In this investigation, the performance of a tower for absorption of sulphur dioxide gas into calcium carbonate solution has been studied. The trays had no downcomer and the tower itself was a scaled down pilot from industrial equipment. The industrial scale tower was used for clean up of 110000 m3/hr gas using 40 m3/hr alkaline solution. The study was composed of two parts. In the first section, hydraulic experiments were carried out and the pressure drops both for dry and wet trays were measured. The measured data were in good agreement with the correlations found in literature. In the second part of the study, the effect of operating parameters such as liquid flow rate, gas flow rate, alkaline solution concentration and sulphur dioxide concentration on the separation efficiency were investigated. Overall, it has been concluded that the separation of sulphur dioxide from air in this tower is always above 80% complete and the equipment offers fairly good efficiency in all the operating conditions considered. The main operating parameters were alkaline solution flow rate 500 – 2000 Lit/hr, alkaline solution concentration 0.1 – 3%, air/sulphur dioxide flow rate 0.15 – 0.4 m3/s and sulphur dioxide concentration in inlet air 100ppm.