توليد اتانول از ساقه سورگوم شيرين با استفاده از قارچ موكوراينديكوس به روش تخمير حالت جامد

چكيده انگليسي :

73 Production of Ethanol from Sweet Sorghum Stalk with Mucor indicus by Solid State Fermentation Maryam Molaverdi m Molaverdi@ce iut ac ir 23 January 2013 Department of Chemical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr Keikhosro Karimi karimi@cc iut ac ir Dr Morteza Khanahmadi Khanahmadi@yahoo com Abstract About 28 of the world energy consumption is utilized for transportation which is directly related to greenhouse gas GHG emissions to the atmosphere Using alcohol fueled engines is an attractive way to prevent harmful greenhouse gas emissions and global warming effects Amongst alcoholic fuels ethanol is the best alternative liquid fuel since it is less toxic and can be produced from abundant renewable resources all around the world Ethanol is produced biologically from different wastes such as sugary e g sugarcane and sweet sorghum starchy e g corn and weat and lignocellulosic waste materials e g agricultural and forestry residues Sweet sorghum is one of the most promising energy crops for ethanol production It is also considered as a drought resistant plant and can be cultivated in temperate subtropical and tropical climates Sweet sorghum stalk is rich in soluble sugars i e sucrose glucose and fructose and insoluble carbohydrates i e cellulose and hemicelluloses which both can be utilized as raw materials for fermentative ethanol production As the sweet sorghum stalk harvested the juice can be extracted and fermented by submerge fermentation Meanwhile avoiding the sugar loss the juice has to be concentrated However the juice is very dilute typically contains 15 sugar and its concentration e g up to 80 has a high energy demand Drying of the fresh stalk is suggested as an alternative to the sugar extraction The sugars in the stalk can be then converted to ethanol by solid state fermentation Fungal solid state fermentation FSSF of dry sweet sorghum stalk particles DSSSPs for ethanol production was conducted using fungus Mucor indicus and followed by simultaneous saccharification and fermentation SSF of the residual bagasse without any pretreatment and addition of fresh micro organism cells The effects of important variables including initial fungal inoculation rate 0 001 1 and 5 g l time 24 48 72 and 96 h temperature 28 32 and 36 C moisture level 65 75 80 and 85 and particle size 80 20 80 and 20 mesh on the yield of ethanol production by FSSF were investigated The results showed that M indicus was able to utilize almost all the glucose and fructose within 48 h whereas the maximum ethanol yield 0 48 g produced ethanol g consumed sugars was achieved by FSSF at 32 C 80 moisture and particle size of 20 80 mesh with 5 g l fungal biomass Moreover The sweet sorghum bagasse is a lignocellulosic material containing cellulose hemicellulose and lignin simultaneous saccharification and fermentation of the residual bagasse 10 25 and 50 g l was performed at 32 35 and 37 C with different cellulase and glucosidase enzymes loading for 48 h In the best case 86 of ethanol yield was achieved when 50 g bagasse l was saccharified using 15 FPU cellulase and 30 IU glucosidase per gram glucan and simultaneously fermented to ethanol at 37 C for 48 h The results indicated that the fungal solid state fermentation acted as a pretreatment stage and assisted the subsequent simultaneous saccharification and fermentation of the residual bagasse resulted in up to 4 3 folds improvement in the ethanol production yield Key Words Ethanol sweet sorghum Mucor indicus solid state fermentation PDF created with pdfFactory trial version www pdffactory com

ملاوردي، مريم

توليد اتانول از ساقه سورگوم شيرين با استفاده از قارچ موكوراينديكوس به روش تخمير حالت جامد