Review of SO2 Control Alternatives for Colstrip Units No. 3 and No. 4

摘要

Montana Power Company is planning construction of two additional coal-fired electric generating units at its facility at Colstrip, Montana. Colstrip Units no. 3 and no. 4 will be equipped with scrubbers to remove particulates and sulfur dioxide, as required to meet New Source Performance Standards (NSPS) and Class I Prevention of Significant Deterioration (PSD) regulations. The objective of this study is to evaluate the SO2 control alternatives for Units no. 3 and no. 4. The design and performance of the scrubbers serving Units no. 1 and no. 2 are described. Sulfur dioxide emission rates from Units no. 3 and no. 4 are predicted, assuming a similar scrubber design and performance as reported for the existing units. Potential modifications to the planned scrubber design which might be expected to improve SO2 collection efficiencies are described. A brief summary of alternative SO2 control systems potentially available for Colstrip Units no. 3 and no. 4 is presented along with cost performance information and associated environmental and engineering sacrifices.