An atomic contribution model for the prediction of speed of sound

Speed of sound is an important property in many applications and it is being increasingly used in different technological areas. In this work a database of speed of sound and density at atmospheric pressure for n-alkanes, branched alkanes, n-alkenes, aromatics, alcohols, ethers and esters were collected from the open literature. Using these data a Wada group contribution model recently proposed by us was used as the basis for the development of a new atomic contribution model to predict speed of sound for all the families of compounds investigated in this work. It is shown that the proposed model is able to predict the speed of sound for compounds of these families with deviations close to the experimental reproducibility. This work also discusses the effect of branching on the Wada's constant, pointing out the importance of new measurements for this type of compounds. (C) 2013 Elsevier B.V. All rights reserved

Experimental Densities and Speeds of Sound of Substituted Phenols and Their Modeling with the Prigogine-Flory-Patterson Model

This work provides new experimental data of speed of sound and density for seven pure components of pyrolysis bio-oil at atmospheric pressure for several phenols (phenol, o-, m-, and p-cresol), two phenolic ethers (2-methoxyphenol and eugenol) and one phenolic ester (methyl salicylate) at temperatures of (288.15 to 343.15) K. Densities and sound velocities are correlated with the Prigogine-Flory-Patterson (PFP) model. The properties are well described with the PFP model showing a better performance for the denser substances. The relation between density and speed of sound evidence the complex thermophysical behavior of substituted phenols

Application of Wada's Group Contribution Method to the Prediction of the Speed of Sound of Biodiesel

Biofuels are an important alternative to environmental sustainability, and biodiesel has a detached contribution to this scenario. The increasing use of biodiesel requires the knowledge of several thermophysical properties of this biofuel. This work addresses the measurements of the speed of sound and density at atmospheric pressure of five fatty acid methyl esters (methyl caprylate, methyl caprate, methyl palmitate, methyl stearate, and methyl linoleate). These data are used to test Wada's group contribution method recently proposed by us and its ability to predict the speed of sound of biodiesel fuels and to expand the application of this model to the prediction of the speed of sound of biodiesel fuels. The overall average relative deviations (OARD) obtained were 0.12% for the methyl esters and 0.29% for biodiesels. An extension of this model to high pressures is also proposed and tested with success, presenting an OARD of 1.0% for six biodiesel fuels