A group contribution model for determining the vaporization enthalpy of organic compounds at the standard reference temperature of 298K

Abstract

A group contribution model for determining the vaporization enthalpy of organic compounds at the standard reference temperature of 298 K, Fluid Phase Equilibria (2013), http://dx.doi.org/10. 1016/j.fluid.2013.09.021 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. , recently published a comprehensive compilation of phase change enthalpies, including vaporization enthalpies of pure organic and organometallic compounds. This collection of vaporization enthalpies for 2811 compounds at the standard temperature of 298.15 K was used in this study for the development of a predictive model. The compounds in the collection are composed of a combination of the following atoms, viz. carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfur, fluorine, chlorine, bromine, and iodine. This paper presents a reliable group contribution model for the prediction of the vaporization enthalpies of organic compounds. The group contribution model developed is able to predict the standard molar enthalpies of vaporization to within an average absolute relative deviation of 3.7%, which is of sufficient accuracy for many practical applications in chemical and petrochemical engineering.

Kinetic Treatment of Evaporation via Thermogravimetric Analysis: The Case of d-Limonene

“…When this correction is applied, both the 180 and 200 mL/min flow rate values fall within the standard deviation of the reported Δ vap H values (49.5 ± 0.3 kJ mol –1 ). The results are also in agreement with theoretically calculated value of 49.3 kJ mol –1 by Gharagheizi . Under these conditions, the energetics of the diffusion barrier are on the order of the experimental error of the measurement.…”

“…In contrast, a variety of methods can be used to measure Δ vap H , such as direct vapor pressure measurements, − transpiration techniques, ,− and gas chromatography. − Tables of Δ vap H determined via these methods as well as others have been compiled, − and several prediction methods have been developed. , Thermogravimetric analysis (TGA) has also been used to determine vapor pressures and Δ vap H . , …”

Prediction of Physical-Chemical and Fire Hazard Characteristics by Carbon Chain Rules 2. Carboxylic Acids

“…The results of prediction of physico-chemical and fire hazard properties of carboxylic acids (2)-(77) by CCR1, CCR2 and by comparison methods are given in Table 1. The correlation coefficient (r), RMSE (Root Mean Squared Error), AARD (Average Absolute Relative Deviation) [16], average absolute deviation (ɛ) and average square deviation (σ) are chosen as the comparison criteria [11].…”

Phase-Transition Thermodynamics of Tolbutamide

“…One can also compare the differences, Δ 4.5.2. Phase-Transition Enthalpies at 298.15 K. Here, we tested the ability of two recent schemes proposed by Gharagheizi et al 51 and Naef and Acree Jr, 52 which cover sulfur-containing organic compounds. The first scheme estimates Δ l g H(298.15 K) as 109.6 kJ mol −1 which is significantly lower than the experimental value.…”