method for simultaneous dry absorption of as amp; darr; 2 amp; darr; and no amp; darr; x amp; darr;

摘要

It is known that the addition of, for example, limestone or dolomite, quick-lime or dolomite lime, calcium hydrate or dolomite hydrate, to coal or to the heating oil of furnaces, in particular fluidized bed furnaces, reduces the SO2?, HCl and HF pollution contained in the fumes emitted. It has now been found surprisingly that in the 350-450?oC range particles of suitably pre-treated calcium-containing sorbents can be blown in or fluidized. The sorbent particles of quick-lime or dolomite lime produced by calcination of limestone or dolomite or calcium (aluminium) silicates in the fluidized bed display a special porous structure with a pore diameter of around 10 nm (ten millionths of a mm). A carrier which is expanded in this manner, for example fluidized bed calcinated lime or calcium hydrate produced with steam, but always enriched with ammonium salts, is brought to the pre-determined temperature range of 350 to 450?oC so that not only are the acid components such as SO2?, HCl, HF bound, but also the reduction of nitrogen oxides to nitrogen and steam by the ammonia released is effected without the combustion of ammonia into newly-formed nitrogen oxides.