The Production Of Alcohol With Acid-enzymatic Hydrolysis Method

Straw waste is a kind of most abundant biomass in the world. It can be used for fuel-ethanol production after being pretreatment, fermentation and hydrolysis. Ethanol is a kind of widely used chemical material. It can be added into the gasoline or as a new fuel. Also it was named cleaning resources. The usual methods of hydrolysis process is simply acid or enzymatic hydrolysis, have the disadvantages of large energy consumption and the yield of sugar is low or high cost. In this dissertation, has mainly studied the influence on different hydrolys process for the yield of sugar, and explored a better hydrolysis process:acid enzymatic hydrolysis and product ethanol for fermentation.Hydrolysis of straw paper pulp using sulfuric acid and three cellulase from different company. The results show that:(l)Sulfiiric acid hydrolysis optimization:temperature170～180℃, liquid to solid was20:1, sulfuric acid concentration was2.4%, reaction time was2h, the yield of reducing sugar hydrolysis was27.55%.(2)Optimum conditions for enzymatic hydrolysis:GC220, Xiasheng and Solarbio enzyme dosage were14%(Vcellulase/Vsolvent,147.28IU/gmaterial),150IU/gmateriai and150IU/gmatenal;substrate concentration were2.9%(liquid to solid was35:1),2%and2%; temperature were50℃,55℃and55℃; pH were4.8; hydrolysis time were24h,8h and12h; the yield of reducing sugar hydrolysis were70.00%,73.20%and71.43%. On this basis, combined the acid with enzymatic hydrolysis.(3)Optimum condition for acid enzymatic hydrolysis:the acid hydrolysis solid residue for enzymatic hydrolysis:temperature was55℃, substrate concentration was1%, enzyme dosage was80IU/gmateriai, hydrolysis time was30h, the yield of reducing sugar hydrolysis was67.12%. The yield of total reducing sugar was62.64%.Neutral concentrate after the acid hydrolisis and enzyme hydrolysis fluid to certain multiple. The effect of glucose concentration, volumes of medium, temperature, rotation speed on the fermentation were investigated. The results show that initial glucose concentration was60g/L, volumes of medium was100mL/250mL with erlenmeyer flask, inorganic nitrogen source (NH4)2SO4, rotation speed was100r/min, pH5.5, fermentation48h, ethanol yield rate was49.72%, which was97.0%of the ethanol theoretical yield. The ethanol concentration was26.63g/L.The high conversion was0.28g/g(ethanol/straw paper pulp).