The Phase Behavior Of Supercritical Carbon Dioxide Microemulsion Systems And Their Solubilization Properties To Polyalcohol

Separation and purification play an important role in process industry. Supercritical carbon dioxide extraction is a new separation method, which has been used for the extraction of various fat-soluble substances. It has shown unique advantages in medicinal herbs and natural products, which are thermal sensitive and with high extra value. As a low polarity substance, carbon dioxide can't be used widely. Supercritical microemulsion (reverse micelle) which improves the solvent properties of supercritical fluid greatly is a breakthrough in the research of supercritical fluid technology.Based on the separations of the dilute polyacolhol aqueous solution obtained by fermentation, choose appropriate surfactants and co-surfactants to form thermodynamics stable microemulsions. The solubilization properties can be manipulated easily by and controlling the operating conditions. The research contents and results are as follows:1. The phase behavior of AOT/ethanol/water/CO2 system. To testify the experimental means and data, the cloud data of binary system are compared with literatures. The dosage of asistent surfactant ethanol is chose base on the literatures and experiments. The investigation of the influence to the phase behavior of the concentration of AOT and water content can be used for the supportion as the further research of the polar substance's solubilization2. The phase behavior of adding the developer methyl orange to AOT/ethanol/water/CO2 system. According to the chromogenic conditions, the type of microemusion can be realized. At 30℃, it's Winsor I type, but it is Winsor IV type in the range of 33-45℃.3. The phase behavior of adding the 1,3-propanediol to ethanol/water/CO2 and ethanol/CO2 system. The data indicated:It's easier for ethanol/CO2 system to solubilize pure 1,3-propanediol than low concentration of 1,3-propandiol aqueous. Also, a lot of white droplets are dispersed in these two systems, and arrange very closely, so the system is not very clear and transparent.4. The phase behavior of adding the 1,3-propanediol to AOT/ethanol/water/CO2 and AOT/ethanol/CO2 system. At proper pressure and temperature, the microemulsions can be formed in these two systems, and the selectivity of microemulsion is associated with the temperature and pressure. This indicated that AOT/ethanol/CO2 can solubilize 1,3-propanediol selectively at certain conditions. And it can be used to deal with the dilute aqueous solutions. 5. The phase behavior of TMN-6/ethanol/water/CO2 system. It was found that it's nonlinear relationship between the concentration of TMN-6 and cloud points pressures. There is a optimal concentration, and the cloud point pressure will increase with a concentration higher or lower than optimal concentration. While the relationship between concentration of AOT and cloud point pressure is linear in the AOT supercritical microemulsion system.6. The phase behavior of adding the 1,3-propanediol to TMN-6/ethanol/water/CO2 and TMN-6/ethanol/CO2 system. At proper pressure and temperature, the microemulsions can be formed in these two systems, and the selectivity of microemulsion is associated with the temperature and pressure. This indicated that TMN-6/ethanol/CO2 can solubilize 1, 3-propanediol selectively at certain conditions. And it can be used to deal with the dilute aqueous solutions.7. TMN-6 microemulsion system compared with AOT system:all of them can solubilize 1,3-propanediol in proper conditions, but cloud point pressures of TMN-6 system are higher than AOT system, and the selectivities of AOT system is weaker than TMN-6 system.