Simultaneous Saccharification And Fermentation Of Waste Newspaper To Fuel Ethanol

Lignocellulosic is the most abundant form of carbohydrate on earth. With the inevitable depletion of the world's non-renewable fossil energy resources, there has been an increasing worldwide interest in alternative non-fossil-based sources of energy. Through biotechnology lignocellulosic biomass can be converted to ethanol, a promising alternative energy source for the limited crude oil。The potential of biotechnical processes based on enzymatic hydrolysis of cellulosic materials is enormous.The bioconversion of biomass to fuel ethanol comprises two costly processes, pretreatment and the high enzyme addition, which we have studied in the paper for the purpose of cutting the cost of the whole process. In this paper, waste newspaper, which is cheap and delignified, is used as materials. It doesn't need complicated pretreatment, so it's economical. Meanwhile, Non-ionic surfactants were used as an additive in simultaneous saccharification and fermentation. They can increase hydrolyzation rates of cellulose and the final ethanol yields.Waste newspaper materials are strongly resistant to direct enzymatic hydrolysis apparently due to the presence of various chemical substances used in the process of paper production. After the pretreatment process: waste newspaper 5%, 0.25% H3PO4 at room temperature 20℃for 30 miniutes, the residual fibers were separated by filtration, washed to neutral pH, this adhesive envelope around the cellulose fibers was effectively pretreated, and the materials could be extensively hydrolyzed by the cellulose complex. Angel high temperature tolerant alcohol active dry yeast (TH-AADY) and Danbaoli high temperature tolerant alcohol active dry yeast (TH-AADY) were adopted to produce ethanol. Both of the strains had the advantages of acid resistant, high temperature resistant and could undergo fermentation at 40℃. This adjusted the disagreement of optimum temperature for enzymatic hydrolysis and optimum temperature for fermentation.Simultaneous saccharification and fermentation (SSF) is believed to be the most effective process, and it's also the most commonly used methods. It's simple. In SSF, the process integration obtained when hydrolysis and fermentation are performed in one reactor, so the glucose produced is immediately consumed by the fermenting microorganism, which avoids end-product inhibition. It is propitious to hydrolysis, and can improve saccharification rates and fermentation rates. SSF was selected for producing fuel ethanol in this paper.In the experiment, the effect of different non-ionic surfactants as an additive on SSF including Tween20,Tween60,Tween80,Triton X-100 were evaluated and compared with conventional fermentation. It's indicated that Tween20 had the best effect and it could improve reducing sugar yields and ethanol conversion rates evidently.It has been studied that the influence of the non-ionic surfactant Tween20 on simultaneous saccharification and fermentation of waste newspaper to ethanol and compared with conventional experiments without Tween20. An orthogonal array design and single factor experiments were adopted to investigate effects of fermentable parameters including ferment time, enzyme loading, the quantity of inoculation, Tween20 addition in the simultaneous saccharification and fermentation. The results show that Tween20 can effectively increase reducing sugar and ethanol yields and reduce the amount of high-cost enzyme loading. The ethanol yields were increased by 5.47% (Angel TH-AADY) and 7.24%(Danbaoli TH-AADY) respectively with the addition of 0.15%,and the reducing sugar concentration were also increased 11.8%( Angel TH-AADY) and 12.2%((Danbaoli TH-AADY). The best conditions are: 72 hours,cellulase 20FPU/g substrate,10% yeast inoculum(V/V) and 0.17% Tween20. Under these optimum conditions ethanol production was 0.2416g/g waste newspaper, which corresponded to 62.6% of the theoretical yield. Surfactant Tween20 as an additive in SSF can significantly lower the operational cost of the process.