Portland cement clinker production using circulating fluidized bed boiler involves selecting solid desulfurizer from lime, clay, and/or iron ore, collecting ashes from boiler, removing sulfur adsorbed in ashes and cooling ashes

摘要

Production of Portland cement clinker as a by-product of a circulating fluidized bed (CFB) boiler fueled with high sulfur content fuel comprises selecting a solid desulfurizer from lime, clay, iron ore and their mixtures, collecting ashes evolving from the boiler, removing sulfur adsorbed in ashes by heating to 1200-1300 deg C, cooling the ashes and using them for the production of Portland cement. The desulfurizing agent mixture complies with the following conditions: LSF = %CaO/(2.8 * %SiO2 + 1.18 * %Al2O3 +0.65 * %Fe2O3) = 0.75-0.90; and MS = SiO2/(Al2O3 + Fe2O3) = 2.5-3.5. The cold ashes contain less than 5% CaSO4. Ashes evolving from the boiler are heated in a fluidized bed heater, in which tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite are formed. Hot gas from a combustion chamber is fed to the fluidized bed heater. Hot ashes are cooled with air in a fluidized bed cooler. Effluent gases from the fluidized bed heater are treated to produce sulfur, sulfuric acid and sulfur derivatives. Independent claims are given for (a) a method of operating the CFB boiler fueled with a high sulfur content fuel, preferably, petroleum coke, where the desulfurizing agent increases the overall efficiency of the boiler; and (b) a method of producing Portland cement clinker as a by product of the CFB boiler fueled with the high sulfur content fuel.