Volumetric and viscometric properties of binary liquid mixtures as potential solvents for flue gas desulfurization processes

Abstract

Desulphurization processes (FGD) of flue gases from the thermal power and industrial plants, based on organic liquid solvents with mechanism of physical absorption (tetraethylene glycol dimethyl ether) or combination of physical and chemical absorption (N-methyl-2-pyrrolidone), recently gained its significance. The research results presented in this paper include density and dynamic viscosity measurements of following binary systems at atmospheric pressure: polyethylene glycol 200+tetraethylene glycol dimethyl ether, polyethylene glycol 400+tetraethylene glycol dimethyl ether, in temperature range from 288.15 to 333.15K, and binary systems polyethylene glycol 200+N-methyl-2-pyrrolidone and polyethylene glycol 400+N-methyl-2-pyrrolidone, in temperature range from 288.15 to 323.15K. In order to analyze and comment intermolecular interactions, calculated values of excess molar volumes and viscosity deviations were used. Strong, physical interactions of dipole-dipole type or formation of intermolecular hydrogen bonds lead and contribute to negative VE values that occur in these systems. Calculated values of excess and deviation properties were interpolated using the Redlich-Kister polynomial equation. Viscosity modeling has been performed, using predictive, group contribution models (UNIFAC – VISCO and ASOG – VISCO) as well as correlative models (McAlister, Eyring – UNIQUAC and Eyring – NRTL). For simultaneous modeling of excess molar volumes and viscosities, model based on the equation of state was used. For investigated systems, correlative McAllister models gave the best results and can be used for viscosity calculations.