煤气化化学与技术进展

阐述了煤气化化学及气化过程,说明煤气化过程主要包括煤的热裂解、部分氧化燃烧、炭的气化、炉渣的生成和排出4个转化步骤。论述了固定床气化技术、流化床气化技术、气流床气化技术3种煤气化技术的工艺、设备、优缺点和适用范围。从煤灰液渣对耐火衬里的腐蚀机理、煤灰化学组成、灰熔融性和灰熔融温度、液渣黏度四方面分析了气流床灰/渣特性。最后阐述了美国煤气化技术进展及发展方向,提出应重点开展IGCC煤气化、低阶煤(褐煤和次烟煤)气化技术研究,开展以提高气化炉可靠性、气化效率和煤种适应性为目标的气化炉优化研究,控制多种污染物排放至极低水平的合成气净化技术研究,低成本高效率的O2分离技术及H2和CO2的分离技术研究等。 Chemistry and behavior of coal gasification are elucidated in this paper,including coal pyrolysis,partial oxidative combustion, coke gasification,generation and discharging of slag. The process,equipments,advantages and disadvantages of moving-bed gasification, fluidized-bed gasification and entrained-flow gasification are also summarized. The characteristics of ash / slag are discussed in detail based on the mechanism of refractory lining degradation from slag-refractory interactions,ash chemical composition,ash fusibility and ash fusion temperature,molten slag viscosity. The advances and development trends of coal gasification technology in USA are also analyzed. It is suggested that studies on coal gasification for IGCC and low-rank coal such as lignite and subbituminous coal,gasifier optimization to improve reliability,efficiency and coal feedstock flexibility,syngas cleanup technologies to control multi-contaminants to extremely low levels,O2 separation with low cost and high efficiency,and H2 and CO2 separation with low cost should be focused for clean and high-efficiency coal utilization