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This study aims to produce diisopropyl ether (DIPE) via isopropanol dehydration using cobalt-phosphate-supported natural zeolite catalysts. The catalytic activities of the zeolite/CoO and zeolite/Co(H2PO4)2 were compared. The as-prepared catalysts were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and N2 adsorption-desorption. Surface acidity was determined using the gravimetric method with pyridine as the probe. The results of this study showed that natural zeolite was favorably impregnated by CoO and Co(H2PO4)2 species. The impregnation process affected the textural and acidic features of the catalysts. The zeolite/Co(H2PO4)2 catalyst with a loading of 8 mEq.g-1 exhibited the highest surface acidity of 1.827 mmol.g-1. This catalyst also promoted the highest catalytic activity towards isopropanol dehydration, with an isopropanol conversion of 66.19%, DIPE selectivity, and yield of 46.72% and 34.99%, respectively. The cobalt phosphate species promoted higher catalytic activity for isopropanol dehydration than the CoO species. This study demonstrated the potential of cobalt phosphate-supported natural zeolite catalysts for DIPE production with adequate performance. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Present study explores the extraction mechanism of 211At of 7.21 h half-life used in targeted alpha-ray therapy. We produced 211At and 210At nuclides to investigate the extraction mechanism with diisopropyl ether (DIPE) and At species in the solvent. Thin-layer chromatography results showed that At cation species increased with increasing HCl concentration and the rate of At extraction into DIPE. [ABSTRACT FROM AUTHOR]

Isopropyl alcohol (IPA) and diisopropyl ether (DIPE) are widely used as biofuel additives in fuel processing. When IPA is produced by propylene hydration, a by-product IPA and DIPE is made. Since the existence of azeotropic point formed between IPA and DIPE, the separation of the azeotrope is achieved using special distillation technologies in industry, which requires high energy consumption. Liquid-liquid extraction was used to separate the mixture due to its energy saving in this work. Three imidazolium-based ionic liquids (ILs) 1-butyl-3-methylimidazolium thiocyanate ([BMIM]SCN), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM]NTf 2) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF 4) were synthesized as the extractants. The influence of extraction time, extraction temperature, mass ratio of mixture (IPA + DIPE) to ILs and the initial content of IPA in the mixture (IPA + DIPE) on the extraction performance of ILs were studied. The optimal extraction conditions were determined using the response surface method (RSM). The results showed that the IL [BMIM]SCN had better extraction capacity for separation of the mixture (IPA + DIPE). The interactions between molecules were investigated by quantum chemical calculations. Finally, a conceptual separation process is designed to separate the mixture, which can provide a helpful technology to purify the biofuel additives. • Three ILs [BMIM]SCN, [BMIM]NTf 2 and [BMIM]BF 4 were synthesized as extractants to separate mixture (IPA + DIPE). • The extraction performance of the ILs was assessed and the optimal conditions were determined by RSM. • The interactions between IPA and the ILs were analyzed by quantum chemical calculations. • A separation process for purification of IPA and DIPE is proposed with [BMIM]SCN as the extractant. [ABSTRACT FROM AUTHOR]

The aim of this study was to trace an exposure profile to traffic-derived pollution during pediatric age. For this purpose, two biomonitoring campaigns for the determination of urinary (u-) methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and diisopropyl ether (DIPE) were carried out in two different periods of the year (summer 2017 and winter 2018), among a large sample of healthy children (n = 736; 5-11 years old) living in rural and urban areas in central Italy. The quantification of u-MTBE, u-ETBE, u-TAME, and u-DIPE was performed by HS-SPME-GC/MS technique and information on participants was collected by a questionnaire. u-DIPE concentrations resulted always under the LOQ. u-TAME mean levels were similar in both seasons (18.7 ng L-1 in summer vs. 18.9 ng L-1 in winter), while u-MTBE and u-ETBE levels were, respectively, 69.9 and 423.5 ng L-1 (summer) and 53.3 and 66.2 ng L-1 (winter). Main predictors of urinary excretion resulted the time spent in motor vehicles, being male and younger.

A comparative assessment of the accuracy of determining the density and viscosity has been carried out for diisopropyl ether using the method of classical molecular dynamics using three potentials. The accuracy of determining the viscosity coefficients when using equilibrium and nonequilibrium calculation methods was also investigated. [ABSTRACT FROM AUTHOR]

This study investigated the fabrication of nickel phosphide immobilized on natural bentonite (NiP/bentonite) as a low-cost catalyst with different metal loadings (mEq/g) to produce diisopropyl ether (DIPE) as a potential gasoline additive. The catalysts were prepared using a simple wet-impregnation method. The physicochemical features of the parent natural bentonite and NiP/bentonite were analyzed using FTIR, SEM–EDX, XRD, N2 physisorption, and catalyst acidity using the NH3 gravimetric method. The dehydration reaction was conducted under mild conditions (150 °C for 3 h) using a reflux system. The results suggested that the NiP species did not alter the bentonite structure while increasing its acidity and surface area properties. Using the 8 mEq/g NiP/bentonite catalyst, a DIPE product of 68.52% was achieved owing to the highly acidic sites of the catalyst and high stability over three cycles. This study highlights the potential of nickel-phosphide-supported natural bentonite in the dehydration reaction for DIPE production. [ABSTRACT FROM AUTHOR]

[Display omitted] • LLE data for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP/MIBK. • Study of the effect of TBP and MIBK on the three-phase zone. • Three-phase zone disappeared after the addition of 0.206 of TBP and 0.583 of MIBK. • The mixed solvent (TBP+DIPE) is the best-performing solvent. • The mixed solvent (0.3TBP+0.7DIPE) has the potential to enhance H 3 PO 4 extraction. The three-liquid-phase formation in the ternary system of water + phosphoric acid + diisopropyl ether (DIPE) makes the phosphoric acid extraction only effective for acid mass fractions above 0.69. To avoid the undesirable formation of the third phase and enhance acid extraction, particularly at low concentrations, two phase modifiers, methyl isobutyl ketone (MIBK) and tributyl phosphate (TBP), were systematically studied. In order to quantify the synergetic effect of the mixed solvents of DIPE+TBP and DIPE+MIBK, the liquid–liquid equilibria for the quaternary systems of H 2 O+H 3 PO 4 + DIPE+TBP and H 2 O+H 3 PO 4 + DIPE+MIBK were fully established for different DIPE/phase modifier (TBP or MIBK) mass ratios (90/10, 70/30, 50/50, and 20/80) at 298.2 K under atmospheric pressure using the cloud point and Othmer graphical method. Othmer-Tobias and Hand correlations were used to fit the tie-line data and assess its consistency. In addition, the behavior of the three-phase zone was also studied as a function of the phase modifiers content. Separation factor (S) and acid distribution (D 2) were used to identify the most effective solvent with the potential to enhance phosphoric acid extraction from aqueous solutions. [ABSTRACT FROM AUTHOR]

Catalytic dehydration of isopropanol to propylene is a common reaction in laboratories to characterize the acid–base properties of catalysts. When acetone is produced, it is the sign of the presence of basic active sites, while propylene is produced on the acid sites. About 2/3rd of the world production of isopropanol is made from propylene, and the other third is made from acetone hydrogenation. Since the surplus acetone available on the market is mainly a coproduct of phenol synthesis, variations in the demand for phenol affect the supply position of acetone and vice versa. High propylene price and low demand for acetone should revive the industrial interest in acetone conversion. In addition, there is an increasing interest in the production of acetone and isopropanol from CO/CO2 via expected more environmentally friendly biochemical conversion routes. To preserve phenol process economics, surplus acetone should be recycled to propylene via the acetone hydrogenation and isopropanol dehydration routes. Some critical impurities present in petrochemical propylene are avoided in the recycling process. In this review, the selection criteria for the isopropanol dehydration catalysts at commercial scale are derived from the patent literature and analyzed with academic literature. The choice of the process conditions, such as pressure, temperature and gas velocity, and the catalysts' properties such as pore size and acid–base behavior, are critical factors influencing the purity of propylene. Dehydration of isopropanol under pressure facilitates the downstream separation of products and the isolation of propylene to yield a high-purity "polymer grade". However, it requires to operate at a higher temperature, which is a challenge for the catalyst's lifetime; whereas operation at near atmospheric pressure, and eventually in a diluted stream, is relevant for applications that would tolerate a lower propylene purity (chemical grade). [ABSTRACT FROM AUTHOR]

Growing use of recalcitrant fuel oxygenates like methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and diisopropyl ether (DIPE) poses serious threat to aquatic environments and drinking water sources. Mycolicibacterium sp. strain CH28 was isolated earlier as a potential degrader of DIPE. Optimal culture conditions for strain CH28 were determined to be 32 °C and pH 5.00–6.00. Substrate utilization tests revealed that several n-alkanes, aromatic compounds, short-chain alcohols and acids were metabolized by strain CH28. In resting cell assays, strain CH28 was able to mineralize DIPE with a degradation rate of 1.63 ± 0.03 nmol min−1 mg biomass−1. Complete mineralization of 75 mg l−1 DIPE occurred within 42 hours in microcosm systems using groundwater samples inoculated with strain CH28. 2-propanol, acetone, and acetate were identified as intermediates of DIPE degradation with GC-MS, and a degradation pathway was proposed. Mixed cultures of strain CH28 and Hydrogenophaga sp. strain T4 were able to fully mineralize 200 mg l−1 ETBE in 60 hours. Moreover, strain CH28 could co-oxidize MTBE and TAME in the presence of DIPE as the growth substrate. Our results indicate that strain CH28 holds great potential in the bioremediation of sites contaminated with gasoline ether oxygenates. [ABSTRACT FROM AUTHOR]

Catalytic dehydration of isopropanol to propylene is a common reaction in laboratories to characterize the acid–base properties of catalysts. When acetone is produced, it is the sign of the presence of basic active sites, while propylene is produced on the acid sites. About 2/3rd of the world production of isopropanol is made from propylene, and the other third is made from acetone hydrogenation. Since the surplus acetone available on the market is mainly a coproduct of phenol synthesis, variations in the demand for phenol affect the supply position of acetone and vice versa. High propylene price and low demand for acetone should revive the industrial interest in acetone conversion. In addition, there is an increasing interest in the production of acetone and isopropanol from CO/CO2 via expected more environmentally friendly biochemical conversion routes. To preserve phenol process economics, surplus acetone should be recycled to propylene via the acetone hydrogenation and isopropanol dehydration routes. Some critical impurities present in petrochemical propylene are avoided in the recycling process. In this review, the selection criteria for the isopropanol dehydration catalysts at commercial scale are derived from the patent literature and analyzed with academic literature. The choice of the process conditions, such as pressure, temperature and gas velocity, and the catalysts’ properties such as pore size and acid–base behavior, are critical factors influencing the purity of propylene. Dehydration of isopropanol under pressure facilitates the downstream separation of products and the isolation of propylene to yield a high-purity “polymer grade”. However, it requires to operate at a higher temperature, which is a challenge for the catalyst’s lifetime; whereas operation at near atmospheric pressure, and eventually in a diluted stream, is relevant for applications that would tolerate a lower propylene purity (chemical grade).

Densities and viscosities of binary mixtures for methyl tert-butyl ether (MTBE) with methanol and diisopropyl ether (DIPE) have been measured at temperatures of 308.15, 313.15 and 318.15 K and at atmospheric pressure over the entire composition range. The measured densities and viscosities were fitted using Jouyban-Acree model where mean relative deviation (MRD) lesser than 0.02% are obtained for both predictions. The excess molar volumes and the viscosity deviations are calculated from measured densities and viscosities. Redlich-Kister equation is then used to correlate excess molar volumes and viscosity deviations where good fits have been achieved. Negative excess molar volume and viscosity deviation have been obtained for binary mixture MTBE + methanol at all investigated temperatures which indicating the presence of chemical and structural interactions. However, lack of specific interactions has been observed for binary mixture MTBE + DIPE based on positive excess molar volume and small negative values of viscosity deviation. [ABSTRACT FROM AUTHOR]

Densities and viscosities of binary mixtures of diisopropyl ether (DIPE) with methyl benzoate (MB), ethyl benzoate (EB) and benzyl acetate (BA) were measured experimentally at T = (298.15, 303.15, 308.15, and 313.15) K and P = 0.1 MPa for the entire composition range. The estimated values of the pure liquids and mixtures were subsequently used to determine the properties such as excess molar volume (VE), deviation in viscosity (∆η), and excess Gibbs free energy (∆G*E). These results were fitted into Redlich–Kister polynomial equation to calculate the coefficients and standard errors. [ABSTRACT FROM AUTHOR]

Oxygenated fuels are of great interest as these are more energy efficient and environment friendly. Therefore, thermodynamic properties like density, ultrasonic speed and refractive indices of diisopropyl ether+benzene+n-hexane mixtures were measured experimentally at 298.15 K, 308.15 K and 318.15 K. Excess properties like volume ( V m E ), isentropic compressibility ( K S E ), intermolecular free length ( L f E ) as well as deviation in ultrasonic speed (Δu) and refractive index (Δn) of these mixtures were derived from experimental data. The V m E values were also fitted to the Singh, Cibulka and Nagata equations, and the same were also predicted using Prigogine-Flory-Patterson theory and four geometrical models from constituent binary V m E data. The u data were correlated by Nomato, van Dael, impedance dependence correlations and CFT theory at 298.15 K. L f E and V a E were also calculated using Jacobson free length theory at 298.15 K. The n data were also predicted by Arago-Biot, Gladstone-Dale, Weiner, Heller, Newton, Eyring and John mixing rules. [ABSTRACT FROM AUTHOR]

Diisopropyl ether (DIPE) is considered as a promising gasoline additive due to the favorable blending Reid vapor pressure and the low water solubility. To get a good understanding of the DIPE oxidation chemistry, oxidation experiments of a stoichiometric mixture of DIPE/O 2 /Ar/Kr were performed in a jet-stirred reactor (JSR) at atmospheric pressure over the temperature range of 525–900 K in this work. About 30 intermediates and products were identified and quantified using a photoionization molecular-beam mass spectrometer (PI-MBMS). Furthermore, a detailed kinetic model was proposed for DIPE oxidation, which showed satisfactory performances in predicting the species concentration profiles in this work as well as those in literature. For DIPE oxidation, the fuel consumption was observed only above 750 K, even though DIPE has two tertiary hydrogen atoms that are easy to be abstracted so that low-temperature oxidation reactivity is expected. The low oxidation reactivity at low temperature is because the formed OOQOOH radical mostly dissociates back to QOOH+O 2 , instead of undergoing intramolecular isomerization which leads to the low-temperature chain-branching. At higher temperature, DIPE is mainly consumed by hydrogen abstraction reactions from the carbon atoms adjacent to the oxygen atom, producing dominantly the IC 3 H 7 OC(CH 3) 2 fuel radical, which then decomposes rapidly via C O bond β -scission instead of combining with O 2. In contrast, the minor fuel radical IC 3 H 7 OCH(CH 3)CH 2 tends to go through the O 2 addition reaction and the subsequent chain branching reactions, as confirmed by the detection of cyclic ether intermediates. Propylene and acetone are the most abundant intermediates in DIPE oxidation, both of which predominantly come from the initial fuel decomposition steps. Other intermediates are mainly formed via the consumption of these two species. [ABSTRACT FROM AUTHOR]

The kinematic viscosity (ν) of binary mixture of diisopropyl ether+n-heptane or n-octane or n-nonane or n-decane was measured at 298.15 K, 308.15 and 318.15 K. Using experimental data, the deviation in kinematic viscosity (Δν) was calculated. The Δν follows the sequence: n-heptane

• PGEE was selected as extractant to separate the mixture of IPA + DIPE + NPA. • The charge density surface and the interaction energies were calculated to explore the interaction mechanism. • The VLE data for the systems IPA + PGEE, DIPE + PGEE and NPA + PGEE were measured and correlated. • An extractive distillation process for separating the mixture IPA + DIPE + NPA was proposed. For separation of the mixture {isopropyl alcohol (IPA) + diisopropyl ether (DIPE) + n-propanol (NPA)} by extractive distillation, propylene glycol ethyl ether (PGEE) was used as an entrainer based on selectivity since isopropyl alcohol + diisopropyl ether can an azeotrope. To explore the interaction mechanism between the entrainer PGEE and the components in the mixture, the charge density surface (σ-profiles) and the interaction energies were calculated based on the COSMO-SAC model and Dmol3, which could provide theoretical insight into interactions at the molecular level. Then, the data of isobaric vapour-liquid equilibrium (VLE) for (IPA + PGEE), (DIPE + PGEE) and (NPA + PGEE) systems were measured at 101.3 kPa. The NRTL, UNIQUAC and Wilson equations were applied to correlate the measured VLE data, and the thermodynamic model parameters for the binary systems were obtained by fitting the VLE data, which is helpful for the simulation and optimization of the separation process. [ABSTRACT FROM AUTHOR]

Effective selective catalysts deposited on monolithic metal blocks are developed and tested in reactions of dimethyl ether and diisopropyl ether production at atmospheric pressure from methanol and isopropyl alcohol, correspondingly. The catalysts active phase is based on compounds of Ni, Cu, Mo, W, V and zeolites. The presence of rare-earth elements in the catalysts composition stabilized their activity. The increase of the carrier acidity of the catalyst results in significant increase of iso-propanol transformation, whereas the selectivity in respect to diisopropyl ether decreases slightly. The optimum catalyst composition for diisopropyl ether synthesis is based on molybdenum and nickel compounds. Highly effective stable catalysts providing production of dimethyl ether from methanol with selectivity of 85% - 97% and that of diisopropyl ether from isopropyl alcohol with selectivity of 60% - 69.4% are developed. [ABSTRACT FROM AUTHOR]

Highlights • Diisopropyl ether is proposed to dehydrate 1-propanol by an azeotropic distillation. • Ternary VLLE data of 1-propanol + water + diisopropyl ether are obtained at 101 kPa. • NRTL and UNIQUAC model parameters are obtained after data correlation. • An alternatibe separation sequence, a decanter and a single-feed distillation column) was proposed. • Simulation and economic optimization of distillation process is carried out. Abstract Azeotropic distillation process is widely used to separate non-ideal binary mixtures into their constituent pure components. 1-Propanol dehydration was used as case study and diisopropyl ether was analysed as possible entrainer in an azeotropic distillation. The separation of some alcohols from their aqueous solution is a challenging task because these aqueous mixture forms minimum boiling azeotrope. In this way, isobaric vapor-liquid and vapour-liquid-liquid equilibrium data were measured for the 1-propanol+ water + diisopropyl ether ternary mixture at 101.3 kPa. The data were correlated by NRTL and UNIQUAC models. A separation sequence (a decanter and a single-feed distillation column) for 1-propanol dehydration using diisopropyl ether was proposed. The simulation of the separation sequence was carried out satisfactorily by Aspen Hysys® using the thermodynamic model NRTL with the binary parameters obtained in this work. Moreover, the effect of temperature decantation was investigated in order to reduce the energy demand of the process. [ABSTRACT FROM AUTHOR]

Highlights • 2-Ethoxyethanol and butyl acetate were selected as extractants to separate IPA and DIPE. • The VLE data for IPA and DIPE with extractants were measured. • The VLE data were correlated by the NRTL, UNIQUAC and Wilson models. • An extractive distillation process for separating azeotrope IPA and DIPE is proposed. Abstract For separation of the azeotrope isopropyl alcohol and diisopropyl ether by extractive distillation, 2-ethoxyethanol and butyl acetate were adopted as extractive solvents, and the vapour–liquid equilibrium data for the binary systems of isopropyl alcohol + 2-ethoxyethanol, isopropyl alcohol + butyl acetate, diisopropyl ether + 2-ethoxyethanol and diisopropyl ether + butyl acetate were measured at 101.3 kPa by a modified Rose type recirculating still. The Herington and van Ness consistency method were used to check the thermodynamic consistency of the VLE data. Meanwhile, the VLE data were correlated using the NRTL, UNIQUAC and Wilson models, and the binary interaction parameters of the three models were regressed. The correlation results indicate that the three models can correlate the experimental data with the root-mean-square deviation value of vapour phase mole faction less than 0.0062. Finally, an extractive distillation process for separating the azeotrope of isopropyl alcohol and diisopropyl ether is explored in this work. [ABSTRACT FROM AUTHOR]

• Experimental evaluation of properties of fuel (Gasoline –DIPE mixture) • Properties of fuel density, calorific value, RVP, Distillation, Drivability index and octane number values are studied. • Addition of DIPE improves oxygen content in the fuel up to 4.68%. • Octane number in the fuel increased from 92 to 101. • DIPE improves volatility of fuel. With growing concerns regarding the environment and the depletion of fossil fuels, many researchers have sought a new and suitable alternative fuel. Over the years, researchers have proposed many alternatives to gasoline, most of which belong to the family of alcohols. Furthermore, most researchers consider the octane number to be the main fuel property and have overlooked other fuel properties. In the family of ethers, MTBE and ETBE have been previously studied, but DIPE, a suitable, novel and safe alternative fuel that doesn't mix with water, has not. In this study, diisopropyl ether, a novel oxygenate, is blended with gasoline, and the density, calorific value, Reid vapour pressure, distillation curve, drivability index, research octane number and anti-knock index are studied and reported here. [ABSTRACT FROM AUTHOR]

Abstract Densities and speed of sound for the binary mixture of diisopropyl ether (DIPE) (1) + toluene, n-octane (2) and toluene (1) + n-hexane, n-heptane, n-octane (2) and n-hexane, n-heptane (1) + n-octane (2) were measured from 298.15 K to 318.15 K. The measured data were used to calculate excess molar volume V m E , deviation in ultrasonic speed Δ u , excess isentropic compressibility K s E , excess intermolecular free length L f E and excess available volume V a E . For theoretical interpretation of V m E values, Prigogine-Flory-Patterson theory and Graph theory were applied at 298.15 K. Ultrasonic speed data were predicted at 298.15 K using various empirical correlations like Nomoto, Van Dael, Impedance dependence and also by Schaaff's collision factor theory. The temperature effect on K s E and V m E was also discussed. The results were analyzed in the light of unlike interactions, packing effect, cohesion forces and change in orientation order. Highlights • Measured density and ultrasonic speed of mixtures of alkanes, DIPE and toluene. • Excess volume was interpreted in terms of PFP and Graph theory. • Jacobson's free length and Schaaff's collision factor theory were applied. • Available volume and intermolecular free length calculated. • Results were discussed in terms of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Abstract Densities and speed of sound for the binary mixtures of diisopropyl ether (1) + n ‑hexane, n ‑heptane, benzene (2) and benzene (1) + n ‑hexane, n ‑heptane, n ‑octane (2) and n ‑hexane (1) + n ‑heptane (2) were measured from 298.15 K to 318.15 K. The measured data were used to calculate excess molar volume V m E , deviation in ultrasonic speed Δ u , isentropic compressibility K s E , excess intermolecular free length L f E and excess available volume V a E . All the derived properties were fitted to Redlich-Kister equation. For theoretical interpretation of V m E values, Prigogine-Flory-Patterson theory and Graph theory were used at 298.15 K. Various empirical correlations like Nomoto, Van-Dael and impedance dependence relation were applied to predict the experimental ultrasonic speed data. Schaaff's collision factor theory was used for prediction of experimental ultrasonic speed data at 298.15 K. The excess intermolecular length (L f E ) was calculated from Jacobson free length theory at 298.15 K. The effect of temperature for K s E and V m E was also discussed in terms of intermolecular interactions. Graphical abstract Excess molar volume of binary (1 + 2) mixtures as functions of mole fraction (x 1) at 298.15 K. Unlabelled Image Highlights • Measured density and ultrasonic speed of mixtures of DIPE, benzene and alkanes. • Excess volume was interpreted in terms of PFP and Graph theory. • Jacobson's free length and Schaaff's collision factor theory were applied. • Available volume and intermolecular free length calculated. • Results were discussed in terms of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Highlights • New speed of sound data for HFE7500 + DIPE are reported. • The pressure and temperature intervals are 0.1–100 MPa and 293.15–353.15 K. • Density data have been calculated by integration of speed of sound data. • A correlation was proposed to represent density data. • Isothermal compressibility is reported. Abstract Speeds of sound for the binary system HFE-7500 + Diisopropyl ether have been measured at pressures up to 100 MPa and within a temperature interval from (293.15 to 353.15) K. High pressure density measurements were carried out by using a U-tube densimeter up to 140 MPa and at temperatures from (293.15 to 393.15) K. Additionally, the density and the isentropic compressibility were evaluated from integration of speed of sound data in the pressure range from (0.1 to 100) MPa and in the temperature interval from (293.15 to 353.15) K. This work also reports a correlation for both the density and the speed of sound within their estimated uncertainties to evaluate the volume and its derivatives with respect to pressure and temperature. [ABSTRACT FROM AUTHOR]

The technique of catalytic flow microreactor has been combined with the gas flow-through microcalorimetry to correlate the catalytic activity of supported heteropolyacids with both the acid strength of protons as well as the protons’ accessibility. Multiwall carbon nanotubes (CNT) were used as a support for Keggin (H 3 PW 12 O 40 ) and Wells-Dawson (H 6 P 2 W 18 O 62 ) structured heteropolyacids, in order to produce catalysts combining high acidity from the parent acids with the inherent microporosity of the support. Prior to the catalytic tests, the obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Raman spectroscopies as well as by the nitrogen adsorption-desorption analysis (BET). The latter technique confirmed overall improved porosity of the obtained materials. Upon testing for activity in the isopropyl alcohol dehydration, the supported Wells-Dawson catalysts turned out to be superior to both the Keggin-based materials, as well as to the unsupported H 6 P 2 W 18 O 62 . It has been found that the improvement of catalytic performance in the isopropanol conversion is mostly related to the increase of the accessibility of protons, rather than to the changes in the acid strengths. [ABSTRACT FROM AUTHOR]

Accurate knowledge of physical and acoustical properties is of importance in many fields of science and engineering. In this work, density and speed of sound measurements of diisopropyl ether (DIPE) are reported. The speed of sound has been measured up to 100 MPa and in the temperature range (293.15–353.15) K by using an apparatus based on a pulse echo technique working in transmission mode, and a correlation for this property was proposed. By using a procedure which rests on the Newton-Laplace relationships, density and its derivatives were determined. To show the reliability of this method, high pressure density measurements were carried out up to 140 MPa and within the temperature interval (293.15–393.15) K with an Anton Paar densitometer. [ABSTRACT FROM AUTHOR]

Accurate density data of binary mixture of diisopropyl ether (DIPE) with acetone are essential for the engineering design and operation of their separation. Densities of acetone + DIPE binary mixtures have been measured over the entire range of composition and at temperatures from (283.15 to 323.15) K under atmospheric pressure. The volume-translated Peng-Robinson equation of state has been applied to predict the densities of the liquid mixtures with an overall average relative deviation of only 0.095%, yielding a substantial improvement to the untranslated Peng-Robinson equation with an average relative deviation over fifty times lower. Excess volumetric properties of excess molar volumes and excess isobaric expansibility coefficients are derived from the experimental density data and well correlated by the Redlich-Kister type polynomial equation. The resultant positive excess volumetric properties confirm the existence of dispersive interactions and dipolar/orientational order change in the binary mixture during mixing. [ABSTRACT FROM AUTHOR]