Preheating Analysis of Semi-Coke in a Circulating Fluidized Bed and Its Kinetic Characteristics

Semi-coke has difficulties with stable ignition and high-efficiency combustion due to its low volatile content. Preheating in a circulating fluidized bed before offers novel method for the improvement of fuel properties. During preheating, semi-coke was converted preheated composed coal gas char. When increasing preheating temperature, ratio CO/CO2 significantly increased, while CH4/CO2 remained almost unchanged. After release ratios different species from followed order C >H > N S. Thermogravimetric analysis used evaluate kinetic characteristics. We found that burnout temperatures char decreased compared those semi-coke, reaction rate constant increased by 20 times. Three models were predict variations conversion time, modified volumetric model showed good agreement experiment. This investigation provides support better developing technology future.