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.