The Use of Naturally Clean Coals to Achieve Cleaner Coal Technology

Cleaner coals have been used to achieve lower and more restrictive environmental regulations, primarily in older plant designed to use only more energy-intensive bituminous coals. So far, some of these naturally clean coals have been able to meet some of the most restrictive regulations without the addition of environmental equipment. In some places these coals are used where environmental equipment has been installed so that the solid and liquid wastes can be minimized. Nitrogen and sulphur oxides are/can be significantly lowered by using these naturally clean coals. The emissions of these pollutants per ton of carbon dioxide produced are also lower with the cleaner coals, compared to traditionally used bituminous coals. However, because of the lower thermal efficiency of the cleaner coals, the amount of carbon dioxide produced is slightly higher than typically used coals. This paper discusses some of these phenomena.