Investigation of the combustion behavior and ash composition of Umutbaca coal-Na ₂ CO ₃ addition

In the study, the effect of Na2CO3 addition on the combustion process of Umutbaca coal and its ash composition was investigated. It was understood that valuable components such as Na2SiO3 and Na2SiO5 could be obtained through this reaction at 725°C. To better understand the combustion process, TG-DTG/DTA analysis, XRD, XRF, SEM-EDS, FTIR, and BET analyses were used to identify and characterize the ash produced from coal combustion with Na2CO3. The kinetics analysis parameters were obtained by Ortega method. It has been understood that the Na2CO3 addition to Umutbaca coal has a catalytic effect on its combustion process, and significantly reduced the volatilization and ignition temperatures. The activation energy of the combustion process decreased from 112.32 to 106.71 kJ/mol. XRD, SEM-EDS, and FTIR analysis displayed that SiO2 in the ash has largely transformed into silicate structures. In SEM images, it was observed that the combustion ash of coal with Na2CO3 exhibited a very different morphological structure, compared to the combustion ash of raw coal. In the FT-IR analysis, the silicate (O-Si-O) structure, which is dominant in the raw coal ash, was replaced by Na-O-Si bonds with the addition of Na2CO3.