Separation of pollutants from flue gases during the combustion and gasification of fossil fuels.

摘要

The flue gas from combustion or gasification of fossil fuel contains flyash and other pollutants such as sulfur oxides, nitrogen oxides, alkali vapors and carbon monoxide. The other pollutants and the flyash are separated from the flue gas in a plurality of standleg moving granular-bed filter modules whose beds are composed of the ash from the combustion which is pelletized to form agglomerates of substantially greater volume than the particulate of which the ash as it leaves the combustor or gasifier is composed. The ash flows through the bed only once; it is not recycled. Each module includes a dipleg through which the ash flows into the standleg. The ash forms a first mass having a first frustro-conical surface in a frustro-conical member at the entrance to the standleg and a second mass having a second frustro-conical surface of substantially greater area than the first surface after is passes through the standleg. Sorbents and catalyzers are added to the ash in the pelletizer. The gas is fed tangentially into the module above the first surface. The pollutants are at least in part converted into solid particulate and atmospheric gases by the sorbents and catalyzers. The particulate and the flyash are captured on the first frustro-conical surface and any residual solids are captured in the bed. The processed gas flows out through the second frustro-conical surface. IMAGE