Thermodynamic Properties of {Diethyl Phosphate-Based Ionic Liquid (1) + Ethanol (2)} Systems, Experimental Data and Correlation

Abstract

In this work, three solutions consisting of ionic liquid and ethanol were considered for forward-looking use in absorption refrigeration technology. It is proposed to use the following ionic liquids as absorbents: 1-ethyl-3-methylimidazolium diethyl phosphate (abbreviated as [EMIM]­[DEP]), 4-ethyl-4-methylmorpholinium diethyl phosphate ([EMMOR]­[DEP]), and 1-ethyl-1-methyl-pyrrolidinium diethyl phosphate ([EMPYR]­[DEP]). Since the thermodynamic and physicochemical properties of working fluids determine the efficiency of the refrigerator while looking for alternative operating fluids, it is crucial to perform their extensive characteristics. Therefore, in this work, (vapor + liquid) phase equilibria (VLE), liquid density (ρ), and dynamic viscosity (η) were determined for the ethanolic solution of the three mentioned diethyl phosphate-based ionic liquids. The isothermal VLE was measured by an ebulliometric method within a temperature range from T = (328.15 to 348.15) K with an increment of 10 K and pressures up to 90 kPa. Non-random two-liquid (NRTL) equation with temperature-dependence parameters was used to correlate experimental data. Physicochemical properties including liquid density and dynamic viscosity were determined at temperatures from (293.15 to 338.15) K at ambient pressure over the whole concentration range. These properties were correlated using empirical equations. From experimental density and viscosity data, the excess molar volumes and the deviations from additivity were determined and correlated using the Redlich–Kister-type equation. Two of the tested ILs, [EMMOR]­[DEP] and [EMPYR]­[DEP], were synthesized and characterized using NMR analysis. The thermophysical characterizations of pure compounds, including glass transition temperature (T g) and heat capacity at the glass transition temperature (Δg C p), have been determined using a differential scanning calorimetry technique (DSC) at atmospheric pressure. The work presented is a combination of basic studies on the effect of the cation structure of an ionic liquid on the properties of their solutions with ethanol, with the possibility of future application of the tested systems in a viable refrigeration system.

A Zinc–Bromine Battery with Deep Eutectic Electrolytes

“…[ 24–27 ] Similarly, the DES electrolyte showed a down‐field shift (deshielding) of the methyl group peaks, whereas an up‐field shift (shielding) was noted for the peaks related to the ethyl group compared to the powder MEPBr, depicting the stabilization process observed in the DFT results. [ 28 ] These results, therefore, indicate that the conformation of MEPBr readily changes to allow Br − to form a Zn‐halide complex anion with Zn halide salts. The redistribution of Br − in the DES is quite feasible considering the much greater binding energy between Br − and Zn 2+ (− 14.1 eV) in comparison with that between MEP + and Br − (− 4.2 eV).…”

Physicochemical and Thermodynamic Investigation of Ethanolic Solution of Phosphonium-Based Ionic Liquids─Measurements, Correlations, and Application to Absorption Cycles

“…Experimental and literature value of the activity coefficient of water, γ 2 , vs ionic liquid mole fraction, x 1 , for (a) {[cation]­[DMP] (1) + ethanol (2)} ⧫, [C 1 C 1 IM]­[DMP] (this work); red diamond solid, [C 1 C 2 IM]­[DMP] (this work); yellow diamond solid, [N 1,2,2,2 ]­[DMP]; blue diamond solid, [C 1 C 2 PIP]­[DMP]; ◊, [C 1 C 2 PYR]­[DMP]; green diamond solid, [C 1 Py]­[DMP] (this work); pink diamond solid, [C 1 C 2 MOR]­[DMP]; purple diamond solid, [C 1 C 2OH PYR] [DMP] binary systems at temperature T = 348.15 K; (b) {IL (1) + ethanol (2)}: ●, [C 1 C 2 IM]­[DMP] (this work); ○, [C 1 C 2 IM]­[DEP]; ▲, [C 1 C 2 PYR]­[DMP]; Δ, [C 1 C 2 PYR] [DEP]; ■, [C 1 C 2 MOR]­[DMP]; □, [C 1 C 2 MOR]­[DEP] binary systems at temperature T = 348.15 K.…”

“…The binary system of {[cation]­[DMP] + ethanol} exhibits characteristics that satisfy the requirements for use as working fluids in absorption refrigeration technology, according to earlier studies. − All of the systems that have been examined so far exhibited complete miscibility with ethanol across the entire range of composition; in each case, Raoult’s law’s negative deviations from ideality and the excess enthalpy of mixing were also found to be negative. The study currently being conducted on the subject matter is continued in this work.…”

Selection of Conditions in PVB Polymer Dissolution Process for Laminated Glass Recycling Applications

“…The concentration and temperature dependence of density, d , and dynamic viscosity, η , for each system under study was described using the following equations [ 26 ]: where parameters B 1 and B 2 are linear functions of temperature: where , and are regressed parameters. where parameters and are linear functions of concentration: where and are calculated parameters.…”