METHOD FOR THE CLEANING OF OFF-GAS

摘要

The present invention relates to a method for cleaning off-gas comprising the following steps: 1. sulphur dioxide is separated from the off-gas by way of at least one first scrubber stage (c) by means of ammonia or ammonium compounds, 2. the off-gas is transferred into a second scrubber stage (d) and 3. in the second scrubber stage the sulphur dioxide not separated in the first scrubber stage (c), is oxidised to sulphuric acid and separated in at least one scrubber (d) and simultaneously, the ammonia released in the first scrubber stage (d) is separated by means of the formed sulphuric acid, whereby ammonium sulphate is formed, 4. the separated stream of the second scrubber stage (d) is transferred into the first scrubber stage (c).