Study On Efficient Extraction Of Litsea Cubeba Oil And Purification Of Citral

Litsea cubeba (Lour.) Pers. is deciduous shrub or small tree belonged to department of Lauraceae Neolitsea, distributed in China, India, Indonesia, Malaysia and other countries, main distributed in Hunan, Jiangxi, Guangxi, Fujian, Zhejiang, Hubei, Guangdong, Yunnan, Guizhou, Taiwan and other provinces in our country. The volatile oils exist in the root, stem, leaf, flower and fruit of Litsea cubeba. The Litsea cubeba oil, contains a high content of citral as its main constitutnt, which can be used to purify citral, is obtained by steam distillation method from the fruit. And as a kind of natural essential oils, it is widely used in daily chemical, food, pharmaceutical and other industries. Because the Litsea cubeba fruit is perishable, not suitable for long-distance transportation and long storage, the traditional simple homemade distillation apparatus was used widely to extract Litsea cubeba oil by farmers in our country at present. Although the approach is simple, and equipment cost is low, there are shortcomings such as the low yield of the oil, high energy consumption, low efficiency and so on. In addition, because of the deep processing technology of Litsea cubeba oil is backwardness, the majority oil sale and export directly as low value-added products. In order to improve the production efficiency of Litsea cubeba oil, reduce production costs and improve value-added products, the distillation extract device of Litsea cubeba fruit oil was improved and the integrated technology of purifying citral from_Litsea cubeba oil was explored. The main research contents and conclusions are listed as follows.(1) Simple homemade distillation device was improved and miniaturization of industrial distillation device was developed. Comparative experiments were done to explore the technical parameters of the two distillation device. As the study shows, in comparison with the simple homemade distillation device, the oil yield of improved portable distillation device was improved by 18 percent; single-pot distillation time was shortened by 58 percent; energy consumption was reduced by 50.5 percent and the productivity was 13 times higher. Compared to the simple homemade distillation device, the oil yield of small-scale industrial distillation device was improved by 24 percent; single-pot distillation time was shortened by 80 percent; energy consumption was reduced by 54 percent and the productivity was 17 times higher.(2) The method of isolating citral from Litsea cubeba oil by introduction of magnetic technology in the pretreatment and the vacuum distillation process was created. The effects of the efficiency of the tower, reboiler temperature, entry temperature of the tower, reflux ratio and other factors on yield and purity of the product were investigated. The better production condition of citral isolated from Litsea cubeba oil was determined:the column is packed stainless steel 0 rings; diameter and height of the column is 030 mm and 600 mm; the pressure is 3mmHg; tower reactor temperature was controlled at below 150?; the tower top temperature lower than 60? and the reflux ratio is 10:1 when the first fraction is collected; the tower top temperature between in 60 and 75? and the reflux ratio is 6:1 when the middle fraction is collected; the tower top temperature between in 75 and 90? and the reflux ratio is 2:1 when the citral product is collected. The citral product with yield of over 75 percent and purity of over 97 percent was obtained.