A comprehensive study on co-pyrolysis of bituminous coal and pine sawdust using TG Reactivity, product yield, and kinetic constant

A sample consisting of woody biomass and bituminous coal was pyrolyzed in a lab-scale furnace in a nitrogen atmosphere with the temperature increasing by different heating rates of 5, 10, and 50 °C min−1 until the furnace wall temperature reached 900 °C. Five blending ratios (BRs) of coal–biomass were tested. For each BR, the mass loss of the sample and mole fractions of the gaseous species evolved from the sample were measured using a thermogravimetry (TG) and a real-time gas analyzer (GA). Reactivity, product yield, and activation energy were considered as index parameters to co-pyrolysis. While synergy (the difference between the experimental data and calculated results obtained using an additive model) of the reactivity of co-pyrolysis was observed only at specific temperatures, the TG results showed synergy at temperatures between 450 and 500 °C compared to between 450 and 600 °C seen with the GA method for all pyrolyzed gases, and especially between 350 and 650 °C for H2. While there was no synergy in the char yield of the co-pyrolysis, the liquid and total gas exhibited synergy for all three BRs. The pre-exponential factors and the activation energies of BRs of 0.25, 0.5, and 0.75 were obtained using a kinetic study of co-pyrolysis.