Emission of mercury from six low calorific value coal-fired power plants

The feed fuel, bottom ash, fly ash, limestone and gypsum have been sampled in six low calorific value coal-fired power plants in Shanxi province, China. The emission of mercury (Hg) from the six power plants was conducted. The results showed that about 98% of Hg in feed fuel can be released out in the form of gaseous Hg. Electrostatic precipitator (ESP) and fabric filter (FF) used in the six power plants present higher Hg removal efficiencies. About 58.83-88.00% of Hg is highly enriched in fly ash removal by ESP and FF. Furthermore, less than 12% of Hg is transferred into the gypsum. The average Hg emission factor for low calorific value coal-fired power plants in this study is 52.55 μg/kW·h, which is significantly higher than that of coal-fired power plants due to the higher Hg content and the lower net calorific value in feed fuel.