The effect of volatile residence time on flash hydropyrolysis of Zalannoer lignite

Abstract

The effect of volatile residence time (VRT) on flash hydropyrolysis (FHP) of Zalannoer lignite has been studied in an entrained reactor at 6.0 MPa hydrogen pressure. The yields of hydrocarbon liquids (HCL) and gaseous products (GP) were determined for a series of temperatures from 500 to 800°C with a range of VRT from 6.8 to 70.6 s. It was found that the yield of total products (HCL + GP) increased with increasing VRT. At 70 s VRT, the GP and HCL yields were 31.6% and 10.5%, respectively. Maximum HCL yield of 13.5% occurred at 42 s VRT which was greater by a factor of 1.6 over the yield at 2 s VRT. From the results, it was evident that an increase in yields of GP and HCL was closely related to a decrease in tar and the volatility of the char product.