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 x_CO and x_\rmS\rmO_\rm2 gradually decreased with the increase of semicoke blending ratios. As the increase of temperature, the x_CO decreased, x_\rmS\rmO_\rm2 increased while x_NO firstly increased then decreased or slowly grew. The NO emission could be reduced with the addition of semicoke when the temperature was 900 ℃. However, it would aggravate NO emission at other temperatures. With the increase of O₂ concentration, the x_CO decreased, x_NO increased while x_\rmS\rmO_\rm2 firstly decreased and then increased. The minimum x_\rmS\rmO_\rm2 was obtained when O₂ concentration was 20%.