CN1445266A - Method for recycling colvent utilized in producting polyphenylene sulfide - Google Patents
Method for recycling colvent utilized in producting polyphenylene sulfide Download PDFInfo
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- CN1445266A CN1445266A CN 02113483 CN02113483A CN1445266A CN 1445266 A CN1445266 A CN 1445266A CN 02113483 CN02113483 CN 02113483 CN 02113483 A CN02113483 A CN 02113483A CN 1445266 A CN1445266 A CN 1445266A
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Abstract
A process for recovering the solvent used in preparing polyphenyl thioether includes such steps as using the washing water of filter cake as extractant to extract the solvent from filter cake, mixing the extract with the dewatered liquid and/or filtrate generated in production of polyphenyl thioether, adding treating agent to separate out assistant, and dual-tower rectifying to obtain refined NMP solvent. Its advantages are high recovery rate increased by 10%, high content of NMP (99.6% or more), and low cost.
Description
Technical field
The invention belongs to a kind of recovery method that reclaims colvent utilized in producting polyphenylene sulfide.It is particularly a kind of to being used to produce the solvent N of polyphenylene sulfide that---methyl---2---is given a tongue-lashing pyrrolidone, the mixed solution that contains this solvent that produces from each of polyphenylene sulfide production process it is reclaimed, so that the method for Li Yonging once more in stage.
Background technology
In the polyphenylene sulfide production of (being called for short PPS), adopting dichlorobenzene and water cure sodium is arranged is raw material, and alkali metal chloride is a catalyzer, N, and---methyl---2---is given a tongue-lashing pyrrolidone (being called for short NMP) and is made solvent, after the sodium sulphite dehydration, thereby the pressurization polycondensation makes object.Employed NMP is a kind of solvent that prices are rather stiff in this production technique, in order to reduce production costs, it must be recycled.The mixed solution that contains nmp solvent that is produced in the polyphenylene sulfide production process mainly comprises: the dehydration liquid that the dehydration of first stage cure sodium is produced; Separate reacted mixture after the subordinate phase polyphenylene sulfide polyreaction, the filtrate that is produced; The 3rd is the extraction liquid (when adopting Sodium sulphate anhydrous, 99min, can not having dehydration liquid) with solvent produced in the extraction agent extraction polymkeric substance filter cake.Outside in these mixed solutions, desolventizing, also contain just like impurity such as unreacted monomer, oligopolymer, salt, water, solvent products of metamorphism, polyreaction auxiliary agents.To from these mixed solutions, high-level efficiency, high quality reclaim nmp solvent, must remove above-mentioned impurity.To this, open clear 61 the Japanese documentation spy---disclose in 53324 and american documentation literature UA3,9341,664 a kind of with the reaction mixture after the polyphenylene sulfide polyreaction, adiabatic flash makes nmp solvent volatilization under hot conditions, thereby with the method for its recovery.Though this method has the short characteristics of flow process, exists: need set up special flash drum, adopt special alr mode, evaporation mode and thermal source etc. in the flash drum domestic demand, its cost of equipment height, power consumption is big, cost recovery is higher; And can not evaporate owing in groove, also retain a large amount of solvents in the raffinate, thereby also have defectives such as the rate of recovery is also lower.At Japanese documentation 62---253, what 624 disclosed and the applicant also once adopted is a kind of by rectifying tower rectifying mixed solution, obtain distillation solvent and rectifying bottoms, again lower concentration residue in the tower is sent in the vaporizer and concentrated the wherein residual solvent of further recovery.But this method exists: the one, because oligopolymer that contains in the mixed solution and the solidss such as polyreaction auxiliary agent that are dissolved in solvent cause that easily rectifying tower blocks up tower, influence the stability of solvent recuperation; The 2nd, form a kind of mud shape high boiling point solid matter because of containing polyreaction auxiliary agent (as LiCl etc.) this analog assistant and solvent NMP in the mixed solution, this material remains in the raffinate and can not get rid of, in in solvent can not evaporate to dryness, thereby still have the lower defective of solvent recovering yield.In addition, a kind of employing ethanol is also disclosed as extraction agent, with the NMP in the extraction mixed solution in European patent document EP0386641A1.But this method rate of recovery only about 70 percent, and also need set up and be used to reclaim the alcoholic acid rectifying tower and need to adopt chilled brine do refrigerant; Ethanol belongs to inflammable, explosive material in addition, and all electrical equipments of workshop all need adopt explosion-proof equipment, and therefore, facility investment is bigger, to the performance and the operating environment requirement " harshness " of electrical equipment.
Thereby the above-mentioned background technology exists: 1, when rectifying,, easily stop up rectifying tower because of containing the existence of oligopolymer and polyreaction auxiliary agent in the mixed solution, and the difficult recovery of the solvent in the debris, thereby influence solvent recuperation efficient; 2, adopt ethanol to make extraction agent to the explosion-proof of operating environment and electrical equipment defective such as have relatively high expectations.
Summary of the invention
The objective of the invention is on basis of background technology, improve the recovery method of a kind of colvent utilized in producting polyphenylene sulfide of design, improve solvent recovering yield and quality to reach, the investment of reduction equipment reaches the requirement to equipment and production environment condition, and produce easyly, reliable, reduce the purposes such as cost recovery of solvent.
Solution of the present invention is that the wash water after employing is washed the filter cake after the polycondensation is made extraction agent, to extract the solvent NMP in the filter cake, the dehydration liquid that dehydration is produced to this extraction liquid and sodium sulphite is (when adopting Sodium sulphate anhydrous, 99min then, can there be this dehydration liquid), the mixed solution that filtrate after the polycondensation mixes is handled, be settled out the auxiliary agent of polyreaction, to eliminate the mud shape high boiling point affixture that auxiliary agent and nmp solvent form; And then the mixed solution after its filtration is sent into double tower carry out rectification under vacuum, thereby realize its purpose with the recovery nmp solvent.Therefore, the inventive method comprises:
A, collection mixed solution:
A, at first will be through the dehydration liquid after the sodium sulphite dehydration or/and after the polycondensation isolated filtrate import treatment tank (groove) respectively;
B, isolated filter cake after the polycondensation is washed with clear water, then with this washings as extraction agent, filter cake is carried out interrupted extraction, the solvent to the filter cake be lower than 1% (heavy per-cent) and after filtration extraction liquid;
C, with in the b gained extraction liquid input treatment tank (groove) with a in dehydration liquid or/and filtrate mixes, must mixed solution;
Auxiliary agent in B, the separation mixed solution: in A gained mixed solution, add carbonate or the volatile salt of Alkali-Metal Na or K, under alkaline condition, stir mixed evenly to precipitate, to isolate auxiliary agent and part lower-molecular substance; Add auxiliary agent in the amount of carbonate and the solution mol ratio be 0.55～1.15: 1;
C, rectifying mixed solution are to reclaim nmp solvent;
A, at first will send into dehydration tower by the mixed solution that B obtains, be-0.88 in vacuum tightness～-condition of 0.095Mpa, 25 ℃～90 ℃ of tower top temperatures, 45 ℃～110 ℃ of tower still temperature under the rectification under vacuum dehydration; Tower bottoms after the dehydration gets thick nmp solvent behind cooling, filtering separation salinity wherein, then it is sent into solvent recovery tower;
B, be-0.09 in recovery tower vacuum tightness～-0.098Mpa, 90 ℃～130 ℃ of tower top temperatures, 120 ℃～150 ℃ conditions of tower still temperature under rectification under vacuum, to reclaim refining nmp solvent.
In order to prevent that the mixed solution after the sepa-ration aid from because of storage period is long hydrolysis taking place, add hydrochloric acid in the mixed solution after sepa-ration aid, its potential of hydrogen is transferred to neutrality.During auxiliary agent in separating mixed solution,, mixed solution can be heated to 35 ℃～70 ℃ in order to improve the solubleness of carbonate in mixed solution.And described interrupted extraction is the extraction of adverse current gap.
The present invention adopts alcohol to make the disadvantage of existing equipment of extraction agent and Working environment requirement harshness owing to adopt wash water as the extraction agent of nmp solvent in the filter cake and adopt the extraction of adverse current gap thereby overcome; Before rectifying, remove auxiliary agent and part lower-molecular substance in the mixed solution earlier, and employing two-tower rectification technology, improved the rate of recovery and the quality of nmp solvent again effectively, its rate of recovery can improve about 10 than background technology, and NMP content can reach more than 99.6% in the solvent.Therefore, the present invention has the solvent recovering yield height, quality is good, and extracting process is easy, reliable, to equipment and the low characteristics such as cost recovery that also can effectively reduce solvent of production environment conditional request.
Embodiment
Adopting santochlor and water sodium-chlor being arranged is that raw material, alkali metal chloride are auxiliary agent (catalyzer), N---methyl---2---pyrrolidone (being NMP) is made solvent, produces with pressurization in the technology of polyphenylene sulfide:
A, get the dehydration liquid 300kg after the sodium sulphite dehydration, the mixture filtrate 470kg after the polycondensation, make extraction agent, filter cake adverse current gap extraction 3 times nmp solvent content to the filter cake is lower than 1% back gained extraction liquid 500kg with last circulation filter cake wash water; All import and form mixed solution in the treatment tank;
B, add the industrial sodium carbonate 50kg of purity 〉=98% and mixed solution be heated to 50 ℃ to mixed solution and stir, with auxiliary agent with LiCO
3Form be settled out, cutting out partial lower-molecular substance simultaneously, mixed solution 1210kg, contain NMP63.1% in the mixed solution; The mol ratio of yellow soda ash that present embodiment adds and auxiliary agent is 1.03: 1;
C, rectifying mixed solution are to reclaim nmp solvent;
A, will at first import dehydration tower through the mixed solution after isolating auxiliary agent and part lower-molecular substance, under vacuum tightness-0.09MPa, 30 ℃～80 ℃ of tower top temperatures, 50 ℃～100 ℃ conditions of tower still temperature, fractionation water outlet 430kg, again the tower bottoms centrifugation is gone out behind the salinity thick nmp solvent; And send into the solvent recovery tower rectification process;
The thick nmp solvent of b, input is-0.095Mpa, 100 ℃～120 ℃ of tower top temperatures that rectifying goes out nmp solvent 756kg under the condition that tower still temperature is 125 ℃～140 ℃, bottom product 22kg (storing reason elsewhere) in vacuum tightness.Present embodiment solvent recovering rate 95.03%, the purity of solvent NMP are 99.67%.
Claims (4)
1, a kind of recovery method of colvent utilized in producting polyphenylene sulfide is characterized in that this method comprises:
A, collection mixed solution:
A, at first will be through the dehydration liquid after the sodium sulphite dehydration or/and after the polycondensation isolated filtrate import treatment tank respectively;
B, isolated filter cake after the polycondensation is washed with clear water, then with this washings as extraction agent, the weight percent that filter cake is carried out the solvent of interrupted extraction to the filter cake is lower than 1%, and after filtration extraction liquid;
C, with in the b gained extraction liquid input treatment tank with a in dehydration liquid or/and filtrate mixes, must mixed solution;
Auxiliary agent in B, the separation mixed solution: in A gained mixed solution, add carbonate or the volatile salt of Alkali-Metal Na or K, under alkaline condition, stir mixed evenly to precipitate, to isolate auxiliary agent and part lower-molecular substance; Add auxiliary agent in the amount of carbonate and the solution mol ratio be 0.55～1.15: 1;
C, rectifying mixed solution are to reclaim nmp solvent;
A, at first will send into dehydration tower by the mixed solution that B obtains, be-0.88 in vacuum tightness～-condition of 0.095Mpa, 25 ℃～90 ℃ of tower top temperatures, 45 ℃～110 ℃ of tower still temperature under the rectification under vacuum dehydration; Tower bottoms after the dehydration gets thick nmp solvent behind cooling, filtering separation salinity wherein, then it is sent into solvent recovery tower;
B, be-0.09 in recovery tower vacuum tightness～-0.098Mpa, 90 ℃～130 ℃ of tower top temperatures, 120 ℃～150 ℃ conditions of tower still temperature under rectification under vacuum, to reclaim refining nmp solvent.
2, press the recovery method of the described colvent utilized in producting polyphenylene sulfide of claim 1; It is characterized in that adding hydrochloric acid in the mixed solution after sepa-ration aid, its potential of hydrogen is transferred to neutrality.
3, press the recovery method of the described colvent utilized in producting polyphenylene sulfide of claim 1; When it is characterized in that the auxiliary agent in separating mixed solution,, mixed solution can be heated to 35 ℃～70 ℃ in order to improve the solubleness of carbonate in mixed solution.
4, press the recovery method of the described colvent utilized in producting polyphenylene sulfide of claim 1; It is characterized in that described interrupted extraction is the extraction of adverse current gap.
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| CN101805456A (en) * | 2010-03-16 | 2010-08-18 | 苏州兆达特纤科技有限公司 | Method for reclaiming solvent in poly(p-phenytene terephthalamide)resin production |
| CN101205298B (en) * | 2006-12-20 | 2011-05-11 | 自贡鸿鹤化工股份有限公司 | Method for recovering distillation residual liquid of polyphenylene sulfide resin synthesis by compression process |
| CN101289548B (en) * | 2007-04-16 | 2011-11-30 | 常熟市贝斯特皮革有限公司 | Novel method for recovering solvent for polymerization of poly(p-phenytene terephthalamide) |
| CN102352054A (en) * | 2011-08-11 | 2012-02-15 | 深圳市宝力特科技有限公司 | Recovery process of solvent in polyphenylene sulfide resin production process |
| CN103242213A (en) * | 2013-04-22 | 2013-08-14 | 中国石油化工股份有限公司 | Method for dehydrating and desalting solution with salt, water and N-methyl-pyrrolidone generated in synthetic process of polyphenylene sulfide |
| CN103788400A (en) * | 2014-01-15 | 2014-05-14 | 黄斌 | Method for treating failed waste liquid in polyphenylene sulfide production |
| CN103936646A (en) * | 2013-01-17 | 2014-07-23 | 惠州比亚迪电池有限公司 | Recovery method of N-methylpyrrolidone |
| CN104447480A (en) * | 2014-11-06 | 2015-03-25 | 中国科学院过程工程研究所 | Continuous recycling method of NMP (N-methyl pyrrolidone) solvent for polyphenylene sulfide production device |
| CN106366030A (en) * | 2016-10-12 | 2017-02-01 | 南京大学 | High-purity recycling process system of complex chemical waste liquid |
| CN106478481A (en) * | 2016-10-08 | 2017-03-08 | 南京大学 | Waste water ultra-pure separation and purification technique of methyl pyrrolidone containing N and paracide |
| CN106565956A (en) * | 2016-10-21 | 2017-04-19 | 天津科技大学 | Method for comprehensive recycling of by-product slurry in polyphenylene sulfide productive process |
| CN106565581A (en) * | 2016-10-21 | 2017-04-19 | 天津科技大学 | A method for comprehensive recovery and utilization of lithium containing mixed salts in a polyphenylene sulfide production process |
| CN107983393A (en) * | 2017-12-29 | 2018-05-04 | 内蒙古聚贤化工材料科技有限公司 | A kind of method that lithium chloride is recycled in the production for polyphenylene sulfide |
| CN110357802A (en) * | 2018-03-26 | 2019-10-22 | 中国石油化工股份有限公司 | Solvent recovery process in a kind of cleaning solution waste liquid producing p-aramid fiber |
| CN111286027A (en) * | 2020-02-13 | 2020-06-16 | 四川明道和化学新材料有限公司 | Production method of polyphenylene sulfide with low covalent bonding chlorine |
| CN111690166A (en) * | 2020-07-08 | 2020-09-22 | 四川明道和化学新材料有限公司 | Method for recovering polyphenylene sulfide synthetic solvent NMP |
| CN112940244A (en) * | 2019-12-11 | 2021-06-11 | 南通星辰合成材料有限公司 | Pretreatment method for polyphenylene oxide solvent recovery |
| CN113045470A (en) * | 2021-04-06 | 2021-06-29 | 山东智永化工产业技术研究院有限公司 | Method for recovering NMP in polyphenylene sulfide production process |
| CN115746302A (en) * | 2022-11-28 | 2023-03-07 | 宜宾学院 | Recovery process of materials in polyphenylene sulfide production process |
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| CN101205298B (en) * | 2006-12-20 | 2011-05-11 | 自贡鸿鹤化工股份有限公司 | Method for recovering distillation residual liquid of polyphenylene sulfide resin synthesis by compression process |
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| CN106565581B (en) * | 2016-10-21 | 2019-07-12 | 天津科技大学 | The comprehensive reutilization method of mixed salt containing lithium in a kind of polyphenylene sulfide production process |
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| CN111286027B (en) * | 2020-02-13 | 2022-06-10 | 四川明道和化学新材料有限公司 | Production method of polyphenylene sulfide with low covalent bonding chlorine |
| CN111286027A (en) * | 2020-02-13 | 2020-06-16 | 四川明道和化学新材料有限公司 | Production method of polyphenylene sulfide with low covalent bonding chlorine |
| CN111690166A (en) * | 2020-07-08 | 2020-09-22 | 四川明道和化学新材料有限公司 | Method for recovering polyphenylene sulfide synthetic solvent NMP |
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