High pressure density and speed of sound of hydrofluoroether fluid 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane (HFE-7300)

High pressure density measurements were carried out for the hydrofluoroether fluid HFE-7300. A total of 159 points have been measured in the pressure range from 0.1 to 140 MPa and along seven isotherms within the temperature interval (293.15–393.15) K. To perform these measurements, an Anton Paar vibrating tube densitometer was used. The experimental high pressure density data were correlated to a Tait-like equation and compared with the available literature. By deriving the Tait-like equation, the isothermal compressibility and isothermal compressibility were also determined in the same P and T ranges. The speed of sound measurements were performed along six isotherms from 293.15 to 333.15 K at 0.1 MPa. The isentropic compressibilities were also calculated from speed of sound and density data by means of the Laplace equatio

Thermodynamic Properties of Propanol and Butanol as Oxygenate Additives to Biofuels

Alternative and renewable energy technologies are being sought throughout the world to reduce pollutant emissions and increase the efficiency of energy use. Oxygenate second-generation biofuels fuels lead to a reduction in pollutant emissions and their thermodynamic and transport properties allow that the facilities for transport, storage and distribution of fuels could be used without modification. Higher alcohols, like propanol and butanol, enhance the octane number, boosting the anti-knock effect in gasoline. Then the compression ratio of the engines can be increased without risk of knocking, leading to higher delivery of power. From the combustion point of view, the production of carbon monoxide and volatile hydrocarbons from the combustion of alcohols is less than the one of gasoline. This chapter covers mixtures of butanol and propanol with hydrocarbons. The properties reviewed are excess volume or density (VE), vapour-liquid equilibrium (VLE), and heat capacity (Cp)

Engineering Materials and Personal Spaces in Public Repositories: The Case of the MERLOT Digital Library

The open educational resources are learning, teaching and research materials available in open sites for free access, and are frequently grouped into personal collections by users. MERLOT, the well-known online repository, includes amongst its materials Bookmark Collections (BC) created by its contributors. This article evaluates, from the point of view of users other than the creators, the usefulness of the MERLOT personal collections in engineering education. There are at least 895 Bookmark Collections in the Engineering collection of MERLOT. The main assessment criteria are the potential of shareability and reusability of the collection in terms of the engineering content and description, and the coherence of materials and collection with the respective engineering discipline and sub-discipline. Results show that the quality of these collections could be improved if the assignment of the collection would be declared, as the title and description, during the BC creation. The improvement of the BC title and most especially its description would be also a good improvement that will guide the searcher more precisely

Thermodynamics of binary mixtures 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (HFE-7200) + 2-propanol: High pressure density, speed of sound and derivative properties

Awareness about environmental impact of greenhouse gas emissions has lead to search for other alternatives which can cover the same utility range of wellknown CFCs, HCFCs and PFCs but without their undesirable effects on the planet. Since Hydrofluoroether fluids (HFEs) have emerged as a good alternative, it is necessary to characterize their thermophysical properties in order to bring reliable data to the industry. Density and speed of sound are two of the most important physical properties because of the amount of information that they provide in the design of the machinery involved in the utilization of these fluids as well as data for the parametrization of equations of state. This paper reports a set of new data concerning high pressure density, ρ, for the binary mixture x HFE-7200 + (1 − x) 2-propanol in a broad range of pressures (0.1–140 MPa), and at several temperatures (from 293.15 to 393.15 K). Density values were correlated by employing a Tait-like equation in the same p, T ranges, and the derivative properties, that is, the isothermal compressibility κT, and the isobaric expansion αP, were determined. Excess molar volumes VE, which bring information about the change in volume observed in the mixture were also calculated for the eight mole fractions investigated. Speeds of sound, c, at 0.1 MPa were measured experimentally in the temperature range (293.15–333.15 K). By using the Laplace equation, isentropic compressibilities, κS, were calculated from density and sound velocity values

High pressure and high temperature volumetric properties of (2-propanol + di-isopropyl ether) system

New experimental density data are reported for binary mixtures of 2-propanol + di-isopropyl ether over the composition range (6 compositions; 0.15 ≤ 2-propanol mole fraction x ≤ 0.85), between 293.15 and 393.28 K, and for 23 pressures from 0.1 MPa up to 140 MPa. Measurements were performed by means of an Anton Paar vibrating tube densitometer, calibrated with an uncertainty of 7 × 10−4 g cm−3. A Tait like equation was used to fit the experimental density data, with low standard deviations. Excess volumes have been calculated from the experimental data and fitted by the Redlich–Kister equation. Moreover, the isothermal compressibility and the isobaric thermal expansivity have been derived from the Tait-like equation.Ministerio de Ciencia e Innovación, Spain, Project ENE2009-14644-C02-0

Density, speed of sound and refractive index of mixtures containing 2-phenoxyethanol with propanol or butanol at various temperatures

In this work, we reported the new experimental data of densities, speeds of sound, and refractive indices for four binary mixtures: {2-phenoxyethanol (2PhEE) + 1-propanol or 2-propanol or 1-butanol or 2-butanol) over the entire composition range and at temperatures of (293.15, 303.15, 313.15 and 323.15) K and at pressure p = 0.1 MPa. From these experimental data, thermodynamics properties: excess molar volume, isentropic compressibility, deviation in isentropic compressibility and deviation in refractive indices were calculated. Excess molar volume, deviation in isentropic compressibility and deviation in refractive indices data have been correlated using the Redlich–Kister equation. From the obtained results, a discussion was carried out in terms of nature of intermolecular interactions and structure factors in these binary mixtures

Density, viscosity, refractive index, and related thermophysical properties of dibutyl ether +2-butanol + cyclohexane ternary systems

Producción CientíficaNew measured data for density, (ρ), dynamic and kinematic viscosities, (μD and μc), and refractive index, (nD), are presented at T = 298.15 K and p = 0.1 MPa for binary and ternary mixtures containing dibutyl ether, 2-butanol, and cyclohexane. As a result, the derived properties are estimated based on the measured data. Excess molar volume, (VE), dynamic viscosity deviation (ΔμD), and deviation in refractive index, (ΔnD), as derived properties, are fitted using the Redlich–Kister equation. In addition, perturbed-chain statistical associating fluid theory equation of state is employed to correlate the measured data of density

Investigación sobre propiedades de nuevos fluidos industriales de bajo impacto ambiental como sustitutivos de gases fluorados para reducción del cambio climático

A lo largo de los últimos 40 años, y a expensas de los Protocolos de Montreal (1987), Kyoto (1997), y más recientemente el Acuerdo de París (2015), se han ido desarrollando nuevas alternativas de fluidos medioambientalmente más limpios con respecto a los ampliamente utilizados fluorocarbonos (CFCs, HCFCs, HFCs, PFEs, etc), para su empleo en multitud de aplicaciones como son la refrigeración, limpieza de precisión, fluidos de transferencia de calor, entre otros. Los hidrofluoroéteres (HFEs) se presentan como una buena opción dadas sus propiedades termofísicas, y su bajo impacto sobre el medio ambiente. Esta Tesis ha basado su objetivo en la caracterización experimental de varias propiedades termofísicas (equilibrios líquido-vapor, densidad a alta presión, viscosidad a alta presión, velocidad del sonido a alta presión, y capacidades caloríficas), de cuatro hidrofluoroéteres de alto peso molecular, y de sus mezclas binarias con alcoholes o éteres. Para las propiedades obtenidas se han aplicado correlaciones a distintas ecuaciones, así como modelos matemáticos.Along the last 40 years, and at the expense of the Montreal Protocol (1987), the Kyoto Protocol (1997), and more recently, the Paris Agreement (2015), environmentally friendly alternatives to commonly used fluorocarbons (CFCs, HCFCs, HFCs, PFEs, etc), have been developed to be used in multiple applications such as cooling, high precision cleaning, as heat transfer fluids, among others. Hydrofluoroether fluids (HFEs), are a good choice due to their desirable thermophysical properties, and their low environmental impact. This Thesis has based its main objective in the experimental characterization of some thermophysical properties (liquid-vapor equilibria, high pressure density, high pressure viscosity, high pressure speed of sound and heat capacities), of four high molar weight hydrofluoroethers and their binary mixtures with alcohols and ethers. For the obtained properties, equation correlations have been implemented, as well as mathematical models