Measurements and Reference Correlation of the Density and Speed of Sound and Derived Thermodynamic Properties of Methyl Laurate and Methyl Stearate

Abstract

The density (ρ) and speed of sound (u) of two fatty acid methyl esters (FAMEs), methyl laurate and methyl stearate, were measured at temperatures from 283 to 353 K and from 313 to 353 K at atmospheric pressure, respectively. A commercial instrument, Anton Paar DSA 5000 M sound-speed analyzer (viscodensimeter), has been employed to the simultaneous measurements of the density and speed of sound of methyl laurate and methyl stearate as the primary components of biodiesel fuel. The measured values of density and speed of sound were used to calculate other derived key thermodynamic properties such as the adiabatic coefficient of bulk compressibility (βS), coefficient of thermal expansion (α P ), isothermal coefficient of bulk compressibility (βT), isochoric (C V ) and isobaric (CP ) heat capacities, enthalpy (ΔH) and entropy (ΔS) difference, partial temperature derivative of enthalpy (∂H/∂T) P and entropy (∂S/∂T) P , and the partial specific volume derivatives of internal energy (∂U/∂V) T (internal pressure) of methyl laurate and methyl stearate as a function of temperature. The measured values of density and speed of sound together with the reported data have been critically assessed for their accuracy and internal consistency and used to develop reference correlation models that are valid over a wide range of temperature (from the melting point to 353 K) and at an atmospheric pressure of 101.325 kPa. The overall uncertainties (at the 95% confidence level) of the reference correlations of the density and speed of sound of methyl laurate and methyl stearate are 0.025 and 0.045%, respectively.

Thermodynamic Properties of 1-Butanol + Ethyl Laurate Binary Mixtures by Combining Experimental Speeds of Sound with Volume Translated Peng–Robinson Equation of State

“…The adiabatic compressibility is another crucial factor that affects the efficiency of internal combustion engines . Higher adiabatic compressibility leads to increased engine efficiency, resulting in reduced fuel consumption and environmental pollution.…”

Experimental Study of Thermodynamic Properties of Biofuel Components

“…The samples (methyl laurate and methyl stearate) were purchased from a commercial supplier with stated purities greater than or equal to 99 wt %. The density and speed of sound of the methyl laurate and methyl stearate at atmospheric pressure (101.325 kPa) at elevated temperatures have been simultaneously measured with a sound-speed analyzer DSA 5000 M (digital VTD, Anton Paar Instrument, Austria) [8][9][10][11][12][13].…”

“…Measurements of the speed of sound of the same FAMEs samples were performed at atmospheric pressure (101.325 kPa) as a function of temperature over a same temperature range as in density experiment, namely, from (283 to 353) K for methyl laurate and from (313 to 353) K for methyl stearate (Table1). The detailed quantitative comparison of the present measured speed of sound data for methyl laurate and methyl stearate (deviation statistics) with the reported data sources are provided in our publication [13].…”

“…Th e m e as u re m e nt s we r e p e rf or m e d us i n g an Anton Paar DSA 5000 М sound-speed analyzer (viscodensemeter) for the simultaneously measurements of the density and speed of sound temperature range from (283.15 to 353.15) K and atmospheric pressure. This technique was successfully used previously [3][4][5][6][7][8][9][10][11][12][13] to accurate measure thermodynamic, acoustic, and transport properties of different type of natural and molecular liquids. Besides, the key derived thermodynamic properties for practical applications based on the measured data were calculated.…”

Speed of Sound Measurements and Thermophysical Modeling of Binary Mixtures of Methyl Laurate and n-Dodecane

“…Nowadays the speeds of sound of methyl laurate and ndodecane have been reported separately by several authors, and these reports are listed in Table 1. Most authors measured the speed of sound at atmospheric pressure and at low temperatures using the pulse-echo-overlap method or the pulse-type-ultrasonic method, such as Aissa et al, 10 Freitas et al, 6 Lopes et al, 7 and Akhmedova-Azizova et al 11 Moreover, Z ̇arska et al 12 measured the speed of sound of methyl laurate in the range of 0.1−101 MPa and 293−318 K using ultrasonic velocimetry. Neruchev et al, 13 Diego Gonzaĺez-Salgado et al, 14 Troncoso et al, 15 Paredes et al, 16 Luning Prak et al, 17 and Gonzaĺez et al 18 measured the speed of sound of ndodecane at atmospheric pressure, and they used the pulseecho-overlap method or the pulse-type-ultrasonic method.…”