Removal of Sulfur From 4 Central Anatolian Lignites by Naoh

The desulphurization of four samples of Central Anatolian lignites by treatment with aqueous NaOH was examined. NaOH concentration and temperature were the significant parameters but the extraction time had only a slight effect. Organic sulphur was not removed from three of the samples but in the other lignite 12.5 wt % of the organic sulphur was removed by treatment at 70°C for 8 h with 20 wt/v % NaOH solution. Total sulphur contents were considerably reduced by aqueous NaOH treatment but one high-sulphur lignite was found to be more resistant to sulphur removal than the others. This lignite was treated with molten caustic at 300°C and 450°C with the result that the total sulphur and ash contents were reduced by 47- 83 wt % and 77-91 wt % respectively.