The Published Fusion Enthalpy and its Influence on Solubility Estimation for Alcohols

Abstract

This paper aims to compare two different methods of estimating enthalpy of fusion and identify the one which is closer to the already published value. The n-long chain alcohols such asn-octanol(C8), dodecanol(C12), tridecanol(C13), tetradecanol(C14), pentadecanol(C15), hexadecanol(C16), heptadecanol(C17), octadecanol(C18), nonadecanol(C19)and eicosanol(C20)were the systems used for testing the methods. The experimental or estimateddata was available in the literature, and comparisons enabled the determination of the relative deviations for the compounds studied. It was expected that the enthalpy of fusion could be well evaluated by using sublimation and vaporization enthalpy as well as with the use of liquid and solid enthalpies of formation for the compound. However, when the results were compared with the literature ones, it was found that there are problems with the data published (experimental or not) because of the high relative deviations presented. Then, the prediction of solid-liquid equilibrium (SLE)had errors due to the high inconsistencepresented by this thermophysical property specially for C14, C15, C16 and C18. Thefirst method, which used the liquid and solid enthalpy of formationcan be used without restrictions and the second one had a better estimative of fusion enthalpy justfor some of the alcohols tested.