Determination and Modeling of Vapor–Liquid Equilibria for the Sulfuric Acid + Water + Butyl Acetate + Ethanol System

Abstract

A novel azeotropic distillation for sulfuric acid recovery, which uses organic solvents as entrainers, is proposed. This new distillation process may provide significant energy savings. Vapor–liquid equilibria (VLE) data were determined by the quasi-static ebulliometric method for the following systems at (30, 60, and 90) kPa: (1) sulfuric acid + water + ethanol; (2) sulfuric acid + water + butyl acetate; and (3) sulfuric acid + water + butyl acetate + ethanol. Through the use of the OLI software, a chemical model was established via regressing the experimental data to obtain the mixed solvent electrolyte (MSE) model parameters. The average absolute deviations of boiling points for all systems are only 1.34 K. The new model with newly obtained parameters was successfully applied to predict the VLE for the sulfuric acid + water + butyl acetate ternary system at constant pressure, providing important VLE information for the recovery of spent sulfuric acid by this new azeotropic distillation technology.

Determination and Correlation of Vapor–Liquid Equilibria for the Phosphoric Acid + Water + Cyclohexane + Ethanol System

“…The VLE data of the systems were determined by the ebulliometric method. The detailed representation of the equipment can be found in our earlier works. , Two calibrated microthermometers were used in the measuring of the boiling points. The total temperature uncertainty was estimated to be ±0.15 K, including an error of ±0.10 K for nonimmersed stem correction and an error of ±0.05 K for reading.…”

Investigation on Isobaric Vapor–Liquid Equilibria of the Isopropyl Acetate + Water + Ethanol System

“…The VLE data were investigated by the ebulliometric method, and the detailed description about the apparatus is presented in our earlier publication. 9 Two carefully calibrated mercury microthermometers were employed to determine the boiling points. The overall temperature uncertainty is about ±0.15 K, including a nonimmersed stem correction uncertainty of ±0.10 K and a reading uncertainty of ±0.05 K. The pressure variation caused by temperature fluctuation is calculated to be within ±0.7%.…”

A new process for fuel ethanol dehydration based on modeling the phase equilibria of the anhydrous MgCl2 + ethanol + water system

“…The temperature for the condensation of the vapor phase was 275 K. To ensure no condensation occurs in the equilibrium chamber, the right side of the still is covered by a vacuum jacket. The pressure of the whole system was controlled as in Li et al [40][41][42] An inclined ebulliometer 43 is connected with the still to indicate the pressure. The temperature of the still and ebulliometer is measured by calibrated mercury thermometers with an uncertainty of 60.15 K, which causes a pressure uncertainty of 60.6 kPa.…”