Chemical Engineering Research & Design, Vol.133, 243-254, 2018
A comprehensive study on equilibrium and kinetics of morpholine extraction from aqueous stream with CA in toluene: Experimental evaluation, extraction model and parametric optimization employing desirability function
The present study explores the equilibrium and kinetics for the reactive extraction of morpholine, an important industrial reagent from its aqueous stream using capric acid, CA (extractant) in toluene (diluent). An equilibrium model that employs the mass action law was also developed to evaluate the optimum apparent equilibrium constants (KE), stoichiometric ratio (m) and physical constant (S). Equilibrium model was valid in representing the mechanism of morpholine extraction. Moreover, for the first time the study availed the simultaneous optimization of two significant response characteristics; extraction efficiency (%E) and loading ratio (Z) using Box-Behnken design (3(3)) employing multivariate desirability function. The statistical models predicted %E of 80.2 and Z of 0.64 for the optimum combination of process parameters as follows: C-MO = 5%, C-CAO = 5% and T = 303.15 K with the desirability of 0.947. Further, the intrinsic kinetics of the extraction model demonstrated that the reactions between morpholine and CA fall in regime 3 (fast chemical reaction in diffusion film), follows first order kinetics with respect to morpholine and displays exothermicity of the process as revealed from thermodynamic studies. The equilibrium and kinetic data is useful for the development, design and reliable scale-up of the extraction process. (C) 2018 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.
Keywords:Reactive extraction;Loading ratio;Box-Behnken design;Desirability function;Extraction model;Kinetic study