Low-temperature oxidation of some Turkish coals

► Low-temperature oxidation of four Turkish coals was assessed. ► The formation rates of CO and CO2 and the CO/CO2 ratio was tracked. ► Temperature has a pronounced effect on the formation rates. ► High rank coals were oxidized rapidly than low rank coals. ► The coal having the highest inertinite group macerals had the highest CO2 and CO production rates.