Vapor–liquid equilibrium in aqueous amine amino acid salt solution: 3-(methylamino)propylamine/sarcosine

Vapor–liquid equilibrium (VLE) measurements were conducted for both unloaded and CO2 loaded aqueous amine amino acid salt (AAAS) solutions; 3-(methylamino)propylamine/sarcosine (SARMAPA). Vapor–liquid equilibrium for unloaded solutions for 1.0–5.0 M SARMAPA were measured using a Swietoslawski ebulliometer for temperatures 40–100 °C and for total pressures 4.08–99.1 kPa. CO2 equilibrium was determined for loaded 5 M SARMAPA using low and high temperature VLE apparatuses from 40 to 120 °C. A thermodynamic model representing equilibrium in the H2O–AAAS–CO2 system was developed using the extended UNIQUAC thermodynamic framework. The developed model predicts simplified speciations in H2O–SARMAPA–CO2 system and adequately correlates the experimental total and partial pressure data with an average absolute deviation of 8.9%.

► LE experiments for H2O-amine amino acid salt (AAAS) system, SARMAPA (40-100oC).
► VLE experiments for H2O-SARMAPA-CO2 system (40-120oC).
► Dissociation constant determination for aqueous SARMAPA (20-60oC).
► Thermodynamic modeling of AAAS system using extended UNIQUAC.
► Speciation in aqueous SARMAPA system.