The invention relates to a method and an installation for separating sulphur dioxide from exhaust gas, wherein sea water is added to the exhaust gas in an absorption column and the sea water charged with sulphur compounds is extracted from the liquid sump of the absorption column and fresh sea water is added thereto.In order to omit the very expensive and large secondary reaction basis according to the state of the art, it is proposed to extract the liquid, which contains the bisulphates, from the liquid sump of the absorption column and to mix it with fresh sea water in a pipeline for the purpose of sulphate formation and pH adjustment (neutralization).The invention is based upon the finding that the sulphate formation and pH adjustment are completed after a reaction time comprised between 1 and 2 minutes. Thus, the large and expensive secondary reaction basin can be omitted.