Compliance strategy for future capacity additions: The role of organic acid additives

The SO2 allowance program provisions of the Clean Air Act Amendments of 1990 require, beginning January 1, 2000, that owners of all new utility units must hold allowances equal to the annual tonnage of SO2 emissions from the unit. Utilities which are now planning capacity additions must include in their planning the means by which the necessary allowances will be obtained. For any utility which currently owns a generating unit equipped with an FGD system, overscrubbing the existing unit may be one source for the allowances necessary for future coal-fired capacity additions. By significantly increasing the SO2 removal efficiency performance of the existing FGD system, the utility can create a bank of unused allowances sufficient to meet the future needs of a new unit of similar capacity. This paper reports the results of evaluation of the technical feasibility, operational impacts, and cost effectiveness of this overscrubbing scenario. The advantages of using organic acid additives to reduce SO2 emissions from an existing wet limestone FGD system are discussed. The future availability and supply of organic acid additives are also addressed