Abstract: It is very important to study the ignition characteristics of pulverized coal for the design and operation of nozzle and chamber in a pressurized gasifier.In this paper,the ignition characteristics of three types of coal sample were studied by using pressurized thermogravimetry.According to the principle of energy conservation in the process of heating up and Semenov's TET theory,a novel method by processing PTG curve and obtaining ignition temperature,namely the inflection point method was proposed,which was compared with the empirical tangent method.The influences of pressure,oxygen concentration,heating rate,volatile content and particle sizes were discussed.The results show that the ignition temperature range of pulverized coal is from the initial ignition temperature( Ti) to the ultimate ignition temperature( Tig),and the location of tangential point determined by the environmental heat transfer conditions is the only definite condition.The high heating rate of high-temperature industrial furnaces corresponds to the ultimate ignition temperature; during the pressurized combustion of pulverized coal in fixed bed,heterogeneous ignition occurs,and the ignition temperature increases slightly with the increase of volatile content; in the pressure ranges of 0.1-1.0 MPa and 3-5 MPa,the ignition temperature decreases with the increase of pressure,which is much lower than that under atmospheric combustion,but increases slightly at the pressure range of 1-3 MPa.The effect of oxygen volume fraction on ignition temperature is similar to that of atmospheric pressure.With the increase of oxygen volume fraction,the ignition temperature decreases.Although the quick oxidation of pulverized coal under pressure and the ignition temperature obtained by the inflection point method is close to that obtained by the empirical tangent method,the tangent method cannot respond to the change of environmental conditions,and the empirical tangent method cannot give satisfactory results under normal pressure.