| abstract |
A continuous process for the combustion of solid fuels in a fluidized bed of solid particles under conditions such that flue gas is essentially free of dust and oxides of sulfur and nitrogen. Fuel is charged as an aqueous slurry and additional water condensed from the flue gas is recycled to the combustion zone. Combustion is promoted both by water vapor and alkali added with fuel slurry, while the alkali serves also to neutralize and remove sulfur in completely oxidized, or sulfate, form. Useful heat is recovered from the hot gases leaving the combustion zone and, in some cases, from the fluidized bed itself. Under the pressure of the system recovery of heat results in condensation of water which serves to scrub dust from the flue gas, slurry product ash and furnish recycle water, which controls reaction temperature as well as promoting the combustion. |