Study On Fermentation Production Ethanol Separation In Situ By Split Type Gas Cycle Vapor Permeation

With the drying up tendency of fossil fuels, the fule ethanol as regenerate clean energies has attracted more and more attentions. One of the most effective method for avoidding product inhibition is in-situ ethanol separation, which can not only improve the productivity of fermentation, but also simplify the process of separaton and purification. For improving the traditional ethanol fermentation technics, the technology of split type gas cycle vapor permeation was developed to produce fermentation ethanol. This study is mainly based on chemical engineering separation and fermentation engineering to reduce the energy cost. The major experimental results are as follows:Firstly, the split type gas cycle vapor permeation performance of ethanol/water was investigated. The selectivity of this membrane is about 20,and the concentration of ethanol in permeation can reach up to 50%-80%. The process offered theory elements and experimental experience for later split type gas cycle vapor permeation performance of actual fermentation.Secondly, the fermentation parameters of angle brand super alcohol active dry yeast are investigated and confirmed. Experimental results showed that the best fermentation temperature is 35℃, the initiatory pH 4-4.5. The kinetic of yeast batch fermentation by ethanol was studied. The result showed that comparison of test data and the model suggested a reasonable match witch indicated that the model could reflect the fermentation process and the kinetic mechanism very well.Gas stripping is an important step in split type gas cycle vapor permeation process. Through the performance of ethanol/water, the fitting conditions of gas stripping experiment were received. And later, the split type gas cycle vapor permeation process was applied in actual fermentation.In split type gas cycle vapor permeation fermentation process, these aspects were investigated:the effect of fermentation with different experiment methods (inner and outer); the effect of split type gas cycle vapor permeation fermentation in different liquid volume; the feasibility research of supplying glucose in this process. The result showed that this process is fit for the continuous fermentation-separation process.In this work the method can get the ethanol production directly from the fermentation, increase the ethanol productivity, make the most of glucose and shorten fermentation time. This paper would develop the application of vapor permention to the permentation aspect.