Production of butyl acetate by catalytic distillation : reaction kinetics and process design studies

This paper studies reactive distillation for the synthesis of n-butyl acetate from n-butanol esterification with acetic acid over Amberlyst -15. This study is carried out to influence the unwanted side product dibutylether formation, produced by butanol dehydration. First of all, activity based intrinsic reaction kinetics for the main reaction (esterification) and the side reaction (etherification) have been developed. Effect of various parameters such as temperature, mole ratio, catalyst loading and catalyst particle size was studied. The intrinsic kinetic parameters related to Pseudohomogeneous (PH), Eley-Rideal (RE), Langmuir Hinshelwood Hougen Watson (LHHW), and modified LHHW (ML) models were developed. Good agreement between the model predictions and experimental data were obtained. For the main reaction RE model or modified LHHW model and for the side reaction LHHW model are appropriate representations of intrinsic kinetics. The developed rate expression were then used for the simulation based design of reactive distillation column for the production of butyl acetate with the goal of eliminating the side product formation and achieving high purity of desired product butyl acetate. A simple equilibrium stage, steadystate reactive distillation column model was developed and validated using expeimental data from the literature. The following column configurations are invesigated: (a) column with non - reactive rectifying section and reactive stripping section (b) column with non - reactive rectifying section, non - reactive stripping section and reactive middle section; and (c) conventional distillation column with pump around reactor. For each configuration, effect of design parameters such as, reboiler heat duty, catalyst loading, catalyst section length and location, and feed stage location were investigated with the objective to achieve desired goal

Production of butyl acetate by catalytic distillation: Process design studies

A simulation-based design method is employed to figure out the promising reactive distillation process configuration for the production of butyl acetate. The intrinsic kinetics developed for the esterification and the unwanted side reaction etherification over the Amberlyst-15 catalyst(1) are utilized to evaluate the steady-state performance of different reactive distillation processes. A steady-state column model is developed and compared with experimental data from the literature.(2,3) With this model, three different column configurations are investigated for the production of butyl acetate with the goal of eliminating the formation of byproduct dibutyl ether and achieving a high purity of the desired product butyl acetate. The following column configurations are explored: (a) a column with a nonreactive rectifying section and a reactive stripping section; (b) a column with a nonreactive rectifying section, a nonreactive stripping section, and a reactive middle section; and (c) a conventional distillation column with a cocurrent pump-around reactor. Configuration c is compared with the side reactor configuration, where the pump-around reactor is coupled to the column in a countercurrent fashion

Esterification of acetic acid with butanol in the presence of ion-exchange resins as catalysts

The esterification of acetic acid with n-butanol was studied in the presence of ion-exchange resin catalysts such as Amberlyst-15 to determine the intrinsic reaction kinetics. The effect of various parameters such as temperature, mole ratio, catalyst loading, and particle size was studied. Kinetic modeling was performed to obtain the parameters related to intrinsic kinetics. Pseudohomogeneous, Eley-Rideal, Langmuir-Hinshelwood-Hougen-Watson (LHHW), and modified LHHW models were developed. The kinetics for the side-reaction etherification was also investigated. The rate expressions would be useful in the simulation studies for reactive distillation. The experimental data generated for the reaction under total reflux were validated successfully using the developed rate equation and estimated values of kinetic parameters

Some aspects of NOX absorption

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Esterification of acetic acid with butanol in the presence of ion-exchange resins as catalysts

The esterification of acetic acid with n-butanol was studied in the presence of ion-exchange resin catalysts such as Amberlyst-15 to determine the intrinsic reaction kinetics. The effect of various parameters such as temperature, mole ratio, catalyst loading, and particle size was studied. Kinetic modeling was performed to obtain the parameters related to intrinsic kinetics. Pseudohomogeneous, Eley-Rideal, Langmuir-Hinshelwood-Hougen-Watson (LHHW), and modified LHHW models were developed. The kinetics for the side-reaction etherification was also investigated. The rate expressions would be useful in the simulation studies for reactive distillation. The experimental data generated for the reaction under total reflux were validated successfully using the developed rate equation and estimated values of kinetic parameters

Production of Butyl Acetate by Catalytic Distillation : Theoretical and Experimental Studies

The esterification reaction of acetic acid with n-butanol in a continuous catalytic distillation system has been studied. The products of esterification reactions viz, water and butyl acetates are separated by distillation during the course of the reaction, to overcome the equilibrium limitations. A 3-m-tall column with reactive and nonreactive zones, packed with a commercial catalytic packing (KATAPAK-S) and noncatalytic wire gauze packing, was used for this purpose. For a feed concentration corresponding to that obtained in a one-stage continuously stirred tank reactor at reaction equilibrium, conversion of ~100% was realized, with selectivity on the order of 99%. Interestingly, in most of the experiments, the bottom stream contained butyl acetate that was almost free of acetic acid. The influence of various operating parameters, such as feed flow rate, feed composition, feed location, and boil-up rate, on the conversion, selectivity, and separation was studied. A dynamic equilibrium stage model was developed and solved to predict the transient and steady-state results. Reasonably good agreement between the experimental and simulation results was realized

Waste treatment of an aqueous waste stream from a cyclohexane oxidation unit: a case study

Catalytic wet oxidation of an aqueous waste stream, obtained after recovery of Na<SUB>2</SUB>SO<SUB>4</SUB> and butyric acid, valeric acid and caproic acid (BVC acids) from a cyclohe oxidation unit, was carried out at elevated temperature and pressure to detoxify the waste stream with regard to COD to meet local discharge standards. The possibilities for recovery of Na<SUB>2</SUB>SO<SUB>4</SUB> and C<SUB>2</SUB>-C<SUB>6</SUB> carboxylic acids were also explored