Extractive Distillation with Ionic Liquid Entrainers for the Separation of Acetonitrile and Water

Abstract

Ionic liquids (ILs) of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAC]), 1-ethyl-3-methylimidazolium proline ([EMIM][PRO]), and N,N,N-dimethyl-butylethanol amine glycolic acid ([N 1,1,4 C 2 OH][GAC]) are selected as entrainers for the extractive distillation to separate the mixture of acetonitrile and water based on the COSMO-RS method. The isobaric vapor−liquid equilibrium of ternary mixtures containing ILs at atmospheric pressure is determined, verifying that the used ILs can break the azeotropy of acetonitrile and water. On the basis of the thermodynamic analysis, a typical extractive distillation process is designed with Aspen Plus to evaluate the competitiveness of IL entrainers in separation performance. Significant savings of entrainer and energy, in which the solvent ratios in moles reduce from 0.94 to 0.09, 0.12, and 0.12 and the overall heat duties on the reboiler decrease 24.9, 17.5, and 15.4% for [EMIM][OAC], [EMIM][PRO], and [N 1,1,4 C 2 OH][GAC], respectively, can be achieved compared with those of ethylene glycol used as the entrainer.

Process Designs for Separating R-410A, R-404A, and R-407C Using Extractive Distillation and Ionic Liquid Entrainers

“…Other authors have also modeled benzene/cyclohexane and the aromatic–aliphatic separation from naphtha . Designs for dehydration from systems such as ethanol, − tetrahydrofuran, tert -butyl alcohol, acetonitrile, and iso -propanol , have also been investigated with extractive distillation using ILs. Other proposed processes include the use of ILs to separate acetone/methanol, cyclopentane/neohexene, n -heptane/methylcyclohexane, and ethyl acetate/ethanol .…”

Design and optimization of extractive distillation of benzene–n‐propanol with ionic liquid as entrainer

“…[31][32][33] Process design and optimization Two distillation columns are required in the ED process: the first one is the extractive distillation column (EDC) and the other is the solvent recovery column (SRC). 34,35 The process flow sheets of ED are shown in Figs 1-3. In the EDC, the raw material feed conditions are as follows: flow rate is 100 kmol h −1 (50% mole fraction benzene, mainly to avoid the influence of the different content of benzene and n-propanol on the ED process and to simplify the simulation of the system), feed temperature is 25 °C, feed pressure is 1 bar, and the raw materials are fed from the middle part of the column.…”

Thermal conductivity of the ionic liquid [HMIm][Tf2N] with compressed carbon dioxide

“…Moreover, most ILs possess negligible volatility which is an advantage over conventional organic solvents where air pollution is a primary concern. Such exceptional properties of ILs allow for their potential use in a wide variety of applications such as interfacial films in catalytic reactions, 2,3 entrainers in extractive distillation, 4 high‐voltage electrolytes in lithium‐ion batteries and fuel cells, 5,6 stationary phases in gas chromatography, 7 solvents in gas separations, 8–16 heat‐transfer fluids in heat pumps and absorption refrigeration systems, etc 17,18…”