Volumetric and Acoustic Properties of Binary and Ternary Mixtures of Butanol Isomers with Gasoline Surrogate Compounds

Abstract

Substituting butanol, a renewable fuel for internal combustion engine, as the gasoline blend against the conventionally used ethanol requires the knowledge of their thermophysical properties as these properties decide the fuel injection system, flame propagation, and combustion process in a compression ignition engine. Butanols offer higher energy density and lower tendency to absorb moisture. To offer proof of concept of the influence of temperature and composition of various organic solvents in the isomers of butanol, herein, we had experimentally measured the values of densities (ρ) and speeds of sound (u) of butanol isomers with o-xylene, toluene, and 2,2,4-trimethylpentane at different temperatures (T = 298.15 and 308.15 K) and at 101.3 kPa pressure and over the entire composition range. Measured data have been used to calculate the thermodynamic properties, namely, excess molar volumes VmE and excess molar isentropic compressibilities Ks, mE. The behavior and influence of the temperature and proportion of butanol isomers on measured and calculated properties were studied. Experimental VmE data have been fitted to the Redlich–Kister polynomial equation, and standard errors in prediction were determined. Densities of the binary system are predicted by the PC-SAFT equation of state. We further have used the Prigogine–Flory–Patterson (PFP) theory to predict VmE of the studied systems. Results of predicted and experimentally determined VmE over the entire range of proportion of butanols are compared. Influence of isentropic compressibility on the resulting fuel’s combustion characteristics has been cursorily discussed.