Coal cleaning as an acid rain mitigation strategy: an in-depth examination

This study had as its primary focus the question of what SO/sub 2/ reductions could be obtained in the Midwest by applying extensive physical coal cleaning to fuels being burned by major power plants. The issue of concern is strategies for achieving the level of SO/sub 2/ emission reductions (typically at least 50% from 1980 levels) proposed in acid rain legislation. The washabilities of the primary coals delivered to 20 plants in Illinois, Indiana and Ohio were examined in detail. Annual SO/sub 2/ emissions were calculated for each plant under 1980 operating conditions (capacity factor, heat rate, etc.) assuming 1980 fuel use (a combination of coals) and assuming only the major coal source was used (both raw ROM and cleaned to 80% weight recovery). Cleaning ROM coal could result in potential reductions for individual plants from 10 to 50%. In comparison to 1980 emissions, however, these reductions ranged from 4 to 52%. The results of this study show that several specific power plants could achieve a 50% reduction in annual SO/sub 2/ emissions by switching to complete reliance on the main coal source and physically cleaning that coal. Thus, coal cleaning may be a cost-effective SO/sub 2/ control strategy formore » individual plants, but its usefulness as a mandatory acid rain mitigation strategy is limited. PCC has other advantages, however, such as: reducing coal-transportation requirements (reduced secondary emissions and public safety hazards); producing a more uniform fuel; improving boiler efficiency by reducing slagging on boiler tubes; reducing load factors for ash-collection and handling systems; and improving overall plant availability. In addition, PCC may improve the performance and reduce the costs of operating an FGD system for SO/sub 2/ removal.« less