Absorption of CO2 in aqueous solutions of 2-methylpiperidine has been studied at different temperatures, pressures and amine compositions. The enthalpies of solution for carbon dioxide in aqueous solutions of 2-methylpiperidine were measured using a flow calorimetric technique and gas solubility limits were simultaneously estimated from the calorimetric data. A rigorous thermodynamic model of phase equilibria based on a γ–ϕ approach was used to represent the absorption of CO2 in aqueous solutions of 2-methylpiperidine. The model interaction parameters were adjusted using the experimental enthalpies of solution and vapor–liquid equilibrium data.