寻甸褐煤的催化多段加氢热解过程

利用热重技术对寻甸褐煤的催化多段加氢热解过程进行了研究，考察了不同的催化剂制备方式对该过程的影响，并在固定床上研究了产物的分布和焦油组成.结果表明：催化剂的存在明显增加了自由基的生成及其被氢化饱和的速率，从而导致了总转化率的提高；与不加催化剂相比，当Mo负载量为0.2%时, 350 ℃的停留过程使转化率从26%激增到50%；不同Mo负载量下的停留对加氢热解过程中的低温峰和高温峰的影响不同；经超声处理催化剂制备的煤样，其加氢热解在任何温度下的转化率均高于用电磁搅拌制备的结果，而且热解温度越高其效果越明显；超声负载催化剂的多段催化加氢热解的总转化率远远高于通过电磁搅拌制备的煤样；催化条件下的多段加氢热解过程改变了产物的分布，并明显提高了焦油中轻质组分的含量，苯类、酚类和萘类收率分别增加了42%、37.8%和115.4%.

CATALYTIC MULTI-STAGE HYDROPYROLYSIS OF XUNDIAN LIGNITE

The catalytic multi-stage hydropyrolysis (HyPy) of Xundian lignite was investigated by using thermogravimetric technique and fixed bed reactor.The preparation methods for MoS₂ catalyst, including magnetic stirring and ultrasonic treatment, were also studied. The results showed that the total conversion increased due to the increase in formation rate of free radicals and its saturation reaction with catalyst added. When the amount of MoS₂ was 0.2%, the conversion after retention at 350 ℃ was sharply increased to 50% compared to that of 26% without catalyst.The effects of catalyst loading on the conversion at a low temperature peak and a high temperature peak during multi-stage hydropyrolysis (MHyPy) were different. When the catalyst was prepared by using ultrasonic treatment, the conversion in both HyPy and MHyPy was always higher than that with catalyst prepared by magnetic stirring and such effect was even more remarkable at higher temperatures. During MHyPy of coal utilization of catalyst and ultrasonic preparation could notably improve conversion and oil yield. Catalytic MHyPy changeed the product distribution and greatly increased the concentration of light aromatics in the tar, during which benzenes, phenols and naphthalenes increased by 42%, 37.8% and 115.4% respectively as compared with HyPy.