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Synthesis of diethyl carbonate from ethanol through different routes: A thermodynamic and comparative analysis
Author(s) -
Shukla Kartikeya,
Srivastava Vimal Chandra
Publication year - 2018
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22896
Subject(s) - unifac , gibbs free energy , equilibrium constant , thermodynamics , chemistry , enthalpy , diethyl carbonate , chemical equilibrium , carbonate , standard enthalpy of formation , heat capacity , thermodynamic equilibrium , standard molar entropy , activity coefficient , ethylene carbonate , organic chemistry , electrolyte , physics , electrode , aqueous solution
In this study, thermodynamic analysis of various possible synthesis routes of diethyl carbonates (DEC), a benign organic carbonate, was carried out and a comparative analysis was performed. Chemical equilibrium constants at standard conditions were calculated using Gibbs free energy of the system. The Benson group contribution method was used to estimate standard heat of formation and standard entropy change of some raw materials/components like dimethyl carbonate. Variation of heat capacity (C p ) with temperature was estimated for different components from the Rozicka‐Domalski model. Variation of chemical equilibrium constants with temperature and pressure was studied for various routes. Synthesis of DEC from ethylene carbonate (EC) was also found to be better considering equilibrium constants at room temperature. The CO 2 route was found to be the most unfavourable route for DEC synthesis due to stability of CO 2 molecules. Moreover, DEC synthesis through the urea route was found to be best at high temperatures since the equilibrium constants were found to increase exponentially. Experiments were conducted for DEC synthesis using the EC route at two temperatures. Activity coefficients were calculated using the UNIFAC model. Experimentally and theoretically determined chemical equilibrium constant values were found to be similar. PRO/II was also used to minimize Gibbs free energy of the system and estimate the equilibrium constants and the results were comparable with those obtained by the equilibrium constant method and the trend was found to be the same for both the methods.