Flash Pyrolysis of Coal with Solid Heat Carrier in a Fluidized Bed

Abstract

Flash pyrolysis of Shenmu coal with solid heat carrier was carried out in a fluidized bed using semi-coke as the solid heat carrier and nitrogen as the carrier gas. The effects of pyrolysis temperature, reaction time and mass ratio of heat carrier to coal on the yields of products were studied. It is found that the best operating conditions involving pyrolysis temperature 550°C, reaction time 6 min and mass ratio of heat carrier to coal 2. The properties of coal tar from fluidized bed, such as density, viscosity, freezing point, carbon residue and hydrogen carbon atom ratio, are almost higher than that of the above water coal tar and lower than that of the below water coal tar, while the above and below water coal tar obtained from Sanjiang squared retort. The results of simulation distillation show that gasoline and diesel fractions of coal tar from fluidized bed are higher than that of below water coal tar and lower than that of above water coal tar, while the heavy oil fraction is opposed.