Study On The Fermentation Of Rice Straw Producing Fuel Ethanol

With the increasing consumption of energy resources, the world is faced with complex economic and environmental problems which must be seriously treated if we want to maintain and improve our life. So, convering biomass(straw) materials to fuel ethanol becomes an anurgent and significant strategic mission to solve this energy crisis for its enviroment-protecting and resource-saving advantages. There are abundant straw stalk resources in China. In order to make sufficient use of them, conversion of straw stalk to fuel ethanol was studied.Pretreating straw stalk by NaOH to eliminate lignin, enzyme activity produced from fermentation of Trichoderma Viride was studied. After single fator analysis of culture medium and Plackett-Burman to ferment situation, results showed the optimal condition of culture for Trichoderma Viride to produce celluose. Under the same fermentation conditions, Trichoderma Viride could reach an activity of 36.4 U.After the pretreatment of stalk by NaOH, the produce of glucose by this enzyme was evaluated. The methods of single fator analysis and Response Surface Method were used to optimize the culture medium ingredients. Then defined the three most important factors by Plackett-Burman experiment which were pH before fermentation, zymotic time and ratio of water. Optimized by Response Surface Method to obtain the optimal fermentation conditions, the maximum yield of glucose by Trichoderma Viride under the same fermentation conditions was 190.3 mg.g-1.Product of fuel ethanol from fermentation broth of Saccharomyces cerevisiae in the period of pre-fermentation was also researched. Single fator analysis was carried on to decide whether conditions of culture would affect the yield of fuel ethanol. The Response Surface Method process determined the optimal condition of culture for producing fuel ethanol. Under the same fermentation conditions, fuel ethanol got the maximum conversition ratio, that was 10.5%.