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Straw is the important part of the biomass, the major sources of biomass. Of straw resources are very rich, but most are open burning, so that not only cause air pollution, but also a serious waste biomass resources. In order to achieve energy efficiency of conversion of straw, put forward by biological and chemical methods for straw pretreated lignocellulose degradation of straw and straw pretreated using anaerobic digestion to produce biogas for new methods. By biological and chemical pretreatment on the pretreated rice straw lignin, cellulose and hemicellulose content of the content determined, the results indicate that pretreatment of biological and chemical pretreatment part inside the straw can degrade lignin, hemicellulose and cellulose, in which the highest rate of lignin degradation; pretreatment can destroy a certain extent the chemical bond between lignin and carbohydrates and lignin structure, generate more small molecules or soluble carbohydrates. The topic for the anaerobic digestion of straw gas production technique was investigated experimentally. First, rice straw by biological pretreatment, biological pretreatment time, straw length and anaerobic digestion temperature is not the same, straw anaerobic digestion for biogas production efficiency and impact; researchers then chemically pretreated rice straw, the pre- Processing NaOH concentration, straw length and anaerobic digestion temperature is not the same, straw anaerobic digestion for biogas production efficiency and impact, to determine the optimal conditions for anaerobic digestion. Through research, we draw the following conclusions: (1) straw pretreated by biological and chemical pretreatment in different lengths under conditions of anaerobic digestion ,2-3cm lengths of straw anaerobic digestion cumulative gas production to excellent at 10 ~ 12cm, 8 ~ 10cm and 5 ~ 7cm length anaerobic digestion under the cumulative gas production. (2) straw pretreated by biological and chemical respectively at room temperature and the temperature conditions for anaerobic digestion experiments, the results showed that: the straw in the temperature conditions for anaerobic digestion is better than the cumulative gas production in anaerobic digestion accumulate under normal temperature conditions gas production, the maximum increase rate reached 103.9%. (3) learn from biological pretreatment 15d, 30d, 45d and 60d after Tanaka natural dried straw and straw two kinds of pre-rot straw anaerobic digestion experiments, the results showed that: The biological pretreatment 15d pre-rot straw after Tanaka, at room temperature and moderate temperatures, anaerobic digestion is always the highest cumulative gas production; at room temperature, the biological pretreatment 30d dry naturally after anaerobic digestion of straw cumulative gas production is the highest, while the temperature, the air-dry naturally after biological pretreatment 15d Anaerobic digestion of straw cumulative gas production is the highest. (4) The mass fraction of straw 2.5%, 5.0%, 7.5% and 10% NaOH after pretreatment of anaerobic digestion, at room temperature, concentration of 5.0% NaOH pretreated rice straw anaerobic digestion chemical cumulative gas is the highest, while in the temperature, concentration of 7.5% NaOH pretreated rice straw anaerobic digestion chemical cumulative product gas is the highest. Straw biological treatment for anaerobic digestion conducted a feasibility analysis of gas production from the running costs, operating income, saving energy costs, environmental benefits, and environmental and other aspects of economic analysis showing that, through biological pretreatment of straw as the main raw material used for large-scale biogas production is economical and feasible method, and has good practical promotion of significance.
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