초록 ▼

A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from

A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

대표청구항 ▼

A method for burning sulfur-containing fuel in a circulating fluid bed combustion system which comprises: (a) introducing recycle oxidized solids comprising predominantly alkaline oxide and alkaline sulfate to a primary combustion zone; (b) introducing fresh alkaline sorbent to the circulating fluid

A method for burning sulfur-containing fuel in a circulating fluid bed combustion system which comprises: (a) introducing recycle oxidized solids comprising predominantly alkaline oxide and alkaline sulfate to a primary combustion zone; (b) introducing fresh alkaline sorbent to the circulating fluid bed combustion system; (c) introducing sulfur-containing fuel to the primary combustion zone; (d) introducing sufficient primary air to the primary combustion zone to burn the sulfur-containing fuel under partial oxidation conditions and produce reducing gas and entrained solids comprising alkaline sulfate, alkaline oxide, and alkaline sulfide; (e) introducing the reducing gas and the entrained solids to a secondary combustion zone; (f) introducing sufficient secondary air to the secondary combustion zone to burn substantially all the reducing gas and produce oxidized combustion gas having a low sulfur content and entrained solids containing alkaline sulfide; (g) introducing the combustion gas having a low sulfur content and the entrained solids containing alkaline sulfide to a gas/solids separation zone and recovering separated solids containing alkaline sulfide therefrom; (h) introducing separated solids containing alkaline sulfide to a solids oxidation zone and introducing sufficient air to the solids oxidation zone to convert substantially all of the alkaline sulfide in the separated solids to alkaline sulfate; (i) recovering oxidized solids comprising predominantly alkaline oxide and alkaline sulfate from the solids oxidation zone; (j) recovering at least a major portion of the oxidized solids as the recycle oxidized solids; and (k) recovering the combustion gas having a low sulfur content from the gas/solids separation zone.