Proceedings of International Business and Social Sciences and Research Conference
16 - 17 December 2013, Hotel Mariiott Casamagna, Cancun, Mexico, ISBN: 978-1-922069-38-2
Management of Agricultural Renewable Sources (MARS) by
Bioethanol Production from Sweet Corn and Canola
Behzad Sani* and Vida Jodaian**
The aim of this study was to determine the sugar content of sweet corn
(K.S.C.404) and canola (RGS 003) and also determine the plant that will
produce the highest ethanol content. Extract was used for ethanol
production and influence of pH, yeast concentration on the ethanol content
was studied. The results showed that the highest ethanol content (0.41 g.g1) was achieved at pH = 4.3 and yeast concentration = 2.7 wt% from sweet
corn and lowest ethanol content (0.12 g.g-1) was achieved at pH = 4.9 and
yeast concentration = 3.4 wt% from canola. The findings showed that sweet
corn had more ethanol than canola because it is a cereal and has more
starch that helps to produce more ethanol. The results of this study can
help to better management of agricultural renewable sources (MARS) for
achieving sustainable agriculture.
JEL Codes: Renewable sources, bioethanol production, sweet corn, canola
1. Introduction
Ethanol is considered as an alternative to petroleum-based fuels, and much attention has
been focused on the improvement of ethanol production using agricultural raw materials
as the feedstock. Therefore, the development of a fermentation process using economical
raw materials is essential for the biofuel ethanol production at a commercial scale (Tao et
al. 2005). One technology that can increase the productivity and cost effectiveness of
ethanol production is very high gravity (VHG) fermentation. The process involves the
preparation and fermentation of total sugars to completion of mashes containing at least
270 gr or more of dissolved solids per litre (Bayrock and Ingledew, 2001; Bai et al. 2004).
It has several advantages for industrial applications such as increase in both the ethanol
concentration and the rate of fermentation which reduce capital costs, energy costs per
litre of alcohol and the risk of bacterial contamination (Bai et al. 2008). However, the
fermentation of VHG medium may have a negative effect upon the yeast performance due
to the elevated osmotic pressure and the production of high levels of ethanol (PrattMarshall et al. 2003).
2. Management of Agricultural Renewable Sources (MARS)
Bio-ethanol produced from agricultural crops or plants is a clean burning renewable fuel
that is being increasingly used as a substitute fuel for road transport applications
(Sanchez, 2007). In 2009 worldwide ethanol fuel production reached about 19.5 billion
gallons (RFA, 2010). The market for bio ethanol road fuel is growing so rapidly that
demand is starting to exceed supply (Kennedy and Turner, 2004).
*Dr. Behzad Sani, Department of Agriculture, Shahre-e-Qods branch, Islamic Azad University, Tehran, Iran.
Email : dr.b.sani@gmail.com
**Dr. Vida Jodaian. Department of chemistry, Islamshahr branch, Islamic Azad University, Tehran, Iran.
Email:hvidajodaian@yahoo.co.nz
Proceedings of International Business and Social Sciences and Research Conference
16 - 17 December 2013, Hotel Mariiott Casamagna, Cancun, Mexico, ISBN: 978-1-922069-38-2
There is an urgent need for alternative plant species that can produce large volumes of
biomass for conversion into cost effective bio ethanol on a large industrial scale. Plants
used for ethanol production include maize, sugar beet, sugarcane, sweet sorghum and
cassava (Adelekan, 2010).
Fig. 1: Bioethanol Production Process (Chacartegui, 2004)
The production cost of ethanol is not only dependent on the yield but also on the
concentration of ethanol in the fermentation broth, because of the high energy demand in
the distillation step. In this step, the ethanol concentration in the broth after fermentation is
increased to 94% using two stripper columns and a rectification column, which are heatintegrated by operating at different pressures. A significant increase in energy demand is
observed at an ethanol concentration below 4% (Galbe et al., 2007).
The use of bioethanol can reduce our dependence on fossil fuels, while at the same time
decreasing net emissions of carbon dioxide, the main greenhouse gas (McMillan, 1997).
However, large-scale production of bioethanol is being increasingly criticized for its use of
food sources as raw material. Brazil's bioethanol production consumes large quantities of
sugar cane, while in the USA, corn is used (Wheals et al., 1999).
Fig. 2: Bioethanol Production Capability in USA (Chacartegui, 2004)
Proceedings of International Business and Social Sciences and Research Conference
16 - 17 December 2013, Hotel Mariiott Casamagna, Cancun, Mexico, ISBN: 978-1-922069-38-2
Therefore, the aim of this study was management of agricultural renewable sources
(MARS) by bioethanol production from sweet corn and canola at 2012.
3. The Methodology and Model
The aim of this study was to determine the sugar content of sweet corn (K.S.C.404) and
canola (RGS 003) and also determine the plant that will produce the highest ethanol
content. Extract was used for ethanol production and influence of pH, yeast concentration
on the ethanol content was studied. This study was carried out in Iran during 2012. The
field experiment was carried out in a randomized complete block design with four
replications. The main factor was crops (Sweet corn and Canola) and the soil consisted of
22% clay, 31% silt and 46% sand (Table 1).
Table 1 – Some physical and chemical features of the experimental soil
Soil
San Silt Clay
K
P
N
EC
Na
d
(mg/kg
(mg/kg
(mg/kg
(1: pH
(Ds/m) 2.5)
texture (%) (%) (%)
)
)
)
SC.L
58
24
18
120.3
2.7
26.2
0.02
0.1
4
7.
8
The soil bulk density was 1.21 g cm–3 , the field
m). Nitrogen fertilizer added in twice; first, 75 kg ha-1 urea at the stem elongation stage
and 75 kg ha-1 urea at the beginning of flowering stage. Also 150 and 75 kg ha-1 potash
(K2O) and phosphorus (triple super phosphate) fertilizers applied at cultivation time
respectively. At the maturity, we collected 100 plants from each plot randomly for
determination of bioethanol by method of Mutepe et al (2011). Data were subjected to
analysis of variance (ANOVA) using Statistical Analysis System (SAS) computer software
at P < 0.05 (SAS institute Cary, USA 1988).
4. The Findings
The results showed that the highest ethanol content (0.41 g.g-1) was achieved at pH = 4.3
and yeast concentration = 2.7 wt% from sweet corn and lowest ethanol content (0.12 g.g1) was achieved at pH = 4.9 and yeast concentration = 3.4 wt% from canola. The findings
showed that sweet corn had more ethanol than canola because it is a cereal and has
more starch that helps to produce more ethanol. The results of this study can help to
better management of agricultural renewable sources (MARS) for achieving sustainable
agriculture. The use of fossil fuels contributes to global warming and thus there is a need
to resort to clean and renewable fuels. The major concerns with using agricultural crops
for the production of energy are food and water security. Crops that do not threaten food
security can be fermented with a relatively low amount of water and produce high yields of
fermentable sugars is thus needed. Sweet sorghum is a fast growing crop that can be
harvested twice a year and can produce both food (grain) and energy (sugar juice from
stems). The study aim of Mutepe et al (2011) was to determine the sugar content of
different sweet sorghum cultivars at different harvest times and also determine the cultivar
that will produce the highest ethanol yield at optimized fermentation conditions. Four
sweet sorghum cultivars USA 1, USA 2, Honey green and Sugar graze were harvested at
3 and 6 months and the juice was extracted from the stems. The juice was used for
ethanol production and the effect of pH, yeast concentration (Saccharomyces cerevisiae),
dilution factor and the addition of a nitrogen source on the ethanol yield was investigated.
Proceedings of International Business and Social Sciences and Research Conference
16 - 17 December 2013, Hotel Mariiott Casamagna, Cancun, Mexico, ISBN: 978-1-922069-38-2
The results showed that the USA 1 cultivar contained the highest sugar content at 3
months. A maximum ethanol yield (0.48g.g-1) was observed at a pH of 4.5, a yeast
concentration of 3 wt%, a dilution rate of 1:1 and when ammonium sulphate was added to
the fermentation broth as nitrogen source. Glycerol yield formed as a by-product during
fermentation and at a maximum ethanol yield was 0.05 g.g-1 (Mutepe et al., 2011).
Bioethanol can be produced from sugar-rich, starch-rich (first generation; 1G) or
lignocellulosic (second generation; 2G) raw materials. Integration of 2G ethanol with 1G
could facilitate the introduction of the 2G technology. The capital cost per ton of fuel
produced would be diminished and better utilization of the biomass can be achieved. It
would, furthermore, decrease the energy demand of 2G ethanol production and also
provide both 1G and 2G plants with heat and electricity. In the study of Erdei et al (2010)
steam-pretreated wheat straw (SPWS) was mixed with presaccharified wheat meal
(PWM) and converted to ethanol in simultaneous saccharification and fermentation (SSF).
Both the ethanol concentration and the ethanol yield increased with increasing amounts of
PWM in mixtures with SPWS. The maximum ethanol yield (99% of the theoretical yield,
based on the available C6 sugars) was obtained with a mixture of SPWS containing 2.5%
water-insoluble solids (WIS) and PWM containing 2.5% WIS, resulting in an ethanol
concentration of 56.5 g/L. This yield was higher than those obtained with SSF of either
SPWS (68%) or PWM alone (91%). Mixing wheat straw with wheat meal would be
beneficial for both 1G and 2G ethanol production. However, increasing the proportion of
WIS as wheat straw and the possibility of consuming the xylose fraction with a pentosefermenting yeast should be further investigated (Erdei et al., 2010).
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