Combustion characteristics, functional groups, and gaseous emission behavior of different coals by TG-FTIR

The combustion characteristics and gas emissions behavior of Low-calorie Indonesian coal (LC), Shaanxi coal (SC), and Datong coal (TC) were analyzed by a thermogravimetric-Fourier transform infrared spectrometer (TG-FTIR). The results showed that LC was the easiest coal to burn, followed by SC and TC. The main components of LC ash were alkali metals and alkaline earth metals (AAEMS), while SC and TC were clay minerals. The catalytic activity of LC ash was higher than that of SC and TC ash. FTIR results indicated that the main functional groups of three coals were CO₂, CO, H₂O, phenols, C = O, and C-H during combustion. The absorbance peaks of CO₂, CO, SO₂, and HCN against temperature showed single peak characteristics, while NO_x was the bimodal peak. The total CO₂ emission of LC was 1.04 and 1.25 times that of SC and TC. Compared to LC and SC, TC had the highest total CO and SO₂ emissions. The total NO_x emission of LC, SC, and TC was 0.21, 0.21, and 0.16. The study results provide the guidance for selection of coals and control the emission of gas products in the thermal power plant.