Distillable Protic Ionic Liquid 2‑(Hydroxy)ethylammonium Acetate (2-HEAA): Density, Vapor Pressure, Vapor–Liquid Equilibrium, and Solid–Liquid Equilibrium

Recently it has been found that certain ionic liquids (ILs) have notable vapor pressures (Earle et al. <i>Nature</i> <b>2006</b>, <i>439</i>, 831–834). These ILs may be important in various novel technologies, but they may also be important in postcombustion carbon captures as side products. In this work a distillable protic ionic liquid (PIL) 2-(hydroxy)­ethylammonium acetate (2-HEAA) was prepared from monoethanolamine (MEA) and acetic acid (HAc) and it was purified with a Vigreaux type distillation column under vacuum. Density was measured for the MEA + 2-HEAA and HAc + 2-HEAA systems with a DMA HP densimeter from 293 to 363 K. The Redlich–Kister polynomial was used to model the density data. Vapor–liquid equilibrium was measured for the H₂O + HAc + 2-HEAA system with a static total pressure apparatus at 347 K. Solid–liquid equilibrium was measured for the H₂O + HAc + 2-HEAA system with a visual method. The NRTL activity coefficient model was used to model the vapor–liquid and solid–liquid equilibrium data

Reactive Extraction of Levulinic Acid from Aqueous Solutions Using Trioctylamine with Diluents 2‑Ethyl-1-hexanol, 4‑Methylpentan-2-one, and Isoamyl Alcohol

Separating carboxylic acids from aqueous solutions is a challenge, and reactive extraction has been examined as an attractive alternative. This study investigates the reactive extraction of levulinic acid (LA) using trioctylamine (TOA) in various diluents, such as 2-ethyl-1-hexanol, 4-methylpentan-2-one (MIBK), and isoamyl alcohol. For this purpose, liquid–liquid equilibrium (LLE) data was experimentally obtained for the mix of LA + TOA + H2O + diluents at T = 293.15 K and atmospheric pressure. From the obtained data, the ability of various TOA/diluent mixtures was evaluated in terms of distribution coefficient (KD). Isoamyl alcohol was found to be an effective diluent at the diluted region (wLAaq KD value of 9.4. However, increasing the concentration of LA resulted in approximately the same extraction ability as the other tested diluents with TOA. Furthermore, the nonrandom two-liquid (NRTL) excess Gibbs energy model was applied to correlate the tie lines. The root-mean-square deviations (RMSD) in liquid mass fraction obtained with the NRTL model for the experimental data of the above-mentioned different LLE systems of 2-ethyl-1-hexanol, MIBK, and isoamyl alcohol were 0.013, 0.018, and 0.016, respectively. Additionally, the KD values of the systems were also computed

Design of Equilibrium Cells for Phase Equilibria and <i>PVT</i> Measurements in Large Ranges of Temperatures and Pressures. I. Vapor–Liquid–Liquid Equilibria

Acquiring accurate experimental thermodynamic data is very useful for the development of models and chemical processes. Although there are plenty of data in the scientific literature, there are still many missing. In fact, many of the easier measurements have been made, and far more of the remaining ones deal with either complex systems or extreme conditions. Clearly new adequate equipment for acquiring such data are welcome. For these purposes, advice coming from several decades of equipment design experience are exposed herein. After defining the aim pursued and consequently the type of desired thermodynamic quantity, it is necessary to take into account all physical and chemical constraints: viscosity, density, corrosive power of studied chemical systems, temperature, pressure together with other important points such as miniaturization, efficient stirring, avoiding both dead volume and polymer sealing. The other aim of this paper is to present a high temperature and high pressure apparatus capable of measuring the phase equilibria of systems exhibiting vapor–liquid–liquid behavior. The apparatus designed and built consists mainly of an equilibrium cell (70 cm³), novel high temperature, and high pressure samplers and a gas chromatograph. A detailed description of the apparatus is presented. Preliminary measurements are presented for propane in water, cyclohexane in water, and water in cyclohexane up to 498.8 K. In addition the solubility of 2-methylfuran in water up to 413 K and 1548 kPa was measured

Temperature and Pressure Dependence of Density of a Shale Oil and Derived Thermodynamic Properties

The temperature and pressure dependence of density was measured experimentally from 293 to 473 K and 0.1 to 12 MPa for a shale oil produced from Kukersite oil shale in Estonia. The shale oil sample was a fuel oil fraction of a whole oil produced in a commercial plant that uses solid heat carrier retorting technology. The fraction had a boiling range of approximately 460 to 780 K and contained significant quantities of polar phenolic compounds (hydroxyl group content of 5.3 wt %). The effect of these compounds on the properties of the oil was investigated by removing most of the phenolic compounds via extraction to create the second sample (dephenolated sample with hydroxyl group content of 1.1 wt %). The dephenolation resulted in a shale oil with a composition being more similar to that of other shale oils from well explored deposits. On the basis of a review of the literature, these are the first experimental data on the pressure dependence of density for this shale oil, and shale oils generally. Thermal expansion coefficients, isothermal compressibilities, and speeds of sound were calculated from the experimental data. Empirical relationships describing the temperature dependence of the heat capacities between 288 and 423 K at atmospheric pressure are also presented here

Temperature and Pressure Dependence of Density of a Shale Oil and Derived Thermodynamic Properties

The temperature and pressure dependence of density was measured experimentally from 293 to 473 K and 0.1 to 12 MPa for a shale oil produced from Kukersite oil shale in Estonia. The shale oil sample was a fuel oil fraction of a whole oil produced in a commercial plant that uses solid heat carrier retorting technology. The fraction had a boiling range of approximately 460 to 780 K and contained significant quantities of polar phenolic compounds (hydroxyl group content of 5.3 wt %). The effect of these compounds on the properties of the oil was investigated by removing most of the phenolic compounds via extraction to create the second sample (dephenolated sample with hydroxyl group content of 1.1 wt %). The dephenolation resulted in a shale oil with a composition being more similar to that of other shale oils from well explored deposits. On the basis of a review of the literature, these are the first experimental data on the pressure dependence of density for this shale oil, and shale oils generally. Thermal expansion coefficients, isothermal compressibilities, and speeds of sound were calculated from the experimental data. Empirical relationships describing the temperature dependence of the heat capacities between 288 and 423 K at atmospheric pressure are also presented here

Experimental and Theoretical Thermodynamic Study of Distillable Ionic Liquid 1,5-Diazabicyclo[4.3.0]non-5-enium Acetate

A thermochemical study of the protic ionic liquid 1,5-diazabicyclo­[4.3.0]­non-5-enium acetate ([DBNH]­[OAc]), a prospective cellulose solvent considered for the Ioncell-F process, was carried out. The heat capacities of 1,5-diazabicyclo[4.3.0]­non-5-ene (DBN) and [DBNH]­[OAc] were measured by differential scanning calorimetry (DSC) at 223–323 and 273–373 K temperature ranges, respectively. The enthalpies of fusion and synthesis reaction of [DBNH]­[OAc] were measured by DSC and reaction calorimetry, respectively. The gas-, liquid-, and solid-phase enthalpies of formation of [DBNH]­[OAc] and DBN were determined using calorimetric and computational methods. The enthalpy of vaporization of [DBNH]­[OAc] was estimated from the formation enthalpies. The activity coefficients at infinite dilution of 17 and the enthalpies of solution at infinite dilution of 25 organic solutes in [DBNH]­[OAc] were measured by gas chromatography and solution calorimetry methods, respectively. The obtained data will be used in the design and optimization of the Ioncell-F process