A method for crystallization and purification of low-concentration eucalyptus oil

Abstract

The invention discloses a method for crystallizing and purifying low-concentration eucalyptus oil, namely a low-temperature-controlled crystallization method added with a regulator and seed crystals. According to the method for crystallizing and purifying low-concentration eucalyptus oil, by adopting a normal pressure holocrystalline process, high-purity 1,8-eucalyptol is obtained by controlling factors such as the regulator and additive amount of the regulator, additive amount of seed crystals, seed crystal addition temperature, cooling rate, crystallization final temperature, heating rate and heating final temperature, and mother liquor (content of alpha-pinene is higher than 20%, and alpha-pinene can be recycled after being separated) and perspiration (content of eucalyptol is about 68-71%, and eucalyptol can be recycled) are obtained at the same time, wherein eucalyptus oil can be purified to 99% from 60%, the yield of eucalyptol is 15-25%, and the total consumed time is about 12-17 hours. The method for crystallizing and purifying the low-concentration eucalyptus oil has the advantages that the defects in other methods that kinds of equipment are multiple, operation conditions are harsh, the raw material utilization rate is low and the efficiency is low are overcome, a process is simple, and implementation is easy.

Description

technical field [0001] The invention relates to the separation technology of high-purity products of natural product oils, more specifically, relates to a method for crystallization and purification of multi-impurity and low-concentration eucalyptus oil. Background technique [0002] Eucalyptus oil is an aromatic essential oil secreted by eucalyptus leaf oil gland cells. It is a mixture of various organic components, the most important of which is 1,8-cineole. The scientific name of 1,8-cineole is 1,3,3-trimethyl-2-oxabicyclo[2,2,2]octane, which is a colorless oily liquid with antibacterial, insecticidal and wind-dispelling properties It has the functions of heat, dampness and detoxification, and has a good transdermal penetration effect on various drugs. [0003] There are many impurities in crude eucalyptus oil, mainly α-pinene, and also contain other small amounts of limonene, p-scavengerin, γ-terpinene, β-pinene, myrcene, α-phellandrene and α-pinene - terpineol, etc. ...

AI Technical Summary

Problems solved by technology

This type of method first needs to purify the eucalyptus oil raw material with a content of about 62% to a certain concentration through rectification, and then it can be crystallized. Although high-purity eucalyptol can be obtained like this, there are four disadvantages as follows: rectification The method usually consumes a lot of energy and takes a long time; it is difficult for eucalyptus oil to produce shaped crystals without external force or seed crystal addition; the operation is not flexible, and the intermediate process cannot be monitored so that it is difficult to predict the results; The yield is greatly affected by the distillation yield

[0006] In the purification method invented by the Chinese patent (CN1436783A), the concentration of the raw materials used is above 70%, while the concentration of the general raw material eucalyptus oil is about 55%-63%. There are many kinds of impurities in this content range, which is the key to the initial stage of purification. stage, how to obtain more than 70% eucalyptus oil on this basis is the key to the operation, and the method generally adopted is rectification, which increases the diversity of equipment and complicates the process

The purity of crude eucalyptus oil extracted from eucalyptus leaves is generally about 55%-63%. There are many types of impurities in this concentration range, and it is difficult to increase the concentration to more than 70%. Difficulties in starting the crystallization of leaf oil are basically obtained through rectification and other methods to obtain a certain concentration of eucalyptus oil, and then crystallized. The production steps are cumbersome, the utilization rate of raw materials is low, and the process is complicated