Thermodynamics of glycerol and diols valorisation via reactive systems of acetals synthesis

Abstract

Glycerol and diols are valuable renewable sources for manufacturing of fuel additives via reactive systems of acetals synthesis. Knowledge of thermodynamic data for reactions participants involved in valorisation of glycerol and diols is required. The liquid phase standard molar enthalpy of formation of glycerol formal was measured by the high-precision combustion calorimetry. Standard molar enthalpies of vaporisation of glycerol formal, 1,3-dioxane, 1,4-dioxane, and dimethyl-1,3-dioxanes were derived from temperature dependences of vapour pressure measured with help of transpiration method. Temperature dependences of vapour pressures for acetals available in the literature have been collected and treated uniformly in order to derive recommended sets of vapour pressures and vaporisation enthalpies at the reference temperature 298.15 K. Enthalpies of vaporisation of these compounds were obtained by the transpiration method. Experimental results for glycerol formal were validated by the high-level G4 quantum-chemical method. Enthalpies of the acetalisation reactions of glycerol and diols were estimated and discussed.