【作者】 鲁许鳌；

【导师】 阎维平；

【作者基本信息】 华北电力大学（北京） ， 动力工程及工程热物理， 2010， 博士

【摘要】 化石燃料的过度开采及温室气体排放使得生物质燃料资源的利用受到极大关注。本文采用热重质谱联用仪研究了四种生物质热解的气体产物特征,采用小型固定床进行了稻壳、稻秸热解实验,分析半焦的微观形貌、元素组成和物相组成；进行了生物质和煤流化床共气化的实验,研究不同掺混比例、空气当量比、水蒸气／燃料质量比对共气化过程的影响规律,分析生物质和煤共气化机理,探索共气化过程的协同效应,并建立了一维稳态鼓泡流化床生物质气化模型；进行了300MW煤粉炉的稻壳和煤共燃的工业实验研究,分析煤粉炉中燃烧的稻壳飞灰特性,并研究生物质和煤共燃对锅炉飞灰利用的影响。本文所取得的主要研究结论总结如下。(1)采用热重质谱联用仪进行生物质热解实验结果表明,四种生物质依据最大失重温度排序为：稻壳>松木屑>棉秆>稻秸；CH4的析出曲线在100℃左右由于植物腐烂会形成小峰值,在最大失重温度处达到最大值,在400～560℃区间内维持较高的释放量；H2O的析出曲线由于自由基水分蒸发在110℃形成小峰值,一次挥发份的形成使得H2O、CO、CO2在最大失重温度处达到最大释放量,CO、CO2在高温段(>500℃)维持一定释放量。(2)采用SEM、EDX、XRD分析了小型固定床中不同热解终温的半焦物化特性,当温度高于800℃,半焦中的钾元素所占比例逐渐减小；以有机物形式存在的氯、硫在热解温度低于500℃进行迁移,在800℃-1000℃之间,半焦中氯、硫大部分会析出；稻壳和稻秸半焦的主要孔隙结构产生在500℃-800℃之间的碳化阶段。(3)在鼓泡流化床反应器中采用新型床料陶粒砂进行生物质单独气化、生物质和煤共气化的热态实验,研究不同掺混比例、空气当量比、水蒸气／燃料质量比对燃气组分、气化效率和碳转化率的影响,结果表明在松木屑、稻秸分别与烟煤、褐煤共气化过程中存在协同效应；阐释了反应器不同区域的共气化主要反应原理。(4)建立了一维稳态生物质气化模型,采用不同的流体动力学模型模拟反应器不同区域的流动状况,分析空气当量比、水蒸气／燃料质量比、自由空间区域对气化过程的影响,计算结果和流化床生物质单独气化试验结果基本吻合。(5)进行稻壳和煤共燃工业试验研究,确定稻壳的合理输送浓度为0.9～1kg／m3(标准状况),输送风温在150-180℃；分析了共燃的稻壳灰的元素分布、孔隙特性等性质；进行了稻壳和煤共燃的飞灰用于混凝土的实验研究。更多还原

【Abstract】 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更多还原