Abstract: The co-combustion and gaseous pollutants emission characteristics of pyrolysis semi-coke and lignite under high heating rates（100-250 ℃/min）were investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometer（TG-FTIR）.Results showed that adding lignite into blends could lower the ignition temperature and shorten the burnout time of the blends.All of the index for ignition，burnout and comprehensive combustion performance increased significantly with the increment of lignite blending ratio.Higher heating rates in TG experiments would lead to a higher ignition temperature and temperature at maximum weight loss rate.Meanwhile，the burning rates would also accelerated， which resulted in improved comprehensive combustion performance.The release temperature range of gaseous pollutants was consistent with the main weight loss stages. With the increase of lignite blending ratios，CO2 emission gradually decreased，while NO and NO2 emission generally increased，and the SO2 and CO emission fluctuated.In conclusion，cocombustion exerted certain suppression effect on NOx emission.

Key words: pyrolysis semi-coke, lignite, co-combustion, TG-FTIR, heating rates, gaseous pollutants