Corn Stalks Preparation Of The Key Technologies Of Bio-ethanol

The world is confronting the depletion of the fossil energy and environmental crisis due to its increasingly expanded consumption. It is thought to be attractive to produce bioethanol because of its advantages such as abundant raw material, high combustion value, renewable and clean. This paper mainly studies the bioethanol production from corn stover under the certain circumstances.The microbe was mainly screened from lignocellulose abundant environment to ferment cellulase with acid treated corn stover as substrate. After primary screening and reelection by Congo red and sodium carboxymethylcellulose culture media, a fungus was gained with highly cellulase production. It has been generally identified as Penicillium sp.CLF-Y through biological identification.One model for cellulase production media was built up with Response Surface Methodology and the final optimized culture media components (per 100 ml culture media) were as follows:carbon-nitrogen ratio was 14.65 (mol:mol), liquid-solid ratio was 34.36 (ml: g), buffer solution volume was 13.29 ml, corn stover-bran ratio was 7:3 (g:g), culture loading was 120 ml, trace element volume was 1.5 ml and initial pH value was 5.2. Theβ-D-glucosidase activity reached 1215.38 u/L which increased by 84.64% in comparison to the control value.The studies on kinetic ofβ-D-glucosidase indicated that Km and Vmax are 1.951mg/mL and 0.427 mg/(mL-min) respectively. The optimum reaction temperature and pH value are 50℃and 4.8. The half-life of crude enzyme increased from 216.6h to 495.1h after adding glycerol which indicated that glycerol can improve the thermal stability of cellulase. On the other hand, it can be verified with the value ofΔH*,ΔS*,ΔG* and activation energy.Simultaneous Saccharification and Fermentation (SSF) and Simultaneous Hydrolysis and Fermentation (SHF) were adopted to product bioethanol with reducing sugar that produced by enzymatic hydrolysis of corn stover, and the ethanol yield of corn stover reached 0.176 g/gDCS and 0.128g/gDCS, respectively.