Study On Novel Pretreatment Methods Of Biomass To Ethanol Production From Biomass

Energy issue is very important as it relates to the development and safety of a nation and society. As the world's fossil energy resources draining away, finding substitute energy is extremely urgent. Energy problem has become one of the core concerns in both political and research areas in many countries.Fuel ethanol produced from lignocellulosic biomass is the second generation biofuel. It has many significant advantages, such as clean, safe, recyclable, and environmentally friendly, which make it being the most promising new energy and becoming a focus of researches.Pretreatment is the most important step in the process of fuel ethanol production from biomass. Based on progenitors'experiences, three new pretreatment techniques are proposed in this paper. These techniques are tested with different biomasses. The effects on cellulose conversion yield, inhibitor production control, and fermentability of hydrolysates are investigated. The results indicate great potential in developing these techniques, and are very helpful in developing new pretreatment method and broadening the scope of mind of industrialization for fuel ethanol production.Electrolyzed water is firstly used as pretreatment reagent instead of acid and alkaline. Relatively high conversion of cellulose can be obtained while avoiding equipment damage and environment pollution. The experiment results indicate that electrolyzed water pretreatment has impressive effect on treating industrial byproduct (DDGS), agricultural waste (corn stover) and energy plant (switchgrass). After pretreatment, the slurries can be enzymatic hydrolyzed without the removal of pretreatment liquids. The obtained hydrolysates can be directly fermented without concentration or detoxification. Mixture fuel and ethanol can be produced.Hydrogen peroxide pretreatment is firstly introduced with a purpose of extracting hemicellulose as value-added product. Switchgrass is used as feedstock in experiments. In the first step of hydrogen peroxide pretreatment, more than 40% hemicellulose can be extracted from switchgrass. Thus the temperature in the second step pretreatment can be greatly reduced. 89% cellulose conversion yield can be obtained after hydrolysis. The inhibitors concentrations in hydrolysates are very low. Hydrolysates can be fermented without concentration or detoxification. Mass balance result shows that 12g ethanol can be produced from 100g dry swtichgrass. Ethanol pretreatment is firstly introduced and corn stover is used as feedstock in the experiments. This method targets lignin as value-added product. Lignin- ethanol solution obtained after first step pretreatment can be used as high energy liquid fuel after certain treatment. The temperature in the second step pretreatment can be greatly reduced.83% cellulose conversion can be obtained after hydrolysis. The inhibitors concentrations in hydrolysates are very low. Hydrolysates can be fermented without concentration or detoxification. Mass balance result shows that 13g ethanol can be produced from 100g dry corn stover.The enzymatic hydrolysis of switchgrass and corn stover pretreated with electrolyzed water is modeled with a fractal first-order equation. The fit is very well, which means enzymatic hydrolysis in this biomass-enzyme system can be described by fractal theory, and follow first-order rule. Meawhile, pretreatment severity and orthoganol analysis are performed. The results indicate that temperature has more effect on the final cellulose conversion yield.