The Research Of Anaerobic Digestion Of Sugarcane Bagasse Pretreatment And Pig Manure For Biogas Production

Sugarcane bagasse is a main kind of by-products in sugar industry. Traditional utilization of sugarcane bagasse is inefficient, which led to a waste of resource and environment pollution. Sugarcane bagasse is rich in cellulose, hemicellulose, it’s a suitable biomass material of anaerobic digestion for producing biogas. Pretreatments can effectively improve gas production rate of sugarcane bagase. Bagasse mixed with pig manure can effectively change C/N ratio and also promote gas production. The main research contents and results were as the following.(1) The effects of pretreatments for sugarcane bagasse on anaerobic digestion for biogas production. The effects of NaOH, Ca(OH)2, hydrothermal and hydrothermal under pressure pretreatments for sugarcane bagasse on biogas production, methane content and cellulose content were studied through batch anaerobic digestion.3%NaOH pretreatment was better with biogas production235.10mL/g-VS and methane content66.2%.8.5%Ca(OH)2pretreatment was better with biogas production265.18mL/g-VS and methane content67.1%.180℃hydrothermal pretreatment was better with biogas production234.34mL/g-VS and methane content65.0%.180℃hydrothermal pretreatment under pressure was better with biogas production282.35mL/g-VS and methane content67.3%. Pretreatments degraded hemicellulose and lignin of sugarcane bagasse partially. Among four pretreatment methods, the effect of hydrothermal pretreatment under pressure was better than other methods. Infrared spectroscopy results showed the degradation of hemicellulose and lignin. The surface of sugarcane bagasse mercerized and the fiber stripped after pretreatments under SEM.(2) The effects of sugarcane bagasse and pig manure co-degistion on batch anaerobic digestion for biogas production. The effects of different C/N ratio of sugarcane bagasse and pig manure co-degistion on biogas production, methane content and cellulose content were studied through batch anaerobic digestion. When C/N ratio of sugarcane bagasse and pig manure co-degistion was23:1, methane production was146.08mL/g-VS, cumulative gas production was219.33mL/g-VS.(3) The effects of sugarcane bagasse and pig manure co-degistion on continuous anaerobic digestion for biogas production. The effects of different organic loading rates on gas production rate, methane content, nitrogen content, pH value and alkalinity were studied through continuous anaerobic digestion. When the organic loading rate controlled within1.95～2.69g-VS/(L·d), the tank volume gas production rate ranged steadily between0.370and0.516m3/(m3·d), methane production rate ranged between138.68and290.71L/kg-VS, the average of methane content was51.6%-66.4%. If organic loading rate was3.42g-VS/(L·d), there’s a little VFAs accumulation.(4) The kinetic study of methane production of sugarcane bagasse pretreatments and pig manure during anaerobic digestion. Cheynoweth equation and second-stage first order kinetic equation can both fit methane production for NaOH pretreated group, Ca(OH)2pretreated group,160℃hydrothermal pretreated group. Cheynoweth equation can also fit methane production for co-degistion with pig manure. After modification, Cheynoweth equation can be used to fit methane production process of180℃.200℃、220℃hydrothermal under pressure pretreatment group.