Measurement of vapour-liquid equilibrium and e-NRTL model development of CO2 absorption in aqueous dipropylenetriamine.
Neha Kumari Agarwal, Bikash Kumar Mondal, Amar Nath Samanta
Environmental science and pollution research international April 1, 2021 Peer reviewed DOI: 10.1007/s11356-020-12019-w via PubMed
Summary
The study investigates the vapour-liquid equilibrium (VLE) of CO2 in aqueous dipropylenetriamine (DPTA), demonstrating that DPTA has a higher CO2 loading capacity than conventional solvents like MEA and AMP, as well as newer polyamine solvents. CO2 solubility was measured at temperatures from 313 to 333 K and pressures from 1 to 100 kPa, with DPTA concentrations between 5-15 mass%. The e-NRTL model effectively correlated the experimental data, achieving an average absolute deviation of 22.3%.
Study at a glance
| Key finding | Aqueous dipropylenetriamine (DPTA) exhibits a higher CO2 loading capacity compared to several conventional and newly developed solvents. |
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Abstract
Vapour-liquid equilibrium (VLE) of CO2 in aqueous dipropylenetriamine (DPTA) is investigated experimentally using a stirred equilibrium cell setup. Equilibrium solubility of CO2 is measured in the temperature and pressure range of (313-333) K and (1-100) kPa respectively. Composition of aqueous DPTA solvent used for the absorption study is in the range of (5-15) mass%. Experimental data shows higher CO2 loading capacity of this solvent compared to conventional solvents like monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), and N-methyldiethanolamine (MDEA) as well as recently developed polyamine solvents like aminoethylethanolamine (AEEA), piperazine (PZ), and hexamethylenediamine (HMDA). Experimental VLE data is then correlated using the electrolyte non-random two-liquid (e-NRTL) theory which is an activity coefficient-based model for the electrolyte system. Data regression system (DRS) in Aspen Plus® (V8.8) is employed to fit the e-NRTL model equation with the experimental data by regressing the model parameters. Model-predicted data is found to be in good agreement with the experimental VLE data with an average absolute deviation of 22.3%. Performance of aqueous DPTA solvent is also analysed by predicting solvent capacity, equilibrium liquid-phase speciation, and heat of CO2 absorption using the newly developed e-NRTL model for the investigated system.