Boiler briquette coal versus raw coal: Part I - Stack gas emissions

Stack gas emissions were characterized for a steam-generating boiler common ly used in China. The boiler was tested when fired with a newly formulated boiler briquette coal (BB-coal) and when fired with conventional raw coal ( R-coal). The stack gas emissions were analyzed to determine emission rates and emission factors and to develop chemical source profiles. A dilution so urce sampling system was used to collect PM on both Teflon membrane filters and quartz fiber filters. The Teflon filters were analyzed gravimetrically for PM10 and PM2.5 mass concentrations and by X-ray fluorescence (XRF) for trace elements. The quartz fiber filters were analyzed for organic carbon (OC) and elemental carbon (EC) using a thermal/optical reflectance techniqu e. Sulfur dioxide was measured using the standard wet chemistry method. Car bon monoxide was measured using an Orsat combustion analyzer. The emission rates of the R-coal combustion tin kg/hr), determined using th e measured stack gas concentrations and the stack gas emission rates, were 0.74 for PM10, 0.38 for PM2.5, 20.7 for SO2, and 6.8 for CO, while those of the BB-coal combustion were 0.95 for PM10, 0.30 for PM2.5, 7.5 for SO2, an d 5.3 for CO. The fuel-mass-based emission factors tin g/kg) of the R-coal, determined using the emission rates and the fuel burn rates, were 1.68 for PM10, 0.87 for PM2.5, 46.7 for SO2, and 15 for CO, while those of the BE-c oal were 2.51 for PM2.5, 0.79 for PM2.5, 19.9 for SO2, and 14 for CO. The t ask-based emission factors tin g/ton steam generated) of the R-coal, determ ined using the fuel-mass-based emission factors and the coal/ steam convers ion factors, were 0.23 for PM10, 0.12 for PM2.5, 6.4 for SO2, and 2.0 for C O, while those of the BE-coal were 0.30 for PM10, 0.094 for PM2.5, 2.4 for SO2, and 1.7 for CO. PM10 and PM2.5 elemental compositions are also present ed for both types of coal tested in the study.