Heterogeneous Kinetics and Residue Curve Map (RCM) Determination for Synthesis of n-Hexyl Acetate Using Ion-Exchange Resins as Catalysts

Abstract

Esterification of dilute acetic acid with n-hexanol was studied with cation-exchange resins (macroporous and gelular) in a jacketed stirred batch reactor to synthesize a value-added ester, namely, n-hexyl acetate. The effect of various parameters such as speed of agitation, catalyst particle size, molar ratio of n-hexanol to acetic acid, reaction temperature, catalyst loading, and reusability of catalysts was studied for optimization of the reaction condition. The nonideality of each component in the reacting mixture was accounted for by using the activity coefficient via use of the UNIFAC group contribution method. The kinetic data were correlated with both pseudo-homogeneous (PH) and adsorption-based reaction rate models, e.g., Eley−Rideal (ER), Langmuir−Hinshelwood−Hougen−Watson (LHHW), and the modified LHHW (ML). Residue curve maps (RCM) were experimentally generated under different conditions to elucidate the feasibility of n-hexyl acetate synthesis in a reactive distillation column (RDC).