Study On The Fermentation Technology Of Mixed Raw Materials For Fuel Ethanol Production

High-concentration mash fermentation is a research hotspot of alcohol production, which contributes to improve the alcohol yield and capacity factor of equipment, as well as reduce energy consumption and waste discharge. This study carried out High-concentration mash alcohol fermentation research with mix raw material (wheat, maize and cassava) to development an efficient production technology.Firstly, liquefaction process conditions were optimized to enhance the liquefaction effect and reduce mash viscosity. After study on the enzyme amount, material-water ratio of starch gelatinization curve, liquefaction temperature and liqufication time, a suitabl double enzyme process was determined as follow:pH of slurry mixing was 5.5,dry matter content 31%, amount of enzyme as the raw material of the 10 U/g, liquefaction temperature 95℃ and time 2h.Seclondly, saccharification process was optimized by investigatin effects of enzyme amount, temperature, pH and processing time and an suitable process was set as follow:aduste the mash pH to 4.5 when liquefied mash cooled to 60℃ and add enzyme of 170U into one garm raw materials, followed cooled to 33℃ and saccharification for 30min.Thirdly, optimization of fermentation with the saccharified mash was performed and the effects of fermentation temperature, pH, time, different nitrogen source on fermentation were investigated. The optimized conditions were determined as follow: fermentation temperature was 33℃, fermentation and initial pH 4.5, inoculation amount was 10%, fermentation time for 48h, which making 500mL flask fermentation mature mash alcohol concentration up 15.7%(V/V), starch utilization rate of 92.8%.Finally, the above determined optimal process conditions were applied to a large bulk alcohol production process combined cleaner production research. Through technological innovation and conditions optimization, the fermentation efficiency as improve markedly and the average alcohol content raised to 14.58%(V/V), residual sugar lowerd to 0.31 g/100mL, residual sugars 1.92 g/100mL. Such achievements acchivments remarkable effects of energy saving and emission reduction as well as enterprise of cleaner production and higher economic benefit was realized.