Production of Bioethanol from Corn Cob Hydrolysate
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Date
2019-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
All societal activities depend up on energy services to meet the daily. The environmental issues,
the growing demand for energy, increasing petroleum-based oil prices and the depletion of
petroleum created the need for the development of sustainable and safe alternative energy source.
Bioethanol is one of the alternative energy sources. In this study of ethanol production from corn
cob dilute sulfuric acid method of hydrolysis was employed because it is easy and productive
process. The samples were mixed with distilled water in a ratio of 1:10 (w/v) and pretreated using
1% dilute sulfuric acid in autoclave at temperature of 120℃ for 30 minutes. It was hydrolyzed
using diluted H2SO4 of 2%, 3% and 4% at a temperature of (100 ℃, 120 ℃ and 140 ℃) for (20,
30 and 40) minutes. Sugar concentrations were determined using phenol sulfuric acid method.
The maximum, medium and minimum sugar yields were 53.56536, 47.46514 and 41.64815 g/l
respectively. Fermentation was conducted using the hydrolysates(sugars) obtained in previous
process, inoculum level of (5, 10, 15 %v/v) and temperature of (25, 30, 35 ℃) for 72 hours. Sugar
concentration and inoculum level have a statistically significant effect on ethanol yield with pvalue
of
0.0021
and
0.0068
respectively.
Ethanol
yield
was
maximum
at
middle
values
of
the
fermentation
parameters
and
it
is
negatively
affected
at
their
minimum
and
maximum
values.
From
the
statistical
analysis
maximum
ethanol
yield
of
0.530
mL/g
was
found
at
sugar
of
4.917
g,
inoculum
of
12.17
%v/v,
and
at
a
temperature
of
29.977
℃
with
89.8
%
desirability.
In
FTIR,
it
was
observed
that
the
ethanol
produced
from
corn
cob
contains
O-H
functional
group,
C-O,
CH2,
and
CH3
groups.
Finally,
a
good
yield
of
ethanol
was
obtained.
So,
corn
cob
is
a
potential
feedstock
for
ethanol
production.
Description
Keywords
Bioethanol, Corn cob, saccharomyces cerevisiae, glucose equivalent, Pretreatment, Hydrolysis, Fermentation, FTIR