Current and future emissions of primary pollutants from coal-fired power plants in Shaanxi, China

A high-resolution inventory of primary atmospheric pollutants from coal-fired power plants in Shaanxi in 2012 was built based on a detailed database compiled at unit level involving unit capacity, boiler size and type, commission time, corresponding control technologies, and average coal quality of 72 power plants. The pollutants included SO₂, NO_x, fine particulate matter (PM_2.5), inhalable particulate matter (PM₁₀), organic carbon (OC), elemental carbon (EC), carbon monoxide (CO) and non-methane volatile organic compounds (NMVOC). Emission factors for SO₂, NO_x, PM_2.5 and PM₁₀ were adopted from standardized official promulgation, supplemented by those from local studies. The estimated annual emissions of SO₂, NO_x, PM_2.5, PM₁₀, EC, OC, CO and NMVOC were 152.4, 314.8, 16.6, 26.4, 0.07, 0.27, 64.9 and 2.5kt, respectively. Small units (<100MW), which accounted for ~60% of total unit numbers, had less coal consumption but higher emission rates compared to medium (≥100MW and <300MW) and large units (≥300MW). Main factors affecting SO₂, NO_x, PM_2.5 and PM₁₀ emissions were decontamination efficiency, sulfur content and ash content of coal. Weinan and Xianyang were the two cities with the highest emissions, and Guanzhong Plain had the largest emission density. Despite the projected growth of coal consumption, emissions would decrease in 2030 due to improvement in emission control technologies and combustion efficiencies. SO₂ and NO_x emissions would experience significant reduction by ~81% and ~84%, respectively. PM_2.5, PM₁₀, EC and OC would be decreased by ~43% and CO and NMVOC would be reduced by ~16%.