Mercury transformation behavior on a bench scale coal combustion furnace

The mercury release behavior in bituminous coals, and the partitioning rate of mercury in solids and gaseous in flue gases have measured to develop technologies for evaluating the partitioning of mercury in coal combustion process and develop in-situ adsorption and removal technologies using three kinds of experiment equipments - a thermo-balance, a drop-tube furnace (DTF), a bench-scale pulverized coal combustion furnace. The results showed that about 20 to 60% of the mercury in coal was released between 573 K and 673 K, which was the range of temperature in which the release of the volatile matter of coal began. And more than 90% of the mercury was released at 773 K, the temperature at which the release of the volatile matter was completed. The rate of mercury partitioned into bottom ash in a bench-scale pulverized coal combustion furnace was the smallest irrespective of the type of coal. The rate of mercury partitioned into cyclone ash was also low for all types of coal with values generally below 10%. The rest of the mercury was partitioned into mercury in gaseous form, but the rate partitioned into dust, oxidized mercury and elemental mercury varied slightly depending on the flue gas temperature and the type of coal.