Study on the oxy-fuel co-combustion of coal gangue and semicoke and the pollutants emission characteristics

The oxy-fuel co-combustion of coal gangue and semicoke and the pollutants emission characteristics were studied by thermogravimetric analyzer and tube furnace experiments. The effects of semicoke blending ratios, O2 concentration and temperature were investigated. The results showed that the combustion performance of blended fuel could be improved with the addition of semicoke and the increase of O2 concentration. The maximum ignition and burnout index were obtained when semicoke blending ratio was 75%. The xCO and xSO2 gradually decreased with the increase of semicoke blending ratios. As the increase of temperature, the xCO decreased, xSO2 increased while xNO firstly increased then decreased or slowly grew. The NO emission could be reduced with the addition of semicoke when the temperature was 900 °C. However, it would aggravate NO emission at other temperatures. With the increase of O2 concentration, the xCO decreased, xNO increased while xSO2 firstly decreased and then increased. The minimum xSO2 was obtained when O2 concentration was 20%.