Boiling Points of Short-Chain Partial Acylglycerols and Tocopherols at Low Pressures by the Differential Scanning Calorimetry Technique

Abstract

Boiling points of monocaprylin, monocaprin, dicaprylin, and dicaprin were measured at low pressures (1.0 kPa up to 13.2 kPa) using a differential scanning calorimetry technique and correlated by empirical equations (Clapeyron and Antoine). Parameters of the Design Institute for Physical Property Research (DIPPR) equations were also regressed considering calculated values of normal boiling points and critical points using the Marrero and Gani method. Heats of vaporization were estimated using the Clausius–Clapeyron relation with the inclusion of a correction term to account for deviations at higher pressures. Boiling points of α-, β-, δ-, and γ-tocopherol were measured at 1.1 kPa. A DIPPR equation was also proposed for estimating the vapor pressure of this class of compounds, and an equation for predicting heat of vaporization was derived. Data presented in this work can be valuable for process design in the edible oil industry and for development of biodiesel purification steps.