The Ginkgo Biloba Extract Concentrated By Nanofiltration

For energy-conservation, the effect of the nanofiltration on lotion of porous resin has been studied in attempt to replace the low-temperature and three-effect evaporation during the process of GBE production in the paper.The research on GBE ethanol-water solution was carried out using the membrane DK and membrane DL firstly adopted in the feasible experiment. The experiment result shows that for the two membranes, the flux increases with improvement of pressure, circulative velocity and temperature, and reduces with addition of the feed concentration; besides, permeate concentration falls with accretion of pressure and circulative velocity, and rises with increment of temperature and feed concentration; however, the content of active component in the permeate is very low , and it's rejection rate is about 99% or even more .According to the influence of the operating conditions and the separating effect difference between the two membranes, the GBE ethanol-water solution would be concentrated by membrane DL from 1% to 10%, and the optimum operating condition is that operating pressure: 1.2～1.5 MPa, circulative velocity: 0.18～0.2m/s and the temperature: about 40℃.The studies of the fouling and regeneration of membrane indicates that the pollution degree will be enforced by the improvement of pressure and feed concentration and almost unchanged by the accretion of circulative velocity, whereas, the pollution degree is so weak that the fouling of membrane can be resolved by physical cleaning.Several experiments using DK roll membrane were brought into effect in the plant, in which the flux is all above 10.0 L/m~2.h and permeate concentration and the content of active component in the permeate are both undetected, which will be satisfied in practical production.The flux model of ethanol-water solution was established based on the Mehardad binary liquid phase pressure-driven membrane process, which suggests that the flux increases with improvement of pore radius and porosity of the membrane, and reduces with addition of ethanol fraction in the ethanol-water solution, effective thickness of membrane and interaction between the membrane and the ethanol-water solution.For the characteristic of the GBE ethanol-water solution, the new model was formed by combination mass transfer model inside the membrane (Irreversible Thermodynamics Model) and the mass transfer model outside the membrane (Concentration Polarization Model), in which permeate concentration was neglected. In addition, the predictions of the GBE ethanol-water solution nanofiltration at 40℃were carried out by both one dimension combination model and two dimensions combination model, which imply the theory result is as same as the experiment result in the tendency, however, the theory value is a bit lower than experiment value.