| Due to the problem of the excessive use of fossil fuels and the greenhouse gas emission, the utilization of biomass resources is continuously sought. Firstly, in this thesis by monitoring the pyrolysis profiles using TG-MS the characteristic of the gas products of 4 biomass pyrolysis is investigated. The coke's micro-morphology, elemental composition and phase composition from rice husk and rice straw pyrolysis are analyzed. Secondly, the fluidized bed experimental system is designed to study the different mixing ratio, air equivalence ratio, steam/fuel mass ratio on the impact of the biomass and coal co-gasification process. The mechanism of co-gasification is discussed and synergies are explored. One-dimensional steady-state model for bubbling fluidized bed biomass gasification is presented. Lastly, the industrial co-combustion test of rice husk and coal on 300MW pulverized coal boiler is carried out. The physical and chemical properties of the rice husk ash separated from the co-combustion fly ash are analyzed. The effect of the co-combustion mode on the fly ash application is investigated. The main conclusions are as follows.The order of 4 kind of biomass according to the maximum weight loss temperature is:rice husk>pine sawdust>cotton stalk>rice straw. During the biomass pyrolysis process, the releasing profile of CH4 forms a small release peak at about 100℃since the plants have decomposed, which reaches the maximum at the maximum weight loss temperature and maintains a high release in the range of 400-560℃; The releasing profile of H2O forms a small release peak corresponding to the evaporation of free water. During the formation of primary volatiles H2O, CO and CO2 gets the maximum at the maximum weight loss temperature. CO and CO2 in high-temperature segment (>500℃) maintain a certain release due to thermal decomposition of lignin.During the pyrolysis of rice straw, when the final temperature is higher than 800℃the proportion of potassium gradually decreased. In the range of less than 500℃, chlorine and sulfur in organic form will be migrated. Most of the remaining chlorine and sulfur will vaporize in the range of 800-1000℃.The co-gasification test of biomass and coal with air-steam is carried out in bubbling fluidized bed using new bed material (ceramite). The rules of the temperature variation in different regions are obtained. The effect of the different mixing ratio, air equivalence ratio, Steam/fuel mass ratio on gas composition, gasification efficiency and carbon conversion rate is studied. The results show that there is synergistic effect during co-gasification process of pine sawdust, rice straw and bituminous coal, lignite. The main principles of the co-gasification reaction in the different regions of the reactor are explained.One-dimensional steady-state model for bubbling fluidized bed biomass gasification is presented. Based on the simulated results the effects of air equivalence ratio, steam/fuel mass ratio, free-board region on the gasification process are analyzed. The calculation results and the experimental results are basically consistent.The industrial co-combustion test of rice husk and coal is carried out. The reasonable transportation concentration of rice husk is 0.9-lkg/m3, the temperature of the conveying air should be in the range of 150-180℃. The characteristics of micro-morphology, elemental composition, phase composition and pore structure of the rice husk ash separated from the co-combustion fly ash are analyzed. The tests that the co-combustion fly ash is used as the mixing material of the concrete are done. Key words:biomass, coal, co-gasification, co-combustion, bubbling fluidized bed, pulverized coal boiler...
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