(714g) Green and High Efficient Enzyme Hydrolysis Process for Sweet Sorghum Bagasse
In order to improve enzymatic hydrolysis efficiency, several approaches including liquid hot water (LHW) pretreatment, adding surfactant, magnetic stirring and fed-batch hydrolysis were investigated, in which Sweet sorghum bagasse (SSB) was chosen as the feedstock. The experiment results showed that with the LHW pretreatment, the SSB conversion ratio reached 35.91% , nearly 75% xylan and 33% lignin were removed. Using the LHW-pretreated SSB, glycan conversion ratio raised from 16.6% to 37.9% by adding surfactant Tween80 with the optimum dosage of 0.175ml/g DM. The virulence test showed that Tween80 nearly had no influence to the growing of ethanol fermentation yeast- Saccharomyces cerevisiae. Comparing stirring and shaking mode for the enzyme hydrolysis, the glycan conversion rate was 57.3% in stirring mode, higher than 44.4% obtained from shaking mode. The image of Scanning Electron Microscope (SEM) showed that LHW pretreatment could destroy the tight structure of SSB and the comminution of pretreated material could smaller the particles to enhance the hydrolysis process. Finally the LHW-pretreated SSB, Tween80 and stirring mode were applied to fed-batch process, the concentration of glucose, cellobiose and xylose reached 88.8g/l, 30.7g/l and 18.9g/l respectively, and the glycan conversion ratio was 89.3% under the optimum condition. These research works lay the foundation for the construction of a green and high efficient sugar platform to facilitate the cellulosic ethanol development.
These research work are financially supported by the National Key Technology R&D Program (2011BAD22B01), National High Technology Research and Development Program of China (2010AA101606) and the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX1-YW-11-A3, KSCX2-YW-G-063)