Measurements and Estimate of Heat Capacity for Some Pure Fatty Acids and Their Binary and Ternary Mixtures

Abstract

The heat capacities in the liquid phase of the fatty acids hexadecanoic acid, octadecanoic acid, and cis-9-octadecenoic acid were measured, as well as those of their binary and ternary mixtures from temperatures close to solidification to 528 K. The measurements were correlated and contrasted with equations, methods, and values for the pure fatty acids, Ruzicka and Domalski's method providing better results for most of the temperature range studied. For binary and ternary mixtures, molar fraction average and corresponding states methods were used. The convenience of the former with respect to the latter was demonstrated; it is easier to apply and provides suitable results. Furthermore, in the case of the mixtures, only slight variations in heat capacity with composition were experienced. All the measurements were carried out using a DSC differential scanning calorimeter.

Effects of the properties and the structural configurations of fatty acid methyl esters on the properties of biodiesel fuel: a review

“…Ceden˜o et al 192 have proposed equations to estimate the heat capacity of pure palmitic acid, stearic acid and oleic acid for a range of temperatures. For palmitic acid (between 343 K and 428 K), where T is the absolute temperature (K).…”

“…Sources: reproduced with kind permission from Cedeno et al192 Copyright Ó 2000, American Chemical Society; reproduced with kind permission fromFisher. 193 …”

Droplet evaporation behaviour of a liquid fuel from chicken litter

“…For n-alkyl acids [32] discrepancies were similar at room temperature, but rose to as high as 11% at 400 K.…”

Prediction of heat capacities and heats of vaporization of organic liquids by group contribution methods

“…The last column of Table 5 gives the average relative deviations using Eq. (15). Note that the inclusion of the correction term improved the prediction of the heat of vaporization of oleic acid notably.…”

“…The correction term included in Eq. (15), as suggested by Haggenmacher [44], is supposed to handle these deviations. The last column of Table 5 gives the average relative deviations using Eq.…”