Research On Improve Ethanol Yield Of Sugarcane Juice

It is an important problem to improve alcohol degree of ethanol fermentation in our country's alcohol industry, It's high energy consumption, high grain consumption, high water consumption and high contamination are restricted the development of alcohol industry. There has been increasingly attention to the issue of how to enhance fermented liquor concentration, to enhance alcohol degree, to reduce energy consumption and to save cost. Sugarcane is one of the major economic crops in Guangxi, it not only can squeeze sugar but also be used to produce fuel alcohol, sugarcane ethanol production has the advantages of source extensively and simple process. Producing ethanol by non-food crops is advocated in our country. Using sugarcane juice to produce alcohol can save cost, at the same time, enterprises can avoid risk when sugar market price is too low. For obtained higher alcohol degree that we use concentration, sugar adding and glucose of cassava hydrolysis adding to exchange initial concentration of sugarcane juice. Three main aspects of work and its results were finished.It was studied that the process conditions of direct fermentation using sugarcane juice. The fermentation condition has been studied, such as temperature, pH value, ammonium chloride, urea, magnesium sulfate, calcium chloride anhydrous and potassium dihydrogen phosphate, and so on. Orthogonal experiment was arranged based on single factor experiment. The optimum conditions was found for saccharomyces cerevisiae GJ2008: pH 4.0, temperature 33℃, NH4Cl 1.4 g/L, KH2PO4 0.6g/L, it can obtained ethanol degree 8.35(%,v/v) in 40h under these conditions.It was studied that ethanol fermentation of sugarcane juice by concentration method, sugar adding and glucose of cassava hydrolysis adding. It was investigated such as method of adjust sugar degree and the effect of nutrient salt. The results showed that sugar adding was better than concentration,in contrast glucose of cassava hydrolysis adding was not as good as expected, and it can increase fermentation efficiency via add proper amount of nutrient salt. The conversion rate could reach to 91.65% when sugar concentration to the point 187.0g/L by sugar adding, added KH2PO4 1.4g/L and CON2H4 0.6g/L, pH 4.0,temperature 33℃,rotational speed 120r/min in 56h.It was studied that ethanol fermentation of 5L,30L bioreactor based on the optimum condition that added KH2PO4 1.4g/L and CON2H4 0.6g/L, temperature was 33℃, pH was 4.0 and rotational speed was 120r/min. The results showed that it could obtained ethanol 11.0(%,v/v) in 36h when sugar concentration to the point 183.3g/L by sugar adding method and its conversion rate could reached to 92.66%.