Purification method for 1, 8-cineole

Abstract

The invention discloses a purification method for 1, 8-cineole and particularly discloses a separation and purification method for 1, 8-cineole in low-content raw oil. The method is characterized by comprising the steps of (1) adding raw oil, acetic acid or a water solution of acetic acid and a catalyst into a reaction flask, wherein the raw oil contains 1, 8-cineole and limonene; (2) heating and stirring to react; (3) after the reaction is ended, filtering a reaction solution to recycle the catalyst, and carrying out reduced pressure distillation on an oil phase to obtain 1, 8-cineole with high purity. By using the purification method, the content of 1, 8-cineole in the raw oil can be kept constant after being treated, and the content of limonene as an impurity can be reduced to 0.2-1.1%, so that 1, 8-cineole with high purity can be obtained. Meanwhile, after reacting, limonene in the raw oil generates alpha-terpinene, gamma-terpinene, alpha-terpilenol and the like which all have higher additional values and can not affect the distillation of 1, 8-cineole, therefore, the purification method is a low-cost and green-chemical purification method.

Description

technical field [0001] The invention relates to a method for purifying 1,8-cineole, in particular to a method for removing impurities that are difficult to separate by rectification in the process of purifying 1,8-cineole. Background technique [0002] 1,8-Cineole is also known as eucalyptol, eucalyptol, 1,8-epoxy-p-mentane, okanabutol, chemical name 1,3,3-trimethyl-2-oxa Bicyclo[2.2.2.]octane (CAS NO 470-82-6) is widely used in pharmaceutical products, cough drops, artificial mints, gargles, toothpaste, and air cleaners. [0003] The development of 1,8-cineole separation process has benefited from the purchase of high-purity products by foreign customers, but it is not easy to separate and purify high-purity 1,8-cineole from raw material oil, mainly because the raw materials In addition to the high content of 1,8-cineole, there are limonene, pinene and other terpinene substances in the oil; these substances are either isomers with 1,8-cineole, or It has similar physical a...

AI Technical Summary

Problems solved by technology

[0008] 3) For the raw material oil with relatively low 1,8-cineole content, it is difficult to separate high-purity 1,8-cineole from it, and the raw material utilization rate is low;

[0009] 4) The operation and process are complicated, and the requirements for equipment are high;

[0010] 5) The catalyst used is highly toxic, difficult to recycle, and pollutes the environment