Study On The Separation Of Essential Oil Of Traditional Chinese Medicine From Oil-in-water Emulsion By Microfiltration

The oil-water separation of essential oil by the method of ultrafiltration had been studied, on the basis of which the method of microfiltration is studied. The optimization of microfiltration technology, analysis of membrane pollution and mechanism of oil-water separation by membrane method are discussed. Through the analysis of experiments date, provide consult information for development of oil-water separation of essential oil of Chinese medicine, and reach the purpose of promoting the progress of membrane separation technology for the collection of essential oil from oil-in-water emulsion. The content and results of paper are as follows.1 Nine kinds of essential oil of Chinese medicine were chosen, their physical and chemical properties are different from each other. In the experiments, analogue systems of essential oil were used to optimize the technology of oil-water separation, and by comparing the gas chromatography fingerprint of original essential oil and essential oil gathered by membrane method to discover their difference in chemical composition. Through comparing the best operation technology of each oil-in-water emulsion, and every factor's influence to membrane flux and retain rate of essential oil, we found that aperture was the first factor that affects the membrane flux and retain rate of essential oil, the next were pressure and temperature. For different kind of essential oil-in-water emulsion, the change tendency is similar. The flux increases with the increase of aperture, the retain rate decreases with the increase of aperture, the higher pressure and temperature are, the higher flux is. However, differences also existing, for different kind of essential oil-in-water emulsion, membrane flux and retain rate of essential oil change at different degree.2 The analysis of date are mainly discussed. Correlation analysis of experiment date was carried out first to discover the factors affecting the membrane flux and retain rate of essential oil. The results show that the factors affecting the membrane flux and retain rate of essential oil are different because of membrane aperture's difference. The factors affecting the flux are membrane aperture, pressure, temperature and so on. The factors affecting the retain rate of essential oil are membrane aperture, pH, surface tension and so on. According to the result of correlation analysis, Back-propagation network, Support Vector Machine method, Radical Basis Function neural networks and General Regression neural network are applied to predict the membrane flux, and among them Radical Basis Function neural networks and General Regression neural network work better.3 The microfiltration membrane pollution of oil water separation was studied, mainly including the resistance distribution of membrane. The influence of operating condition to the membrane pollution are analyzed to get the message of membrane's pollution extent and its composition. The results show that all the factors of membrane aperture, pressure, temperature and mixer's speed change the resistance distribution at different extent. Under all the conditions, the resistance distribution of membrane have something in common, such as that the source of most pollution are membrane itself and concentration polarization, the inreversible pollution is not severity.4 The mechanism of oil-water separation by microfiltration method was discussed. According to the literature and experiment of resistance distribution and size distribution, we suppose that the mechanism are combination of screening mechanism and phase separation mechanism.The innovations of this article lie in the following ways:(1) studying the parameters which affect oil water separation of nine kinds of essentional oil-in-water, and showing it can retain oil's chemical matter very well by the comparison of fingerprints. (2) applying several date analysis methods to analyze factors affecting membrane process, and establish model to predict the flux. (3) explaining the membrane pollution and mechanism of oil water separation by membrane, and to guide the study of operation technology and application.