METHOD OF REDUCING SULFUR DIOXIDE CONTENT IN FLUE GAS EMANATING FROM A CIRCULATING FLUIDIZED BED BOILER PLANT

摘要

A method of reducing sulfur dioxide emissions in a circulating fluidized bed boiler plant (10) comprising: supplying sulfur-containing carbonaceous fuel to a furnace (12) of a boiler; Supplying a calcium carbonate-containing adsorbent having a predetermined d50 particle size to the furnace; Supplying an oxygen-containing gas to the furnace and burning the fuel with oxygen, thereby oxidizing the sulfur to sulfur dioxide; Calcining the calcium carbonate with calcium oxide in the furnace and sulfating the first portion of the sulfur dioxide with calcium sulfate in the furnace utilizing a portion of the calcium oxide; Discharging flue gases containing a second portion of sulfur dioxide, and particles comprising calcium oxide particles, accompanied by flue gases, from the furnace; Separating the first portion of entrained particles from the flue gases in a particle separator (14) having a cutoff size and returning the separated particles to the furnace (12); Conveying a second portion of the entrained particles from the furnace (12) with flue gases to a semidry sulfur reduction stage (38, 52) disposed downstream of the furnace; And reducing the sulfur dioxide content of the flue gases at the semi-dry sulfur reduction stages (38, 52), wherein the predetermined d50 particle size of the calcium carbonate containing adsorbent is less than 50% of the cut- A method for reducing sulfur dioxide emissions in a plant (10).