Co-pyrolysis of bituminous coal and biomass in a pressured fluidized bed

An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor. The blend ratio of biomass in the mixture was varied between 0 and 100 wt%, and the temperature was over a range of 550-650℃ under 1.0 MPa pressure with different atmospheres. On the basis of the individual pyrolysis behavior of bituminous coal and biomass, the influences of the biomass blending ratio, temperature, pressure and atmosphere on the product distribution were investigated. The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor, especially when the condition of bituminous coal and biomass blend ratio of 70:30 (w/w), 600℃, and 0.3 MPa was applied. The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis. The tar yields were higher than the calculated values from individual pyrolysis of each fuel, and consequently the char yields were lower. The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel. The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.