Additives Research With Cassava To Produce Ethanol

Bio-ethanol becomes more and more popular because it is an important chemicalraw materials and renewable clean energy. Under the multiple pressures from foodsecurity, resource shortages, environmental pollution, developing bio-ethanol usingnon-staple crops that do not compete for food with the people is a promising way. Asa kind of non-staple crop, cassava which has strong vitality and resistance to dry andbarren is widely planted in Guangxi, Yunnan and Guangdong in China. The starchproportion of cassava is high, so cassava is recognized as high quality raw materialsfor bio-ethanol production.In China, bio-ethanol development faces two problems. One problem is rawmaterial shortage; another is high production cost. Two factors result in highproduction cost: first, cassava price which accounts for70%of total cost is expensive;Second, backward technology result in rawer ethanol production rate, higher waterconsumption, higher energy consumption and higher costs of protein feed as aby-products.For solving the problems above, this paper tries to improve production rate fromstarch material to bio-ethanol, by adding additives. This research divided into twoparts as following.First part is a study about the influence of corn flour to cassava producingethanol. The results show that when adding1%corn flour the yield of ethanol is thelargest, so corn is a good additive.Second part is a study about the influence of inorganic ions on cassava alcoholfermentation. In this part, four kinds of metal ions and three kinds of anions arerespectively examined to the influence of ethanol production rate. The anionsexperiment result shows that when the anions concentrations of SO42-, NO3-are1.5mg/g,2mg/g and2mg/g, the ethanol production rates have good performance.Especially, SO42-can improve ethanol production rate about2.8%which is highestcompared to other anions in this experiment. The ions experiment found a recipe thatcomposed of multiple enzyme and metal ions can improve much ethanol production rate about4%, and the elements of the recipe includes1.2mg/g Mg2+,0.8mg/g Fe2+,0.4mg/g Mn2+,0.4mg/g Co2+,2.5U/gα-amylase,50U/g saccharifying enzyme,2U/gcellulose,3U/g pectinase,4U/g beta glucan enzyme,7U/g pullulanase.Generally, this study shows that adding additives is a good way that couldincrease ethanol production rate to some extent.