超临界CO_2精密分离技术提纯薄荷脑

Fractionation of Peppermint Essential Oil by Supercritical Carbon Dioxide

进行了利用超临界CO2精密分离技术从薄荷原油中提纯薄荷脑的研究,分别考察了分馏塔温度梯度、升压速率等操作参数对分离效果的影响。结果表明,分离精馏塔内形成一定的温度梯度或在一定的温度梯度下改变升压速度都可以有效改善分离效果,当塔内温度梯度为20℃、升压速率为0.1 MPa·(15 min)-1时,ω(薄荷脑)>90%,产物产率为80%;对ω(薄荷脑)=90%的产品进行二次分离,可获得ω(薄荷脑)=99.9%的产物。

The purification of the menthol from peppermint essential oil has been investigated with supercritical carbon dioxide fractionation at different temperature gradient and step-by-step pressure increasing programming. The experimental results showed that the separation efficiency could be improved when the temperature gradient was established in the fractionation column. The temperature gradient 20℃ and step-by-step pressure increasing programming 0. 1 MPa·（15min）^-1 was considered ideally as a good-quality product was obtained together with a good fractionation rate and yield. In addition, the further purification of the crude menthol and the mint oil that has certain content of menthol was also performed. Under the optimized condition, with supercritical carbon dioxide, the menthol content of 99.9%（m） fractions and the fraction of 80%（m） which had the menthol content over 90%（m） more than could be acquired.