Heterogeneous Kinetics of the Liquid Phase Synthesis and Hydrolysis of Isopropyl Lactate
Advancing the chemical engineering fundamentals
Chemical Reaction Engineering (T2-2P)
Keywords: Esterification, hydrolysis, lactic acid, isopropyl lactate, ion-exchange resins, liquid phase adsorption, chemical equilibrium.
Separation and purification of lactic acid from fermentation broth is a daunting problem because of its non-volatile nature and also due to the presence of other organic impurities. Esterification of lactic acid with isopropanol followed by hydrolysis of the separated ester (isopropyl lactate) to produce pure lactic acid is an effective technique for the recovery of lactic acid. Moreover, isopropyl lactate is used as a very important pharmaceutical intermediate. In the present work, esterification of lactic acid with isopropanol and the subsequent hydrolysis of the corresponding ester, i.e. isopropyl lactate, have been studied in a jacketed stirred batch reactor using macroporous and gelular cation-exchange resins. The influence of different operating parameters such as speed of agitation, catalyst particle size, initial reactant molar ratio, reaction temperature and catalyst loading has been studied for optimisation of the reaction condition. Additionally, the adsorption constants for water and isopropanol on Purolite® CT-124 (a gelular cation-exchange resin) have been determined by performing liquid phase adsorption experiments. Experimental kinetic data of esterification and hydrolysis reactions have been correlated simultaneously. The kinetic data have been correlated with both pseudo-homogeneous (PH) and adsorption based reaction rate models, e.g., Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW). The non-ideality of each component in the liquid phase reacting mixture has been accounted for by using the activity coefficient via the use of UNIQUAC equation.
Presented Tuesday 18, 13:30 to 15:00, in session Chemical Reaction Engineering (T2-2P).
