Measurement of vapour-liquid equilibrium and e-NRTL model development of CO2 absorption in aqueous dipropylenetriamine

AbstractSimulation of a hydrocarbons mixture separation by extractive distillation was based on binary vapor-liquid as well as liquid-liquid equilibrium data. Sulfolane was considered as extractive solvent for the selective toluene separation from a model mixture with heptane. For simulation of the chosen hydrocarbons mixture separation in the presence of an extractive solvent, the NRTL model was considered. A set of temperature-dependent binary NRTL parameters was evaluated independently by fitting the experimental vapor-liquid and liquid-liquid equilibrium data of the respective binary subsystems. In order to improve the description of the ternary vapor-liquid equilibrium, original NRTL model extended by the ternary contribution term was used. Parameters of the ternary contribution were obtained by direct fitting of available ternary liquid-liquid equilibrium data while employing the original binary NRTL parameters. Quality of the ternary vapor-liquid-liquid equilibrium description using the original and the extended excess Gibbs energy models was assessed by comparing the calculated compositions of conjugate liquid phases with experimental data. Using the extended NRTL model, mean deviation of the computed mole fractions decreased by approximately four times (9.73 × 10−3) compared to the value obtained using the original NRTL model. Both original and extended NRTL models were employed for the simulation of a model mixture separation by extractive distillation. At chosen experimental conditions, high purity distillate (x 1 > 0.999) was obtained. Results of the aromatics extractive distillation in the presence of sulfolane were compared to those obtained with N-methylpyrrolidone as the extractive solvent.

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Liquid-liquid equilibrium constant for acetic acid in an olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water system

Hemijska industrija ◽

10.2298/hemind141210024j ◽

2016 ◽

Vol 70 (2) ◽

pp. 165-175 ◽

Cited By ~ 1

Author(s):

Milovan Jankovic ◽

Olga Govedarica ◽

Snezana Sinadinovic-Fiser ◽

Jelena Pavlicevic ◽

Vesna Teofilovic ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Acetic Acid ◽

Olive Oil ◽

Equilibrium Constant ◽

Water System ◽

Liquid Equilibrium ◽

Nrtl Model ◽

In Situ Epoxidation ◽

Flash Calculation ◽

Activity Coefficient Models

The liquid-liquid equilibrium constant for acetic acid in a quinary system olive oil-epoxidized olive oil-acetic acid-hydrogen peroxide-water was experimentally determined for temperatures and component ratios relevant for in situ epoxidation of plant oils. The values has the constant range from 1.52 to 2.73. To predict the equilibrium constant for acetic acid, the experimental data were correlated with UNIQUAC (universal quasi chemical) and NRTL (non-random two liquid) activity coefficient models. For simplified calculation of the phase equilibrium the insolubility of olive oil and epoxidized olive oil in the water, as well as insolubility of water and hydrogen peroxide in the olive oil and epoxidized olive oil, was assumed. The root mean square deviation (RMSD) of the experimental and calculated values of the liquid-liquid equilibrium constant for acetic acid is 0.1910 for the UNIQUAC model and 0.1815 for the NRTL model. For rigorous flash calculation, when the partitioning of all components between the phases was assumed, the RMSD for the NRTL model is 0.1749.

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