Measurements and correlations of solubility of N 2 O in and density, viscosity of partially CO 2 loaded water-lean amino acid salts

Abstract

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.