energy recovery because corn trash/skin and stem are
bulky and non-uniform fuel with high moisture content
which leads to the difficulty in collection, transportation
as well as in thermal conversion. Hence, the corn residues
to further be considered in this study are trash/skin/stem
only. Table III shows the CRR as well as the amount of
corn residue in Petchaboon and Nakorn Sawan in 2011.
Fig. 2. Life Cycle for Corn Cultivation and Utilization
Fig. 3. Corn cob (Left) and Trash/Skin/Stem (Right)
TABLE
III
CRR
AND
A
MOUNT OF
C
ORN
RESIDUES
IN
P
ETCHABOON AND
N
AKORN
S
AWAN IN
2011
Product
(ton/year)
Residues
CRR Available
Residues
Petchaboon
675,140
Trash/Skin/Stem
1.95
1,315,971
Corn cob
0.19
128,277
Nakorn
Sawan
299,737
Trash/Skin/Stem
1.76
529,475
Corn cob
0.19
56,950
B. Fuel Characteristics of Corn Residues
The characteristic used to indicate the energy potential
of biomass is its heating value. In addition to heating
value, proximate and ultimate analysis is also important
indicator for converting biomass to energy. Table IV
shows the fuel characteristics of corn residues obtained
from Petchaboon and Nakorn Sawan.
From Table IV, it can be conclude that corn cob and
trash/skin/stem originated in Petchaboon and Nakorn
Sawan has almost the same characteristics. The higher
heating value ranges from 15-16 MJ/kg for corn cob and
13-15 MJ/kg for trash/skin/stem. After harvesting for 2
weeks, moisture content of corn cob is less than 10%,
where the moisture content of trash/skin/stem varies from
6% to 12%.
TABLE
IV
F
UEL CHARACTERISTICS OF
C
ORN
RESIDUES
IN
P
ETCHABOON AND
N
AKORN
S
AWAN
Petchaboon
Nakorn Sawan
Trash/
Skin/Stem
Corn
cob
Trash/
Skin/Stem
Corn
cob
Proximate analysis
-
Moisture content
1
(%)
-
Volatile matter
2
(%)
-
Ash
2
(%)
-
Fixed carbon
2
(%)
6.12
73.35
7.20
19.45
9.97
83.13
1.98
14.89
11.90
78.85
5.60
15.55
9.94
84.71
2.33
12.96
Ultimate analysis
2
(%)
-
Carbon (C)
-
Hydrogen (H)
-
Oxygen (O)
-
Nitrogen (N)
-
Sulfur (S)
44.53
5.88
42.16
0.17
0.047
44.83
6.01
47.07
0.05
0.056
44.65
6.50
46.18
2.68
0.027
47.00
6.55
44.75
1.66
0.055
HHV (kJ/kg)
14,975
15,073
13,157
16,093
1
as received basis (after 2 week harvesting)
2
dry basis
C. Supply Chain Management of Bio-fuel from Corn
Residues
The supply chain management starts from the
harvesting or collection of biomass, transportation and
finally processing of corn residues to bio-fuel.
Because of the uniform and compact shape of
corncobs, they are completely utilized as fuels in a stoker
fired boiler for heat production. In contrast, corn
trash/skin and stem are leftover in the field or burnt on
field without any energy recovery because corn trash/skin
and stem are bulky and non-uniform fuel with high
moisture content which leads to the difficulty in
collection, transportation as well as in thermal
conversion. Therefore, this section will consider only
trash/skin/stem as alternative energy source.
Collection: In this case study of Petchaboon and
Nakorn Sawan Province, corn cobs have already
commercially been sold to corn mills for heat production,
hence, no corn cobs is available for further energy
production. However, corn trash/skin/stem is still
available on-field. The harvesting and collecting of these
residues can be done by imported machineries. Because
the imported machineries are very expensive and the
geography of Northern part of Thailand is the mountains
which limit the collection by large machines, the manual
collection of corn trash/skin/stem is the most suitable
method. By manual collection, trash/skin/stem should be
left on field for 1 week until its moisture content can be
reduced to 15%. One labor can collect trash/skin/stem in
the area of 0.5 Rai or corresponds to 501.28 kg of
trash/skin/stem (15% moisture content). Fig. 4 shows the
manual collection of corn trash/skin/stem on-field.
Fig. 4. Manual collection of corn trash/skin/stem
Corn Cultivation
Area / Field
Corn Cob
with Grains
Corn Mill
for Grains
Extraction
Corn Grain
Empty Corn cob
Trash/Skin/
Stem
Eliminated by
landfilling or
burning on field
Selling
Already used as
supplementary in
corn mill
2013 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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