The Forms of Nitrogen in the Coal Char and Analysis of Char-nitrogen Conversion by TG-FTIR

The forms of nitrogen in experimental blended coal/char and combustion characteristics as well as char-nitrogen conversion rules of the char in air atmosphere were investigated by the ways of X-ray photoelectron spectroscopy (XPS) and thermogravimetry-fourier transform infrared spectroscopy (TG-FTIR). The results show that the pyrrolic nitrogen (N-5) in char is relative instability after high-temperature pyrolysis by comparing main occurrence modes of nitrogen between the experimental blended coal and the corresponding char. The TG curve of experimental char gradually falls in the range of 460~756 °C and the DTG curve reaches the peak at 666 °C. The activation energy of the char combustion is 93.9 KJ/mol in the range of the same temperature above based on the method of Coats-Red fern. The main gases include CO2, CO, NO, NO2, N2O, HNCO and HCN.