CN1243820A - Method for producing aromatic carboxylic acid - Google Patents
Method for producing aromatic carboxylic acid Download PDFInfo
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- CN1243820A CN1243820A CN99110733A CN99110733A CN1243820A CN 1243820 A CN1243820 A CN 1243820A CN 99110733 A CN99110733 A CN 99110733A CN 99110733 A CN99110733 A CN 99110733A CN 1243820 A CN1243820 A CN 1243820A
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
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Abstract
A process for producing a purified aromatic carboxylic acid, comprising oxidizing an alkyl aromatic compound by a liquid phase oxidation with a molecular oxygen-containing gas in a liquid reaction solvent comprising an aliphatic carboxilic acid in the presence of an oxidation catalyst in an oxidizing reactor to convert the alkyl aromatic compound into an aromatic carboxylic acid, which is deposited as crystals in the reaction solvent to form a slurry, subjecting the resulting slurry to a purification treatment, followed by a recrystallization of the so-treated aromatic carboxylic acid in a crystallizer, and separating the re-crystallized acid to obtain purified aromatic carboxylic acid, wherein a stirring tank, having provided at its lower portion with a stirrer driven by a rotary shaft arranged through the reactor bottom, is used as the oxidizing reactor and/or the crystallizer and the liquid phase oxidation and/or the recrystallization is performed in the stirring tank while controlling the stirrer performance in such a manner that the average particle size of the formed crystals of the aromatic carboxylic acid in the slurry is maintained so as not to exceed over 500 mum and the concentration of crystals in the slurry is maintained so as not to exceed over 60% by weight.
Description
The present invention relates to produce aromatic carboxylic acid's method, this method is the substituent Alkylaromatics (hereinafter to be referred as " liquid-phase oxidation ") that has alkyl and/or partial oxidation alkyl in liquid reaction medium with the gas cyaniding of molecule-containing keto.
The aromatic carboxylic acid is important basic chemical industry product, and especially, aromatic dicarboxilic acid is useful to raw materials such as fiber, resins.For example, in the last few years, the requirement that the discovery terephthalic acid is made the trevira raw material constantly increased.
With regard to producing the aromatic carboxylic acid, so far generally use a kind of like this method, the aromatic substance that wherein has the substituting group alkyl is in containing the liquid reactions solvent of lower alphatic carboxylic acid such as acetate, in oxidation reactor, under the situation that the oxide catalyst of being made up of heavy metal compound and bromine compounds exists,, it carries out liquid-phase oxidation by being contacted with the gas of molecule-containing keto.By this production method, with introduce molecular oxygen-containing gas to oxidation reactor, in the time of as air, passing through under the stirring state of agitator, replace aromatic substance such as p-Xylol by the alkyl of making raw material, make the acetate of reaction solvent and the mixture of catalyzer composition and supply with oxidation reactor, obtain aromatic carboxylic acid thus resemble the terephthalic acid to cause oxidizing reaction.
In Fig. 4, show in Japan's special permission with the form of system's block diagram to disclose the prior art that openly is used to produce the aromatic carboxylic acid among clear-63-83046A.The device that is shown among Fig. 4 comprises the oxidation reactor 1 that is designed to the vertical cylindrical container shape, and it is equipped with plate washer 2 that places on this container side wall internal surface and the agitator of installing along this container central axis 3.Agitator 3 is made up of rotating shaft 4 and multi-stage rotary blade 5.Supply with oxidation reactor 1 by the starting mixt that Alkylaromatics, oxide catalyst and reaction solvent are formed through material feeding tube line 6, molecular oxygen-containing gas is also supplied with oxidation reactor 1 through gas feed pipeline 7, and discharges through slurry vent line 8 by the coarse particles that the aromatic carboxylic acid that reaction forms generates.
At the top of oxidation reactor, discharge of steam pipeline 9 is installed, install heat exchanger 10 in the above, so that separate the condensable composition in the waste gas.Might load onto a distillation tower (not shown) and be used for replacing heat exchanger 10, perhaps refill a distillation tower outside the heat exchanger 10.In the process by cooling condensation in heat exchanger 10, isolating composition is collected in the drum separator 11 as phlegma, through pump 13 Returning oxidation reactors 1, and draw pipeline 14 through phlegma and tell on demand in the distillation unit of delivering to again subsequently to reclaim reaction solvent by another part phlegma by circulation line 12 for partial condensation liquid.Lose the remainder of exhaust gas of condensable composition, be eliminated out this system through removing pipeline 15.
Coarse particles through slurry vent line 8 is discharged before the recrystallization, experiences refinement treatment such as oxidation, reduction earlier in described purification step subsequently in the crystallizer of using for production refining crystallization aromatic carboxylic acid.In crystallizer, separate out the crystalline slurry with the agitator stirring that is similar to the agitator 4 in the oxidation reactor 1.
In the prior art oxidation reactor or crystallizer of the agitator 3 that multistage blade 5 is installed, be equipped with and extend to the rotating shaft 4 that exceeds the whole height of vertical vessel, cause complicated and driving power corresponding increase of device structure with the enhancing of vibrating in the operating process.In addition, part more than vertical vessel is installed drive unit needs private station or support, and this will follow to take place to stop and effectively utilize the above space of container and the difficulty of multiplying arrangement in proportion.
The object of the present invention is to provide the method for producing the aromatic carboxylic acid, this method can make the simplicity of design and the miniaturization of agitator, make driving power along with the reducing and reduce of device operation vibration thus, thereby can reach and effectively utilize the above space of container and the amplification in proportion of plant bulk.
The invention reside in the refining aromatic carboxylic acid's of the following production that limits method:
(1) a kind of method of producing refining aromatic carboxylic acid comprises
Use the gas of molecule-containing keto, in the liquid reactions solvent of fatty family carboxylic acid, in oxidation reactor in the presence of the oxide catalyst, make the Alkylaromatics oxidation so that make this Alkylaromatics transform into the aromatic carboxylic acid by liquid-phase oxidation, it separates out the formation slurry as crystal in reaction solvent
Make the slurry that is generated carry out refinement treatment, then the aromatic carboxylic acid who so handled in crystallizer recrystallization and
The acid that the separation recrystallization is crossed is to obtain the purified aromatic carboxylic acid, wherein
Steel basin uses as oxidation reactor and/or crystallizer, be equipped with in its underpart by by jar shaft-driven agitator of revolution of end configuration and
Liquid-phase oxidation and/or recrystallization are to control the agitator performance in the mode that keeps the formed crystal median size of aromatic carboxylic acid in the slurry to be no more than 500 μ m and to keep crystal concentration in the slurry to be no more than 60% (weight) and finishing in stirred pot.
(2) method that limits by above-mentioned (1), wherein agitator is the turbine blade formula, this blade keep with the oxidation reactor diapire certain distance arranged and rotate.
(3) method that limits by above-mentioned (1), wherein agitator is the rake formula, this agitator is with its blades turning along oxidation reactor lower surface overlap joint.
(4) by the method for each qualification in above-mentioned (1)-(3), wherein agitator drives by the hydropneumatic motor.
(5) by the method for each qualification in above-mentioned (1)-(4), wherein oxidation reactor is equipped with heat exchanger at an upper portion thereof.
(6) inlet that is used for to wherein injecting molecular oxygen-containing gas is equipped with, wherein the stirred pot of operation in its underpart, so that the injection effect of gas helps the effect that stirs as oxidation reactor by the method for each qualification in above-mentioned (1)-(5).
(7) method that limits by above-mentioned (6) be that 1.5-8 times of its diameter and molecular oxygen-containing gas are with 2000-9000Nm as the stirred pot height value of oxidation reactor operation wherein
3/ m
2The tower linear resonance surface velocity of/hr is to wherein injecting.
(8) method that limits by above-mentioned (6) or (7), wherein the stirred pot as the oxidation reactor operation is equipped with distillation tower at an upper portion thereof.
(9) by the method for each qualification in above-mentioned (1)-(5), wherein the stirred pot height value as crystallizer operation is its diameter 0.5-4 times.
Fig. 1 represents to be used for the oxidation reactor embodiment signal vertical cross section of the inventive method.
Fig. 2 represents to be used for the signal vertical cross section of another embodiment of oxidation reactor of the inventive method.
Fig. 3 represents to be used for the signal vertical cross section of another embodiment of crystallizer of the inventive method.
Fig. 4 represents to be used to produce the exemplary system figure of aromatic carboxylic acid's prior art equipment.
In the method for producing the aromatic carboxylic acid according to the present invention, as the raw material for the treatment of oxidation, can use Has the aromatic compounds of one or more substituent alkyl and/or partial oxidation alkyl (lower Literary composition is sometimes referred to as the oxidation raw material). Such aromatic compounds or be monocycle or for many rings. As substituent alkyl, can enumerate the alkyl that for example has 1-4 carbon atom, as methyl, Ethyl, just-propyl group and isopropyl. As the alkyl substituent of partial oxidation, can for example enumerate Aldehyde radical, acyl group, carboxyl and hydroxyalkyl.
Initial aromatic compound with alkyl, i.e. the instantiation of the aromatic hydrocarbons of alkyl replacement comprises: Two and polyalkylbenzene with 2-4 alkyl of 1-4 carbon atom, as-diisopropylbenzene (DIPB), Right-diisopropylbenzene (DIPB) ,-cymene, right-cymene ,-dimethylbenzene, right-dimethylbenzene, Trimethylbenzene and durol; Two and many alkane with 2-4 alkyl of 1-4 carbon atom The base naphthalene is such as dimethylnaphthalene, diethyl naphthalene and diisopropyl naphthalene; And have a 1-4 carbon atom Many alkyl biphenyls of 2-4 alkyl, such as dimethyl diphenyl etc.
For the aromatic compounds with partial oxidation alkyl, can enumerate that those are above given Initial aromatic compounds in one or more alkyl partially oxidized become for example aforesaid Aldehyde radical, acyl group, carboxyl or hydroxyalkyl. As its instantiation, can enumerate the 3-tolyl aldehyde, The 4-tolyl aldehyde ,-toluic acid, right-toluic acid, 3-carbamoyl benzoate, 4-carbamoyl benzoate and 2-methyl-6-formyl naphthalene. They or separately or two or more with it The mixture of planting uses.
In the methods of the invention, heavy metal compound and bromine compounds are as catalyst, and be wherein following It is the example of these compounds. As the heavy metal that heavy metal compound is used, can enumerate cobalt, manganese, Nickel, chromium, zirconium, copper, lead, hafnium and cerium. They can use separately, also combinable use, Especially think that the combination of cobalt and manganese is better.
As the compound of described heavy metal, can enumerate acetate, nitrate, acetylacetonate Thing, naphthenate, stearate and bromide are worth mentioning and wherein particularly preferredly are as an example Acetate.
The compound of bromine can be selected from inorganic bromine compounds, such as molecular bromine, hydrogen bromide, sodium bromide, bromine Change potassium, cobaltous bromide and manganous bromide; And organbromine compound, such as methyl bromide, methylene bromine, bromofom, Benzyl bromide a-bromotoluene, xylyl bromide, Bromofume, tribromoethane and tetrabromoethane. These bromine compounds Can use separately two or more the mixture that also can be used as in them to use.
For with in the methods of the invention and be combined with bromine compounds by heavy metal compound and form Catalyst, wherein the bromine atoms mol ratio of relative heavy metal atom is at the heavy metal of each mole Be the 0.05-10 mole, the scope of preferred 0.1-2 mole is favourable. These catalyst are with heavy The densimeter of metal in reaction dissolvent, general addition in reactant mixture is 10-10000ppm is preferably at 100-5000ppm.
By means of method of the present invention, as the aromatic compounds of oxidation raw material in oxidation step In the oxidation reactor, use the liquid reactions solvent that contains lower alphatic carboxylic acid, deposit at above-mentioned catalyst Situation under, make it carry out liquid phase oxidation with the gas of molecule-containing keto, in order to causing aromatics The crystal of carboxylic acid is separated out the formation slurry.
As the gas of molecule-containing keto, can enumerate for example oxygen and surrounding air, its Air is to reality With being useful. Oxidation raw material with regard to the oxidation aromatic compounds becomes the aromatic carboxylic acid, and is logical The normal molecular oxygen-containing gas that uses is excessive than the required ratio of stoichiometry. Making molecule-containing keto with air In the situation of gas, be 2-20 to the reaction system feeding speed by every μ g initial aromatic compounds Nm3, preferred 2.5-15Nm3Air be favourable.
As the lower aliphatic carboxylic acid as reaction dissolvent, can lift acetic acid, propionic acid and butyric acid and make example The son explanation. These lower aliphatic carboxylic acids can use separately as reaction dissolvent, also can be with water Form of mixtures is used. The instantiation of reaction dissolvent comprises acetic acid, propionic acid, butyric acid and mixing thereof The mixture of thing and they and water. In the middle of them, the mixture of acetic acid and water is preferred, Can enumerate wherein particularly preferred is that those per 100 parts of (weight) acetic acid water content are that 1-20 part is (heavy Amount), the mixture of preferred 5-15 part (weight).
Usually the temperature range of oxidation reaction is at 100-250 ℃, preferred 150-220 ℃. Instead Seasonable pressure can be in any level, as long as can make reactant mixture keep liquid.
By as above finishing reaction under the condition, can obtain the aromatics corresponding to initial aromatic compounds Carboxylic acid. As aromatic carboxylic acid's instantiation, can enumerate aromatic dicarboxilic acid, as terephthalic acids, Isophthalic acid, NDA and 4,4 '-diphenyl dicarboxylic acid; The fragrant tricarboxylic acid is such as inclined to one side benzene three Acid and 1,3,5-benzenetricarboxylic acid; And aromatic polycarboxylic acids, such as 1,2,4,5-benzenetetracarboxylic acid etc.
The inventive method is for the production of aromatic dicarboxilic acid, especially, and for the production of resembling in used reaction Do not dissolve or dissolve the aromatic carboxylic acid of difficulty in the solvent, it is favourable particularly producing terephthalic acids.
The aromatic carboxylic acid who generates will separate out the formation slurry as crystal in reactant mixture, this slurry Gu material is discharged oxidation reactor and is produced such as the coarse crystallization of terephthalic acids with acquisition by liquid/separating treatment Product.
The coarse crystallization product that so obtains contains impurity and intermediate product usually, therefore, should follow Make with extra care in suitable solvent by again dissolving coarse crystallization, make again the solution process that generates Comprise the refinement treatment step that oxidation or reduction are processed, then with purpose product such as terephthalic acids one The crystallizer recrystallization, acquisition contains the slurry of crystalline product thus. From so a kind of slurry, reclaim brilliant Body can obtain the purified product such as terephthalic acids.
For refinement treatment, it is favourable that hydrotreatment is processed as reduction. With regard to hydrotreatment , can use so far the catalyst that always is used for described reduction reaction, for example, based on palladium, The catalyst of ruthenium, rhodium, osmium, iridium, platinum, platinum black, palladium black iron and cobalt-nickel. The solid catalyst load Be stated from above the carrier, preferably support on adsorbing agent carrier, such as active carbon, and make fixed bed and be Favourable.
In hydrotreatment, make the crystalline dispersion in water of thick terephthalic acid, the formation solid content is 10-40% (weight), be preferably the aqueous slurry of 24-30% (weight), be not less than 230 ℃ in temperature again, under the preferred 240-300 ℃ of steady state, pressure range is in 1-11MPa (gauge pressure), and preferred 3-9MPa (gauge pressure) heats described slurry, crystal with the dissolving terephthalic acid, subsequently the terephthalic acid aqueous solution that is obtained is supplied with reduction reactor, so that flow through catalyst bed, meanwhile to its supply of hydrogen, its feed rate is at least 1.5 times of 4-CBA supply mole in the terephthalic acid solution, preferably is at least 2 times of its mole.The temperature of reaction of carrying out hydrotreatment is not less than 230 ℃, and preferably at 255-300 ℃, pressure range is 1-11MPa (gauge pressure), is preferably 3-9MPa (gauge pressure), and the hydrogen dividing potential drop of use is at least 0.05MPa, and preferable range is at 0.05-2MPa.
By hydrotreatment, the 4-CBA in the thick terephthalic acid is reduced into soluble paratolunitrile in water at a lower temperature.Therefore, by in 300 ℃ of temperature or following, preferably under 100-280 ℃ temperature.Recrystallization terephthalic acid in crystallizer separates the crystal separate out again from mother liquor, can obtain not contain the pure crystalline product of the terephthalic acid of paratolunitrile.Under the situation that reduces Tc gradually, with multistage crystallization, for example the 2-7 level is finished recrystallization.
So far, this stirred vessel is equipped with agitator, agitator has and runs through top cover from the top of this container and extend to the vertical axis of rotation of container bottom and the agitating vane of each section of entire depth that is distributed in liquid phase this container of configuration thereon downwards always, wherein rotating shaft drives by the drive unit that is placed in the container top, and such stirred vessel can be used for oxidation reactor and crystallizer.
By above-mentioned agitator, the fluid contents that can expect to reach in the container stirs, finishes reaction and homogeneously crystallized uniformly.Just be used for the situation of oxidation reactor, can expect can be raw material, reaction solvent and catalyzer and oxygen uniform mixing, so that finish reaction and can cause that the aromatic carboxylic acid who is formed by oxidizing reaction contacts with the crystallization of separating out already, separates out thereby help crystal by crystal growth.Just be used for the situation of crystallizer, can expect to cause that the aromatic carboxylic acid contacts with the crystal of separating out already, separate out thereby help crystalline by crystal growth, described aromatic carboxylic acid is the solution state existence and can makes the supersaturation attitude.
The inventor has analyzed the mechanism of oxidizing reaction when following the lenticular reaction product to separate out, must stir the starting mixt of forming by raw material, reaction solvent and catalyzer equably although can understand thus,, they finish oxidizing reaction effectively so that directly contacting with gas oxygen, but be evenly dispersed in the reaction liquid always necessary to aromatic carboxylic acid's crystal, yet be enough to guarantee that the new aromatic carboxylic acid who forms in the reaction liquid has sufficient probability to go to contact with existing crystal, so that the aromatic carboxylic acid of formation separates out.
Situation with regard to oxidation reactor, at first appear in the reaction solvent and accumulate by the aromatic carboxylic acid that forms of reaction in wherein till supersaturation concentration with the form of solution, the aromatic carboxylic acid separates out with crystalline form subsequently, and the crystal of separating out can play nucleus and by crystal growth oversaturated aromatic carboxylic acid be separated out on nucleus.For the situation of crystallizer, can make aromatic carboxylic acid's solution become supersaturation by the temperature that reduces solution, separate out with crystalline form thus.
When the aromatic carboxylic acid's crystal contact frequency existing with it that forms increased because of the stirred crystallization slurry, even crystal itself does not disperse equably, the crystalline growth also can obtain quickening.Because slurry is discharged from stirred pot continuously, so essential additional new nucleus.This new nucleus is to be provided by the crystal that newly forms in the liquid medium part in the slurry, does not have the crystal that can play the nucleus effect in the slurry.Therefore, even allow not crystalliferous liquid medium partly to exist, aromatic carboxylic acid's crystal also there is no need to be dispersed in the slurry, but will be enough to keep them under condition of stirring, so that they are can be in liquid medium floating and can not sink in the bottom and go.
In oxidation reactor, should keep raw material, reaction solvent, catalyzer, oxygen etc. under evenly stirring.When the gas of molecule-containing keto was blasted in the reaction mixture, this injection of gas can cause stirred reaction mixture, therefore can utilize this effect for the homogenizing of reacting.In addition, as long as agitator design become is allowed stirred reaction mixture but do not make the crystal deposition of separating out, then this agitator is used in reactor, and still to be used in crystallizer all be enough.
According to above-mentioned basic understanding, the present invention has found to use the agitator technique means that is suitable for oxidation reactor and crystallizer, and described stirred pot has the agitator of agitating vane just in order to stop the crystalline deposition at its underpart device.Be equipped with in the configuration of agitating vane in this bottom at stirred pot, agitator leans on drive unit to drive, and this drive unit is configured in the jar below with rotating shaft, and rotating shaft passes the diapire installation of jar.
As agitating vane, can use the turbine blade formula of keeping at a distance with jar end internal surface and rotating, inclined plate turbine blade formula especially, or be favourable with rake formula agitating vane of its blade rotation of extending along the bottom surface of jar.For the agitating vane of turbine blade formula, it is desirable on the internal surface of pot sidewall, plate washer is installed.But, then do not need baffle plate for rake formula agitating vane.These agitating vanes only are installed in the bottom of jar with the single-stage form, although also allow to install multistage blade.
To be designed so that they can be configured on the rotating shaft top that the diapire that passes jar installs and the drive unit of side drives under the stirred pot by being installed in to above-mentioned agitating vane.As drive unit,, so can use the hydropneumatic motor, all be useful, although other device as electro-motor, also can use as oil motor or pneumatic motor because vibration is lighter.When using pneumatic motor, various driving gases can use, as compressed oxygen, pressurized air with from the compressed exhaust gas of oxidation reactor.
Oxidizing reaction or aromatic carboxylic acid's recrystallization is handled, can get rid of under the settled situation of crystal in as above finishing in a kind of like this stirred pot in the condition of all many-sides such as reacted constituent, reaction and slurry discharge of supplying by control, in commission, can keep that the crystalline median size is 500 μ m or following in the slurry, preferable range is at 10-300 μ m, better scope is at 50-200 μ m, and the crystal concentration that can keep slurry is not more than 60% (weight), preferable range is more preferably 20-50% (weight) in 10-55% (weight).
By using a kind of like this agitator, the agitating vane that is its installation can be at stirred pot than the lower curtate internal rotation, this section is equivalent to leave in this jar the liquid level at the end (for oxidation reactor, liquid level contains bubble) whole height maximum 1/3, preferred maximum 1/4, preferably mostly be most 1/5 especially, as long as slurry has above-mentioned scope median size under above-mentioned concentration crystal, the settled effect of prevention crystal then can be satisfactory.For the agitator of turbine blade formula, at 0.5-15m/sec, be preferably under the circumferential speed of 3-10m/sec, it is 20-300rpm that stirring intensity is equivalent to rotating speed, is preferably 30-70rpm.For mixer., at 0.5-15m/sec, preferred under the circumferential speed of 1-5m/sec, it is 2-50rpm that stirring intensity is equivalent to rotating speed, preferably at 5-20rpm.
In the method for the invention, there is no need provides any agitating vane at the top and the middle part of jar, also there is no need to provide in stirred pot rotating shaft.When drive unit was placed in the beneath side of jar, drive shaft rotating can be passed the diapire of jar and be installed, and can make whole device compactness and energy miniaturization Design like this.Now just might be at the device of the top of stirred pot installation as heat exchanger and/or distillation tower, thereby the effective area of use device, and these devices have to additionally be placed on other the part before this.
When stirred pot is used as oxidation reactor,, the reaction solution physical efficiency utilization in the jar is stirred to the effect of wherein injecting molecular oxygen-containing gas by jar is designed to bubble tower.At this moment, best can be by nozzle being fixed on below the agitating vane, although this is optional and disperse by agitating vane rotation causing bubble.Nozzle is fixed on the bottom of bubble tower, and according to the size of tower, nozzle preferably is distributed on many positions, as one, two, three etc.
When stirred pot uses as bubble tower, in the tower height value of liquid level be the tower internal diameter 1.5-8 doubly, in the time of preferred 2-4 times is favourable, and wherein the long-pending linear resonance surface velocity (tower linear resonance surface velocity) of the unit's of being expressed as tower section is that the injection speed of the molecular oxygen-containing gas (ambient air) of base can be at 2000-9000Nm with the volume before reacting
3/ m
2In the scope of/hr, preferred 3,500-4500Nm
3/ m
2/ hr can realize the even stirring of liquid mixture in the tower thus and can not cause the short circuit of injecting gas, therefore for the stirred liq layer agitating vane is installed and can be exempted.
When stirred pot uses as oxidation reactor, through material feeding tube alignment jar supply oxidation raw material, catalyzer and reaction solvent, introduce molecular oxygen-containing gas through the gas feed pipeline to jar again, so that in by the agitator stirred reaction mixture, induce reaction generation.Oxidation oxidation raw material thus, promptly Alkylaromatics becomes corresponding aromatic carboxylic acid.When reaction is carried out, becoming the supersaturation attitude by the concentration of reacting the aromatic carboxylic acid who forms in reaction liquid therefore will separate out as crystal, this crystal can play the effect of nucleus and the crystal of separating out contacts with the aromatic carboxylic acid of new formation by the effect of agitator consumingly, owing to aromatic carboxylic acid's separating out thereon causes the crystalline growth, discharge section slurry and it is transferred to thereafter purification step continuously meanwhile.
When using stirred pot as crystallizer, the depth value of liquid level is advantageously at 0.5-4 times that is jar internal diameter in jar, and preferred 0.7-2.5 doubly.Although crystallizer need not inject any gas, the aqueous solution by oxidizing reaction or reduction reaction processing aromatic carboxylic acid during step-down can produce water vapor, makes solution obtain corresponding cooling thus, causes the reduction of temperature, thus the stirring effect of bringing.Because this temperature descends, make aromatic carboxylic acid in the solution reach its state of saturation and even can reach hypersaturated state, thus the aromatic carboxylic acid can be from solution recrystallize.The crystal slurry that contains formation like this stirs by means of agitator, and the aromatic carboxylic acid who exists with the supersaturation attitude in crystal and the slurry is contacted, and causes that the aromatic carboxylic acid separates out on crystal as crystal growth.The slurry that part generates is discharged from and is transferred to subsequent step continuously.
As mentioned above, according to the present invention, contain the agitator of agitating vane and by the shaft-driven stirred pot of installing by jar end of revolution at the stirred pot lower unit, use as oxidation reactor and/or as crystallizer, and the performance of agitator is controlled so that be no more than a kind of like this mode of 60% (weight) so that be no more than 500 μ m and keep the crystal concentration of slurry with keeping formed aromatic carboxylic acid's crystalline median size in the slurry, a kind of method that allows to amplify oxidation reactor and/or the refining aromatic carboxylic acid of crystallizer size production might be provided thus, wherein agitator designs by simple and miniaturization structure and driving power is reduced along with reducing of vibration, may effectively utilize the space above the stirred pot simultaneously.
When stirred pot used as oxidation reactor, reaction liquid obtained effective oxidizing reaction thus by obtain stirring to the interaction energy that wherein injects molecular oxygen-containing gas.
Hereinafter, further describe the present invention by embodiment with reference to the accompanying drawings.
Two different embodiments of the present invention are shown in respectively among Fig. 1 and Fig. 2, and each represents oxidation reactor with the form of vertical cross section, wherein show identical or corresponding component or assembly with used same-sign of Fig. 4 and numeral.
In the embodiment of Fig. 1, stirred pot 20 is by oxidation reactor 1 and is placed in the heat exchanger 10 that the reactor top becomes one with it and constitutes.Oxidation reactor 1 has vertical cylinder configuration, its diameter to the process of wherein injecting molecular oxygen-containing gas for the 1.5-8 of liquid level 21 degree of depth doubly.Be equivalent to the bottom that the degree of depth of liquid level 21 apart from the bottom mostly is 1/3 jar most, device agitator 3 is also installed baffle plate 2 around agitator 3 on the pot sidewall internal surface.
When producing the aromatic carboxylic acid by the inventive method, the starting mixt of being made up of oxidation raw material, reaction solvent and catalyzer 24 is supplied to oxidation reactor 1 by material feeding tube line 6 through the feed(raw material)inlet, and injects molecule-containing keto is introduced in gas from import 26 to reactor through gas from gas feed pipeline 7.Reaction mixture in the reactor 1 stirs with the promotes oxidn reaction by agitator 3, forms the aromatic carboxylic acid thus.The aromatic carboxylic acid who so forms separates out the formation slurry with the crystalline form afterwards, and the outlet 25 that its part is discharged from slurry through slurry vent line 8 is discharged from continuously, causes the refinement treatment step again.
Under the injection effect of molecular oxygen-containing gas, promoted the stirring of the reaction liquid in the oxidation reactor 1, therefore oxidizing reaction is carried out effectively.The aromatic carboxylic acid's crystalline slurry that forms in reactor 1 stirs by agitator 3, stops the crystal sedimentation thus and helps contacting with the new aromatic carboxylic acid who forms in the reaction liquid, so that cause it effectively to separate out on crystal by crystal growth.This is for being useful keep the crystal median size to be no more than finishing oxidizing reaction in the process that 500 μ m and crystal concentration value be no more than 60% (weight), even use agitator 3 and blade that the single-stage agitating vane is housed to be installed in the bottom of oxidation reactor 1 as shown in Figure 1, also can reach effective reaction in the settled process of crystal gratifying preventing.
Steam that is produced by the oxidizing reaction in the oxidation reactor 1 and waste gas have passed through heat exchange when flowing through the heat exchanger tube 27 of heat exchanger 10 processing and thus cooling formed phlegma, non-subsequently condensable composition, as waste gas etc., be discharged through waste line 15.Phlegma is collected in draws pipeline 14 through phlegma again on the phlegma susceptor 30 and causes the distillation tower (not shown).The water coolant of supplying with heat exchangers 10 through cooling water pipeline 28 flows and is heated generation steam by heat exchange round heat exchanger tube 27, and this steam is through 29 dischargings of discharge of steam pipeline.
In the embodiment of Fig. 2, agitator 3 is equipped with the mixer. with the blade rotation of 23 internal surface overlap joint at the bottom of the reactor.Distillation tower 32 is installed in the reactor 1 between liquid level 21 and the phlegma susceptor 30.Other structural element is identical with Fig. 1 embodiment.Although distillation tower 32 expressions become packed tower,, other pattern also is operable as tray column and spray column.
When using device shown in Figure 2 to produce the aromatic carboxylic acid, the stirring of slurry can be undertaken by mixer. 3.The water vapor and the waste gas that are produced by oxidizing reaction enter distillation tower 32 so that reclaim reaction solvent, carry out distillatory as lower aliphatic carboxylic acid, catalyzer etc. and handle.The steam and the gas of distillation tower of flowing through carries out heat exchange again in heat exchanger 10, form phlegma thus, and phlegma is drawn pipeline 14 as the make up water with low levels impurity through phlegma and reclaimed.Other is identical with Fig. 1 embodiment.
In the embodiment shown in Fig. 1 and 2, by the reaction mixture in agitator 3 stirred reactors that are configured in reactor lower part, the crystal that makes the aromatic carboxylic acid directly contacts with the new aromatic carboxylic acid who forms and can not cause that crystalline deposits, and causes crystal growth thus.Because comparing about the liquid level degree of depth and reactor inside diameter as mentioned above and the introducing of these conditions of input speed of relevant molecular oxygen-containing gas (atmospheric air), can or flow through the thorough homogenizing that is issued to reaction liquid in the bypass effect of getting rid of gas, under the situation that evenly stirs raw material, catalyzer and gas, realize effectively reaction whereby.Therefore allow the agitator of employing miniaturization and can realize low cost, low fuel consumption and low vibration production aromatic carboxylic acid.By additional unit is installed, as heat exchanger 10 and distillation tower 32 etc., might realize effectively utilizing the device area more than the stirred pot, even allow the size of multiplying arrangement.
Fig. 3 represents another embodiment of stirred pot as crystallizer operation with the form of constructed profile.Stirred pot 20 has heat exchanger 10 and is arranged in the structure of incorporate therewith crystallizer more than 33.The structure of crystallizer 33 and the similar of oxidation reactor 1 shown in Figure 1 and be designed to 0.5-4 that the liquid level degree of depth 21 is of a size of jar internal diameter doubly, crystallizer is connected and is connected with slurry vent line 8 at lower position with the treatment soln feeding line 6a that is used for adding to jar the pending aqueous solution at middle portion.Between by middle portion section on earth, on the internal surface of pot sidewall, assemble baffle plate 2.23 had the jar bottom of a segment distance and are driven by drive unit 22 at the bottom of agitating vane 5 was arranged in and leaves jar, and drive unit 22 is via passing the below that the rotating shaft of installing at the end 23 4 is installed in the end 23.
In stirred pot 20, carry out crystallization in the following manner.The slurry that dissolving is earlier discharged by oxidation reactor 1 carries out refinement treatment by for example oxidation or the reduction reaction that resembles hydrotreatment again.The solution of so handling is introduced crystallizer 33 by the solution feed pipeline 6a that handles, the pressure that discharges subsequently in the crystallizer causes water vapor partly with the corresponding decline of following temperature, solution becomes oversaturatedly as a result, causes that thus the aromatic carboxylic acid of lenticular separates out.The phlegma that treated water solution is stirred under the effect of water ebullient and forms in heat exchanger 10 is drawn pipeline 14 through phlegma and is told.
When starting agitator 3 and make agitating vane 5 rotation, the crystal of separating out can keep floating shape in slurry, because meanwhile can reach the supersaturation part excellent contact of crystal and solution, so can stop favourable its growth of crystal sedimentation.So the slurry that forms is discharged from by slurry vent line 8.By assembling many crystallizers and repeating used said procedure, can obtain high-purity aromatic carboxylic acid's product.
In addition, in crystallizer 33 shown in Figure 3, might use the agitator 3 of miniaturization as the oxidation reactor in Fig. 1 and 21, finish the recrystallizing technology under low vibration and the low power whereby, allow device up-sizing and effective use device area simultaneously, to carry out effective production of aromatic carboxylic acid.
Although above description is to point to relevant the inventive method to be used in and to use stirred pot 20 in the two situation of oxidation reactor 1 and crystallizer 33, stirred pot still might be used in a kind of among both.Although in the above description, specify heat exchanger 10 or distillation tower 32 to be installed in the embodiment of stirred pot more than 20, other Unit Installation or also be possible without any such installation.
The agitator 3 that replaces as above given agitating vane 5 with turbine blade or rake formula, also can the using certainly of other form.
Although the suitable what of method of the present invention is produced terephthalic acid, this method also can be used to produce other aromatic carboxylic acid.
Claims (9)
1. produce refining aromatic carboxylic acid's method, comprise
Gas with molecule-containing keto, in containing the liquid reactions solvent of aliphatic carboxylic acid, in oxidation reactor, have in the presence of the oxide catalyst, make the Alkylaromatics oxidation by liquid-phase oxidation, to transform this Alkylaromatics is the aromatic carboxylic acid, it separates out the formation slurry as crystal in reaction solvent
Make the slurry that is generated carry out refinement treatment, the aromatic carboxylic acid who so handled subsequently in crystallizer recrystallization and
The acid that the separation recrystallization is crossed is to obtain the purified aromatic carboxylic acid, wherein
Stirred pot is used as oxidation reactor and/or crystallizer to be used, and described jar is equipped with in its underpart and is turned round shaft-driven agitator, this axle pass jar diapire install with
Liquid-phase oxidation and/or recrystallization are not exceed 500 μ m and keeping in the slurry crystalline concentration and be no more than the such mode of 60% (weight) and control under the situation of agitator performance and finish in stirred pot to keep the aromatic carboxylic acid's crystal median size that forms in the slurry.
2. by the described method of claim 1, wherein agitator is the agitator of turbine blade formula, and it rotates under the condition of oxidation reactor diapire one segment distance in maintenance.
3. by the described method of claim 1, wherein agitator is a mixer., and its blade is along the rotation of oxidation reactor basal surface overlap joint.
4. by each described method among the claim 1-3, wherein agitator is driven by the hydropneumatic motor.
5. by each described method among the claim 1-4, wherein oxidation reactor is equipped with heat exchanger at an upper portion thereof.
6. by each described method among the claim 1-5, wherein the stirred pot of operating with oxidation reactor is equipped with in its underpart and feeds to the inlet that wherein injects the molecule-containing oxygen body and function, so that the injection effect of gas helps mixing effect.
7. by the described method of claim 6, wherein the height value that has with the stirred pot of oxidation reactor operation in its diameter 1.5-8 scope doubly with to its gas tower linear resonance surface velocity that injects molecule-containing keto at 2000-9000Nm
3/ m
2In/hr the scope.
8. by claim 6 or 7 described methods, wherein the stirred pot with the oxidation reactor operation is equipped with distillation tower at an upper portion thereof.
9. by each described method among the claim 1-5, wherein the height value that has with the stirred pot of crystallizer operation is in its diameter 0.5-4 scope doubly.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP213175/98 | 1998-07-28 | ||
| JP21317598A JP3885373B2 (en) | 1998-07-28 | 1998-07-28 | Method for producing aromatic carboxylic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1243820A true CN1243820A (en) | 2000-02-09 |
| CN1090170C CN1090170C (en) | 2002-09-04 |
Family
ID=16634796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99110733A Expired - Lifetime CN1090170C (en) | 1998-07-28 | 1999-07-28 | Method for producing aromatic carboxylic acid |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP3885373B2 (en) |
| KR (1) | KR100550021B1 (en) |
| CN (1) | CN1090170C (en) |
| ID (1) | ID23078A (en) |
| TW (1) | TW536535B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114105767A (en) * | 2020-08-28 | 2022-03-01 | 中国石油化工股份有限公司 | Fixed bed production device for continuously producing 1,4-cyclohexanedicarboxylic acid and using method |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5069829B2 (en) * | 2001-04-04 | 2012-11-07 | 株式会社ダイセル | Method for separating reaction product and imide compound |
| JP2005053799A (en) * | 2003-08-05 | 2005-03-03 | Satake Chemical Equipment Mfg Ltd | Terephthalic acid crystallizer |
| US7399882B2 (en) * | 2004-09-02 | 2008-07-15 | Eastman Chemical Company | Optimized liquid-phase oxidation |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH078821B2 (en) * | 1986-09-26 | 1995-02-01 | 三井石油化学工業株式会社 | Method for producing aromatic carboxylic acid |
| CN1036757A (en) * | 1988-02-15 | 1989-11-01 | 三井石油化学工业株式会社 | The preparation method of 4,4 ＇-methylene-dianiline |
| US5567842A (en) * | 1994-11-16 | 1996-10-22 | Mitsubishi Chemical Corporation | Process for producing terephthalic acid |
| KR0184741B1 (en) * | 1996-11-11 | 1999-04-15 | 우덕창 | Process and apparatus for preparing a porous silica gel powder |
-
1998
- 1998-07-28 JP JP21317598A patent/JP3885373B2/en not_active Expired - Fee Related
-
1999
- 1999-07-26 KR KR1019990030330A patent/KR100550021B1/en not_active IP Right Cessation
- 1999-07-27 TW TW088112682A patent/TW536535B/en not_active IP Right Cessation
- 1999-07-28 CN CN99110733A patent/CN1090170C/en not_active Expired - Lifetime
- 1999-07-28 ID IDP990714A patent/ID23078A/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114105767A (en) * | 2020-08-28 | 2022-03-01 | 中国石油化工股份有限公司 | Fixed bed production device for continuously producing 1,4-cyclohexanedicarboxylic acid and using method |
| CN114105767B (en) * | 2020-08-28 | 2024-06-11 | 中国石油化工股份有限公司 | Fixed bed production device for continuously producing 1, 4-cyclohexanedicarboxylic acid and application method |
Also Published As
| Publication number | Publication date |
|---|---|
| KR100550021B1 (en) | 2006-02-09 |
| ID23078A (en) | 2000-02-03 |
| TW536535B (en) | 2003-06-11 |
| JP3885373B2 (en) | 2007-02-21 |
| JP2000044510A (en) | 2000-02-15 |
| KR20000011971A (en) | 2000-02-25 |
| CN1090170C (en) | 2002-09-04 |
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