A 24-h real-time emissions assessment of 41 uncontrolled household raw coal combustion stoves in four provinces of Northern China

Air pollutants from household heating stoves are attracting growing public concern. Although several previous studies have investigated pollutant emissions from the household heating stoves, the emission factors reported might be less representative because most of the studies conducted the measurement only during the relatively short period for one combustion process, which is far from the real case. In this study, therefore, 24-h continuous measurements of CO, PM2.5, SO2, NOx, and CO2 emissions from the chimneys of household stoves fueled with raw coal in four provinces of Northern China were conducted during winter heating periods to reveal their actual emissions. The measured emission factors of CO, CO2, SO2, NOx, and PM2.5 were 6.163 +/- 2.113, 82.875 +/- 4.709, 0.190 +/- 0.113, 0.076 +/- 0.046, and 0.127 +/- 0.061 g/MJ for the radiant heating stove; 5.801 +/- 2.323, 86.602 +/- 8.376, 0.083 +/- 0.048, 0.062 +/- 0.033, and 0.119 +/- 0.081 g/MJ for the water heating stove, respectively. Compared with previously published results with relatively short-time measurements, a lower PM2.5 emission factor (p < 0.05) in this study were observed, but no significant difference for others. The difference of household stove emission factors may be caused by the testing method depending on the attribution of the combustion phase with short-time measurement, although no other factors such as fuel type and stove type were taken into account. More laboratory and field studies should be carried out to quantify those effects besides testing methods to develop the inventories of residential heating stoves in the rural areas for the north part of China with the 24-h field measurement.