Clean fuel and scrubbing compared

The combustion of coal produces air-borne emissions of particulates, nitrogen (NO/sub x/), and sulfur oxides (SO/sub x/). In coal-fired electricity-generating plants, particulates are routinely controlled by well-established technology, such as precipitators, bag filters, or venturi scrubbers, and NO/sub x/ emissions can usually be reduced to acceptable levels by certain combustion-system modifications that are now accepted by the industry. SO/sub x/ emissions, however, are more difficult to control, with only two alternative approaches considered technologically feasible: coal conversion to produce a clean fuel and flue-gas desulfurization (FGD). This article contrasts these two approaches and compares their costs as related to the generation of electricity.