关键词: 下行床, 循环流化床, 煤拔头, 快速热解

Abstract: A hot downer reactor system integrated with a circulating fluidized bed was built to examine its performance in the coal topping process. The effects of reaction temperature and coal particle size on the total product distribution and liquid composition were determined for Huolin River coal (Inner Mongolia, China). The results show that increasing temperature can increase the yields of gas and liquid products, and a larger coal particle size leads to a lower liquid yield. The experimental results exhibit a promising product distribution. As the pyrolysis temperature was 660℃, the coal particle size was less than 0.28 mm and feed rate was 4.7 kg/h, the yield of light tar (hexane soluble fraction) reached 7.5% (dry coal basis, w). The composition of light tar was phenols (57.1%, w), crude gasoline (aliphatics, 12.9%), aromatics (21.4%), and polar and basic groups (8.6%). The closeness to plug flow pattern of the gas and solids in the downer makes it a promising reactor for the coal topping process.

Key words: downer, circulating fluidized bed, coal topping, fast pyrolysis