Selection Of Sweet Potato Varieties For Fuel Ethanol And Research On Ethanol Fermentation Technology

Fuel ethanol has been widely adopted as the substitution for traditional energy in many countries since its renewablity,full combustion and low pollution properties.In our country,fuel ethanol is usually manufactured through fermentation.Traditionally,the grain,such as wheat and corn is used as raw material.Obviously,this method is a great threat to the grain security.Hence,sweet potato is adopted as a new kind of raw material for the manufacture of fuel ethanol since its great yield,great planting area and high energy production.However,it is rarely reported which kind of sweet potato is the most suitable for the production of fuel ethanolIn order to seek for a new type of sweet potato which is low-price and high-energy-production,the paper studied several kinds of sweet potato,and through analysis,the inner inter interactions were established.The fermentable sugar content,fermentable sugar content per unit area,fermentation efficiency and fermentation mash viscosity of five different types of sweet potato were inspected and analyzed.It is found that the south sweet potato 007 is the best.The inspection results indicate that among all specimens,south sweet potato 007 has the highest fermentable sugar content,highest fermentation efficiency,relatively high fermentable sugar content per unit area and relatively low fermenting mash viscosity.The south sweet potato 007 can be ascertained as raw material.Orthogonal experiments were carried out to analyze the effects of different material-water ratio,saccharifying enzyme contents,enzymolysis time,initial pH value,fermentation time,inoculation quantity,fermentation temperature and nitrogen source content.According to the results,an optimal fermentation process is determined:100g potato starch with 70mL water,liquidation pH value is 5.0,liquefying enzyme content is 50KNU,liquidation temperature is 95 ? liquefying time is 25min.During saccharification process,pectinase and cellulase should be added.Saccharifying enzyme content is 100 ?L,pH adjustment is not necessary.Inorganic salts and nitrogen source are not necessarily added before mash fermentation.The fermentation time is 60h by maintaining the temperature at 30?.