CHEMICAL ENGINEERING TRANSACTIONS
VOL. 32, 2013
A publication of
The Italian Association
of Chemical Engineering
Online at: www.aidic.it/cet
Chief Editors: Sauro Pierucci, Jiří J. Klemeš
Copyright © 2013, AIDIC Servizi S.r.l.,
I SBN 978-88-95608-23-5; I SSN 1974-9791
Heat Transfer Evaluation of Multicomponent Batch
Distillation of the Wine of Sugarcane Fermentation
Mario E. T. Alvarez
a,
*, John H. Bermúdez
a
, Elenise B. de Moraes
b
, Anderson J.
Bonon
a
, Maria R. Wolf-Maciel
a
a
School of Chemical Engineering, University of Campinas-UNICAMP, Av. Albert Einstein, 500, CEP13083-852,
Campinas, SP, Brazil
b
Brazilian Bioethanol Science and Technology Laboratory (CTBE), CP 6170, CEP 13083-970,Campinas-SP, Brazil
mario@feq.unicamp.br
Experimental data and simulations in Aspen Plus
for the batch distillation process were obtained from
wine of sugar cane fermentation. The experimental data was analyzed in order to verify the effectiveness
of the batch distillation process for recovering ethanol, using a packed column. The reflux ratio was
maintained equal to two and the temperature of the distillation flask was 180 °C. The distillates and the
main components of wine (ethanol, acetaldehyde, acetone, ethyl acetate, n-propanol, n-butanol, 3-methyl-
1-butanol, 2-metil-1-propanol, acetic acid, and glycerine) were quantified using gas chromatography
analyses. It was found that the highest ethanol concentration was obtained in one hour of distillation and
the accumulate ethanol concentration was above 80 % (w/w) when operated at constant reflux. Therefore,
it is possible to obtain high yields and concentrations of ethanol in a short period of time.
1. Introduction
In the 1970s, the Brazilian government started a program for the production of ethanol from sugarcane in
order to effectively replace gasoline on a large scale. For a time, this program was discontinued, but due to
the production instability of the world´s largest oil producers and other energy concerns, the search for
alternative sources of energy, preferably from renewable sources, has again sparked interest in this
subject (Junqueira et al., 2009). The fermentation processes employed in the Brazilian ethanol industry
requires low substract concentration and produce wine of low ethanol content (around 7.0 to 8.5
w/w).When the intention is to use ethanol as a fuel, ethanol concentration must be at least 92.5 to 93.8
w/w. In the batch distillation column, the feed is loaded to the distillation flask at the beginning of the
process. It is then heated to its boiling point and the products are withdrawn sequentially from the column’s
top, according to their boiling point (Demicoli and Stichlmair, 2004). Batch distillation has been used to
evaluate the effect of the recycling of foreshots and feints in the grappa distillation (Porto et al. 2010) and
in the separation of a complex azeotropic mixture, comparing two methods of separation, showing that the
column’s hold-ups have influence on the component separation (Watson et al., 1995). In this work, a batch
distillation column was used to concentrate ethanol. The distillate fractions containing ethanol, fusel oil and
other volatile components were collected and analysed by gas chromatography and the performance of
the batch distillation was evaluated. Simultaneously, a simulation using Aspen Plus
was performed to
evaluate the separation and the heat consumption of the process.
2. Batch Distillation Column
2.1 Details of the batch distillation column
A batch distillation column, model Autodest 800AC of Fischer Technology with a capacity of 80 L was used
and conditioned for ethanol distillation. The packed column is filled with Propak 6 mm 316 and equipped
with a silvered vacuum mantle. The distillation flask and the packed column have an external heat mantle
and the temperature is controlled by a Pt 100. The vapour temperature at the top of the column is also
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