Sis, H.2024-08-042024-08-0420091556-70361556-7230https://doi.org/10.1080/15567030802089037https://hdl.handle.net/11616/94912Model-free kinetic approaches were employed to investigate the combustion kinetics of coals with different ranks, namely, lignite, bituminous coal, and anthracite. The experimental data were provided under non-isothermal conditions at different heating rates in the range of 2-25C min-1. The activation energy values were estimated by two model-free methods, that is, Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose methods. Slightly higher activation energy values were obtained by Ozawa-Flynn-Wall method at a wide range of conversion extent. Variation of activation energy was found to be comparably more significant for lower rank lignite (between 44.82 and 287.56 kJ mol-1) while less significant for higher rank bituminous coal (between 101.97 and 155.64 kJ mol-1) and anthracite (between 106.04 and 160.31 kJ mol-1).eninfo:eu-repo/semantics/closedAccessactivation energycoal rankiso-conversional modelsthermal analysisArticle31121016102710.1080/155670308020890372-s2.0-70449556527Q2WOS:000265452700003Q2