CN112940244B - Pretreatment method for polyphenylene oxide solvent recovery - Google Patents
Pretreatment method for polyphenylene oxide solvent recovery Download PDFInfo
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- CN112940244B CN112940244B CN201911268172.6A CN201911268172A CN112940244B CN 112940244 B CN112940244 B CN 112940244B CN 201911268172 A CN201911268172 A CN 201911268172A CN 112940244 B CN112940244 B CN 112940244B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
- C08G65/34—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from hydroxy compounds or their metallic derivatives
- C08G65/46—Post-polymerisation treatment, e.g. recovery, purification, drying
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
Abstract
The invention belongs to the technical field of polyphenylene ether solvent recovery, and particularly relates to a pretreatment method for polyphenylene ether solvent recovery. The pretreatment method for polyphenylene ether solvent recovery comprises the following steps: (1) detecting the water content in the polyphenylene ether solvent to be recovered; (2) When the water content reaches a target value, adding carbonate into the water, stirring, standing and filtering; (3) And (4) continuously heating and distilling the filtrate, and feeding the distilled fraction into a distillation tower for distillation and separation. By adopting the pretreatment method, copper, morpholine, methanol, toluene and the like in the mother liquor and the washing liquid can be effectively recovered, and pipelines and a distillation tower are prevented from being blocked, so that the subsequent organic solvent distillation recovery process is ensured to be smoothly carried out.
Description
Technical Field
The invention belongs to the technical field of polyphenylene ether solvent recovery, and particularly relates to a pretreatment method for polyphenylene ether solvent recovery.
Background
The synthesis method of the polyphenyl ether mainly comprises two methods, one is a precipitation method; the other is a solution method. Because the molecular weight distribution of the polyphenyl ether produced by the precipitation method is narrow, the effective components are concentrated, and the requirement can be met by using a small amount of polyphenyl ether in downstream modification, the precipitation method becomes the main synthetic method for industrially producing the polyphenyl ether at present.
The precipitation method is that 2, 6-dimethylphenol reacts with organic amine to generate a monovalent or divalent copper amine complex serving as a catalyst in an aromatic compound or an alcohol solvent by using monovalent copper salt or divalent copper halide salt to generate polyphenylene oxide; meanwhile, energy conservation and emission reduction are considered, and a large amount of organic solvent in the reaction mother liquor and the washing liquor is generally recycled and reused in the actual production.
However, in the actual production, after the polyphenylene ether is filtered or precipitated, the reaction mother liquor and the material for washing the polyphenylene ether usually contain residual unreacted 2, 6-dimethylphenol, a large amount of organic amine (such as morpholine), inorganic salt (such as cuprous bromide), copper-amine complex and the like. In the materials, inorganic salt is separated out along with the evaporation and recovery of a large amount of organic solvent, so that the distillation tower is blocked; 2, 6-dimethylphenol can generate quinone or low molecular weight polyphenyl ether under the action of a copper-amine complex catalyst and under the high-temperature oxygen-free condition, and forms copper hydroxide and cuprous oxide or cupric oxide with the copper-amine complex; when a large amount of the organic solvent is distilled off and recovered, the viscosity of these materials increases, and they adhere to the inside of the pipe to cause interruption of distillation.
Disclosure of Invention
In order to overcome the technical problems, the invention provides a pretreatment method for recovering a polyphenylene ether solvent. By adopting the pretreatment method, copper, morpholine, methanol, toluene and the like in the mother liquor and the washing liquid can be effectively recovered, and pipelines and a distillation tower are prevented from being blocked, so that the subsequent organic solvent distillation recovery process is ensured to be smoothly carried out. The method has the advantages of high solid-liquid separation speed, high copper removal rate and good fluidity of the residual liquid after distillation.
The pretreatment method for recovering the polyphenyl ether solvent comprises the following steps:
(1) Detecting that the water content in the polyphenyl ether solvent to be recovered reaches a target value;
(2) When the water content reaches a target value, adding carbonate into the water, stirring, standing and filtering;
(3) And (4) continuously heating and distilling the filtrate, and feeding the distilled fraction into a distillation tower for distillation and separation.
According to the invention, by controlling the water content in the polyphenyl ether solvent to be recovered, and utilizing the carbonate to react with the materials in the polyphenyl ether solvent to be recovered, basic copper carbonate and 2, 6-dimethyl sodium phenolate which are insoluble in water and the solvent are generated, and copper in the mother liquor and the washing liquor is removed by filtering, so that the blockage of a pipeline and a distillation tower is avoided, and the smooth operation of the subsequent organic solvent distillation recovery process is ensured.
According to some embodiments of the present invention, the polyphenylene ether solvent to be recovered is obtained by: mixing reaction mother liquor for synthesizing polyphenyl ether with washing liquid to form mixed liquid; and heating and distilling the mixed solution, feeding the distilled fraction into a distillation tower for distillation and separation, and obtaining distillation residual liquid which is the polyphenyl ether solvent to be recovered. The research shows that the toluene, the methanol and the morpholine in the mixed solution can be removed by heating and distilling, and the subsequent recovery of the polyphenyl ether solvent is facilitated. Wherein the mixed solution comprises the following components in parts by weight: 60-65 parts of methanol, 0.1-0.3 part of morpholine and 30-40 parts of toluene.
According to some embodiments of the present invention, in the step (1), the target value of the water content in the polyphenylene ether solvent to be recovered is 5 to 7% by mass. Research shows that when the moisture content in the polyphenylene ether solvent to be recovered reaches 5-7% by mass concentration, the reaction in the step (2) is more fully facilitated, and the precipitation is more thorough, so that the moisture content in the polyphenylene ether solvent to be recovered is strictly controlled, and when the target content is reached, the heating distillation is stopped, and the step (2) is carried out.
From the viewpoint of industrial production, sodium carbonate is preferred as the carbonate, but the practice of the present invention is not limited to sodium carbonate, and any carbonate which reacts with the materials in the raffinate to form basic copper carbonate which is poorly soluble in water and toluene methanol as will be understood by those skilled in the art can be used.
According to some embodiments of the present invention, in step (2), the molar ratio of the carbonate to copper in the polyphenylene ether solvent to be recovered is (1.2-1.5): 1. research shows that when the addition amount of the carbonate is too large, the caking is easy to occur; when the addition amount is too small, the solution is green and turbid, and no precipitation phenomenon exists.
According to some embodiments of the invention, in the step (2), the carbonate is added in the form of an aqueous solution of sodium carbonate with a mass concentration of 8-10%.
In research, the research also finds that if the proportion relation of the components in the polyphenyl ether solvent to be recovered is not appropriate, the precipitation effect is not ideal enough; in order to solve the problem, before the carbonate is added, the proportion relation of the components in the system is adjusted, and the generation of precipitation is more favorably promoted. Research shows that when the mass ratio of methanol to toluene in the polyphenylene ether solvent to be recovered is (61-62): (35-36), the precipitation effect was the best, and no scorched material was produced. Preferably, the adjustment of the ratio of the components can be realized by adding methanol and toluene.
In order to better recover the toluene and the methanol in the polyphenyl ether solvent, 2, 6-dimethylphenol rectification residual liquid or heavy oil is added into the filtrate before the heating distillation in the step (3), so that the materials can be prevented from generating coking in the distillation process, and the methanol and the toluene in the filtrate can be completely distilled out. The 2, 6-dimethylphenol rectification residual liquid is residual liquid remaining in a tower kettle after the rectification of the 2, 6-dimethylphenol in the process of synthesizing the polyphenylether by the precipitation method. Preferably, the mass fraction of the 2, 6-dimethylphenol rectification residual liquid or heavy oil added is 10-15%; research shows that excessive addition of 2, 6-dimethylphenol rectification residual liquid or heavy oil easily causes material waste, and excessive addition can cause pipeline blockage by subsequent distillation residues.
The reaction mother liquor and the washing liquid are reaction mother liquor obtained after polyphenylene ether is synthesized by adopting a precipitation method, and the washing liquid generated after polyphenylene ether is washed by adopting methanol with the mass concentration of more than 95% as a washing agent.
The precipitation method is that in poor solvent methanol and good solvent toluene, 2, 6-dimethylphenol reacts in the catalysis of a copper-amine complex to generate polyphenyl ether; wherein the copper-amine complex is a complex formed by copper bromide or cuprous bromide dissolved by hydrogen bromide (mass fraction of 48.5%) and morpholine.
The invention has the following beneficial effects:
the pretreatment method can efficiently recover copper, methylbenzene, methanol, morpholine and the like in the mother liquor and the washing liquid, thereby avoiding blockage of pipelines and a distillation tower and ensuring smooth operation of a subsequent organic solvent distillation recovery process; and simultaneously, the recovery pressure of the subsequent process is reduced.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
Example 1
This example provides a method for synthesizing polyphenylene ether by precipitation, comprising:
(1) Adding reaction liquid consisting of 280g of good solvent toluene of polyphenyl ether, 30g of poor solvent methanol, 3g (cuprous bromide and 48.5% hydrogen bromide are prepared into solution) and 9.45g of morpholine (amine compound) into a stirring kettle;
introducing oxygen-containing gas, and oxidatively coupling 150g of 2, 6-dimethylphenol;
the reaction was terminated with an aqueous solution containing 1.3g of citric acid as a complexing agent to obtain a reaction solution containing polyphenylene ether.
(2) The reaction solution containing polyphenylene ether was filtered, and the filter cake was washed with 450g of methanol having a mass concentration of more than 95%.
(3) Collecting the mother liquor and the washing liquid to obtain a mixed liquid. The mixture composition is shown in Table 1.
TABLE 1
| Water (W) | Methanol | Morpholine | Toluene | |
| Content% | 2.63 | 61.52 | 0.21 | 35.62 |
(4) Taking the mixed solution, and pumping the mixed solution into a 2000ml three-neck flask with a stirrer and a condenser by using a peristaltic pump; when the volume is about 1200ml, heating and distilling by using an electric heating jacket;
maintaining the liquid level in the three-neck flask constant at the feeding speed of the peristaltic pump, and allowing the distilled fraction to enter a distillation tower for distillation and separation to obtain methanol and toluene with higher purity;
when the water content in the distillation residual liquid reaches more than 7 percent, stopping heating, wherein the distilled liquid reaches 20000ml, the three-neck flask is clean, no wall-sticking coking substance appears in the flask, and pouring the distillation residual liquid for later use.
The distillate composition is shown in table 2.
TABLE 2
| Water (I) | Methanol | Morpholine | Toluene | |
| Content% | 7.00 | 62.04 | 0.14 | 31.41 |
Example 2
The embodiment provides a pretreatment method for polyphenylene ether solvent recovery, which comprises the following steps:
(1) The procedure of example 1 was followed.
(2) Taking 600g of distillation residual liquid, putting the distillation residual liquid into a beaker, additionally adding 248g of methanol and 162g of toluene, stirring uniformly, and then adding 54g of sodium carbonate aqueous solution with the mass concentration of 10%.
After stirring is stopped, the supernatant liquid is clear; and the precipitate formed in 1 minute dropped to one fifth of the total, observing that the beaker did not have any stickies.
Filtering rapidly (not more than 5 minutes) by using a Buchner funnel, collecting filtrate and adding the filtrate into a three-neck flask;
(3) 100g of 2, 6-dimethylphenol rectification raffinate was added to the filtrate, and distillation was carried out with stirring until the temperature reached 110 ℃ and heating was stopped. The flask was observed for the presence of no sticky wall coke.
Example 3
This example provides a pretreatment method for polyphenylene ether solvent recovery, comprising:
(1) The procedure of example 1 was repeated.
(2) Taking 600g of distillation residual liquid, and putting the distillation residual liquid into a beaker; 230g of methanol and 172g of toluene were added, and after stirring uniformly, 54g of an aqueous sodium carbonate solution having a mass concentration of 10% was added with stirring.
After stirring is stopped, the supernatant is clear; and the precipitate formed in 1 minute dropped to one fifth of the total, observing that the beaker did not have any stickies.
Filtering rapidly (not more than 5 minutes) by using a Buchner funnel, collecting filtrate and adding the filtrate into a three-neck flask;
(3) 100g of 2, 6-dimethylphenol rectification raffinate was added to the filtrate, and distillation was carried out with stirring until the temperature reached 110 ℃ and heating was stopped. The flask was observed for the presence of no sticky wall coke.
Example 4
The embodiment provides a pretreatment method for polyphenylene ether solvent recovery, which comprises the following steps:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 230g of methanol and 165g of toluene were added, and after stirring uniformly, 54g of an aqueous sodium carbonate solution having a mass concentration of 8% was added with stirring.
After stirring is stopped, the supernatant liquid is clear; and the precipitate formed in 1 minute dropped to one fifth of the total, observing that the beaker did not have any stickies.
Quickly filtering the mixture by using a Buchner funnel (not more than 5 minutes), and collecting filtrate to be added into a three-neck flask;
(3) 100g of 2, 6-dimethylphenol rectification raffinate was added to the filtrate, and distillation was carried out with stirring until the temperature reached 110 ℃ and heating was stopped. The flask was observed for the presence of no sticky wall coke.
Example 5
This example provides a pretreatment method for polyphenylene ether solvent recovery, comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 230g of methanol and 170g of toluene were added, and after stirring uniformly, 54g of an aqueous sodium carbonate solution having a mass concentration of 8% was added with stirring.
After stirring is stopped, the supernatant is clear; and the precipitate formed in 1 minute dropped to one fifth of the total, observing that the beaker did not have any stickies.
Quickly filtering the mixture by using a Buchner funnel (not more than 5 minutes), and collecting filtrate to be added into a three-neck flask;
(3) 150g of 2, 6-dimethylphenol rectification residue was added to the filtrate, and distillation was carried out with stirring. The temperature reached 120 ℃ and heating was stopped. No fouling of the flask occurred.
Example 6
This example provides a pretreatment method for polyphenylene ether solvent recovery, comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 248g of methanol and 162g of toluene were added, and after stirring uniformly, 54g of an aqueous sodium carbonate solution having a mass concentration of 10% was added with stirring.
After stirring is stopped, the supernatant liquid is clear; and the precipitate formed in 1 minute dropped to one fifth of the total, observing that the beaker did not have any stickies.
Filtering rapidly (not more than 5 minutes) by using a Buchner funnel, collecting filtrate and adding the filtrate into a three-neck flask;
(3) 150g of heavy oil was added to the filtrate, and distillation was carried out with stirring. The temperature reached 120 ℃ and heating was stopped. No fouling of the flask occurred.
Comparative experiment 1 (without methanol and toluene)
This example provides a pretreatment method for polyphenylene ether solvent recovery comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 54g of a 10% sodium carbonate aqueous solution was added thereto with stirring.
After stirring is stopped, the solution is green and turbid, and is placed for 2 hours without precipitation; the material was filtered through a buchner funnel at a slower rate for 3 hours and was not filtered.
Comparative experiment 2 (sodium carbonate added too much)
This example provides a pretreatment method for polyphenylene ether solvent recovery comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 248g of methanol and 162g of toluene are added, and after stirring uniformly, 70g of a sodium carbonate aqueous solution with a mass concentration of 10% is added dropwise with stirring.
After stirring is stopped, the supernatant liquid is clear; the precipitate formed in 1 minute dropped to one fifth of the total; but again stirred with the glass rod, a solid which precipitated adhered to the glass rod.
Comparative experiment 3 (sodium carbonate addition too little)
This example provides a pretreatment method for polyphenylene ether solvent recovery, comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 248g of methanol and 162g of toluene were added, and after stirring uniformly, 45g of sodium carbonate having a mass concentration of 10% was added with stirring.
After stirring is stopped, the solution is green and turbid, and is placed for 2 hours without precipitation; the precipitate was filtered through a buchner funnel at a slower rate for 3 hours and was not filtered.
Comparative experiment 4 (methanol only, no toluene)
This example provides a pretreatment method for polyphenylene ether solvent recovery comprising:
(1) The procedure of example 1 was repeated.
(2) 600g of distillation residue is taken and put into a beaker. 216g of methanol was added, and after stirring uniformly, 54g of a 10% by mass aqueous solution of sodium carbonate was added dropwise with stirring.
The addition was clear at the beginning and gradually cloudy, and finally a large suspension formed and the addition was stopped. After standing for 120 minutes, no complete sedimentation was clear.
The amounts of materials added and the processing conditions in the processes described in examples 2 to 6 and comparative experiments 1 to 5 are shown in Table 3.
TABLE 3
As can be seen from Table 3, after the pretreatment method of the invention is adopted, the solid-liquid separation speed is high, the copper removal rate is 99.8%, and the fluidity of the residual liquid after distillation is very good, so that the blockage of a pipeline and a distillation tower is avoided, and the smooth operation of the subsequent organic solvent distillation recovery process is ensured; and simultaneously, the recovery pressure of the subsequent process is reduced.
Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (5)
1. A pretreatment method for polyphenylene ether solvent recovery, characterized by comprising:
(1) Detecting the water content in the polyphenyl ether solvent to be recovered;
(2) When the water content reaches a target value, adding carbonate into the water, stirring, standing and filtering;
(3) Continuously heating and distilling the filtrate, and feeding the distilled fraction into a distillation tower for distillation and separation;
in the step (1), the target value of the water content in the polyphenylene ether solvent to be recovered is 5-7% by mass concentration;
in the step (2), the molar ratio of the carbonate to the copper in the polyphenylene ether solvent to be recovered is (1.2-1.5): 1;
in the step (2), before adding the carbonate, the mass ratio of methanol to toluene in the polyphenylene ether solvent to be recovered is adjusted to (61-62): (35-36);
adding 2, 6-dimethylphenol rectification residual liquid or heavy oil into the filtrate before the heating distillation in the step (3); the mass fraction of the 2, 6-dimethylphenol rectification residual liquid or heavy oil added is 10-15%.
2. The pretreatment method for solvent recovery of polyphenylene ether according to claim 1, wherein in step (2), the carbonate is selected from sodium carbonate.
3. The pretreatment method for solvent recovery of polyphenylene ether according to claim 1 or 2, wherein in step (2), the carbonate is added in the form of an aqueous solution of sodium carbonate having a mass concentration of 8 to 10%.
4. The pretreatment method for polyphenylene ether solvent recovery according to claim 1, wherein in the step (2), said adjustment is effected by adding toluene and methanol.
5. The pretreatment method for polyphenylene ether solvent recovery according to claim 1, characterized in that the polyphenylene ether solvent to be recovered is obtained by: mixing reaction mother liquor for synthesizing polyphenyl ether with washing liquid to form mixed liquid; heating and distilling the mixed solution, feeding the distilled fraction into a distillation tower for distillation and separation, and obtaining distillation residual liquid which is the polyphenyl ether solvent to be recovered;
the reaction mother liquor and the washing liquid respectively refer to the reaction mother liquor after polyphenylene ether is synthesized by adopting a precipitation method and the washing liquid generated after polyphenylene ether is washed by adopting methanol with the mass concentration of more than 95% as a washing agent.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6307010B1 (en) * | 1999-02-05 | 2001-10-23 | General Electric Company | Process for the manufacture of low molecular weight polyphenylene ether resins through redistribution |
| CN1345892A (en) * | 2000-09-30 | 2002-04-24 | 四川省华拓实业发展股份有限公司 | Technology for recovering dissolvent and catalyst in producing polyphenyl-thioether |
| CN1445266A (en) * | 2002-03-20 | 2003-10-01 | 自贡鸿鹤化工股份有限公司 | Method for recycling colvent utilized in producting polyphenylene sulfide |
| WO2014197458A1 (en) * | 2013-06-03 | 2014-12-11 | Polyone Corporation | Low molecular weight polyphenylene ether prepared without solvents |
| CN107236124A (en) * | 2016-03-28 | 2017-10-10 | 旭化成株式会社 | The manufacture method of polyphenylene oxide |
| CN108623433A (en) * | 2017-03-21 | 2018-10-09 | 南通星辰合成材料有限公司 | Inorganic saline and alkaline method and system in a kind of sedimentation separation polyphenyl ether residual liquid |
-
2019
- 2019-12-11 CN CN201911268172.6A patent/CN112940244B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6307010B1 (en) * | 1999-02-05 | 2001-10-23 | General Electric Company | Process for the manufacture of low molecular weight polyphenylene ether resins through redistribution |
| CN1345892A (en) * | 2000-09-30 | 2002-04-24 | 四川省华拓实业发展股份有限公司 | Technology for recovering dissolvent and catalyst in producing polyphenyl-thioether |
| CN1445266A (en) * | 2002-03-20 | 2003-10-01 | 自贡鸿鹤化工股份有限公司 | Method for recycling colvent utilized in producting polyphenylene sulfide |
| WO2014197458A1 (en) * | 2013-06-03 | 2014-12-11 | Polyone Corporation | Low molecular weight polyphenylene ether prepared without solvents |
| CN107236124A (en) * | 2016-03-28 | 2017-10-10 | 旭化成株式会社 | The manufacture method of polyphenylene oxide |
| CN108623433A (en) * | 2017-03-21 | 2018-10-09 | 南通星辰合成材料有限公司 | Inorganic saline and alkaline method and system in a kind of sedimentation separation polyphenyl ether residual liquid |
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