A suggested process for removing sulphur oxides from boiler flue gases requires as a first stage the oxidation of sulphur dioxide to sulphur trioxide, followed by the removal of sulphur trioxide as ammonium sulphate or sulphuric acid. Only work on the first stage is reported in this paper. As little attention has been given previously to the catalytic oxidation of sulphur dioxide in flue gases, bench‐scale experiments with simple apparatus were made to examine the reaction under these conditions. Four vanadium pentoxide catalysts of differing composition were compared, and the best was then used in a brief study of the following variables: contact time, sulphur dioxide concentration, and oxygen concentration.
The results suggest that it might be technically feasible to oxidise the sulphur dioxide in flue gases, and that normal variations in flue gas composition would have little effect on the reaction.