CN103121950A - Method of refining crude terephthalic acid - Google Patents
Method of refining crude terephthalic acid Download PDFInfo
- Publication number
- CN103121950A CN103121950A CN2012104617158A CN201210461715A CN103121950A CN 103121950 A CN103121950 A CN 103121950A CN 2012104617158 A CN2012104617158 A CN 2012104617158A CN 201210461715 A CN201210461715 A CN 201210461715A CN 103121950 A CN103121950 A CN 103121950A
- Authority
- CN
- China
- Prior art keywords
- water
- terephthalic acid
- mentioned
- acid
- crude terephthalic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- Y02W90/11—
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention provides a method of refining a crude terephthalic acid and a system capable of recycling the used water mediums by just simple processing to thereby reduce the usage amount of the water medium. The refining method of the invention is characterized by comprising the steps of adding terephthalic acid crystallizations in the following at least one processing drainage to make a suspension liquid, carrying out solid-liquid separation, and recovering the separated crystallization and the separated water. The above drainages comprise the condensate water generated by cooling the vapor generated when the depressurization and cooling are carried out, a gas separated from the condensate water and the exhaust coming from the circulation and sealing gases used for the devices, such as a solid separator, etc., and the storage tanks, such as a mother liquor, etc., the processing drainage of a scrubber generated by the washing of the water medium, and the washing drainage for washing the solid obtained from the above solid-liquid separation and recovered separately. The fractional crystallization is used as a part of the raw materials for preparing the crude terephthalic acid, at the same time, the separation water is used as a part of the water medium for dissolving the crude terephthalic acid.
Description
[technical field]
The present invention relates to the process for purification of crude terephthalic acid.
[background technology]
As purified terephthalic (Purified Terephtalic Acid; PTA) preparation method, known for example following method.That is, take p-Xylol (p-dimethylbenzene) as raw material in acetic acid solvent, under the existence of catalyzer, carry out liquid-phase oxidation with oxygen-containing gas, preparation crude terephthalic acid (Crude Terephtalic Acid; CTA).Then, the crude terephthalic acid for preparing in this operation is dissolved in the water medium of high temperature, high pressure and carries out hydrofining.Then, make by making refining crystallization with the Purified Water solution step-down after hydrofining is cooling, slurry is carried out solid-liquid separation, and purification and recover terephthaldehyde acid crystal can prepare highly purified purified terephthalic (high purity terephthalic acid) thus.
According to such method, need a large amount of water mediums in various operations, must be discharged to the outside with the water medium of crossing simultaneously.As concrete operation, can enumerate the solid-liquid separation process that goes out the operation of purified terephthalic, above-mentioned Crystallization Separation is reclaimed by crystallization (partial crystallization) in the water solvent that is dissolved with crude terephthalic acid, Purified Water solution; Be used for the crystallization of reclaiming is made dried powder so that the drying process of its goods etc.
As the water medium that uses in the preparation section of above-mentioned purified terephthalic, must use the water medium (with respect to 2～5 times of amounts of the crude terephthalic acid of supplying with) of the water solvent of maximum conduct dissolving crude terephthalic acids, then must supply with the washing water (with respect to 0.5～2 times of amount of purified terephthalic) that a lot of water mediums are used as washing purified terephthalic when the purification and recover terephthalic acid.
And then, also must supply with washing water (with respect to 0.5～2 times of amount of purified terephthalic) in the washer (absorption column of gas), pressurize and the Exhaust Gas and the recycle gas that seal with gas wash for use in each equipment, each tower and each groove to above-mentioned preparation section.In addition, different from common process water from preparing the purpose of highly purified purified terephthalic, these water mediums that use must be the high purity water of purity such as deionized water, boiler blow-down water.Thereby the common manufacturing cost of this water is high.
So, be not discharged to the producing apparatus outside if do not want to allow these supply to water medium in each treatment process in a certain treatment process, as long as can process that draining purifies, recycling just can be reused and for the processing of other forms.For this reason, the new water medium of supplying with is saved, and can seek to reduce simultaneously wastewater treatment capacity and lighten the load.Thereby this is just relevant with the preparation cost that reduces the high purity terephthalic acid.
Therefore, technology as the consumption that reduces the high water medium of such purity, for example put down in writing the preparation method of the terephthalic acid that uses at least one following step in patent documentation 1: the mother liquor (mother liquor) of processing water-based prepares low-purity precipitation and the second mother liquor that is formed by terephthalic acid, then, following step: (a) precipitation that purity is lower turns back in reaction medium directly or indirectly; (b) with at least a portion former state of this second mother liquor be directly used in or indirectly be used for dissolving after treatment rough solid; And (c) this second mother liquor is sent to fractionation, and reclaim through this fractionation treated water, then this water is used for wash the precipitation that reclaims from solution reduction phase after.
In addition, put down in writing high purity terephthalic acid's preparation method in patent documentation 2, the method cooling steam that produces of step-down and/or its phlegma in the partial crystallization operation of being undertaken by the partial crystallization groove use as the part of water-medium, in order to make p-methylbenzoic acid (paratoluylic acid) concentration that 1 time of obtaining in the 1st solid-liquid separation separates in mother liquor become 890～2000ppm.
And then, the inventor etc. propose in International Patent Application PCT/No. JP2011/0530701, when carrying out the processing such as cooling by the mother liquor (mother liquor) to above-mentioned water-based and prepare the low terephthaldehyde's acid crystal of purity and the second mother liquor (secondary mother liquid), receive back and forth the treatment process of a mother liquor of the secondary mother liquid that p-methylbenzoic acid content reduces by add terephthaldehyde's acid crystal in this mother liquor.
The prior art document
Patent documentation
The international communique that discloses No. 2004/63136 of patent documentation 2
[summary of the invention]
Invent problem to be solved
When making p xylene oxidation prepare terephthalic acid, terephthalic acid generates in successive reaction.Therefore, produce in this preparation section and remain in crude terephthalic acid in removing of 4-carboxyl benzaldehyde be large problem.Particularly terephthalic acid is usually as the raw material of the polymerization reactants such as polyester, therefore, can cause sneaking into of by product that this polyreaction stops and not preferred.
But the chemical affinity that is blended into 4-carboxyl benzaldehyde in crude terephthalic acid and terephthalic acid is high, usually is difficult to remove.Therefore, for example put down in writing in above-mentioned patent documentation 2, optionally with 4-carboxyl benzaldehyde reduction, make p-methylbenzoic acid (p-toluic acid), can expect to remove the refining crude terephthalic acid by the dissolving of the p-methylbenzoic acid that will generate.
For this reason, owing to containing the by product such as p-methylbenzoic acid in the aqueous mother liquor (mother liquor) after the crystallization of purified terephthalic is reclaimed, therefore, this by product to remove for reducing the new water medium (deionized water etc.) that uses be important.For this reason, by this mother liquor is carried out the processing such as cooling reclaim contain p-methylbenzoic acid etc. low-purity terephthaldehyde's acid crystal (precipitation) afterwards, generated the second mother liquor (secondary mother liquid).In addition, propose patent documentation 1(Unexamined Patent 5-58948 communique): at least a portion former state ground of this secondary mother liquid that p-methylbenzoic acid has been reduced is directly used in or indirectly is used for dissolving after treatment the water medium of crude terephthalic acid crystallization.
Therefore, when for the water medium that reduces new use, used water medium being recycled, the by product (being specially p-methylbenzoic acid) in the water medium that preferably will prepare to recycle is removed as far as possible.In addition, by this secondary mother liquid is processed, the water medium of having removed to greatest extent by product is relevant to the water medium of cutting down new use, therefore proposed the technology described in patent documentation 1 and patent documentation 2 due to such use.
Namely, in the described technology of patent documentation 1, specifically, use that reflux ratio is 2～10, theoretical plate number is the distillation column of 25 grades～125 grades, secondary mother liquid is carried out fractionation, although can reduce significantly p-methylbenzoic acid etc. like this, need very large energy in order to remove p-methylbenzoic acid, this is the problem that exists.And then needing to be used for that the cost of distillation column is set and the place is set is also the problem that exists.
In addition, in the described technology of patent documentation 2, distill or remove p-methylbenzoic acid with membrane sepn, synthetic sorbing material for the either party of the steam that produces in crystallization (partial crystallization) operation from the purified terephthalic in above-mentioned Purified Water solution and/or its phlegma and secondary mother liquid.For this reason, the removing of p-methylbenzoic acid causes cost to increase, or because the use of the selection of separatory membrane and use, synthetic sorbing material, the discarded etc. of synthetic sorbing material after absorption make removing of p-methylbenzoic acid produce new cost.
in view of above-mentioned problem and the various technology take secondary mother liquid as object, the invention provides the process for purification of crude terephthalic acid, present method be with except mother liquor of discharging in the process for purification of crude terephthalic acid and the used water medium (processing draining) secondary mother liquid as object, to be used for reducing the convenient disposal formation of p-methylbenzoic acid content, can cut down the consumption of new water medium, described used water medium comprises: the water of condensation that 1) is cooled to by the cooling steam that produces of step-down in crystallization (partial crystallization) operation of above-mentioned Purified Water solution, 2) to this condensed moisture from gas, process draining from the exhaust of the gas of the sealing that is used for solid-liquid separator, moisture eliminator, circulation and from the scrubber that the exhaust of the storage tank sealed gas that separates mother liquor (mother liquor), washing draining of solid-liquid separator is washed, 3) comprise processing draining from the washing draining of solid-liquid separator.
Be used for solving the means of problem
The inventor etc. have carried out the result that studies intensively in order to solve above-mentioned problem, be provided for reclaiming the easy treatment process of fractional crystallization and Separation of Water, and this fractional crystallization is supplied with as the part of crude terephthalic acid raw materials; This treatment process is to as adding terephthaldehyde's acid crystal in the used water medium (processing draining) of object, carries out solid-liquid separation after making suspension.The method that can cut down the supply of new water medium is provided in addition, and the method is utilized this Separation of Water again as the part of the water medium of dissolving crude terephthalic acid.The system that reasonably recycles Separation of Water also is provided in addition, and this system is according to the content as the p-methylbenzoic acid in the various processing drainings of object, the treatment system of adding above-mentioned terephthaldehyde's acid crystal branched into a plurality of, reasonably recycles Separation of Water.The inventor finds, can more effectively solve above-mentioned problem by above-mentioned system is provided, and has so far completed the present invention.
The effect of invention
According to the present invention, provide the process for purification that consists of the crude terephthalic acid that just can cut down new water medium consumption with easy processing.In addition, be circulated in oxidizing reaction by the fractional crystallization that will be recovered, the toluylic acid that can will adhere under the condition of not losing the terephthaldehyde's acid crystal that adds helps to increase the preparation receipts amount of terephthalic acid thus as terephthaldehyde's acid recovery.
In addition, by recycling the processing draining, can alleviate the processing load of wastewater treatment operation.
[description of drawings]
Fig. 1 recycles the general flowchart of system for pay the water medium that adds in comprising high purity terephthalic acid (PTA) preparation technology of crude terephthalic acid (CTA) preparation section and refinement of crude terephthalic acid operation.
Fig. 2 is the sketch chart of the filtration test device that uses in embodiment.
Nomenclature
1 oxidizing reaction groove
2 solid-liquid separation tanks
3 CTA slurries make-up tanks
4 well heaters
5 hydrogenators
6 partial crystallization grooves
7 solid-liquid separators
8 moisture eliminators
9 condensers
10 water of condensation suspension grooves
11 washing drainage trays
12 solid-liquid separators
13 scrubbers
14 suspension grooves
15 solid-liquid separators
100 Preparation equipments
200 filtration test devices
201 strainers
202 susceptors
203 washing water injectors
TA terephthaldehyde acid crystal
[embodiment]
Be used for implementing the solution of the present invention (present embodiment) referring to Fig. 1 explanation.
［ 1. high purity terephthalic acid's preparation flow ］
As shown in Figure 1, in high purity terephthalic acid preparation technology 100, adopt mainly comprise (i) crude terephthalic acid preparation section and (ii) these 2 operations of refinement of crude terephthalic acid operation prepare purified terephthalic (high purity terephthalic acid).In addition, in Fig. 1, heavy line represents to begin until as the schema of the purified terephthalic (PTA) of final product from the p-Xylol as raw material.Below describe each operation in detail.
(i) crude terephthalic acid preparation section
In this operation, with the p-Xylol liquid-phase oxidation, the crystalline powder of preparation crude terephthalic acid.Specifically p-Xylol (raw material), acetic acid (solvent), catalyzer etc. are supplied in oxidizing reaction groove 1, make the p-Xylol liquid-phase oxidation with oxygen-containing gas, cooling in partial crystallization groove (not shown), the crystallization of terephthalic acid is fully separated out.Wherein, be gradual reaction by the reaction that makes p xylene oxidation prepare terephthalic acid, therefore, residual have as the 4-carboxyl benzaldehyde of intermediate product etc., and the 4-carboxyl benzaldehyde etc. that contains conduct product in the middle of it of trace in the crystallization of crude terephthalic acid.
Then, the reaction of having separated out terephthaldehyde's acid crystal in partial crystallization groove (not shown) is generated during slurries supply to solid-liquid separator 2.In addition, in solid-liquid separator 2, will contain the crude terephthalic acid (CTA of crystallization; Solid phase) separate with the acetic acid solvent that contains catalyzer (liquid phase).After the crude terephthalic acid crystallizing and drying that separates, it is supplied to following refinement of crude terephthalic acid operation.On the other hand, isolated acetic acid solvent is directly circulated as shown in Figure 1 and circulate by acetic acid recovery zone (not shown), recycling in oxidizing reaction groove 1.
Be explained, as shown in Figure 1, except with above-mentioned raw material p-Xylol, fractional crystallization is also merged supply to together in oxidizing reaction groove 1.Fractional crystallization is described below.
(ii) refinement of crude terephthalic acid operation
In this operation, crude terephthalic acid (CTA) is refining, prepare refining high purity terephthalic acid (PTA) with this.Below at length describe.
In will supplying to CTA slurries make-up tank 3 together with the water medium (deionized water) of the crude terephthalic acid that obtains in the crude terephthalic acid preparation section (CTA) and 2～5 times of weight, allotment CTA slurry.Then, (pressure of this moment is about 50～90Kg/cm deployed CTA slurry to be heated to 260 ℃～300 ℃ by well heater 4
2G(is explained, and " G " represents gauge pressure.Below identical)), with dissolving crystallized, become aqueous terephthalic acid solution.Be explained, also be dissolved with the 4-carboxyl benzaldehyde in this aqueous terephthalic acid solution.
Be explained, in the water medium that supplies to CTA slurries make-up tank 3, also contain the used processing draining (that is the water medium that, contains p-methylbenzoic acid etc.) that produces in following operation directly or the water medium that recycles after purifying treatment.The below is described this point.
With aqueous terephthalic acid solution and hydrogen (H
2) supply to together in hydrogenator 5.In hydrogenator 5, be filled with the activated-carbon catalyst of supported palladium.Therefore, when aqueous terephthalic acid solution being supplied in hydrogenator 5, the aldehyde radical that the 4-carboxyl benzaldehyde in aqueous terephthalic acid solution has will be reduced, thereby is reduced to p-methylbenzoic acid.That is, in operation thereafter, it is supplied with as the aqueous terephthalic acid solution that contains p-methylbenzoic acid.
The aqueous terephthalic acid solution that to reduce in hydrogenator 5 supplies in partial crystallization groove 6.Partial crystallization groove 6 is the plural serial stage partial crystallization groove (4～6 grooves namely, comprise a plurality of partial crystallization grooves) that stage ground reduces pressure.In addition, in partial crystallization groove 6, make aqueous terephthalic acid solution cooling (temperature reduction) by stage ground step-down, make crystallization (partial crystallization), generate the approximately purified terephthalic slurries (slurry) of 120 ℃～170 ℃.
The slurry that generates is supplied to solid-liquid separator 7(such as pressure filter etc. under the state that keeps this temperature) in, in terephthaldehyde acid crystal (solid phase) Separation and Recovery of High Temperature High Pressure with generation.Be explained,, therefore make and contain most p-methylbenzoic acid in liquid phase in this temperature dissolving due to p-methylbenzoic acid.
And then, will be integrated strainer of type etc. such as solid-liquid displacement zone and washing section at solid-liquid separator 7() in after terephthaldehyde's acid crystal water medium of obtaining fully washs, the purified terephthalic crystallization is reclaimed as wet cake.Then, this wet cake is supplied in moisture eliminator 8, it is fully dry.After drying, obtain purified terephthalic (PTA).Be explained, in solid-liquid separator 7, the aqueous mother liquor that will separate from the purified terephthalic crystallization (mother liquor) is discharged (not shown), simultaneously, will discharge as the washing draining for the water medium of washing.The part of this mother liquor according to processing like that of proposing in patent documentation 1 for example, is reused as water medium, and all the other are discharged in the wastewater treatment operation.In addition, with the washing draining temporary storage that reclaims respectively in washing drainage tray 11, as shown in Figure 1, with its directly and/or after processing the part as the water medium that is used for the dissolving crude terephthalic acid recycle.Detailed processing is below described.
In addition, will be by solid-liquid separator 7(such as the decantor etc. as the solid-liquid separator of not following washing section) wet cake of Separation and Recovery makes slurries again together with the water medium that is used for washing, and then with solid-liquid separator (not shown) with the wet cake of purified terephthalic crystallization with wash the draining Separation and Recovery.And then, wet cake is transferred to moisture eliminator 8, will wash draining and be transferred to washing drainage tray 11.
［ the 2. recycling system of water medium ］
The following flow process of the recycling system of (ii) each of the refinement of crude terephthalic acid operation of the above-mentioned Fig. 1 of explanation processing draining (used water medium) of discharging in processing.
The water of condensation of the steam of for example, discharging from partial crystallization groove 6, separate the gas of this water of condensation, the aqueous mother liquor (mother liquor) (not shown) separated from solid-liquid separator 7, be discharged from from being used for the treated water media such as processing draining that washing discharged by the scrubber 13 of the circulation of the storage tank 11 of washing draining, moisture eliminator 8 etc., each Exhaust Gas that sealed gas is discharged.in addition, removed the aqueous mother liquor (mother liquor) of discharging from solid-liquid separator 7 and certainly general from above-mentioned condensation (discharges) water of partial crystallization groove 6 be all almost transparent, be used for those at above-mentioned each equipment, the circulation of storage tank, sealed gas (the rare gas element such as nitrogen, but the gas that separates above-mentioned water of condensation contains refining remaining hydrogen) in contain evaporation, the draining that scrubber that the Exhaust Gas of the trace impurity of following (p-methylbenzoic acid etc.) washs is processed be almost also usually transparent (can be due to temperature, pressure decreased and cause the water medium of crystallization).As mentioned above, necessary water medium is owing to being highly purified in (ii) in the refinement of crude terephthalic acid operation, so menu cost is high.In addition, used water medium (processing draining) is therefore considered from the viewpoint of further reduction carrying capacity of environment owing to containing organic compound, does not also discharge to the outside as far as possible, preferably recycles.
Except the roughly transparent above-mentioned used water medium mother liquor as the processing draining of object of the present invention.For used water medium is recycled, must reduce, purify contained p-methylbenzoic acid, add terephthaldehyde's acid crystal in water of condensation suspension groove 10 and suspension groove 14 for this reason, after crystallization is disperseed to make suspension, separate in solid- liquid separator 12,15 respectively.And then fractional crystallization that will be separately supplies to together with p-Xylol in oxidizing reaction groove 1, with the part of Separation of Water as the water medium that uses when crude terephthalic acid (CTA) and water medium are allocated slurries together, supplies in CTA slurries make-up tank 3.
Be explained, in used water medium the amount of contained impurity (p-methylbenzoic acid) according to discharging the place difference, therefore, the flow process that more preferably branches into two systems of 10/12 and 14/15 of suspension groove/solid-liquid separator carries out recycling after purifying treatment.
The water of condensation of the steam of for example discharging from partial crystallization groove 6, contain the p-methylbenzoic acid of 500ppm～600ppm left and right.On the other hand, as shown in Figure 1, supply with from discharge the gas of emptying for the recycle gas of the gas that solid-liquid separation 7, separation mother liquor tank (not shown) and washing drainage tray 11 etc. are sealed and moisture eliminator 8 to scrubber 13, but, 13(is following from this scrubber) the used water medium of discharging, contain the following p-methylbenzoic acid of 100ppm of having an appointment.Therefore, it is irrational these used water mediums similarly being processed and recycled.
Therefore, according to the content of p-methylbenzoic acid contained in water medium recycling system, the water medium recycling flow process of design 2 systems.So, design the water medium recycling flow process of a plurality of systems by the amount according to contained p-methylbenzoic acid, can effectively apply flexibly the water medium that is reused, thereby can further cut down the water medium of new importing.
Below, the limit is with reference to the flow process of Fig. 1 limit explanation water medium recycling system again.
Thick dashed line in Fig. 1 represents the recycling flow process of used water medium (Separation of Water and washing draining).In addition, in Fig. 1, the equipment of giving hachure is the treatment facility of participating in recycling directly.
At first the water of condensation recycling flow process of separating and condensing water is used in explanation.
The steam of discharging from partial crystallization groove 6 device 9 that is condensed is cooling, is separated into water of condensation medium and hydrogeneous gas.In addition, p-methylbenzoic acid (the about 500ppm～600ppm) that contains high-content in this water of condensation medium.After cooling, the water of condensation medium is supplied in water of condensation suspension groove 10.Be explained, the above-mentioned Exhaust Gas that the device 9 that is condensed separates is fed in scrubber 13, is discharged from through washing.In addition, the heat (being specially the heat of capturing from steam) that produces in condenser 9 is used for heating the slurry of above-mentioned well heater 4.
In addition, the used water medium from washing drainage tray 11 also is fed in water of condensation suspension groove 10.Particularly, detailed is described below, and the poor used water medium of p-methylbenzoic acid (the used water medium of namely discharging from scrubber 13) is used as the part of the washing water of the purified terephthalic crystallization solid-liquid separator 7.Owing to sneaking into some separation mother liquors from solid-liquid separator 7 (mother liquor) in the washing draining of reclaiming respectively, this is to cause the reason that as a result of contains the p-methylbenzoic acid of high-content in this washing draining.
In water of condensation suspension groove 10, add terephthalic acid (TA).Research according to inventor etc. is appreciated that if add terephthalic acid in the used water medium that contains p-methylbenzoic acid p-methylbenzoic acid is adsorbed in the terephthalic acid that is added.Therefore, by adding insoluble terephthalic acid in water medium, the p-methylbenzoic acid in can used water medium is adsorbed by terephthalic acid and removes.
Adding the terephthalic acid in water of condensation suspension groove 10 to, can be the filter cake etc. of dry crude terephthalic acid, dry purified terephthalic or moistening purified terephthalic.Wherein, be appreciated that the viewpoint of the p-methylbenzoic acid content from the used water medium of further reduction is considered, compare the preferred terephthalic acid that adds drying with moistening terephthalic acid.In addition, use purified terephthalic rather than crude terephthalic acid, the effect that reduces p-methylbenzoic acid content is better.That is, as the terephthalic acid that adds, dry purified terephthalic particularly preferably.
Be explained, as the filter cake of the crude terephthalic acid of drying or dry purified terephthalic, moistening purified terephthalic etc., can suitably use the terephthalic acid of discharging from each equipment of high purity terephthalic acid preparation technology 100.For example, when using dry purified terephthalic, the purified terephthalic that obtain as long as use dry by moisture eliminator 8.In addition, as this class terephthalic acid, also can use the product of supplying with from the outside.
The inventor etc. find through research, when terephthalic acid is dry, make aqueous solvent (water molecules) when the surface of terephthaldehyde's acid crystal and the inner evaporation, cause variation on the surface tissue of terephthaldehyde's acid crystal, thereby improved the adsorption activity of p-methylbenzoic acid.That is, as mentioned above, by using dry terephthalic acid, can further improve the efficient of removing of p-methylbenzoic acid.
There is no particular restriction as the mode of adding, can suspend to water of condensation and directly add terephthaldehyde's acid crystal and it is suspended in used water medium in groove 10, the water medium that is suspended with in advance terephthalic acid can be supplied with as slurries yet.
In addition, the addition of terephthalic acid does not have particular restriction yet.But, the inventor etc. find through research, be equivalent to that (about 250ppm～300ppm) just can re-use whole water of condensation of supplying to water of condensation suspension groove 10 from partial crystallization groove 6 part as the water medium of dissolving crude terephthalic acid from half of the p-methylbenzoic acid concentration in the steam of partial crystallization groove 6 as long as the content of p-methylbenzoic acid can be reduced to.Consider from this viewpoint, add the terephthalic acid amount in water of condensation suspension groove 10 to, more than preferably being equivalent to 0.2 % by weight as the used water medium that adds object.By adding in this scope, can make the content of p-methylbenzoic acid suitably reduce at least half left and right.
Wherein, when using crude terephthalic acid as the terephthalic acid of this interpolation, more than being preferably 0.4 % by weight.And then, when using the filter cake of moistening purified terephthalic, more than being preferably 0.5 % by weight.
In addition, as the higher limit of the addition of terephthalic acid, although when the amount of the terephthalic acid that adds increases, the adsorptive capacity of p-methylbenzoic acid also increases, but this also can make the internal circulating load of high purity terephthalic acid's preparation section integral body increase, thereby can affect the preparation cost of terephthalic acid.Therefore, the amount of the terephthalic acid that adds preferably is equivalent to below 2 % by weight as the used water medium that adds object.
Add terephthaldehyde's acid crystal of above-mentioned concentration in water of condensation suspension groove 10, after it is fully suspended, suspension is supplied in solid-liquid separator 12.Then, in solid-liquid separator 12, be separated into separating and condensing water and fractional crystallization.Contain the terephthalic acid that has adsorbed p-methylbenzoic acid in this fractional crystallization.As solid-liquid separator 12, can use such as rotary filter, decantor etc.Wherein, from can continuous separate from viewpoint consider, preferably use the decantor (sedimentation centrifuge) of collar plate shape or spiral ball-type.
Then, the fractional crystallization that obtains is supplied in (i) crude terephthalic acid preparation section, become the part of raw material.That is, the methyl that p-methylbenzoic acid has is oxidized in oxidizing reaction groove 1, becomes terephthalic acid.As mentioned above, contain the more p-methylbenzoic acid that is adsorbed on terephthalic acid in fractional crystallization, therefore, use as the part of the raw material of oxidizing reaction by terephthaldehyde's acid crystal that will contain p-methylbenzoic acid, can increase the production efficiency (yield) of terephthalic acid.And can produce more frugally terephthalic acid, thereby can seek to cut down raw materials cost.
In addition, the part of separating and condensing water as water medium supplied in CTA slurries make-up tank 3.In addition, all the other compositions are supplied in the wastewater treatment operation.Therefore, can cut down the new consumption of water medium, thereby reduce the lifting capacity of wastewater treatment.Its result can seek to cut down the preparation cost of terephthalic acid.
Secondly, illustrate that being used for the low scrubber of p-methylbenzoic acid content processes the flow process that the water medium of draining recycles system.
For wash from the sealing of solid-liquid separation tank 7 and moisture eliminator 8, in recycle gas exhaust, condenser 9 divided gas flow and from the exhaust in the sealed gas that separates mother liquor (not shown), washing drainage tray 11 of solid-liquid separation 7, these exhausts are supplied in scrubber 13.In addition, owing to containing volatile p-methylbenzoic acid etc. in this gas, therefore use water medium that they are washed in scrubber 13 and remove, then washing gas is discharged to the outside.Therefore, the used water medium of discharging from scrubber 13, contain the p-methylbenzoic acid of low levels.Its content is less than above-mentioned from the p-methylbenzoic acid content in the steam of partial crystallization groove 6.Specifically, the p-methylbenzoic acid content in the used water medium of discharging from scrubber 13 is generally approximately 100ppm or lower.
Then, will supply in suspension groove 14 from the used water medium of scrubber 13.In suspension groove 14, similarly add terephthaldehyde's acid crystal with above-mentioned water of condensation suspension groove 10.The amount of the terephthalic acid that adds, the form of terephthalic acid etc. do not have particular restriction, as long as set in the same manner with the occasion of water of condensation suspension groove 10.
Be added with the used water medium of terephthalic acid in suspension groove 14, same with solid-liquid separator 12, Separation and Recovery fractional crystallization and Separation of Water in solid-liquid separator 15.Then, the fractional crystallization that obtains is supplied in oxidizing reaction groove 1 for the preparation of crude terephthalic acid.
On the other hand, the Separation of Water that obtains is used as the part of the washing water of the purified terephthalic in solid-liquid separator 7, perhaps use as the part of the water that is used for the dissolving crude terephthalic acid,, it is supplied in CTA slurries make-up tank 3 for this reason.Namely, add terephthaldehyde's acid crystal in from the used water medium of scrubber 13 p-methylbenzoic acid is poor in suspended layer 14, after making it become suspension, will use from Separation of Water washing water as refining terephthaldehyde's acid crystal in solid-liquid separator 7 of solid-liquid separator 15.Then, should wash draining and be recycled in washing drainage tray 11, use as the part of the water medium that is used for the dissolving crude terephthalic acid.In addition, due to solid-liquid separator 7 in the recovery respectively that separates mother liquor (mother liquor) abundant not, therefore, the washing draining that the content of p-methylbenzoic acid has been improved supplies in water of condensation suspension groove 10, mix with the water of condensation from above-mentioned condenser 9, it is carried out purifying treatment, so namely recycling.
［ the 3. modification of the recycling system of water medium ］
As shown in Figure 1, in high purity terephthalic acid preparation technology 100, will supply to from the used water medium of scrubber 13 in suspension groove 14, add terephthaldehyde's acid crystal.Wherein, as mentioned above, contained p-methylbenzoic acid amount is low levels from the used water medium that scrubber 13 is discharged.
Therefore, the used water medium from scrubber 13 also can not add terephthaldehyde's acid crystal and directly use as the water medium that dissolves crude terephthalic acid.Even according to such formation high purity terephthalic acid preparation technology, also can provide to consist of the process for purification of the crude terephthalic acid of the consumption of cutting down new water medium with easy processing.In addition, due to suspension groove 14 and solid-liquid separator 15 need not be set, therefore, can seek reduction and the place is set and make the further simplicity for the treatment of facility.
In addition, about adding terephthalic acid in used water medium, although be that water medium for 2 systems of corresponding p-methylbenzoic acid concentration respectively adds respectively 1 time, also can divide and carry out for several times.
And then the water medium as being used for scrubber 13 though use new water medium in Fig. 1, also can use the purification separation water (Separation of Water) that obtains in solid- liquid separator 12,15.
［ the 4. modification of high purity terephthalic acid's preparation flow ］
The high purity terephthalic acid preparation technology 100 of the process for purification that applicable the present embodiment relates to consists of without any restriction technique shown in Figure 1.For example, solid-liquid separator 7 is not limited to 1 grade of separation, also can arrange multistage.
In addition, the number of the scrubber 13 in this technique does not limit 1 yet, can arrange more than 2 yet.
Below enumerate embodiment and be described more specifically the present invention.
In the present embodiment, in high purity terephthalic acid preparation technology's 100 shown in Figure 1 actual preparation facilities, the water of condensation sampling that will form from the vapour condensation of partial crystallization groove 6 is used.So, with 4 of tapered tubes, this water of condensation is respectively gathered 50ml with centrifugation.In these 4 tapered tubes, respectively will do not add purified terephthalic powder (crystalline powder) sample (0 % by weight), add the 0.05g(0.1 % by weight), the 0.1g(0.2 % by weight), the 0.25g(0.5 % by weight) the sample mixing of fully vibrating, after crystalline powder is fully disperseed, be placed in centrifuge separator.
With centrifuge separator with rotation number 7500rpm(6200G) centrifugal treating is after 5 minutes, gathers the supernatant liquor in tapered tube, measures the p-methylbenzoic acid content of each supernatant liquor.The results are shown in table 1.Be explained, the p-methylbenzoic acid decrement, expression p-methylbenzoic acid content is with respect to the minimizing ratio of the p-methylbenzoic acid content of comparative example 1.
[table 1]
Find out from this result, for the content that makes p-methylbenzoic acid reduces by half, preferably add at least 0.1g left and right (about 0.2 % by weight) with respect to water of condensation 50ml.
＜embodiment 4～6＞
Similarly water of condensation is collected in 4 tapered tubes with embodiment 1～3.Then, add purified terephthalic powder (crystalline powder) 0.5g(1 % by weight in 1 tapered tube wherein), fully vibration mixes, and after crystalline powder is fully disperseed, is placed in centrifuge separator (embodiment 4).
Add moistening (approximately 11%) the purified terephthalic filter cake 0.28g(0.5 % by weight before purified terephthalic dry in another 1 tapered tube), fully vibration mixes, and after crystalline powder is fully disperseed, is placed in centrifuge separator (embodiment 5).
In addition, and then add crude terephthalic acid powder 0.2g(0.4 % by weight in another 1 tapered tube), fully vibration mixes, and after crystalline powder is fully disperseed, is placed in centrifuge separator (embodiment 6).
Then, do not add any material in 1 remaining tapered tube, be placed in centrifuge separator (contrast is used).
With the same condition of embodiment 1～3 under carry out centrifugation, calculate the decrement of p-methylbenzoic acid content and p-methylbenzoic acid for supernatant liquor.Its result and comparative example 1 are shown in table 2 in the lump.
[table 2]
As shown in table 2, if the form of the terephthalic acid that adds as can be known is different, the decrement of p-methylbenzoic acid is also different.Wherein as can be known, if use the dried powder (embodiment 4) of purified terephthalic, decrement is high especially.
Be explained, the stripping quantity of contained 4-carboxyl benzaldehyde in the crude terephthalic acid powder (impurity in purified terephthalic a kind of) in supernatant liquor is micro-(below 5ppm).
＜embodiment 7, comparative example 2 〉
In high purity terephthalic acid preparation technology's 100 shown in Figure 1 actual preparation facilities, will respectively gather 50ml 2 tapered tubes from the used water medium that scrubber 13 is discharged.
Then, add purified terephthalic powder 0.8g(0.8 % by weight in this tapered tube), fully vibration mixes, and after crystalline powder is fully disperseed, is placed in centrifuge separator (embodiment 7).Sample that what does not add as a comparative example 2 will be prepared in addition.
Then, with the same condition of embodiment 1～6 under carry out centrifugally, measure p-methylbenzoic acid content for the supernatant liquor after solid-liquid separation, and calculate the decrement of p-methylbenzoic acid.To the results are shown in table 3.
[table 3]
From this result as can be known, for the used water medium from scrubber 13, by adding terephthalic acid, also can remove significantly p-methylbenzoic acid.
＜embodiment 8, comparative example 3 〉
Partial crystallization groove 6 in actual preparation facilities in high purity terephthalic acid preparation technology 100 as mentioned above, comprises a plurality of partial crystallization grooves.That is, will supply in a plurality of partial crystallization grooves through hydrorefined aqueous terephthalic acid solution in hydrogenator 5, the step-down of interim ground is cooling, at final partial crystallization groove (4Kg/cm
2G, 150 ℃) in generate the slurries of purified terephthalic.Then, the slurries of this purified terephthalic are supplied in above-mentioned solid-liquid separator 7, be separated into purified terephthalic crystallization and mother liquor.Then, this crystallization with water medium (new water medium or recycling water medium) washing, is reclaimed the purified terephthalic crystallization.
At this, washing water as the crystallization in solid-liquid separator 7, in order to confirm to use the effect when scrubber 13 being processed drainings and add the Separation of Water (scrubber 13 is processed draining → suspension groove 14 → solid-liquid separator 15 → Separation of Waters) that obtains after the processing of terephthaldehyde's acid crystal, as solid-liquid separator 7, make filtration test device 200 shown in Figure 2 with SUS 304 stainless steels.
Filtration test device 200 possesses the following equipment that can regulate at high pressure, high temperature, by filtration area 82.2cm
2Strainer 201, susceptor 202, washing water injector 203 consist of.
Be explained, the circulation in each one and the control of pressure can be undertaken by the switch of controlling ball valve 204a～204f.In addition, filtration test device 200 possesses 2 pressure warning unit 206a, 206b, utilizes valve 207a, 207b to control inert gas pressure, thus can the controlled filter tester pressure of 200 inside.And then filtration test device 200 possesses thermometer 205, can measure the temperature of filtration test device 200 inside.In addition, filtration test device 200 utilizes valve 207c, 207d to control the circulation of heating steam, thereby can adjust the temperature of washing water.In addition, the temperature of filtration test device 200 inside can be controlled by periphery being carried out electrically heated band heater (not shown).
In addition, possesses filter cloth (the middle tail strainer TR9B processed of the company) 201a that is supported in the polyester on the stainless steel porous plate (not shown) of by the ring flange clamping in strainer 201.Be explained, the state after filtering shown in Fig. 2, filtering layer (crystallizing layer) 201b filters with filter cloth 201a, forms filter cake.
Drop into slurry (purified terephthalic slurry) from the top of strainer 201.Then, input slurry is filtered with filter cloth 201a, only have mother liquor (liquid phase) to be discharged to the bottom by susceptor 202.On the other hand, filtering layer is deposited in filter cloth 201a upper (the filtering layer 201b shown in Fig. 2).Then, the filtering layer 201b that piles up is sprayed together with rare gas element with the washing water of having prepared through heating in washing water injector 203, wash.
Below specifically describe the operation of the filtration test device 200 in embodiment.
In the present embodiment, filtration test device 200 is installed to test on the short tube that in the partial crystallization groove 6 in the preparation facilities of Fig. 1 and the way of the pipe arrangement between solid-liquid separation tank 7, branch ground arranges.With filtration test device 200 internal adjustments to and equal pressure, the temperature (5Kg/cm of above-mentioned pipe arrangement (pipe arrangement between partial crystallization groove 6 and solid-liquid separation tank 7)
2G, 150 ℃), then, supply with 200～300ml slurry from top.After supply, the pressure reduction that pressure is adjusted to pressure warning unit 206a, 206b becomes 0.5Kg/cm
2(adjusting with valve 204b and valve 207b) is with filter cloth 201a filtering for crystallizing slurries.Separate the mother liquor temporary storage in susceptor 202, be discharged to outside (by come in the maintenance strainer 201 pressure of valve 204b passs → valve 204c).As shown in Figure 2, crystallization is stratiform (crystallizing layer 201b) and is deposited on filter cloth 201a.
Secondly, will supply in advance washing water injector 203, and use rare gas element and heating steam to depress (about 5.5Kg/cm adding
2G) being adjusted to approximately, the washing water 100ml of 110 ℃ of temperature utilizes the pressure feed of rare gas element in strainer 201., as washing water, use at the supernatant liquor of collecting under the condition of above-described embodiment 7 (100ml) and the supernatant liquor (100ml) collected under the condition of comparative example 2 herein, study respectively (being respectively embodiment 8 and comparative example 3).Then, the pressure reduction with pressure warning unit 206a, 206b is adjusted to 0.5Kg/cm
2(adjusting with valve 204b and valve 207b), wash crystallization layer 201b.To wash draining and above-mentioned mother liquor is similarly collected in susceptor 202, and reclaim, measure the p-methylbenzoic acid content in the washing draining.
And then, open after filtration test device 200 is cooling, take out crystallizing layer 201b, after making its drying, its weight and p-methylbenzoic acid content are measured in dried crystallization (purified terephthalic crystallization).
The above table 4 that the results are shown in.Be explained, in table 4, " washing water ratio " mean dry after the value of the washing water yield of per unit crystallization weight.In addition, as a reference example, illustrate in the lump with the occasion of using deionized water as washing water.
[table 4]
From the result shown in table 4 as can be known, compare with the comparative example 3 that does not add terephthalic acid, add the occasion of the embodiment 8 of terephthalic acid in advance, the content of the p-methylbenzoic acid in dried crystallization and washing draining both all seldom.In addition, the occasion of embodiment 8, the content of p-methylbenzoic acid amount with uses the reference example of deionized water to be equal extent, obtained the result with use equal extent during deionized water.That is, as can be known, can suitably recycle the water medium of having removed p-methylbenzoic acid by adding terephthalic acid and replace the deionized water that in the past used.
Claims (6)
1. the process for purification of crude terephthalic acid, this process for purification carries out liquid-phase oxidation in acetic acid solvent take p-Xylol as raw material, after the preparation crude terephthalic acid, above-mentioned crude terephthalic acid is dissolved in the water medium of high temperature, high pressure, then carry out hydrofining, the aqueous solution that obtains by the cooling crystallization that makes of step-down, after obtaining the purified terephthalic slurry, is carried out solid-liquid separation with this purified terephthalic slurry; It is characterized in that,
Process to following at least a kind and add terephthaldehyde's acid crystal in draining and after making suspension, carry out solid-liquid separation, reclaim fractional crystallization and Separation of Water, above-mentioned processing draining comprises:
The cooling water of condensation that generates of steam that produces when above-mentioned step-down is cooling,
By to this condensed moisture from gas and from the exhaust of the gas of the circulation of the storage tank that is used for solid-liquid separator, moisture eliminator, aqueous mother liquor etc., sealing with water medium wash the scrubber that generates process draining,
By the solid that obtains in above-mentioned solid-liquid separation being washed and reclaims respectively the washing draining that obtains;
This fractional crystallization is used as the part of the raw material of preparation during above-mentioned crude terephthalic acid, simultaneously,
This Separation of Water is used as at least a portion of the water medium of the above-mentioned crude terephthalic acid of dissolving.
2. the process for purification of crude terephthalic acid claimed in claim 1, is characterized in that,
Add terephthaldehyde's acid crystal at least one party of above-mentioned water of condensation and above-mentioned washing draining, obtain Separation of Water,
This Separation of Water and above-mentioned scrubber processing draining are directly used as at least a portion of the water medium that dissolves above-mentioned crude terephthalic acid.
3. the process for purification of crude terephthalic acid claimed in claim 1, is characterized in that,
Add terephthaldehyde's acid crystal at least one party of above-mentioned water of condensation and above-mentioned washing draining, obtain Separation of Water, simultaneously, process in draining to above-mentioned scrubber and also add terephthaldehyde's acid crystal, obtain Separation of Water,
To use as at least a portion of the water medium of the above-mentioned crude terephthalic acid of dissolving by using this Separation of Water that above-mentioned water of condensation and/or above-mentioned washing draining obtain, simultaneously,
This Separation of Water that uses above-mentioned scrubber to process draining and obtain is used as at least a portion of the washing water of the above-mentioned purified terephthalic crystallization of washing.
4. the process for purification of crude terephthalic acid claimed in claim 3, is characterized in that,
The washing draining of having washed above-mentioned purified terephthalic crystallization is used as at least a portion of the water medium of the above-mentioned crude terephthalic acid of dissolving.
5. the process for purification of wantonly 1 described crude terephthalic acid in claim 1～4, is characterized in that,
So that more than being respectively 0.2 % by weight with respect to above-mentioned processing draining and the ratio below 2 % by weight add above-mentioned terephthaldehyde's acid crystal.
6. the process for purification of wantonly 1 described crude terephthalic acid in claim 1～4, is characterized in that,
Above-mentioned terephthaldehyde's acid crystal is at least a crystallization that is selected from the filter cake of dry above-mentioned crude terephthalic acid, dry above-mentioned purified terephthalic and moistening above-mentioned purified terephthalic.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011-252149 | 2011-11-18 | ||
| JP2011252149A JP5802115B2 (en) | 2011-11-18 | 2011-11-18 | Method for purifying crude terephthalic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103121950A true CN103121950A (en) | 2013-05-29 |
| CN103121950B CN103121950B (en) | 2015-10-14 |
Family
ID=48453137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210461715.8A Expired - Fee Related CN103121950B (en) | 2011-11-18 | 2012-11-16 | The process for purification of crude terephthalic acid |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP5802115B2 (en) |
| CN (1) | CN103121950B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104817454A (en) * | 2014-01-30 | 2015-08-05 | 株式会社日立制作所 | Preparation method for refining terephthalic acid |
| CN108301064A (en) * | 2018-01-23 | 2018-07-20 | 东南新材料（杭州）有限公司 | The manufacturing method and its device of a kind of doping vario-property copolyesters, profiled filament |
| CN115108902A (en) * | 2022-03-29 | 2022-09-27 | 泰安渤洋化工科技有限公司 | Preparation method of 2,4, 6-trimethyl benzoic acid |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004063136A1 (en) * | 2003-01-08 | 2004-07-29 | Mitsubishi Chemical Corporation | Method for producing high purity terephthalic acid |
| CN101045683A (en) * | 2006-03-27 | 2007-10-03 | 三井化学株式会社 | Method of preparing high-purity terephthalic acid |
| CN101096334A (en) * | 2006-06-30 | 2008-01-02 | 中国石化上海石油化工股份有限公司 | Method for reclaiming oxidation sludge of terephthalic acid prepared by dimethylbenzene |
| CN101914013A (en) * | 2010-07-30 | 2010-12-15 | 浙江大学 | Water-saving terephthalic acid production method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9310070D0 (en) * | 1992-05-29 | 1993-06-30 | Ici Plc | Process for the production of purified terephthalic acid |
| WO2009141968A1 (en) * | 2008-05-20 | 2009-11-26 | 株式会社日立プラントテクノロジー | Method for treating separated mother liquor from terephthalic acid refinement |
-
2011
- 2011-11-18 JP JP2011252149A patent/JP5802115B2/en not_active Expired - Fee Related
-
2012
- 2012-11-16 CN CN201210461715.8A patent/CN103121950B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004063136A1 (en) * | 2003-01-08 | 2004-07-29 | Mitsubishi Chemical Corporation | Method for producing high purity terephthalic acid |
| CN101045683A (en) * | 2006-03-27 | 2007-10-03 | 三井化学株式会社 | Method of preparing high-purity terephthalic acid |
| CN101096334A (en) * | 2006-06-30 | 2008-01-02 | 中国石化上海石油化工股份有限公司 | Method for reclaiming oxidation sludge of terephthalic acid prepared by dimethylbenzene |
| CN101914013A (en) * | 2010-07-30 | 2010-12-15 | 浙江大学 | Water-saving terephthalic acid production method |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104817454A (en) * | 2014-01-30 | 2015-08-05 | 株式会社日立制作所 | Preparation method for refining terephthalic acid |
| CN104817454B (en) * | 2014-01-30 | 2017-01-04 | 株式会社日立制作所 | The manufacture method of purified terephthalic |
| CN108301064A (en) * | 2018-01-23 | 2018-07-20 | 东南新材料（杭州）有限公司 | The manufacturing method and its device of a kind of doping vario-property copolyesters, profiled filament |
| CN115108902A (en) * | 2022-03-29 | 2022-09-27 | 泰安渤洋化工科技有限公司 | Preparation method of 2,4, 6-trimethyl benzoic acid |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103121950B (en) | 2015-10-14 |
| JP2013107835A (en) | 2013-06-06 |
| JP5802115B2 (en) | 2015-10-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1032132C (en) | Process for preparation of arude terphthalic acid suitable for reduction to prepane purified terephthalic acid | |
| RU2035966C1 (en) | Method for extracting crystals from suspension | |
| CN1035815C (en) | Improved process for recovery of purified terephthalic acid | |
| JP3757995B2 (en) | Method for producing high purity isophthalic acid | |
| RU2114098C1 (en) | Method of producing of crude aromatic polycarboxylic acid | |
| EP0764627B1 (en) | Process for producing highly pure terephthalic acid | |
| CN1085889A (en) | The preparation method of refining terephthalic acid | |
| RU2599636C2 (en) | Method of purified terephthalic acid producing | |
| CN1150945A (en) | Process for production of terephthalic acid | |
| CN212941831U (en) | Multifunctional waste organic solvent recovery equipment | |
| CN103121950B (en) | The process for purification of crude terephthalic acid | |
| JP4055913B2 (en) | Method for producing high purity terephthalic acid | |
| CN106943775B (en) | Device and method for continuously separating solid phase from liquid phase in caprolactam distillation heavy residual liquid | |
| CN102026952B (en) | Method for treating separated mother liquor from terephthalic acid refinement | |
| CN100402482C (en) | Method for producing aromatic carboxylic acid | |
| CN103183607A (en) | Method for producing mixed aromatic dioctyl phthalate | |
| JP7121049B2 (en) | Method for producing hydrogen sulfide and method for recovering sulfur | |
| JP3859178B2 (en) | Method and apparatus for producing high-purity aromatic dicarboxylic acid | |
| CN103443064B (en) | The treatment process of purified terephthalic mother liquor | |
| EA024634B1 (en) | Process and system for purification of aromatic dicarboxylic acid and feed preparation vessel used therein | |
| CN1960961B (en) | Method for producing high-purity terephthalic acid | |
| CN101186573A (en) | Process for producing terephthalic acid | |
| KR101013489B1 (en) | Recovery of catalysts and aromatic acids from the wastes aromatic acid production plants | |
| CN106422479A (en) | Rotary filter | |
| JP2004175797A (en) | Method for producing terephthalic acid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: HITACHI,LTD. Free format text: FORMER OWNER: HITACHI PLANT TECHNOLOGIES LTD. Effective date: 20140110 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20140110 Address after: Tokyo, Japan Applicant after: Hitachi Ltd. Address before: Tokyo, Japan, Japan Applicant before: Hitachi Plant Technologies Ltd. |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20151014 Termination date: 20201116 |