Investigation of pollutant‐removal performance and energy efficiency characteristics of wet electrostatic precipitator

Energy conservation and efficiency enhancement are the options to achieve carbon neutrality in coal‐fired power plants. Wet electrostatic precipitator (WESP) is an important pollutant removal and energy consumption equipment in coal‐fired power plants, which emits a large amount of CO2 indirectly and has a great potential for emission reduction. In this paper, the emission reduction characteristics of multiple pollutants and energy consumption were analyzed by collecting 158 datasets of WESP. The results showed that WESP was effective at removing PM, PM2.5, SO3, droplets, and Hg with the following concentrations at the outlet: 1–10, 3, 1–5, 15, and 5 µg/m3, respectively. The emission factors of different pollutants were sorted in the descending order of size as droplets (average value 51.59 g/MWh), PM (19.15 g/MWh), SO3 (17.32 g/MWh), PM2.5 (8.21 g/MWh), and Hg (9.74 mg/MWh). Specific power/water/alkali consumptions were found as 0.5–2.5×10–4 kWh/m3, 10 × 106 t/m3, and 0.06–9.79 ×10–8 t/m3, respectively. These consumptions were negatively correlated with the inlet concentration of PM/SO3. The average annual emission of CO2 per unit installed capacity by the application of WESP was found to be 13.88 t/MW. It was estimated that the CO2 annual emissions by using WESP in coal‐fired power plants in China were 1.68×106 t. The CO2 annual emission reduction of 7.33×105 t could be achieved through grade 2 energy efficiency WESP (7.83 t/MW) of GB/T 37484‐2019. A further reduction of 3.18×105 t could be achieved if it could be controlled at grade 1 (5.20 t/MW). This study can provide a valuable reference for the subsequent operation of ultra‐low emission units to conserve energy and reduce CO2 emissions. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.