Experimental Study of Liquid-Liquid Equilibrium and Thermodynamic Modeling for Systems Containing Alcohols plus Biodiesel plus Diesel

Energy crisis and emission problems have led to investigationson alternative fuels. In this respect, partial substitution of dieselwith alcohol and biodiesel has proved to be successful. The presentstudy focuses on the use of biodiesel as an additive to stabilizealcohols in diesel blends and proposes new fuel formulations basedon thermodynamic studies of liquid-liquid equilibrium (LLE)data from ternary systems containing methanol/ethanol/1-butanol +biodiesel + diesel at atmospheric pressure and 300.15 K. The authenticityof phase equilibrium data was validated by the Othmer-Tobiasand Hand equations. The distribution and selectivity coefficientscalculated for immiscibility regions indicated that an increase inthe carbon chain strengthens biodiesel solubility. Experimental dataalso correlated with universal quasi-chemical (UNIQUAC) and non-randomtwo liquids (NRTL) thermodynamic models. Both models showed high agreementwith the experimental data, with deviation values (root-mean-squaredeviation, RMSD) less than 1.78%.