下行床煤拔头工艺的产品产率分布和液体组成

基于循环流化床锅炉燃烧技术和下行床技术相结合，在处理能力为8 kg/h的煤拔头工艺热态实验装置上，以内蒙古霍林河褐煤为原料，普通河砂为固体热载体，考察了反应温度和煤粉粒径对气液固产品产率分布和液体组成的影响规律. 结果表明，在实验温度范围内，随着温度的升高，气体和液体产品的产率增加；液体产率随粒径的增大而降低. 当反应温度为660℃、煤粉粒径小于0.28 mm、加料率为4.7 kg/h时，轻质焦油(焦油中的正己烷可溶物)的产率可达7.5%(干煤基，w)，其中酚类占57.1%，粗汽油(脂肪烃类)占12.9%，芳香烃占21.4%，极性组分和其他组分占8.6%. 实验表明，下行床由于气固沿重力场并流向下流动的特点，是适合煤拔头工艺的比较理想的反应器.

Total Distribution and Liquid Composition of Products from Coal Topping Process in a Downer Reactor

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.