The multi-stage hydropyrolysis (holding near the peak temperature of 500 and 600℃ for 10min

respectively)of Xianfeng lignite was investigated at heating rates of 5℃·min-1 and 25℃·min-1 in a 10g fixed-bed reactor.The effects of residence time

heating rate

gas flow and pressure on product yields of hydropyrolysis with different heating methods were studied.Higher yields of tar are obtained in multi-stage HyPy than in normal HyPy.The results showed that the tar yields and overall conversions at high heating rates in multi-stage hydropyrolysis approximated to those at constant slower heating rates;the retention effect is remarkable with increasing heating rate

pressure and hydrogen flow.The experiments under syngas exhibited the potential advantage of multi-stage HyPy in industrial utilization.