A major consideration for post-combustion CO₂ capture is the adverse effect of the presence of SO₂ on the absorption desorption process. The most common approach is to remove the SO₂ from the flue gases in a flue gas desulfurization (FGD) unit prior the CO₂ recovery process. This paper reports the experimental and modeling results of a new process for simultaneous removal of CO₂ and SO₂ for post-combustion applications. This process is named CASPER (CO ₂-capture And Sulphur Precipitation for Enhanced Removal), and is based on the precipitation of K₂SO₄ for sulphur removal. The selected CO₂ absorbing solvent is an amino-acid, preferably a potassium amino-acid salt solution. The presence of potassium leads to the subsequent formation of K₂SO₄, which solubility in the CO₂ loaded aqueous solvent solution changes depending on the applied conditions. The optimal crystallization conditions were first determined by characterization of K₂SO₄ solubility window and then evaluated in the lab-scale crystallization unit. In the next step the model system based on potassium beta-alanate solutions, also with addition of sulphate, were tested for CO₂ absorption and desorption pressures by performing VLE (Vapor Liquid Equilibrium) measurements at 40°C and 120°C, respectively. Obtained values were included in preliminary technical assessment, which showed an energetic improvement of 0.7%-points for the CASPER model solvent system in comparison to the baseline 30wt% MEA case.