Mechanistic Investigation of Isobutanol/Isobutyl Acetate Separation by Extraction Using Low-Transition Temperature Mixtures

Abstract

In this work, low-transition temperature mixtures (LTTMs) are used for the first time in the separation of isobutanol (IBA) and isobutyl acetate (IBAC) by extraction, and the relationship between weak interactions and phase equilibrium behavior is systematically investigated. LTTMs are screened using the conductor-like screening model segment activity coefficient (COSMO-SAC), with ethylene glycol as the hydrogen bond donor (HBD) and benzyltrimethylammonium chloride, choline chloride, and tetramethylammonium chloride as the hydrogen bond acceptor (HBA). The effectiveness of the screened LTTMs is further demonstrated through liquid–liquid equilibrium (LLE) experiments, and the NRTL model is chosen to correlate the experimental data for process design. Finally, quantum chemical calculations provide insights into the effect of the structure of LTTMs on the LLE of the IBA/IBAC system, and the results show that the extraction properties are mainly dependent on the type of HBAs and increase with the enhanced electron-donating ability of the moiety.

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

“…Additionally, researchers also used lipids and alcohols as entrainers, such as propyl acetate identified as having entrainer properties in the azeotropic separation of 1-propanol and water, and the potential of isobutanol as an entrainer was explored for the azeotropic equilibrium between 1-propanol and water . The ILs have tens of thousands of species by the combination of cations and anions; therefore, the selective screening of ILs with COSMO-RS was carried out to separate the azeotropic system. − Simultaneously, the geometry configuration and energies for the components and ILs were optimized to validate the reasonability of the selected ILs by the DFT method. − However, the separation effect predicted for ILs becomes exceedingly dilemma due to the diverse types of ILs with various structures and properties. , …”