen bromide, 0.23 gram cobalt acetate tetrahydrate, 0.3 gram magnesium acetate tetrahydrate and 60 gram acetic acid.Solution temperature is heated to 110 ℃ with dissolving CTA and evaporate the phlegma of 79ml.This solution is cooled to room temperature immediately with precipitation, and to obtain the wet cake of 278 grams after methanol wash and the leaching filter cake.Should mix with 133 gram water by wet cake, and this solution temperature is heated to 110 ℃ of phlegmas with evaporation 88ml, and this solution is cooled to room temperature with precipitation.This filter cake obtains the wet cakes of 160 grams after with methanol wash and leaching.Should wet cake then with the methanol mixed of 160 grams, the acetic acid that then add 180 grams are with the precipitation terephthalic acid.Should wet cake with the water washings of 500 grams and leaching, and with 35 gram methyl alcohol leachings 3 times to obtain the wet cakes of 123 grams.The wet cake that is placed on the sorbent material was heated 20 minutes with moderate power in microwave oven, in baking oven, get the dried cakes of 73 grams thereupon after 4 hours in about 250 ℃ of dryings.The B-value of this cake is 2.22, and all metal contents all are lower than specified value, and the HPLC analysis shows that the foreign matter content of this PTA is as shown in table 8.

Table 8	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 8	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	Detection less than	Detection less than	Detection less than

Embodiment 4 (with the hertzian wave pyrolysis)

The pure salt sample of 10.05 gram embodiment 2 is dissolved in the water of 6 grams.Solution was heated 3 minutes in 600 watts of microwave ovens, and this residual mixture contains the solid of 9.29 grams of having an appointment.6.27 the water of gram mixes with this solid, and heats 3 minutes to obtain the solids of 8.82 grams in microwave oven.Then, the water of 6.66 grams mixes with solid and heats 3 minutes to obtain 8.49 gram solids.This solid mixes with the water of 10.85 grams again, and heats 4 minutes to obtain the solids of 8.14 grams in microwave oven.This solid continuation is heated 3 minutes to get the solids of 7.82 grams with mixed being incorporated in of the water of 9.59 grams in the microwave oven.More than in each step, the minimizing of weight system is from the decomposition of salt.

Embodiment 5 (thick NDC)

Thick 2 with 150 grams, 6-and 2,7-naphthalene diformic acid dimethyl ester (NDC) sample restrain water with 161 gram morpholines and 180 to be mixed.Then this solution temperature is heated to 110 ℃ of solvents with evaporation 86ml.The solution cooling is made thereupon and be settled out crystallization, and filter to separate with mother liquor.The mixture of this filter cake with the morpholine that contains 10wt% water washed to obtain the wet cakes of 186 grams.Wet cake is dissolved in the water and 18 morpholines that restrain of 72 grams again, and this solution is heated to evaporate the phlegma of about 35ml.Cool off this solution to precipitate, to filter, also to use the solvent mixture washing of the morpholine that contains 10wt% water thereupon, obtain the 158 wet cakes that restrain.To contain the water of 16 grams and the mixture of 158 acetic acid that restrain then and add in this purification of salts, to precipitate this product acid.Obtain the purifying acid of 85 grams after washing more after filtration,, the drying.This thick NDC is purified to 99.993% purity.The capillary electrophoresis analysis of thick acid shows 11 peaks, and its time and area are respectively in (8.86,3.824), (8.92,2.891), (8.92,5.518), (9.06,10.038), (9.18,36.226), (9.45,18.536), (9.52,13.944), (9.57,8.298), (11.87,0.106), (11.99,0.598).The capillary electrophoresis of purifying acid shows two peaks, and its time and area are respectively in (9.49,99.993) and (9.55,0.007).Embodiment 6 (with hertzian wave dissolving and use NMP) in the ethanol intercrystalline

The CTA sample that 12.5 grams are as described in Table 1 mixes with the NMP of 60 grams, and this NMP was prior to preheating in 600 watts of microwave ovens 30 seconds.This CTA heats about 3.5 minutes with dissolving fully with the low power microwave stove again.During crystallization, the ethanol of 13 grams are added in the solution then, and place about 60 minutes of ice bath to cool off this solution.And this salt of after-filtration, and with the washing of the mixed solvent of 50% ethanol and 50%NMP to obtain the salt of 26.2 grams.This salt is incorporated in the microwave oven with low power heating dissolving fully after 2.7 minutes with the NMP of 31 grams is mixed again.Ethanol with 15 grams add in the solution during crystallization again, and place about 60 minutes of ice bath to cool off this solution.And this salt of after-filtration, and with the washing of the mixed solvent of 50% ethanol and 50%NMP to obtain the pure salt of 16 grams.Wherein the pure salt of 3 grams are placed on a pile and inhaled between the filter paper of water.And with being located at low power in the microwave oven with this pure salt of thermal degradation, no longer change until weight, obtain the PTA of 1.2 grams.Table 9 shows the impurity that this HPLC analyzed.

Table 9	?4-CBA	Phenylformic acid	P-methylbenzoic acid
Table 9	?4-CBA	Phenylformic acid	P-methylbenzoic acid	PTA(ppmw)	Detection less than	Detection less than	Detection less than

Above embodiment mainly is in order to the understanding of help to the inventive method, rather than in order to limit to the scope of the invention in a certain specific compound or treatment step.Scope of the present invention is defined by book.

Claims

1. method that is used to make pure organic acid or derivatives thereof, it comprises:

Thick organic acid or derivatives thereof is dissolved in the alkali cpd;

Remove impurity; And

When reclaiming this pure organic acid or this derivative, remove the residual alkali compound.

2. method as claimed in claim 1, wherein this thick organic acid or this derivative dissolve by thermal agitation under hertzian wave.

3. method as claimed in claim 1, wherein this thick organic acid or this derivative are thick aromatic polycarboxylic acids.

4. method as claimed in claim 1, wherein this thick organic acid or this derivative are dissolved in this alkali cpd and the solvating agent.

5. method as claimed in claim 1 is also removed excessive alkalization and is closed when wherein removing impurity.

6. method that is used to make pure organic acid or derivatives thereof, it comprises:

Dissolving is by thick organic acid or derivatives thereof and the formed salt of alkali cpd;

Adopt one or more to be selected from following method, remove impurity and excessive alkali cpd from the salt of this thick organic acid or derivatives thereof, described method is: pre-treatment, crystallization, the composition by controlled chilling and crystallization by cooling, in the presence of the alkali extraction solvent crystal salt, in the presence of the alkali extraction solvent precipitated product, the direct extractive crystallization of salt, salinization crystallization again, saline and alkaline replacement, wash and with the leaching of alkali extraction solvent with the alkali extraction solvent; And

From this salt, reclaim this pure organic acid or derivatives thereof, remove the residual alkali compound simultaneously.

7. method as claimed in claim 6, wherein this thick organic acid or derivatives thereof is thick aromatic polycarboxylic acids.

8. method as claimed in claim 7, wherein this thick aromatic polycarboxylic acids is terephthalic acid or m-phthalic acid.

9. method as claimed in claim 7, wherein this thick aromatic polycarboxylic acids is 2,6-naphthalene dicarboxylic acids, 2,7-naphthalene dicarboxylic acids or blended naphthalene dicarboxylic acids.

10. method as claimed in claim 6, wherein this salt dissolves by thermal agitation under hertzian wave.

11. method as claimed in claim 6, wherein this alkali cpd is oxygen containing alkali cpd.

12. method as claimed in claim 6, wherein this salt is dissolved in this alkali cpd and the solvating agent.

13. method as claimed in claim 6, wherein this alkali cpd is a morpholine, and this salt is soluble in water.

14. method as claimed in claim 6, wherein this alkali cpd is Trimethylamine 99, triethylamine or trolamine, and this salt water-soluble or pure in.

15. method as claimed in claim 6, wherein this alkali cpd is an amide compound.

16. as the method for claim 15, wherein this amide compound is N-methyl-pyrrolidone.

17. method as claimed in claim 6, wherein this alkali cpd is an amide compound, and this salt is dissolved in the solvating agent.

18. method as claimed in claim 6, wherein said impurity utilize the alkali extraction solvent to remove, and this alkali extraction solvent comprises water, methyl alcohol, ethanol, aklylene glycol, acetone, tetrahydrofuran (THF) or tetrahydropyrans.

19. method as claimed in claim 7 wherein by in the presence of the alkali extraction solvent, adds acid replacement solvent and reclaims pure organic acid from this salt.

20. method as claimed in claim 7 is wherein by using the hertzian wave pyrolysis to reclaim pure organic acid from this salt.

21. method as claimed in claim 7, wherein this residual alkali compound is removed from pure organic acid by being selected from one or more following methods, and described method comprises: leaching, stripping, hertzian wave thermal agitation and evaporation pyrolysis.

22. a method that is used to make pure organic acid or derivatives thereof, it comprises:

Adopt one or more to be selected from following method, remove impurity from this salt, described method comprises: the direct extractive crystallization of salt, crystal salt in the presence of the alkali extraction solvent, in the presence of the alkali extraction solvent precipitated product, the crystallization of salinization again of using the alkali extraction solvent, saline and alkaline replacement and with the leaching of alkali extraction solvent.

23. as the method for claim 22, wherein this thick organic acid or derivatives thereof is thick aromatic polycarboxylic acids.

24. as the method for claim 22, wherein this salt dissolves by thermal agitation under hertzian wave.

25. as the method for claim 22, wherein this salt is dissolved in the solvating agent.

26. as the method for claim 22, wherein this alkali cpd is oxygen containing alkali cpd.

27. as the method for claim 22, it further comprises by acid replacement, pyrolysis or electrolysis mode, reclaims this pure organic acid or derivatives thereof from this salt.

28. method as claim 27, it further comprises one or more the following methods that are selected from that adopt, when from this salt, reclaiming this pure organic acid or derivatives thereof, remove this residual alkali compound simultaneously, described method comprises: leaching, stripping, hertzian wave thermal agitation and evaporate with pyrolysis.

29. a method that is used to prepare the purification solution of being made up of aromatic polycarboxylic acids or derivatives thereof and monomer or oligomer, it comprises:

The aromatic polycarboxylic acids or derivatives thereof that will contain residual solvent mixes with monomer or oligomer; And

Increase temperature to 50 ℃-350 ℃ to remove residual solvent.

30. as the method for claim 29, wherein this monomer is an aklylene glycol.

31., wherein under hertzian wave, add this residual solvent of heat extraction as the method for claim 29.

32. a method that is used to make pure aromatic polycarboxylic acids or derivatives thereof, it may further comprise the steps:

In the presence of catalyzer and solvent, the alkyl on the oxidizing aromatic compounds is to make thick aromatic polycarboxylic acids or derivative;

Dissolving is by this thick aromatic polycarboxylic acids or derivatives thereof and the formed salt of alkali cpd;

Remove the impurity in this thick aromatic polycarboxylic acids salt or derivatives thereof salt;

When from this salt, reclaiming this pure aromatic polycarboxylic acids or derivatives thereof, remove this residual alkali compound simultaneously; And

Reclaim solvent and catalyzer.

33. as the method for claim 32, wherein this salt is dissolved in this alkali cpd and the solvating agent.

34. as the method for claim 32, wherein this thick aromatic polycarboxylic acids or derivatives thereof prepares by flash evaporation and evaporation.

35. a method that is used to prepare pure organic acid or derivatives thereof, it comprises:

Under hertzian wave, the thick organic acid or the derivative that will contain impurity by thermal agitation are dissolved in the alkali cpd; And

Remove this impurity.

36. as the method for claim 35, wherein this thick organic acid or derivatives thereof is dissolved in this alkali cpd and the solvating agent.

37. as the method for claim 35, it further comprises this pure organic acid or derivatives thereof of recovery.

38., wherein when reclaiming this pure organic acid or derivatives thereof, remove this residual alkali compound simultaneously as the method for claim 36.