The reaction of butanal with ethanol in the presence of Amberlyst-15 wet to form 1,1-diethoxybutane, which is a potential diesel additive, was optimized for maximum equilibrium conversion by a parametric study with temperature, reactants ratio, and catalyst loading as factors. Thermodynamic and kinetic studies were also carried out. The kinetic model was validated by means of the experimental data.

Abstract

1,1-Diethoxybutane is a high-potential biofuel additive that enhances various fuel properties, which include cetane number, lubricity, biodegradability, and flash point. This work presents a kinetic and thermodynamic study on the acetalization reaction between butanal and ethanol in the presence of Amberlyst-15 wet in a batch reactor. The experiments were conducted in the temperature range 313–333 K at atmospheric pressure with three different initial molar ratios of reactants and catalyst loadings. An optimal parameter setting to achieve maximum equilibrium conversion of butanal was derived from a parametric study with these three factors. The equilibrium constant for the reaction was determined. Standard thermodynamic properties of the reaction, such as enthalpy, entropy, and Gibbs free energy, were experimentally evaluated. The activity-based two-parameter Langmuir-Hinshelwood-Hougen-Watson rate expression was used for reaction kinetics. The activity coefficients were calculated by the UNIFAC method. The kinetic parameters and the activation energy were evaluated from the experimental data. The experimental data and data predicted by the model were found to be in good agreement.