Cooled naoh flue gas scrubbing prior to co2 removal

Abstract

In a process for removing pollutants from a flue gas stream (31) formed in the firing of a fossil fuel in a combustion chamber of a power station in a plurality of process stages (1, 2, 3), which comprise a first process stage (1) in which the flue gas stream (31, 9, 10) is subjected to gas scrubbing with a first chemical absorbent (6), and a process stage (3) which precedes the first process stage (1), in which the flue gas stream (31) is subjected to a flue gas desulphurization treatment (11) with a calcium-containing chemical absorbent (32), a solution should be provided which makes it possible to reduce the pollutant and solids contents of a flue gas stream formed in the combustion of fossil fuels, in particular coal, to the extent that directly after, with sufficient service life CO2 separation can be carried out continuously by means of a flue gas scrubber and can be integrated into the exhaust gas purification of a power station, in particular coal power station. This is achieved in that, in the first process stage (1) in at least one first absorber (4, 4a, 36) or flue gas scrubber, a flue gas scrubbing is carried out by means of caustic soda solution or a sodium-hydroxide-containing solution which is fed to the flue gas stream (31, 9, 10) as the first chemical absorbent (6), wherein at least some of the caustic soda solution or sodium-hydroxide-containing solution in this first process stage (1) is returned (13), preferably in circulation, outside the flue gas stream (31, 9, 10) to the site of feeding this chemical absorbent (6) to the flue gas stream (31, 9, 10) and in the course of its return (13), before reaching the site of feeding to the flue gas stream (31, 9, 10) is cooled (16) outside the flue gas stream (31, 9, 10) and/or wherein the flue gas stream (31, 9, 10) is cooled within the first absorber (4, 4a, 36) or flue gas scrubber by means of a cooler or heat exchanger arranged therein.

Dependencies are inferred from the claim text.