Process and plant for the purification of flue gas

摘要

The invention relates to a process for the purification of flue gas in which the flue gas is desulphurised by scrubbing with a lime-containing suspension and then the nitrogen oxides are catalytically selectively reduced by mixing with ammonia, and an apparatus for carrying out this process. According to the invention, the desulphurised flue gas, prior to the catalytic reduction of the nitrogen oxides, is heated by regenerative heat exchange with the clean gas and by supply of additional heat to the NOx reduction temperature of 220 to 270 DEG C. <IMAGE>