2-07　Chemical Structure Analysis for Moisture Coal Oxidized at Low Temperature Using Solid Sate ¹³C MAS NMR

Abstract

To characterize chemical structure of oxidized coal, solid state ¹³C MAS NMR spectra were acquired for bituminous coal with lower water contained (=low moisture) and with higher water contained (=high moisture) before and after estimation of their self-heating property using R70 apparatus. It was found that low moisture coal reached 80°C in shorter time than high moisture one. The chemical structural change in low moisture coal during oxidation was found to be increasing aldehyde, ketone and carbonyl, while that in high moisture one was found to be decreasing aldehyde and ketone. It is suggested that the dominant chemical reaction which induces self-heating of coal depends on the amount of water contained in coal before oxidation.