Process for separating tert-butyl acetate in medicine waste solvent through vacuum rectification by using super-gravity bed

Abstract

The invention relates to a vacuum rectification method using a super-gravity bed as core separating equipment, and discloses a process for separating and recycling a waste solvent in the synthetic process of statins or other medicines and recovering tert-butyl acetate in the solvent. During operation, the waste solvent enters from a place located between the two-layer and three-layer rotors of thesuper-gravity bed, wherein the rotating speed is 1000r / min, the reflux ratio is 4-10, the vacuum degree at the top of a tower is 20kPa-70kPa, and the temperature of a tower kettle is controlled at 70DEG C-85 DEG C, a tert-butyl acetate product with higher purity can be recovered in the tower kettle, the purity can reach 95% or more, the residual amount of isoprene is less than 1%, and the moisture content is less than 1000ppm, thereby fully meeting the requirements of recycling; and compared with traditional tower-type rectification operation, the process provided by the invention has the advantages of having a simple technological procedure, low energy consumption, a small occupied area of equipment, and high recovery rate of the product tert-butyl acetate, and being capable of effectively improving economic benefits.

Description

technical field [0001] The invention relates to the field of chemical waste solvent treatment, in particular to a vacuum rectification method with a high gravity bed as the core separation equipment, which separates and recovers tert-butyl acetate in waste solvents in the synthesis process of statins or other drugs, In particular, processes in which isoprene, the highest azeotrope, can be formed with tert-butyl acetate are removed. Background technique [0002] During the synthesis and production of drugs, a large amount of organic solvents are needed as solvents to dissolve macromolecular drugs or drug intermediates. Taking the production of statins as an example, a large amount of solvents such as isoprene, methyl tert-butyl ether, tetrahydrofuran and tert-butyl acetate need to be used in the synthesis process. Therefore, the pharmaceutical production industry is a large demand for solvents, but also a large producer of waste solvents. If the waste solvent is discharged ...

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Problems solved by technology

Shi Huahui et al. (Journal of Nanjing University of Technology, September 2010, Volume 32, No. 5, Page 24-27) published a rectification separation process for the purification of tert-butyl acetate, using two towers of deacidification tower and purification tower The process separates tert-butyl acetate, and the reflux ratio of the purification tower reaches 35, and the energy consumption is too high, which is obviously not suitable for the in-situ solvent recovery process of pharmaceutical companies

[0005] In view of the fact that tert-butyl acetate-isoprene can form the highest azeotrope, the general atmospheric distillation method not only cannot obtain the tert-butyl acetate solution of qualified purity, but also causes a large amount of loss of tert-butyl acetate, acetic acid The utilization rate and recovery rate of tert-butyl ester are greatly reduced

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