哈萨克斯坦褐煤热解特性试验研究

Experimental study on the pyrolysis characteristics of lignite in Kazakhstan

哈萨克斯坦褐煤的挥发分含量高且碳氢比较大,能够产生丰富的油气资源,因而需研究哈萨克斯坦褐煤的热解特性,以期为其高效利用提供数据参考。选取哈萨克斯坦某褐煤为研究对象,利用1 kg固定床热解装置考察不同热解温度对各热解产物的产率、煤气组分、轻质焦油含量、破碎粉化程度、孔隙结构的影响规律。试验结果表明:随着热解温度升高,半焦、焦油产率逐渐下降,煤气产率升高,热解水产率基本稳定;热解温度的升高可促进热解气中氢气含量升高,甲烷含量逐渐降低,一氧化碳和二氧化碳含量升高;轻质焦油含量随着热解温度升高则呈现先升高后降低的变化趋势,在750℃达到最高;热解温度越高,细颗粒半焦(<0.5 mm)产生越多;半焦孔隙结构随热解温度升高不断发育,直至受热应力破坏发生坍塌。

The lignite produced in Kazakhstan has a high volatile matter content and a high carbon hydrogen ratio,which can generate abundant oil and gas resources.Therefore,it is necessary to study the pyrolysis characteristics of Kazakhstan lignite in order to provide data reference for its efficient utilization.This work selects typical brown coal from Kazakhstan as the experimental raw material.The effects of different pyrolysis temperatures on the yield of pyrolysis products,gas components,light tar content,degree of pulverization,and pore structure were investigated using a 1 kg fixed bed pyrolysis device.The experimental results show that as the pyrolysis temperature increases,the yield of semi coke and tar gradually decreases,the yield of coal gas increases,and the yield of pyrolysis water remains basically stable.The increase in pyrolysis temperature promotes an increase in hydrogen content,a gradual decrease in methane content,and an increase in carbon monoxide and carbon dioxide content.The light tar first increases and then decreases with the increase of pyrolysis temperature,reaching its highest point at 750℃.The higher the pyrolysis temperature,the more fine semi coke particles(<0.5 mm)are produced.The pore structure of semi coke continuously develops with the increase of pyrolysis temperature,and the pore structure is mainly composed of micropores.