Estimation of emissions of SO2, PM2.5, and metals released from coke ovens using high sulfur coals



Coal combustion processes have inherent characteristics that lead to the release of both gaseous and particulate matter in the atmosphere that have primary and secondary impact on air quality, human health, and climate. Coals from Northeastern region of India have high sulfur, low ash, and high volatile matter. In the present investigation, sulfur, metals and ash contents of feed coals were considered for making an emission inventory for these coals. For the calculation of emission factors of SO2 and metals, mass balance method was used, while for PM2.5, measured values near the coke ovens were taken. The emission factors and emission rates of SO2 for coke ovens ranged between 0.80 to 4.8 Kg/t and 204 to 1226 t/yr respectively. The emission factors for PM2.5, total carbon (TC), black carbon (BC) and organic carbon (OC) varied between 0.7 to 3 Kg/t, 0.48 to 2.1 Kg/t, 0.007 to 0.03 Kg/t and 0.47 to 2.1 Kg/t, respectively. Total emissions for PM2.5, TC, BC and OC ranged between 72–306 t/yr, 49–217 t/yr, 0.71–2.9 t/yr and 48–214 t/yr, respectively. Emission rates of metals (V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Te, Hg, Pb, and Bi) showed dependency on the volatility of the metals, condition of coke ovens (reductive) and rank of coal. Present investigation provides preliminary information on source profile of coke oven emissions (SO2, PM2.5 and trace metals) which is useful for assessing the impact of coke oven on ambient air quality, source apportionment study in the area and for designing the coke ovens to regulate the emissions. © 2010 American Institute of Chemical Engineers Environ Prog, 2011