In-stack condensible particulate matter measurements and issues

Particulate matter (PM) emitted from fossil fuel-fired units can be classif ied as either filterable or condensible PM. Condensible PM typically is not measured because federal and most state regulations do not require sources to do so. To determine the magnitude of condensible PM emissions relative to filterable PM emissions and to better understand condensible PM measurem ent issues, a review and analysis of actual U.S. Environmental Protection A gency (EPA) Method 202 (for in-stack condensible PM10) and EPA Method 201/2 01A (for in-stack filterable PM10) results were conducted. Methods 202 and 201/201A results for several coal-burning boilers showed that the condensib le PM, on average, comprises approximately three-fourths (76%) of the total PM10 stack emissions. Methods 202 and 201/201A results for oil- and natura l gas-fired boilers showed that the condensible PM, on average, comprises 5 0% of the total PM10 stack emissions. Methods 202 and 201/201A results for oil-, natural gas-, and kerosene-fired combustion turbines showed that the condensible PM, on average, comprises 69% of the total PM10 stack emissions . Based on these limited measurements, condensible PM can make a significan t contribution to total PM10 emissions for fossil fuel-fired units. A posit ive bias (indicating more condensible PM than is actually emitted) may exis t in the measured data due to the conversion of dissolved sulfur dioxide to sulfate compounds in the sampling procedure. In addition, these Method 202 results confirm that condensible PM, on average, is composed mostly of ino rganic matter, regardless of the type of fuel burned.