On the basis of thermogravimetric-Fourier transform infrared spectroscopy(TG-FTIR) technology

the pyrolysis of Shenhua lignite was studied and the release rules of oxygen-containing gas during the pyrolysis process were explored. Meanwhile

the occurrences and content of oxygen functional groups in char were analyzed at different temperatures by Fourier transform infrared spectroscopy. The information of macroscopic product and the change of microscopic oxygen functional groups were combined to deduce the evolution and reaction of oxygen functional groups during the pyrolysis process. Therefore

the pyrolysis mechanism of lignite was revealed. The results showed that the generation features of oxygen-containing gas during the pyrolysis process can reveal the evolution of oxygen functional groups such as hydroxyl groups

carboxyl groups and carbonyl groups. The oxygen functional groups had high activity. In addition

the conversion of most of organic oxygen functional groups occurred below 500 ℃. And above 500 ℃

other oxygen functional groups cannot be detected except a small amount of hydrogen bonds which is difficult to remove. The release of oxygen-containing gas above 500 ℃ was mainly due to the decomposition of minerals in coal.