Process for the desulphurisation of flue gas and reactor usable for this

摘要

The invention relates to a process for the desulphurisation of flue gases, in which a part-stream of the SO2- and/or SO3-containing flue gases which is required to maintain the maximum permissible emission limit values and is controllable in relation to the furnace throughput is impinged with NaOH-containing scrubbing solution in a scrubber for the absorption of SO2/SO3 as sodium hydrogen sulphite in the acidic pH range and then is added back to the main stream, characterised in that the scrubbing solution used is NaOH-containing waste water; in that the acidic sodium hydrogen sulphite solution leaving the scrubber is neutralised in a neutraliser with further NaOH-containing waste water to form sodium sulphite; in that the sodium sulphite solution is then treated with air in an oxidation stage, with sodium sulphite being converted into sodium sulphate; and in that, finally, the neutral sodium sulphate solution is supplied for waste water disposal, and to a reactor for use in such a process.