Control of particulate and SO/sub 2/ emissions from an industrial boiler plant

Determination of the most economical route to control industrial-boiler-plant particulate and SO/sub 2/ emissions for a specific site requires an in-depth analysis of the factors applicable to that site. The major factors are fuel cost and availability, how they are expected to vary with time, the confidence in the forecast, and the relative technical risk of pollution-control alternative selection. This evaluation resulted in several conclusions for the specific site, based on many judgement factors as well as economic evaluations. Natural gas or No. 2 fuel oil when gas is not available is the preferred route so long as current price and availability forecasts hold. On a cash-flow basis, the most economic alternative to natural gas and No. 2 oil is 0.7 percent-sulfur coal using either bag filters or electrostatic precipitators. However, this conclusion is valid only if the fuel price differential between low- and high-sulfur coal holds as forecast. SO/sub 2/ control is entirely dependent upon an assumed 10-yr supply of 0.7 percent-sulfur coal. Tail-end limestone flue gas scrubbing offers the greatest potential on an annual operating-cost basis. However, investment is high and risk is great, as system reliability has not been demonstrated. This should be the preferred route becausemore » it permits the use of the nation's most abundant fuel resource. However, more demonstration of technology is required before the investment risk is reasonable. The following program has been adopted at the site involved to prepare for the time when natural gas is not an available boiler fuel: continuing with natural gas and No. 2 oil as long as possible, maintaining an ongoing program to determine if flue gas scrubbing is practical, and staying intimately familiar with all changes in fuel prices and availability. (Gas Abstr.)« less