SUPPLEMENTARY CONTROL OF SO2 IS PRACTICAL AND COST-EFFECTIVE.

A study was made of methods of static and dynamic control of SO//2 emissions from power plant stacks. In static control changes in effective stack height are achieved by regulating stack gas temperature or/and velocity. In a dynamically controlled system continuous data from a network of SO//2 sensors are combined with short-term weather forecasts from meteorological instrumentation. They are used in a program supplemented by air pollution concentration simulation modeling. When this network determines that the ambient allocation is likely to be exceeded, the power company responds by reducing the emissions from the stack that is contributing most to the problem. The change will temporarily result in a more costly mix of operations. Simulation will be used to determine the least costly strategy. When a later prediction determines that the ambient allocation will not be exceeded, the utility resumes normal operation.