Reducing pollutant content of crude gas from combustion plant

摘要

The pollutant content of crude gas from combustion plants is reduced by continuous addn. of a suspension of Ca(OH)2 to the area of the combustion chamber during operation of the plant. Pref. a 2-20% (10%) aq. suspension of Ca(OH)2 is used, in amt. of 0.9-2.7 wt.% Ca(OH)2 w.r.t. the material to be burned. The suspension may contain additives, esp. up to 10 wt.% of additive promoting absorption, esp. furnace coke. The suspension is fed to an area of the plant where the temp. is above 250 (250-800) deg.C, or into a combustion chamber or post-combustion chamber of the plant at a temp. of 800-1400 deg.C. It may be added to the heat-exchanger of a combustion plant, pref. in the inlet area, and may be sprayed as a mist, esp. by a system of nozzles controlled by compressed air. In plant for treatment of waste, etc., the suspension is sprayed into the combustion chamber at 600-1300 deg.C, using 0.5-2 wt.% of Ca(OH)2' w.r.t. material to be burned.