The investigation of the effects of the oxygenated functional groups in coals during the preparation of clean coal

Tunçbilek and Çan coal were extracted with NMP, Tetraline and Quinoline, NMP/Tetraline (1:1 v/v) and Tetraline/ Quinoline (1:1 v/v) mixtures at 350°C. Pre-treated Çan and Tunçbilek coals were also extracted at the same conditions. The extracts of the all extractions were as ?clean coal? since their ash content reduced to as well as 0, 2 ? 0, 6 %. The effect of oxygenated functional groups such as COOH on the extraction yield was also investigated. Acid pre-treatment did not show any significant effect on the extraction yield. On the other side, in both extraction processes, Çan coal gave higher extraction yields then those of Tunçbilek coal