Studies on low-temperature pyrolysis characteristics and kinetics of the binder cold-briquetted lignite

In this study, pyrolysis process of the binder cold-briquetted lignite (BCBL) was studied comprehensively. The effects of temperature in the range of 350-650 °C, heating rate in the range of 5-20 °C/min, the residence time at constant temperature in the range of 30-120 min, pyrolysis atmosphere of H2, CO, CH4, CO2 and N2 and the particle size in the range of 0.45-6 mm were investigated. The main generated gas species were quantified by two gas chromatographs: H2, CO, CO2, CH4 and trace amounts of C2H4 and C2H6. A semi-quantitative method was established to proceed the pyrolysis kinetics fitting by the thermal analysis-mass spectrometry (TA-MS) signals of pyrolytic products. The kinetic parameters of different gas pyrolysates were calculated by the first-order kinetics. The activation energies for H2, CO, CO2, CH4, C2H4 and C2H6 were found to be close to the reference results. The results reported in this work may provide a theoretical and technical basis for the BCBL pyrolysis and lignite upgrading technology which may have potential application in fuel utilization.