Measurement of PM2.5 and ultra-fine particulate emissions from coal-fired utility boilers

The new international regulations that limit the ambient PM2.5 levels necessitated reliable methods to monitor and report these very fine particulate matter emissions from contributing sources. Due to the inadequacies of conventional stack sampling methods, source dilution techniques were developed in particulate matter (PM) measurement from combustion sources to closely simulate realistic atmospheric conditions where hot stack gases transform to very fine secondary aerosols. Using such dilution samplers, a PM2.5 database from coal-fired utility boilers was initiated using field measurement results. Fuels include blends of Canadian subbituminous, Canadian lignite and US Powder River Basin coals. PM2.5 concentration results, along with their elemental and sulphate constituents found in emissions from utility boilers, are discussed in conjunction with coal feed properties. The nature of ultra-fine components found in stack emission is briefly reported.