Combustion characteristics and reaction kinetics of Shenhua Shangwan slow and flash pyrolysis chars

In order to investigate the surface characteristic and combustion properties of Shenhua Shangwan slow pryolysis char (SHs) and flash pyrolysis char (SHf), based on the investigation of Shenhua Shangwan slow pryolysis char (SHs) and flash pyrolysis char (SHf), a non-isothermal thermogravimetry method was used to study the combustion properties of coal char in terms of the surface morphology and functional group. The combustion kinetics was simulated by using modified random pore model (MRPM). The results indicate that SHs is composed of a dense-like structure, and SHf possesses a large number of holes structure. Compared with the infrared spectrogram of SHf, SHs has the following unique characteristics: the contents of hydroxyl and carbonyl decrease, the degree of aromatic condensation increases and the stretching vibration bands of aliphatic-CH3 and-CH reduce. The combustion characteristics parameters of SHs show a higher ignition temperature, lower burnout temperature and better combustion property compared to that of SHf. The MRPM is appropriate for describing the combustion process of the coal char samples, in which the correlation coefficients R2 is 0.9997 and the root mean square errors (RMSE) is 0.006. In comparison, for SHs the combustion apparent activation energy E is 60.01 kJ/mol and the structural parameter ψ is 1.00, and for SHf the E is 44.88 kJ/mol and the ψ is 0.62. © 2015, China Coal Society. All right reserved.