PROCESS AND APPARATUS FOR REMOVING DUST, SULFUR COMPOUNDS AND NITROGEN OXIDES FROM COMBUSTION EXHAUST GASES

摘要

A process is described which serves to remove dust, sulfur compounds and nitrogen oxides from combustion exhaust gases and in which the dust-containing combustion exhaust gases are mixed with NH3 and are then supplied as fluidizing gas to a fluidized bed reactor, which contains mixed solids comprising fly ash, iron sulfates and the calcium compounds Ca(OH)2, CaCO3, CaO, CaSO4 and CaSO3 and is supplied with Ca(OH)2 and FeSO4 and is operated at a temperature between 300 and 450.degree.C, the combustion exhaust gases which have left the fluidized bed reactor are supplied to a multi-stage electrostatic precipitator, the solids collected in the first stage of the electrostatic precipitator are recycled to the fluidized bed reactor, and the solids collected in the further stages of the electrostatic precipitator are partly recycled to the fluidized bed reactor and partly discharged.