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

New process for recovery of acetic acid from waste water

This paper addresses an industrially important problem of acetic acid recovery from a waste water stream via reactive distillation route. The presence of a three-phase regime on the column stages due to a liquid liquid phase split between aqueous and organic phases is a typical characteristic of this process. A modern modeling approach is presented to detect the existence of potential phase splitting in this column. A good agreement of a phase splitting model with the literature data has been shown. The theoretical study for the recovery of acetic acid from its 30 wt.% aqueous solution by esterification with n-butanol is presented. Alternate column structures were investigated and two structures rendering theoretically close to 100 % conversion of acetic acid were identified. The dynamic simulations were performed on proposed structures to see transient responses wrt. to common process disturbances

Dynamic simulation of reactive distillation processes with liquid-liquid phase splitting

This work presents a modern modeling approach for reactive distillation processes with potential phase splitting. It is based on a classical model (pseudo-homogeneous) in connection with a robust and reliable phase splitting algorithm (through homotopy-continuation method), performed at each simulation step. Model validation stage and a simple case-study (by applying the new approach to a reactive distillation column for waste water treatment) are also presented. All simulation scenarios revealed a good agreement between simulation results and the real system behavior, much better than using a classical pseudo-homogeneous mathematical model