(329e) Simulation Study of Different Alternatives for Isoamyl Butyrate Production by Using Aspen Plus®

Simulation
Study of Different Alternatives for Isoamyl Butyrate Production by Using Aspen
Plus^®

Jairo
Duran, Karen Cañón, Iván Gil, Gerardo Rodríguez, Julio
Vargas

Grupo
de Procesos Químicos y Bioquímicos. Department of
Chemical and Environmental Engineering. Universidad Nacional de Colombia.
Bogotá. Colombia

The
Isoamyl butyrate is a value-added product
widely used in fragrances and flavors, therefore its production can be interesting
for this kind of industries and can be the basis for business approach. Otherwise,
the production process may be included in the green chemical engineering field
because the use of raw materials from renewable resources, for instance,
isoamyl alcohol can be obtained from fusel oil, a well known by-product from
ethanol production. This work presents the simulation and the analysis of the
conventional scheme for ester production and the coupled reactor/column configurations.
The total annual cost (TAC) has been used as a comparison and evaluation
criterion to explore the alternatives of production and determine which one
presents the best performance at a lower cost.

Due
to the lack of experimental data on vapor-liquid equilibrium (VLE) of the
isoamyl butyrate ? isoamyl alcohol, it was necessary to obtain experimentally
those data. Vapor-liquid equilibrium
data were measured at 101.3 kPa. A dynamic equilibrium apparatus was used for
the measurements (Fischer Labodest VLE-602). Equilibrium data were fitted with
UNIFAC and NRTL models, obtaining a maximum absolute error of 2.5%. Herrington
area test was performed using some criteria reported at literature. Also, Van
Ness test was used as modelling capability test for NRTL and UNIFAC models.
Good thermodynamic consistency was found with both tests.

After
obtaining reliable thermodynamic data, it was possible to begin an analysis of
each scheme of production. The process simulation has
been performed by using Aspen Plus^®. UNIFAC and Peng-Robinson with
Wong Sandler mixing rules were set as property methods. It was preferred to use
Wong Sandler mixing rules over others because the benefits of extrapolation on
the model to other pressures as reported in the literature. Operations where the
isoamyl butyrate-isoamyl alcohol VLE is relevant for the design, such as
distillation columns, were simulated by using parameters obtained from
regressed model, however for the other operations, default UNIFAC parameters
were used for modeling. Economic analysis includes the estimation of fixed and
variable costs of the process by using equations and heuristics from
literature. Coupled reactor/column resulted with the lower TAC using a base
production of 200 000 kg/yr which is the average consumption of isoamyl
butyrate in Colombia. It is expected that the results presented in this work
will be the comparison criteria of a base study on reactive distillation
process for this system.

Keywords: Acidic
catalysts, coupled reactor/column, esterification, fixed costs, Isoamyl
butyrate, liquid-vapor equilibrium, operational costs.

Some
Cited References

µ  Kang
J.W., Diky W., Chirico R., Magee J.W., Muzny C.D., Abdulagatov I., Kazakov A,
Frenkel M. Quality Assessment Algorithm for Vapor-Liquid Equilibrium Data. J. Chem. Eng. Data, 2010, 55 (9), pp 3631?3640.

µ  Stanley
I., Orbey H. Mixing and Combining Rules. Available on Equations of
State for Fluids and Fluid Mixtures by Sengers J.V., Kayser R.F., Peters
C.J., White Jr. H.J. (Editors). International Union of Pure and Applied
Chemistry. 2000. pp 321-357.

µ  Luyben
W., Yu C. Reactive Distillation Design and Control. AIChE and John
Wiley & Sons, Inc. United States of America. 2008.

µ  Luyben
W., Distillation Design and Control Using ASPEN^TM Simulation. AIChE
and John Wiley & Sons, Inc. United States of
America. 2006.

µ  BACEX,
Foreign Trade Databank. Ministerio de Comercio, Industria y Turismo. Republic
of Colombia. Consulted on December 16, 2010.

Graphic
Abstract

Measured
vapor-liquid equilibrium data for isoamyl butyrate-isoamyl alcohol at 101.3
kPa. NRTL model using the three parameters regressed (continuous line).