Treatment method for recovering tetrahydrofuran from grignard reaction

Abstract

A treatment method for recovering tetrahydrofuran from a grignard reaction. Water-containing tetrahydrofuran recovered from a grignard reaction is dehydrating by a static dehydration treater; the static dehydration treater is provided with a sieve plate and a stratification machine; the dehydrant of sodium hydroxide or anhydrous calcium chloride is placed on the sieve plate; a static treatment manner is adopted; and fractionation treatment is performed to obtain qualified tetrahydrofuran. With the technical scheme of the invention, the recovery rate of tetrahydrofuran is up to 90-96%; the tetrahydrofuran content is more than 99.7%; the water content is less than 0.1%; since the using amount of tetrahydrofuran is large and the price is high, the recovery of tetrahydrofuran from a grignard reaction realizes the recycling, and greatly reduces raw material cost; the alkaline liquor obtained during the treatment process is in an absolutely saturated condition, has minimal residual tetrahydrofuran, and can be used in other neutralization reactions; a saturated calcium chloride aqueous solution is obtained by using anhydrous calcium chloride, and can be used for the supplement of frozen saline. Therefore, the invention is more economical, and is more applicable to industrial application.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a treatment method for tetrahydrofuran recovered from Grignard reaction. Background technique [0002] In the fine chemical production process, tetrahydrofuran is generally used as the solvent for the Grignard reaction, and tetrahydrofuran participates in the reaction, wherein the oxygen atom in tetrahydrofuran forms a coordination bond with the magnesium atom, which needs to be hydrolyzed to generate products, and at the same time free tetrahydrofuran is released. Through atmospheric or reduced pressure distillation, recovery of tetrahydrofuran containing water. Since the Grignard reaction requires anhydrous THF, the recovered THF containing water cannot be directly reused, and because THF is miscible with water and forms an azeotrope, the recovery and treatment of THF is generally quite difficult and expensive. [0003] At present, the recovery and treatment of tet...

AI Technical Summary

Problems solved by technology

This method adds the amount of the inorganic strong base that forms alkali-saturated solution amount and is difficult for controlling, and alkali amount is insufficient, and low water content can't reach, and alkali amount is excessive, easily blocks pipeline, and easily obtains turbid suspension under stirring condition, still needs Add filtering and other operations

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