Isobaric Vapor–Liquid Equilibrium Experiment of N-Propanol and N-Propyl Acetate at 101.3 kPa

Abstract

N-Propanol (NPA) and n-propyl acetate (NPAC) can form an azeotrope under normal pressure, so their separation cannot be carried out by conventional distillation. Therefore, 1-butyl-3-methylimidazole acetate ([BMIM][OAC]) and ethylene glycol (EG) were selected as entrainers for extractive distillation of the two substances. Isobaric vapor–liquid equilibrium data were obtained by experiments of NPA + NPAC, NPA + NPAC + [BMIM][OAC], and NPA + NPAC + EG at normal pressure; the experimental results showed that the separation effect of [BMIM][OAC] is significantly better than that of EG. Finally, the data were fitted and correlated with the NRTL model. The ARD (average relative deviation) of NPA + NPAC, NPA + NPAC + [BMIM][OAC], and NPA + NPAC + EG is less than 5%, indicating that the NRTL model has good applicability to the vapor–liquid system.

Vapor–Liquid Equilibrium Experiment and Thermodynamic Correlation of n-Propanol + n-Propyl Acetate + 1-Ethyl-3-methylimidazolium Acetate and 1-Hexyl-3-methylimidazolium Acetate

“…Experimental VLE data of n -propanol + n -propyl acetate and thermodynamic consistency test have been shown in Figure and Table S3, respectively. Figure also contains the comparison with the literature , (ref ). Besides, Fredenslund test, van Ness test, and Herington test − were also introduced to complete the thermodynamic consistency of n -propanol + n -propyl acetate.…”

“…n -Propanol and n -propyl acetate are the commonly used organic solvents in industry, and n -propyl acetate can be produced by the esterification reaction of n -propanol and acetic acid under the catalysis of concentrated sulfuric acid. , In this process, a system where n -propyl acetate and n -propanol coexist will be generated, and the two substances will form an azeotropic point, which makes it impossible for them to be separated completely through common distillation.…”

Isothermal Vapor–Liquid Equilibrium Data for a Binary System of (−)-α-Pinene + (−)-Limonene and a Quaternary System of (−)-α-Pinene + (−)-Limonene + Water + Ethephon at 313.2, 323.2, and 333.2 K

“…The criterion of the Van Ness point test is less than 1 . The method is shown in eq . − where N denotes the number of experimental data, superscript “exp” represents the experimental data, and superscript “cal” represents the calculated data. The values of y i , cal used in the test were obtained from the UNIQUAC model.…”

Measurement and Correlation of Isobaric VLE Data for 1-Propanol + Water + 1-Butyl/Decyl-3-methylimidazole Bromide/Nitrate ILs at 101.33 kPa

“…As this process involved water, impurities of water were often present in the 1-propanol produced. − The task of obtaining high-purity 1-propanol was challenging due to the formation of azeotropes at specific concentration ratios, caused by the small 2.6 °C difference between the boiling points of 1-propanol and water . Hence, choosing the suitable separation technique becomes crucial for the 1-propanol + water azeotropic system. − Various techniques can be utilized to separate azeotropes, such as pressure swing distillation, adsorption separation, membrane separation, and extractive distillation. Pressure swing distillation requires complex equipment and consumes significant energy, adsorption separation necessitates regeneration steps, and membrane separation may be affected by membrane degradation. , In contrast, extractive distillation can be conducted at atmospheric pressure, reducing energy consumption and requiring less complex equipment while offering higher separation efficiency.…”