Reducing mercury emissions from combustion gas by burning coarser coal particles

摘要

A coal-fired power plant includes a combustion zone 24 for coal having a fineness of less than 70%200 mesh (0.075 mm) to produce combustion gas including carbon-containing fly ash and mercury, and a duct 52 wherein the mercury reacts with at least the carbon-containing fly ash. A sobent 54 such as activated carbon may also be injected into the duct 54. The coal fineness may also be greater or equal to 50%200 mesh, or greater or equal to 1%200 mesh. The coarseness of the coal increases the carbon in the flue gases in the duct 52, facilitating the reduction of mercury. Following sorbent injection fly ash and sorbent are collected in a particulate control device (PCD) 58, such as an electrostatic precipitator (ESP) or baghouse. The coal may be bituminous, Powder River Basin or lignite. Heat exchangers 26 heated by the furnace may include fuel cells.