Investigation of combustion kinetics of Umutbaca-lignite by thermal analysis technique

• Published in: Journal of thermal analysis and calorimetry 2017-07, Vol.129 (1), p.531-539
• Main Authors: Naktiyok, Jale, Bayrakçeken, Hatice, Özer, A. Kadir, Gülaboğlu, M. Şahin
• Format: Article
• Language: English
• Subjects: Activation energy; Analysis; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Coating; Combustion; Heating; Ignition temperature; Inorganic Chemistry; Investigations; Lignite; Mathematical models; Measurement Science and Instrumentation; Methods; Physical Chemistry; Polymer Sciences; Thermal analysis
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-017-6149-z

In this study, TG/DSC analysis was used to obtain the information on the combustion behavior, profile, and thermal kinetics of Umutbaca (Turkey) lignite. The thermal analysis data were obtained from 298 to 1273 K at 1, 2.5, 5, and 7.5 K min −1 heating rates in air atmosphere at TG–DSC apparatus. It was seen that when the heating rates increased, the ignition temperature and the burn-out temperature increased. The kinetic parameters were also determined by using two model-free methods [Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS)] and with model-fitting (Coats–Redfern). The activation energies ( E a ) calculated for KAS and FWO were 118 and 129 kJ mol −1 , respectively. ln( A ) was 18.09. It was found that diffusion mechanism [D 4 : (1 − 2 α /3) − (1 −  α ) 2/3 ] depicts the combustion process of Umutbaca-lignite by using Coats–Redfern method.