CN104016847A - Method for removing acetic acid from terephthalic acid filter cake - Google Patents
Method for removing acetic acid from terephthalic acid filter cake Download PDFInfo
- Publication number
- CN104016847A CN104016847A CN201310066456.3A CN201310066456A CN104016847A CN 104016847 A CN104016847 A CN 104016847A CN 201310066456 A CN201310066456 A CN 201310066456A CN 104016847 A CN104016847 A CN 104016847A
- Authority
- CN
- China
- Prior art keywords
- washing
- terephthalic acid
- subarea
- acetic acid
- area
- 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.)
- Pending
Links
Classifications
-
- 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
- C07C51/47—Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption
Abstract
The invention relates to a method for removing acetic acid from a terephthalic acid filter cake, and mainly solves the problems of high energy consumption, complicated process, much equipment and high investment expenses of an oxidization section solid-liquid separation unit and a drying unit of a purified terephthalic acid (PTA) device in the prior art. Slurries which come from the terephthalic acid oxidization section and contain terephthalic acid crystals are introduced into a pressure rotary filter, and sequentially pass through a filter area, a washing area and a discharging area to obtain the terephthalic acid filter cake of which the content of acetic acid is lower than 0.1 percent by weight; the washing area has at least two stages of washing sub-areas; the rotation direction of the filter machine is rotated under the pressure, and washing solution of the last stage of washing sub-area is fresh water; besides a first stage of washing sub-area, the washed water in the later stage of washing sub-area is used as a washing solution of the previous washing sub-area; the washing solution of the first stage of washing sub-area is the acetic acid solution. According to the technical scheme, the problems are solved, and the method can be used for industrial production of terephthalic acid.
Description
Technical field
The present invention relates to a kind of method that removes acetic acid from terephthalic acid cake, particularly a kind of in PTA device oxidation section solid-liquid separation unit removes terephthalic acid cake the method for acetic acid.
Background technology
Pure terephthalic acid (PTA) can be used to production multiple polymers, comprises ethylene glycol terephthalate (PET).Typical technique of producing PET is the polycondensation of terephthalic acid and polyvalent alcohol.In order to make reaction product meet market demands, this esterification need to adopt pure terephthalic acid that purity is high as raw material.
The industrial production of terephthalic acid generally adopts p-Xylol liquid-phase oxidation technology, and the p-Xylol (PX) of take is raw material, and the acetic acid of take generates terephthalic acid (TA) as solvent carries out oxidizing reaction.At p-Xylol (PX), be oxidized in the process of terephthalic acid (TA), can produce by product 4-carboxyl benzaldehyde (4-CBA).At present industrial as disclosed in document US3584039, generally adopting in aqueous environment is the p-methylbenzoic acid (PT acid) that is more dissolved in water by the 4-CBA hydrogenation in thick TA, and then water rinses, and removes wherein remaining dissolving PT acid.The washings that contains PT acid is recovered or gets back to treatment unit for waste water.When residual PT acid concentration is only less than or equal to 200ppm in the pure terephthalic acid after processing, could be used for direct condensation and produces trevira.
The PTA industrial production flow process of main flow can be divided into oxidation section and refining workshop section at present.Oxidation section main purpose is that PX oxidation is generated to TA, and the byproduct of reaction being wherein mingled with in TA (as ritalin) content is higher, and the general address of gained intermediates is CTA(crude terephthalic acid).The solvent that this workshop section adopts is acetum, has very strong corrodibility.Refining workshop section main purpose is for being more dissolved in the p-methylbenzoic acid (PT acid) of water by oxidized byproduct 4-carboxyl benzaldehyde (4-CBA) hydrogenation containing in CTA in oxidation section, so that with TA crystal separation, obtain highly purified TA product (PTA), this workshop section adopts deionized water as solvent.So, at oxidation section, the components such as acetic acid and related by-products ritalin need to be removed, and be the required water of refining workshop section by solvent exchange.And in refining workshop section, be to remove byproduct PT acid.
In traditional PTA technical process, the TA slurry solid-liquid separation of oxidation section and refining workshop section all adopts two-stage separation scheme: Pressure Centrifuges+rotary vaccum filter.Be about to introduce Pressure Centrifuges from the slurry of crystallizer, be separated into filter cake and mother liquor; Filter cake is pulled an oar again, and to enter rotary vaccum filter after (oxidation section adopts acetum to pull an oar again, and refining workshop section adopts deionized water to pull an oar again) again separated; From rotary vaccum filter filter cake out, send into drying machine dry, obtain crystal product (oxidation section is intermediates CTA, and refining workshop section is the finished product PTA).
The solid-liquid separation flow process (Pressure Centrifuges+rotary vaccum filter) of traditional technology exists the shortcoming that process cost is high, flow process is complicated, number of devices is many and investment cost is high.Along with the raising of equipment manufacturing technology, PTA patent Shang He manufacturer roughly adopts two schemes to replace conventional process flow both at home and abroad: one, filter-press replaces Pressure Centrifuges and vacuum filter; Two, filter-press only replaces Pressure Centrifuges, retains vacuum filter.As patent < < reclaims pure terephthalic acid > > (number of patent application: 201010022748.3) just the solid-liquid separation flow process of refining workshop section is optimized, adopt pressure rotary filter to replace original Pressure Centrifuges, reduce operation of equipment expense, reduced quantity of wastewater effluent.
But, in the filter cake of oxidation section, carry oxide catalyst, only by washing, be difficult to remove.And oxidation section CTA filter cake is compared with the PTA filter cake of refining workshop section, it is thin that its filter cake particle is wanted, and filter cake viscosity is higher, and filter cake pressure drop is larger.In addition, due to the severe corrosive of acetic acid, these are all had higher requirement to equipment, not yet have the report that adopts filter-press at oxidation section at present.
Summary of the invention
Technical problem to be solved by this invention is oxidation section solid-liquid separation unit and drying unit energy consumption is high, flow process is complicated, number of devices is many, investment cost is high problem in prior art, and a kind of new method that removes acetic acid from terephthalic acid cake is provided.The method has the advantages that energy consumption is low, flow process is simple, number of devices is few and investment cost is low.
For solving the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of method that removes acetic acid from terephthalic acid cake, by coming from slurry terephthalic acid oxidation section, that contain terephthalic acid crystals, introduce pressure rotary filter, pass through successively filtrating area, washing section and discharge zone on pressure rotary filter rotary drum, obtain acetic acid content lower than the terephthalic acid cake of 0.1 % by weight; Wherein, in described slurry, terephthalic acid crystals content is 35～65 % by weight, and liquid is 80～100 % by weight acetums; Described washing section is divided at least two-stage subarea; In washing section, along the turning direction of pressure rotary filter, the washings in last step washing subarea is fresh water; Except first step washing subarea, the water after rear one-level washing subarea washing is as washing the washings in subarea above; The washings in the first step washing subarea concentration that is weight percentage is the acetum of 80～100 % by weight.
Preferably, the viscosity of described liquid slurry is 1.1～1.8 centipoises; The material of described pressure rotary filter is at least 316L stainless steel.
Preferably, described washing section is divided into 2～8 grades of subareas, and each area that washs subarea equates.
More preferably, described washing section is divided into 2～5 grades of subareas.
Preferably, except first step washing subarea, the water after rear one-level washing subarea washing washs the washings in subarea successively as previous stage.
More preferably, except first step washing subarea, after merging, the water after rear one-level washing subarea washing and fresh water be used as again the washings in previous stage washing subarea.
Preferably, between described pressure rotary filter filtrating area and washing section, be provided with predrying district.
In the inventive method, described washing section is divided into some grades of washing subareas.In washing section, adopt the mode washing leaching cake of countercurrent washing, along the turning direction of pressure rotary filter, the washings in last step washing subarea is fresh water, and except first step washing subarea, the washings after rear one-level washing subarea washing is as the washings in previous stage washing subarea.In order to remove the oxide catalyst carrying in filter cake, dense acetum washing leaching cake is used in first step washing subarea.In order to reduce washing amount of liquor, except adopting the mode washing leaching cake of countercurrent washing, preferably before pressure rotary filter washing section, set up the predrying filter cake in predrying district.
In the inventive method, described washing section preferred version is for being divided into 3～8 washing subareas, and each area that washs subarea equates.Except first step washing subarea, the washings in subarea is washed in the water outlet after rear one-level washing subarea washing successively as previous stage.But dense acetum washing is used in first step washing subarea, the washing water after rear one-level washing subarea washing can not be as the washing water in first step washing subarea.
Terephthalic acid cake after the washing of washing section is gone to discharge zone.Terephthalic acid cake water content is generally between 10～50 % by weight, and filter cake adopts nitrogen or steam blowback discharging, can use if desired the mechanical systems such as scraper plate to assist discharging.Filter cake after discharging is without dry, is sent to refining workshop section after directly using fresh water to pull an oar further to process again.
The fresh water that filter cake washing is used is generally deionized water.
The terephthalic acid cake liquid content that enters washing section on the impact of bath water amount significantly, reduces filter cake liquid content and can reduce washing water consumption, without pre-dried filter cake liquid content generally between 10～50 % by weight.The inventive method is preferably provided with predrying district between pressure rotary filter filtrating area and washing section, reduces filter cake liquid content, and adopts the mode washing leaching cake of countercurrent washing, further to save washing deionized water amount.
Adopt the inventive method, washing section is divided into 3～8 grades of washing subareas, and adopt the mode washing leaching cake of countercurrent washing.Compare with single-stage washing, can save washing and more than 30%, reach the object of the dehydration load that reduces running cost, reduces acetic acid dehydrating tower by deionized water amount, obtained good technique effect.
Accompanying drawing explanation
Fig. 1 is the inventive method schematic flow sheet, take 5 grades washing subareas be example.
In Fig. 1, 1 is filtrating area, 2 is predrying district, 3 is first step washing subarea, 4 is washing subarea, the second stage, 5 is third stage washing subarea, 6 is fourth stage washing subarea, 7 is level V washing subarea, 8 is discharge zone, 9 for coming from the slurry of crystallizer, 10 is filtrated stock, 11 is dry gas, 12 is wet tail gas, 13 is one-level wash filtrate, 14 is one-level washings (acetum), 15 is secondary wash filtrate, 16 is secondary washings (three grades of wash filtrates), 17 is three grades of washingss (level Four wash filtrates), 18 is level Four washings (Pyatyi wash filtrate), 19 is fresh water (Pyatyi washings), 20 is discharging air-flow, 21 is filter cake.
In Fig. 1, the slurry 9 that comes from crystallizer enters the filtrating area 1 of pressure rotary filter, is separated into terephthalic acid cake (liquid content is 10～50 % by weight) and filtrated stock 10.Along with the rotation of filter-press, terephthalic acid cake enters predrying district 2, and it is predrying that use nitrogen or steam (stream thigh 11) carry out filter cake, obtains filter cake and liquid-vapor mixture 12 that liquid content further declines.In flow process, predrying district is preferred version, and when pressure rotary filter is not established predrying district, the filter cake that comes from filtrating area is directly gone to washing section washing.Washing section is divided into 5 washing subareas, and each washing subarea area is identical.Fresh washing enters from level V washing subarea with deionized water 19.In order to remove the oxide catalyst carrying in filter cake, in first step washing subarea, use dense acetum 14 washing leaching cakes, the wash filtrate 13 in first step washing subarea is discharged separately and is not mixed discharge with final wash filtrate 15.Except first step washing subarea, the washings after rear one-level washing subarea washing is as the washings in previous stage washing subarea, and final wash filtrate 15 is discharged from washing subarea, the second stage.After the filter cake washing through multi-stage countercurrent leaves washing section, go to discharge zone 8 dischargings, filter cake adopts nitrogen or steam (stream thigh 20) blowback discharging, can use if desired the mechanical systems such as scraper plate to assist discharging.Filter cake 21 after discharging is without dry, is sent to refining workshop section after directly using fresh water to pull an oar further to process again.
Below by embodiment, the present invention is further elaborated.
Embodiment
[embodiment 1]
Adopt flow process shown in Fig. 1, come from slurry terephthalic acid oxidation section, that contain terephthalic acid crystals and enter filter-press filtration washing, wherein in slurry, terephthalic acid crystals content is 35 % by weight, and liquid is 90 % by weight acetums, and the viscosity of liquid slurry is 1.2cp.The material of pressure rotary filter is 316L stainless steel.
Filter-press washing sub-area division is 2～5 grades of washing subareas, do not establish predrying district, first step washing subarea adopts dense acetum (acetate concentration is 98 % by weight) washing, slurry 9 enters after pressure rotary filter, after filtration, the washing of dense acetic acid and the washing of deionized water multi-stage countercurrent, the filter cake acetic acid content in discharging is not higher than 0.1 % by weight.Deionized water consumption is as shown in table 1:
Table 1
[comparative example 1]
With embodiment 1, when washing subarea is only 1, when filter cake liquid content is 30 % by weight, its deionized water consumption is 6.5t/t TA filter cake (butt).
[embodiment 2]
With [embodiment 1], just between filtrating area and washing section, be provided with predrying district.Slurry 1 enters after pressure rotary filter, and after filtration, the washing of predrying, dense acetic acid and the washing of deionized water multi-stage countercurrent, the filter cake acetic acid content in discharging is not higher than 0.1 % by weight.Deionized water consumption is as shown in table 2:
Table 2
Claims (8)
1. a method that removes acetic acid from terephthalic acid cake, by coming from slurry terephthalic acid oxidation section, that contain terephthalic acid crystals, introduce pressure rotary filter, pass through successively filtrating area, washing section and discharge zone on pressure rotary filter rotary drum, obtain acetic acid content lower than the terephthalic acid cake of 0.1 % by weight; Wherein, in described slurry, terephthalic acid crystals content is 35～65 % by weight, and liquid is 80～100 % by weight acetums; Described washing section is divided at least two-stage subarea; In washing section, along the turning direction of pressure rotary filter, the washings in last step washing subarea is fresh water; Except first step washing subarea, the water after rear one-level washing subarea washing is as washing the washings in subarea above; The washings in the first step washing subarea concentration that is weight percentage is the acetum of 80～100 % by weight.
2. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, the viscosity that it is characterized in that described liquid slurry is 1.1～1.8 centipoises.
3. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, it is characterized in that described washing section is divided into 2～8 grades of subareas, each area that washs subarea equates.
4. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, it is characterized in that described washing section is divided into 2～5 grades of subareas.
5. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, it is characterized in that except first step washing subarea, the water after rear one-level washing subarea washing washs the washings in subarea successively as previous stage.
6. from terephthalic acid cake, remove according to claim 5 the method for acetic acid, it is characterized in that except first step washing subarea, after the water after rear one-level washing subarea washing and fresh water merge, be used as again the washings in previous stage washing subarea.
7. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, it is characterized in that being provided with between described pressure rotary filter filtrating area and washing section predrying district.
8. from terephthalic acid cake, remove according to claim 1 the method for acetic acid, it is characterized in that the material of described pressure rotary filter is at least 316L stainless steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310066456.3A CN104016847A (en) | 2013-03-01 | 2013-03-01 | Method for removing acetic acid from terephthalic acid filter cake |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310066456.3A CN104016847A (en) | 2013-03-01 | 2013-03-01 | Method for removing acetic acid from terephthalic acid filter cake |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104016847A true CN104016847A (en) | 2014-09-03 |
Family
ID=51433903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310066456.3A Pending CN104016847A (en) | 2013-03-01 | 2013-03-01 | Method for removing acetic acid from terephthalic acid filter cake |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104016847A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108623449A (en) * | 2017-03-22 | 2018-10-09 | 天华化工机械及自动化研究设计院有限公司 | The method of " two-stage three-step approach " CTA exchange of solvent |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1990449A (en) * | 2005-12-27 | 2007-07-04 | 艾博特(厦门)设备工程有限公司 | Process for isolating crude terephthalic acid(CTA) |
| CN102126945A (en) * | 2010-01-13 | 2011-07-20 | 中国石油化工股份有限公司 | Method for recycling purified terephthalic acid |
| CN102476994A (en) * | 2010-11-30 | 2012-05-30 | 天华化工机械及自动化研究设计院 | Method for filtering, washing and separating crude terephthalic acid by using oxidizing unit of fine terephthalic acid device |
-
2013
- 2013-03-01 CN CN201310066456.3A patent/CN104016847A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1990449A (en) * | 2005-12-27 | 2007-07-04 | 艾博特(厦门)设备工程有限公司 | Process for isolating crude terephthalic acid(CTA) |
| CN102126945A (en) * | 2010-01-13 | 2011-07-20 | 中国石油化工股份有限公司 | Method for recycling purified terephthalic acid |
| CN102476994A (en) * | 2010-11-30 | 2012-05-30 | 天华化工机械及自动化研究设计院 | Method for filtering, washing and separating crude terephthalic acid by using oxidizing unit of fine terephthalic acid device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108623449A (en) * | 2017-03-22 | 2018-10-09 | 天华化工机械及自动化研究设计院有限公司 | The method of " two-stage three-step approach " CTA exchange of solvent |
| EP3524588A4 (en) * | 2017-03-22 | 2020-06-10 | Tianhua Institute of Chemical Machinery and Automation Co., Ltd. | Cta solvent exchanging method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1910130B (en) | Process for production of a dried carboxylic acid cake suitable for use in polyester production | |
| CN101914013A (en) | Water-saving terephthalic acid production method | |
| TWI468385B (en) | Methods, processes, and systems for treating and purifying crude terephthalic acid and associated process streams | |
| CN103012120A (en) | Method for preparing terephthalic acid by oxidation refining process | |
| CN101941901B (en) | Method for recycling mother solid in PTA-refining wastewater | |
| CN201586429U (en) | Pressure rotary filter | |
| TW201811726A (en) | Method of producing high-purity terephthalic acid | |
| JPWO2002028499A1 (en) | Crystallization method | |
| CN113105056A (en) | Method for resource utilization of purified terephthalic acid wastewater | |
| CN104016847A (en) | Method for removing acetic acid from terephthalic acid filter cake | |
| CN109251139B (en) | PIA production method and production system adopting deep oxidation | |
| CN104853825A (en) | Generation of low-solids second mother liquor from terephthalic acid product filter | |
| CN105585212B (en) | A kind of PTA produces waste water method for reusing synthesized | |
| CN102126945A (en) | Method for recycling purified terephthalic acid | |
| EP2519492B1 (en) | Process and rotary pressure filtration apparatus for slurry separation of aromatic carboxylic acids | |
| WO2010032263A2 (en) | Process and equipment for recovery of valuable materials from terephthalic acid manufacture | |
| CN105056621A (en) | Novel CTA mother liquor recovery utilization system and recovery method | |
| EA038529B1 (en) | Method for removing impurities from crude terephthalic acid particles | |
| CN103030554B (en) | Method of solvent replacement for crude terephthalic acid oxidation slurry | |
| JP4643801B2 (en) | Dispersion medium replacement method and high purity terephthalic acid production method | |
| CN101745410B (en) | Method for recycling catalyst from waste water produced in purifying process of aromatic acids | |
| US9328051B2 (en) | Methods and apparatus for isolating dicarboxylic acid | |
| DE102004002962A1 (en) | Installation for preparing terephthalic acid, comprises oxidation reactor and horizontal decanter-centrifuge, for dewatering and purifying crude product | |
| CN204841193U (en) | Novel CTA mother liquor recycle system | |
| JP2005263653A (en) | Method for producing aromatic carboxylic 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 | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20140903 |