Behavior of Pulverized Coal Combustion in Air and In O_2/CO_2 Condition

摘要

Oxyfuel combustion is one of promising clean coal technologies for capturing CO_2. Different environment in oxyfuel combustion between air condition and O_2/CO_2 condition is required to be studied. Thermo-gravimetric analyzer (TGA) and Fourier-transform infrared (FTIR) spectrometer was used to study the behavior of pulverized coal in different O_2/CO_2 environments. The burning process of pulverized coal in O_2/CO_2 environment was relative similar until burning the volatile matter and then combustion was delayed in burning the char compared with that in O_2/N_2 environment at the same oxygen concentration. In case of the oxygen concentration increase, the burning rate of coal increases and burnout time is shortened. The species in flue gas including H_2O, CO_2, CO, CH_4, SO_2 and NO during burning test in TGA were determined and analyzed using the Fourier-transform infrared (FTIR) spectrometer. Compared with pulverized coal combustion in O_2/N_2 condition, much more CO is produced in O_2/CO_2 coal combustion process.