CN106565466A - Preparation method of purified terephthalic acid - Google Patents
Preparation method of purified terephthalic acid Download PDFInfo
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- CN106565466A CN106565466A CN201510650707.1A CN201510650707A CN106565466A CN 106565466 A CN106565466 A CN 106565466A CN 201510650707 A CN201510650707 A CN 201510650707A CN 106565466 A CN106565466 A CN 106565466A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
- C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
Abstract
The invention discloses a preparation method of purified terephthalic acid. Recrystallization of one organic solvent or a mixture of more than one organic solvent is adopted to replace the hydrogenation reaction production technological process of original purified terephthalic acid (PTA) refining workshop section. during the production technological process of the purified terephthalic acid (PTA) refining working section, crude terephthalic acid is dissolved by one organic solvent or a mixture of more than one organic solvent, and then multi-stage repeated crystallizations, filtration, drying and other technological process are carried out so as to obtain the purified terephthalic acid (PTA) with purity being 99.98%. By the method, high-temperature, high-pressure and flammable and combustible working conditions of equipment of hydrogenation unit are solved, and dangerous process equipment of a hydrogen production unit can be turned off and stopped.
Description
Technical field
The invention belongs to chemical products preparation field, and in particular to a kind of p-phthalic acid (PTA) system
Make new process.
Background technology
P-phthalic acid (PTA) is a kind of important Organic Chemicals, and its raw material is xylol
(PX), source is oil, and the downstream extension product of PTA is mainly polyester (PET), in the world 90%
More than PTA be used for produce PET, be widely used in chemical fibre, light industry, electronics, medicine, food and
The various aspects of the national economy such as building.Traditional p-phthalic acid (PTA) production method is to diformazan
After benzene, acetic acid, cobalt manganese bromine catalyst mix in dispensing blending tank, oxidation reactor is sent into, to diformazan
Benzene carries out reaction in oxidation reactor and generates crude terephthalic acid with air, then subtracts through three crystallizers
Temperature decompression and rotary vaccum filter carry out solid-liquid separation, and finally detached solid is dried, and making purity is
99.7% crude terephthalic acid；Certain density slurry is configured in crude terephthalic acid and desalted water,
Holy dyne of pump boosting of Jing, and after preheated device system heats up, under conditions set into hydrogenation reactor,
In Pd-C beds, react with H2 and convert impurity insoluble in water in crude terephthalic acid
For material soluble in water.Then separate out slurry through Pyatyi crystallization, then solid-liquid separation, isolate
Solid eventually passes heat drying, is the PTA that final products purity is 99.9% after analysis is qualified, delivers to
Raw material of the downstream as polyester factory.
Chinese patent 201310367763.5 discloses a kind of method of purification of p-phthalic acid, using high temperature
High-pressure membrane platen press carries out purification processes to crude terephthalic acid siccative, it is not necessary to using alkali liquor, integrated agent etc.
Various chemical reagents；Chinese patent 96195921.5 disclose a kind of preparation method of pure terephthalic acid (PTA) and
Equipment, N- methylpyrrolidones are dissolved under high temperature by crude terephthalic acid filter cake, by reducing recrystallisation solvent
Solution temperature crystallizes purified terephthalic acid from the solution；Japan Patent 2005200402A discloses a kind of right
The manufacture method of phthalic acid, by heated up under elevated pressure by oxidation of p-xylene obtain it is thick to benzene
Dioctyl phthalate is dissolved in the water, and makes p-phthalic acid that partial crystallization to occur by being evaporated off under reduced pressure water；Deutsche Bundespatent
102012007675-A1 disclose it is a kind of impure TA is dissolved in organic solvent, carry out more than once
Crystallization stage, be precipitated PTA crystallization, then by solid-liquid separation by PTA crystallize with dissolving liquid
Separate.The one kind of Chinese patent 02158557.1 is with special solvent washing method primary purification crude terephthalic acid
(CTA) method, with by the mixed solvent configured to two benzene toluenes (PX), water and acetic acid, washing
The acetic acid slurry Jing of the p-phthalic acid of para-phthalic acid (pta) oxidation reactor institute processed output is aoxidized by PX
Crystallizing containing acetic acid and catalyst CTA obtained by solid-liquid separation.Again after water washing, mix directly with water
As the hydrorefined charging of p-phthalic acid.Without the operation such as p-phthalic acid and drying, storage,
And the shortcoming big with washing water consumption in the thick TA technologies of water washing proposed before overcoming；Chinese patent
201310194202.X discloses a kind of preparation method of p-phthalic acid (PTA), first to crude benzol
Dioctyl phthalate (CTA) is washed, ethanol is washed, again using the mixed solvent of dimethyl acetylamide and ethanol
Recrystallization is carried out to the p-phthalic acid after process, p-phthalic acid (PTA) is obtained.According in document
The production method great majority of the preparation of offer all possessed using high temperature, high pressure or both in the case of producer
Method, while needing in process of production using substantial amounts of water or organic solvent, this easily causes substantial amounts of useless
Water, pollutant.
The content of the invention
The purpose of the present invention is to replace original essence using one or more ORGANIC SOLVENT MIXTURES recrystallization
The hydrogenation reaction technological process of production of p-phthalic acid (PTA) refinement, in p-phthalic acid
(PTA) adopting in the technological process of production of refinement has crude terephthalic acid through one or more
After the dissolving of machine solvent mixture, after the technological process such as multistage repetition crystallization, filtration, dry, obtain
Obtain the p-phthalic acid (PTA) that purity is 99.98%.Solve hydrogenation unit equipment in height
Temperature, high pressure, inflammable and explosive working condition, while the dangerous technological process that can close down Hydrogen Unit sets
It is standby.
The purpose of the present invention can be reached by following measures：
A kind of manufacture method of p-phthalic acid, it comprises the steps：
A, one-level recrystallization：It is cooled to after crude terephthalic acid is dissolved in into solvent at 83～126 DEG C
23～67 DEG C are crystallized, and then filter and isolate 1 grade of filter cake and 1 grade of filtrate；Wherein one-level is tied again
Brilliant solvent is organic solvent or organic solvent and 2 grades of filtrate mixed solvents；
B, two grades of recrystallization：It is cooled to 23 after 1 grade of filter cake is dissolved in into solvent at 71～133 DEG C～
58 DEG C are crystallized, and then filter and isolate 2 grades of filter cakes and 2 grades of filtrates；Wherein two grades recrystallization are molten
Agent is organic solvent or 3 grades of filtrates；
C, three-level recrystallization：It is cooled to 26 after 2 grades of filter cakes are dissolved in into solvent at 81～146 DEG C～
66 DEG C are crystallized, and then filter and isolate 3 grades of filter cakes and 3 grades of filtrates；Wherein three-level recrystallization is molten
Agent is organic solvent or 4 grades of filtrates；
D, level Four recrystallization：It is cooled to 27 after 3 grades of filter cakes are dissolved in into solvent at 73～131 DEG C～
63 DEG C are crystallized, and then filter and isolate 4 grades of filter cakes and 4 grades of filtrates；Level Four recrystallization solvent is
Organic solvent, 1 grade of filtrate Jing after dehydration or other filtrates；
E, washing and drying：To be dried after 4 grades of filter cake washings, obtain p-phthalic acid.
Further, this method also includes Pyatyi recrystallization or Pyatyi recrystallization and six grades of recrystallization, so
To be dried after the washing of afterbody filter cake again afterwards, wherein
Pyatyi recrystallization is：33 ± 5 DEG C are cooled to after 4 grades of filter cakes are dissolved in into solvent at 125 ± 5 DEG C to enter
Row crystallization, then filters and isolates 5 grades of filter cakes and 5 grades of filtrates, and Pyatyi recrystallization solvent is organic molten
Agent, 1 grade of filtrate Jing after dehydration or 6 grades of filtrates (if six grades of recrystallization systems)；
Six grades of recrystallization are：36 ± 5 DEG C are cooled to after 5 grades of filter cakes are dissolved in into solvent at 130 ± 5 DEG C to enter
Row crystallization, then filters and isolates 6 grades of filter cakes and 6 grades of filtrates, and six grades of recrystallization solvents are organic molten
Agent or 1 grade of filtrate Jing after dehydration.
The present invention can pass through 4-6 level recrystallization, you can in p-phthalic acid (PTA) refinement
It is middle without hydrogenation reaction in the case of, obtain purity be 99.98% p-phthalic acid (PTA).Wherein
The organic solvent is in pyridine, dimethyl acetylamide, dimethylformamide, n-butyl alcohol, isobutanol
One or more, the one kind or several being preferably selected from pyridine, dimethyl acetylamide, dimethylformamide
Kind.
The present invention is mixed in dispensing blending tank by traditional xylol, acetic acid, cobalt manganese bromine catalyst
After conjunction, oxidation reactor is sent into, it is thick right that xylol carries out reaction generation with air in oxidation reactor
Phthalic acid (thick TA), is processed with crude terephthalic acid (thick TA) as raw material.Slightly to benzene two
The quality purity of formic acid is generally 99.5～99.7%, particularly relates to the crude terephthalic acid of 99.7% purity.
In a kind of preferred version, the solution temperature of one-level recrystallization is 100 ± 5 DEG C, and crystallization temperature is
32±5℃。
In a kind of preferred version, the solution temperature of two grades of recrystallization is 105 ± 5 DEG C, and crystallization temperature is
28±5℃。
In a kind of preferred version, the solution temperature of three-level recrystallization is 110 ± 5 DEG C, and crystallization temperature is
31±5℃。
In a kind of preferred version, the solution temperature of level Four recrystallization is 120 ± 5 DEG C, and crystallization temperature is
35±5℃.Wherein level Four recrystallization solvent be organic solvent, Jing dehydration after 1 grade of filtrate or other filtrates,
For example when there is Pyatyi recrystallization, level Four recrystallization solvent here may also be employed 5 grades of filtrates；
In a kind of preferred version, in first order recrystallization, the matter of organic solvent and crude terephthalic acid
Amount is than being 5.5 ± 0.2：1.In the recrystallization system of other grades, lysate is 3-6 with the mass ratio of filter cake：
In the range of 1.
In a kind of preferred version, in recrystallization processes at different levels, normal pressure, the time of staying of crystallization is 30 ± 10
Minute, now the filter cake of crystallizer slurry/(filter cake+filtrate) can keep preferably process 30% ± 2%
Ability.
A kind of concrete processing scheme of the present invention, comprises the steps：
Xylol carries out reacting the crude terephthalic acid (thick TA) of generation with air in oxidation reactor,
First order dissolving tank is gone to carry out dissolving 1, lysate is the dehydration at follow-up the 2nd grade mother solution and dehydrating tower bottom
Organic solvent, dissolving tank temperature is set to 83～126 DEG C, normal pressure, and 23～67 DEG C of crystallizations are cooled to after dissolving
1, after go single filter machine filter, filtrate be 1 grade of mother solution, in filter cake add 3rd level mother solution after dissolve,
Be warming up to again 71～133 DEG C dissolving 2, be then cooled to 23～58 DEG C crystallization 2, after go cascade filtration machine mistake
Filter, filtrate is 2 grades of mother solutions, adds the dissolving of the 4th grade of mother solution in filter cake, then be warming up to 81～146 DEG C it is molten
Solution 3, be then cooled to 26～66 DEG C crystallization 3, after go three-stage filtration machine filter, filtrate be 3 grades of mother solutions,
Filter cake add with liquid, be subsequently to distill the lime set for obtaining, after be warming up to again 73～131 DEG C dissolve 4, so
After be cooled to 27～63 DEG C crystallization 4, after go level Four filter filter, filtrate be 4 grades of mother solutions, filter cake use
Water beating after, go filter to filter, filter cake go product drying machine dry fine terephthalic acid products.One
Level mother liquid filtrate removes dehydrating tower, and dehydrating tower top is water, and one or more are organic for dehydration for dehydration tower bottom
The mixture of solvent, returns in system and reuses.
Beneficial effects of the present invention：
(1) original p-phthalic acid (PTA) is replaced using one or more ORGANIC SOLVENT MIXTURES
The hydrogenation reaction technological process of production of refinement.
(2) thick terephthaldehyde is adopted in the technological process of production of p-phthalic acid (PTA) refinement
Acid repeats crystallization, filters, is dried after one or more ORGANIC SOLVENT MIXTURES dissolvings, through multistage
After technological process, the p-phthalic acid (PTA) that purity is 99.98% is obtained.
Description of the drawings
Fig. 1 is a kind of process flow diagram of the present invention.
Specific embodiment
Specifically handling process is：Xylol carries out reacting the thick right of generation with air in oxidation reactor
Phthalic acid (thick TA), goes first order dissolving tank to carry out dissolving 1, and lysate is follow-up the 2nd grade mother
Liquid and the dehydrated organic solvent at dehydrating tower bottom, dissolving tank temperature is set to 83～126 DEG C, normal pressure, after dissolving
Be cooled to 23～67 DEG C crystallization 1, after go single filter machine filter, filtrate be 1 grade of mother solution, in filter cake plus
To enter dissolved after 3rd level mother solution, then be warming up to 71～133 DEG C of dissolvings 2, be then cooled to 23～58 DEG C of knots
Brilliant 2, after go cascade filtration machine to filter, filtrate is 2 grades of mother solutions, and the 4th grade of mother solution dissolving is added in filter cake,
Be warming up to again 81～146 DEG C dissolving 3, be then cooled to 26～66 DEG C crystallization 3, after go three-stage filtration machine mistake
Filter, filtrate be 3 grades of mother solutions, filter cake add with liquid, be subsequently to distill the lime set for obtaining, after heat up again
To 73～131 DEG C dissolving 4, be then cooled to 27～63 DEG C crystallization 4, after go level Four filter filter, filter
Liquid is 4 grades of mother solutions, after filter cake is with water beating, goes filter to filter, and filter cake goes the product drying machine dry
Fine terephthalic acid products.
Embodiment 1
In this example, with a kind of pyridine as organic solvent, fresh solvent and raw material wherein in first order recrystallization
Mass ratio be set in 5.5 ± 0.2, first order crystallization temperature at 32 ± 1 DEG C, first order solution temperature is set to
100 ± 1 DEG C, normal pressure, the time of staying is about 30 ± 2 minutes, now the filter cake of crystallizer slurry/(filter cake+filter
Liquid) 30% ± 2%, preferable disposal ability is kept, the thick TA that quality purity is 99.7% is processed, finally
The purity for obtaining is 99.982% PTA products.
Embodiment 2
With identical with the technological process in embodiment 1, tested according to the same manner as in Example 1.
In this example, with dimethyl acetylamide as organic solvent, fresh solvent and raw material wherein in first order recrystallization
Mass ratio be set in 5.5 ± 0.2, first order crystallization temperature at 32 ± 1 DEG C, first order solution temperature is set to
100 ± 1 DEG C, normal pressure, the time of staying is about 30 ± 2 minutes, now the filter cake of crystallizer slurry/(filter cake+filter
Liquid) 30% ± 2%, preferable disposal ability is kept, the purity for finally giving is 99.982% PTA products.
Embodiment 3
With identical with the technological process in embodiment 1, tested according to the same manner as in Example 1.
In this example, tested with 4 grades of recrystallization methods, 4 grades of repetition crystallization solution temperatures are followed successively by：100±1℃、
105±1℃、110±1℃、120±1℃；Crystallization temperature is followed successively by：32±1℃、28±1℃、31±1℃、
35 ± 1 DEG C, normal pressure, the time of staying is about 30 ± 2 minutes, now the filter cake of crystallizer slurry/(filter cake+filter
Liquid) 30% ± 2%, preferable disposal ability is kept, the purity for finally giving is 99.984% PTA products.
Embodiment 4
With identical with the technological process in embodiment 1 and embodiment 2, embodiment 3, by the He of embodiment 1
Same mode is tested in embodiment 2, embodiment 3.In this example, entered with 6 grades of recrystallization methods
Row experiment, 6 grades of repetition crystallization solution temperatures are followed successively by：100±1℃、105±1℃、110±1℃、120±1℃、
125±1℃、130±1℃；Crystallization temperature is followed successively by：32±1℃、28±1℃、31±1℃、35±1℃、
33 ± 1 DEG C, 36 ± 1 DEG C, normal pressure, the time of staying is about 30 ± 2 minutes, the now filter cake of crystallizer slurry/(filter
Cake+filtrate) 30% ± 2%, preferable disposal ability is kept, the purity for finally giving is 99.99% PTA
Product.
Comparative example is implemented
Comparative example 1：
In this example, the organic solvent N methyl pyrrolidones with outside the present invention carry out reality as a kind of organic solvent
Test, by dissolving crude terephthalic acid (thick TA), experimental technique flow process and work with N methyl pyrrolidones
Skill parameter is identical with the present invention, i.e., crystallized, filtered, being dried etc. after technological process using 4 grades of repetition,
Experiment finally can only obtain quality purity less than 99.5%PTA products, can not reach the present invention
99.98% p-phthalic acid (PTA).
Comparative example 2：
In this example, with the present invention with pyridine, dimethyl acetylamide, dimethylformamide, n-butyl alcohol, different
Based on one or more organic solvents in butanol, experimental technique flow process is less than 3 repetition crystallizations and work
Skill parameter, experiment finally can only obtain quality purity less than 98.5%PTA products, can not reach this
The p-phthalic acid (PTA) of invention 99.98%.
Claims (10)
1. a kind of manufacture method of p-phthalic acid, it is characterised in that comprise the steps：
A, one-level recrystallization：It is cooled to after crude terephthalic acid is dissolved in into solvent at 83～126 DEG C
23～67 DEG C are crystallized, and then filter and isolate 1 grade of filter cake and 1 grade of filtrate；Wherein one-level is tied again
Lysate is organic solvent or organic solvent and 2 grades of filtrate mixed solvents in crystal system；
B, two grades of recrystallization：It is cooled to 23 after 1 grade of filter cake is dissolved in into solvent at 71～133 DEG C～
58 DEG C are crystallized, and then filter and isolate 2 grades of filter cakes and 2 grades of filtrates；Wherein two grades recrystallizers
Lysate is organic solvent or 3 grades of filtrates in system；
C, three-level recrystallization：It is cooled to 26 after 2 grades of filter cakes are dissolved in into solvent at 81～146 DEG C～
66 DEG C are crystallized, and then filter and isolate 3 grades of filter cakes and 3 grades of filtrates；Wherein three-level recrystallizer
Lysate organic solvent or 4 grades of filtrates in system；
D, level Four recrystallization：It is cooled to 27 after 3 grades of filter cakes are dissolved in into solvent at 73～131 DEG C～
63 DEG C are crystallized, and then filter and isolate 4 grades of filter cakes and 4 grades of filtrates；Wherein level Four recrystallization is molten
Agent is organic solvent, 1 grade of filtrate Jing after dehydration or other filtrates；
E, washing and drying：To be dried after 4 grades of filter cake washings, obtain p-phthalic acid；
Wherein described organic solvent selected from pyridine, dimethyl acetylamide, dimethylformamide, n-butyl alcohol,
One or more in isobutanol.
2. method according to claim 1, it is characterised in that the method also includes Pyatyi recrystallization or five
Level recrystallization and six grades of recrystallization, then will be dried again after the washing of afterbody filter cake, wherein
Pyatyi recrystallization is：33 ± 5 DEG C are cooled to after 4 grades of filter cakes are dissolved in into solvent at 125 ± 5 DEG C to enter
Row crystallization, then filters and isolates 5 grades of filter cakes and 5 grades of filtrates, lysate in Pyatyi recrystallization system
Organic solvent, 1 grade of filtrate Jing after dehydration or 6 grades of filtrates；
Six grades of recrystallization are：36 ± 5 DEG C are cooled to after 5 grades of filter cakes are dissolved in into solvent at 130 ± 5 DEG C to enter
Row crystallization, then filters and isolates 6 grades of filter cakes and 6 grades of filtrates, lysate in six grades of recrystallization systems
Organic solvent or 1 grade of filtrate Jing after dehydration.
3. method according to claim 1, it is characterised in that the solution temperature of one-level recrystallization is
100 ± 5 DEG C, crystallization temperature is 32 ± 5 DEG C.
4. method according to claim 1, it is characterised in that the solution temperature of two grades of recrystallization is
105 ± 5 DEG C, crystallization temperature is 28 ± 5 DEG C.
5. method according to claim 1, it is characterised in that the solution temperature of three-level recrystallization is
110 ± 5 DEG C, crystallization temperature is 31 ± 5 DEG C.
6. method according to claim 1, it is characterised in that the solution temperature of level Four recrystallization is
120 ± 5 DEG C, crystallization temperature is 35 ± 5 DEG C.
7. method according to claim 1, it is characterised in that in first order recrystallization, organic solvent with
The mass ratio of crude terephthalic acid is 5.5 ± 0.2：1.
8. method according to claim 1 and 2, it is characterised in that in recrystallization processes at different levels, crystallization
The time of staying is 30 ± 10 minutes.
9. method according to claim 1 and 2, it is characterised in that the organic solvent selected from pyridine, two
One or more in methylacetamide, dimethylformamide.
10. method according to claim 1 and 2, it is characterised in that the quality purity of crude terephthalic acid
For 99.5～99.7%, the quality purity of the p-phthalic acid is more than 99.98%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1314878A (en) * | 1998-05-29 | 2001-09-26 | Hfm国际公司 | Method for preparing purified terephthalic acid and isophthalic acid from mixed xylenes |
| CN102234226A (en) * | 2010-09-02 | 2011-11-09 | 华东理工大学 | Method for recovering and purifying terephthalic acid in alkali-minimization waste liquor |
| CN103387300A (en) * | 2013-07-23 | 2013-11-13 | 苏州英特工业水处理工程有限公司 | Recovery method using membranes for terephthalic acid and sodium hydroxide from printing and dyeing alkali-reduced waste water |
-
2015
- 2015-10-09 CN CN201510650707.1A patent/CN106565466A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1314878A (en) * | 1998-05-29 | 2001-09-26 | Hfm国际公司 | Method for preparing purified terephthalic acid and isophthalic acid from mixed xylenes |
| CN102234226A (en) * | 2010-09-02 | 2011-11-09 | 华东理工大学 | Method for recovering and purifying terephthalic acid in alkali-minimization waste liquor |
| CN103387300A (en) * | 2013-07-23 | 2013-11-13 | 苏州英特工业水处理工程有限公司 | Recovery method using membranes for terephthalic acid and sodium hydroxide from printing and dyeing alkali-reduced waste water |
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Application publication date: 20170419 |