Process for removal of SO
A process for removal of SO 2 in off-gases having a temperature of 30-150° C. and containing 0.001-1 vol % SO 2 in which the SO 2 is oxidised to H 2 SO 4 by spraying an aqueous solution of H 2 O 2 into the off-gas upstream of an aerosol filter removing the produced sulphuric acid from the off-gas.
1. A process for removal of SO 2 in off-gases having a temperature of 50-120° C. and containing 0.001-0.1 vol % SO 2 , comprising the steps of:
oxidizing the SO 2 to H 2 SO 4 without the use of an absorption tower by spraying an aqueous solution of H 2 O 2 into the off-gas upstream of an aerosol filter to form H 2 SO 4 by reaction in the gas phase between SO 2 and H 2 O 2 ; and
removing the produced sulphuric acid from the off-gas in the aerosol filter.
2. A process as in claim 1 , in which the off-gas is cooled by evaporation of the water comprised in the solution being sprayed into the off-gas upstream of the filter.
3. A process as in claim 1 , in which a wet electrostatic separator is used in place of an aerosol filter.