Infulence Of Combined Pretreatment On Performance Of Wheat Stalk Anaerobic Digestion

At present, the irrational utilization of biomass energy such as straw and manure have become increasingly serious in China, which result in a waste of our existing resources.The burning of straw and unscientific stacking of livestock and poultry manure have a considerably negative effect on our living environment. Thus, the development of biomass energy is an effective way to solve the problem of the energy crisis and environmental pollution in China. Currently, the use of agricultural waste straw and manure for anaerobic biogas production is the focus of research. To solve the problem of gas production, poor quality animal manure is insufficient; therefore, the present study pretreated the straw with NaOH and green oxygen(GO) under different simulating seasons(low-temperature/15°C; medium-temperature/35°C; high-temperature/55°C). Specifically, firstly, the optimum pretreatment concentration was selected at different temperatures; secondly, based on the most suitable pre-treatment concentrations at different temperatures, straws were pretreated and mixed with cow manure in ratios of 3:7, 5:5, and 7:3, then underwent anaerobic fermentation. Finally, we determined the optimum ratio of the combined pretreatment mixed fermentation at different temperatures. This experiment was designed to provide theoretical support for efficient biogas use in different regions and seasons of China. The main results were as follows:(1) At the three temperatures of 15, 35, and 55°C, this study exerted pretreatments with different NaOH-green oxygen on straw components, and anaerobic digestion performance was studied in this experiment.The best pretreatment combinations were 3% NaOH +0.05% GO(A3), 2% NaOH +0.05% GO(B2) and 2% NaOH +0.05% GO(C2) at the temperatures of 15°, 35°, and 55°C, respectively. The accumulation of methane gas production of these groups, compared with the group without pretreatment, increased by 86, 93, and 87%, respectively.(2) At 15, 35, 55°C, through utilizing the best combination of treatment at each temperature of straw pretreatments, this study used pretreated straw mixed with cow dung in ratios of 3:7,5:5, and 7:3 and an anaerobic fermentation test at the appropriate temperature. The most suitable ratio combinations wereD3(3:7), E2(7:3), and F2(7:3) at temperatures of 15, 35, and 55°C, respectively. The accumulation of methane gas production of these groups, compared with the group without ratio combinations, increased by 90, 98, and 95%, respectively.