The electrolysis of simulated flue gas solution based on sulphite/sulphuric acid is reported. Two undivided cells were employed, a small batch cell and a sieve plate electrochemical reactor (SPER). With the batch cell, two anode materials were tested for the oxidation of sulphite to sulphate, platinum and graphite. Ebonex and zirconium cathodes were used in connection with both the anodes. High current efficiencies, above 85%, were obtained in all cases, without the formation of elemental sulphur. Comparable results, 85-95%, were obtained with the sieve plate electrochemical reactor, for a current density range of 10-25 mA cm(-2) at low sulphite concentration (0.005 M) in 2-6 M sulphuric acid.