Using the carbon balance method based on fuel-weighted average concentrations to estimate emissions from household...

In China, household coal burning accounts for a large proportion of primary fine particulate matter (PM_2.5), black carbon (BC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs) and carbon monoxide (CO) emissions. Previous field investigations generally measured short-term emissions from heating coal stoves, which did not provide a full characterization of the actual conditions in most cases, or resulted in large uncertainties in the calculated emission factors (EFs). In this study, we propose a sampling design using a chimney partial-capture dilution system in the field measurement of household coal-fired heating stoves emissions during selected periods within the different burn phases and then using the carbon balance method (CBM) based on fuel-weighted average concentrations (FWAC) from the different burn phases to quantify emissions. We evaluated this proposed methodology by comparing the results with a laboratory total-capture dilution-tunnel system. Statistical analysis indicated that emissions measured during the selected burn cycle periods using the dilution sampling system can generally represent emissions at different burn phases; however, different dilution ratios can affect EFs for PM_2.5 and OC. EFs of air pollutants derived by CBM with FWAC are more representative of the actual emissions than simple average concentration (SAC) and time-weighted average concentrations (TWAC). In the field application, to quantify FWAC, it is suggested to determine the ratio of power in the jth burn phase (P_j) to that in the high power phase (P_H) of the stove, i.e., P_j/P_H values with the calorimeter. If measured P_j/P_H values are not available, the recommended value in this study is also suggested.