A kind of separation and recovery method of NMP and catalyst lithium chloride in polyphenylene sulfide production

The technology of a polyphenylene sulfide and a recovery method, which is applied in the direction of chemical recovery and the like, can solve the problems of low recovery rate of lithium chloride, affecting production costs and high prices, and achieve the effects of low cost, simple operation and high purity.

Inactive Publication Date: 2011-12-14
NANJING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The recovery rate of solvent NMP and catalyst lithium chloride is low during production. Due to the high price of NMP and lithium chloride, the production cost is seriously affected

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Take 600ml polyphenylene sulfide polycondensation mother liquor, and carry out vacuum distillation at -0.096MPa pressure and 130°C in a rotary evaporator until it is completely evaporated to dryness. The evaporated solvent NMP is condensed with 20°C water to obtain 465.4g NMP and 121.2 g distillation residue, the total recovery of NMP was 96.9%.

[0016] Take 120ml of clear water, add it to the evaporator bottle, heat to 40°C, stir, and fully dissolve the distillation residue. The feed liquid was filtered, and the filter cake was washed twice with 160ml of clear water, and the combined filtrate and washing water were a mixed solution, a total of 222ml, and the Li concentration measured by an atomic absorption spectrophotometer was 3862mg / L.

[0017] Take 100ml of the mixed solution, add 2.3g of 80% phosphoric acid dropwise, react for 60min under stirring, and form white lithium phosphate precipitate, filter, wash with water and dry to obtain 2.05g of lithium phosphate w...

Embodiment 2

[0019] LiAlO 2 +HCl+H 2 O==LiCl+Al(OH) 3

[0020] The aluminum hydroxide precipitate was washed twice with water, and dried to obtain 8.94 g of aluminum hydroxide, with a content of 96.6%. Add 30% sodium hydroxide dropwise to make it fully dissolved, pH11-12.5, and use it repeatedly as a precipitating agent. The filtrate is a lithium chloride solution, which is reused in the polyphenylene sulfide polycondensation reaction. Take 600ml of polyphenylene sulfide polycondensation mother liquor, and carry out vacuum distillation at -0.085MPa pressure and 160°C in a rotary evaporator until it is completely evaporated to dryness. The evaporated solvent NMP is condensed with water at 20°C to obtain 462.7g of NMP and 123.4 g distillation residue, the total recovery of NMP is 95.2%.

[0021] Take 120ml of clear water, add it to the evaporator bottle, heat to 40°C, stir to fully dissolve the slag. The feed liquid is filtered, and washed twice with 160ml of clear water, and t...

Embodiment 3

[0027] Take 600ml of polyphenylene sulfide polycondensation mother liquor, and carry out vacuum distillation at -0.085MPa pressure and 160°C in a rotary evaporator until it is completely evaporated to dryness. The evaporated solvent NMP is condensed with water at 20°C to obtain 462.7g of NMP and 123.4 g distillation residue, the total recovery of NMP is 95.2%.

[0028] Take 150ml of clear water, add it to the evaporator bottle, heat to 40°C, stir to fully dissolve the slag. The feed liquid was filtered, and the filter cake was washed twice with 50ml of clear water, and the combined filtrate and washing water were a mixed solution of 160ml, and the Li concentration recorded by an atomic absorption spectrophotometer was 5453mg / L.

[0029] Take 200ml of mixed solution, drop into 30% sodium aluminate (NaAlO 2 ) 30ml, and reacted for 90min under stirring to form a white lithium aluminate precipitate, which was filtered, washed with water and dried to obtain lithium aluminate (LiAl...

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Abstract

The invention relates to a separation and recovery method for n-methylpyrrolidone (NMP) and a lithium chloride catalyst during polyphenylene sulfide producing. The method is characterized by: directly carrying out vacuum distillation for a polyphenylene sulfide polycondensation mother liquid until the polyphenylene sulfide polycondensation mother liquid is dried to recover a solvent of the NMP, wherein the NMP can be used in the next recycling production; adding water to the distilled residues, then heating to a temperature of 40 DEG C, carrying out stirring and completely dissolving the distilled residues, carrying out filtering and washing the filter residues, mixing the resulting filtrate and the washing solution, and analyzing lithium content in the mixed solution; adding the mixed solution to a phosphoric acid solution or a sodium aluminate solution, wherein the phosphoric acid solution or the sodium aluminate solution has a lithium reaction equivalent of 105-115%, then completely stirring to enable lithium phosphate or lithium aluminate to be precipitated completely, then carrying out steps of filtering, washing, drying for the lithium phosphate or the lithium aluminate to recover the lithium salt having a purity more than 97%. According to the present invention, the operation of the method is simple; the cost is low; the recovered NMP and the recovered lithium salt havehigh purities.

Description

technical field [0001] The present invention relates to the recovery of N-methylpyrrolidone and catalyst lithium chloride. Background technique [0002] Polyphenylene Sulfide (PPS) is a heat-resistant engineering plastic. High mechanical strength, good hot water resistance, flame resistance, chemical resistance, excellent adhesive performance and excellent electrical insulation performance, good dimensional stability. Due to the good performance and wide application of polyphenylene sulfide, the demand abroad has maintained a nearly double-digit growth rate in the past 10 years. Among them, the average annual growth rate in the United States is 15%. 18% in Japan and 15% in Western Europe. China's polyphenylene sulfide is also developing gradually. Since the technology is monopolized by Western countries, the recovery of solvents and catalysts in its production has become a technical difficulty. [0003] Polyphenylene sulfide is produced by polycondensation of p-dichlorob...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G75/02C08J11/02C08J11/00C08G75/0213C08G75/0254
CPCY02P20/582Y02P20/584
Inventor 赵玉明徐雨芳刘伟
Owner NANJING UNIV
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