Measurements and correlations of solubility of N2O in and density, viscosity of partially CO2 loaded water-lean amino acid salts

Highlights: • Water-lean AAS have potential use for energy-efficient CO₂ capture. • Physical properties of ProK-based and LysK-based water lean systems were measured. • Experimental data were correlated as a function of T, m of AAS and/or CO₂. • The experimental and the predicted data matched well with AAD within 2.5%. A mixture system of water-lean amino acid salts (AAS) using ethylene glycol (EG) as a solvent has potential use for CO₂ capture to reduce energy consumption. In this work, physicochemical properties such as density, viscosity and N₂O solubility of potassium prolinate (ProK) or potassium lysinate (LysK) + water + EG solutions were measured over the temperature range from (303.15 to 353.15) K and molality range from (0.481 to 4.331) mol·kg⁻¹. Partially CO₂ loaded solutions were also investigated. Densities and viscosities of solutions increase with the increasing molality of AAS and CO₂, but decrease with the increasing temperature. The use of EG in the aqueous AAS systems replacing water can substantially increase the N₂O solubility. The Henry's constants of N₂O for water-lean AAS solutions were calculated and compared with those for aqueous AAS solutions. These experimental data of properties were correlated using empirical correlations as a function of temperature, molality of AAS and/or CO₂. The experimental results and the predictions from the models matched well each other for both ProK-based and LysK-based water lean systems, with AAD within 0.12% for density, 2.36% for viscosity and 2.0% for N₂O solubility respectively.