Drying characteristics and kinetics of Shengli lignite using different drying methods

The drying characteristics and kinetics of Shengli lignite were investigated using four different drying methods, namely, the fluidized bed (FB), vibrated fluidized bed (VFB), medium fluidized bed (MFB), and vibrated medium fluidized bed (VMFB) methods, at various inlet air temperatures (80-160 °C). Seven thin layer models were used to analyze the lignite drying kinetics. The drying characteristics results showed that a higher temperature contributed to the drying process in all of the drying methods. Different drying methods also had significant effects on the drying characteristics and kinetics. The VMFB had the best drying characteristics with the shortest drying time and fastest drying rate. The Midilli-Kucuk model best simulated the lignite dewatering processes in all of the drying methods. Moreover, the VMFB obtained the fastest drying kinetics with the highest apparent diffusion coefficients and lowest activation energy.