Research paper published in "Aspects of Mechanical Engineering and Technology for Industry" vol: 2, Issue : 1

1. AN INVESTIGATION OF EFFECTIVENESS OF MESUA FERREA L.
SEED CAKE AS A BINDER IN BRIQUETTES MADE FROM RICE
STRAW, TEAK AND BANANA LEAVES
Madhurjya Saikia1
, Bichitra Bikash2*
, Biswajit Shyam3
, Dr. Kalyan Kalita4
,
Dr. Dilip Kumar Bora5
1
Dibrugarh University, Pin: 786004, madhurjyasaikia3@gmail.com
2*
Assam Down Town University, Pin: 781026, bichi1111@gmail.com
3
GIMT-Tezpur, Pin: 784501, bshyam09@gmail.com
4
Assam Engineering College, Pin: 781013, kalyan1281@rediffmail.com
5
Jorhat Engineering College, Pin: 785007, dilip.bora@gmail.com
Abstract
Biomass feedstocks such as rice straw, banana leaves and teak leaves (Tectona grandis) can be densified to fuel
briquettes by means of wet briquetting process at lower pressures of 200-1000 kPa using a piston press. In wet
briquetting process, biomass feedstocks are decomposed up to a desired level under anaerobic condition. Later,
on this decomposed biomass feedstocks are blended with Mesua Ferrea seed cake as a binder and the whole
mixture is pressurized to wet briquettes or fuel briquettes at different die pressures. Upon drying, these wet
briquettes could be used as solid fuels. The present study aims to determine physical and handling
characteristics such as density, shear strength, durability and impact resistance of briquettes.
Keywords: Feedstocks, Mesua Ferrea, Briquettes.
1. INTRODUCTION
India produces large amounts of bio
waste material every year. This includes rice
straw, wheat straw, coconut shell fibers, rice
husks, stalks of legumes and sawdust. Some of
this biomass is just burnt in air; some like rice
husk are mostly dumped into huge mountains of
waste. Open-field burning has been used
traditionally to dispose of crop residues and
sanitize agricultural fields against pests and
diseases [1]. Instead of burning down these wastes
or letting to decompose in open air which raises
the problem of GHG production, it can be
converted to bio-fuels to produce power either by
direct combustion or transforming these loose
biomass to solid fuels like briquettes [2.3]. So
these processes become automatic candidates for
financing under CDM mode.
Biomass briquetting is the densification
of loose biomass material to produce compact
solid composites of different sizes with the
application of pressure. Three different types of
densification technologies are currently in use.
The first called pyrolizing technology relies on
partial pyrolysis of biomass, which is added with
binder and then made into briquettes by casting
and pressing. The second technology is direct
extrusion type, where the biomass is dried and
directly compacted with high heat and pressure.
The last type is called wet briquetting in which
decomposition is used in order to breakdown the
fibers. On pressing and drying, briquettes are
ready for direct burning or gasification. Apart
from easy briquette making technique, these are
very cheap too. At an average one person
consumes fuel wood around 1.2 kg per day
according to UNDP and World Bank which will
cost as much as Rs 6 in India. Considering only
labour cost and number of briquettes produced per
day, per unit cost of briquettes comes around Rs
1.225.One person uses 2 to 2.5 briquettes per day
at an average, that means around Rs 3 is required
everyday for one person which is half of using
fuel wood for energy purposes [10] .The objective
of the present investigation is to determine the
physical (related to storage and handling)
characteristics of rice straw briquettes on using
mesua ferrea L. seed cake as a binder.
2. MATERIAL AND METHODS
2.1 Identification of biomass and pre-
treatments to lower decomposition periods
While selecting biomass for wet briquetting,
emphasis is given on the local availability of

2. certain type of biomass with lower lignin and ash
content. Rice straw, wheat stalks, maize stalks,
cotton stalks and barley stalks are some locally
available loose biomass or agro residue in rural
India. But, the entire available agro residue is not
suitable for wet briquetting. For wet briquetting,
biomass material is needed to be decomposed
before compaction to briquettes. The
decomposition period of lingo-cellulosic biomass
depends largely on their lignin content. High
lignin containing biomass takes longer time for
decomposition. Similarly, biomass having higher
ash content is not acceptable for conversion to
solid fuel as ash forms clinkers and chances of
build-up on the burn pot surfaces, restricting air
flow and influencing the removal of ash from the
burn chamber. High ash content also means more
frequent dumping of the ash pan. Table 1 shows
lignin and ash contents of some available agro
residues.
Table 1 Lignin and ash contents of some locally
available biomasses (Singh J. et al. 2010, Zohar
K. et al, 1995, Mussatto S.I. et al. 2010 and Han
Y. W. et al. 1975 5,6,7
)
Fibersource
Ricestraw
Bananafronds
Wheatstraw
Barleystraw
Maizestalks
Cottonstalks
Lignin(wt%)
9.9 8.0 8.9 13.8 41.0 21.5
Ash(wt%)
17.5 4.7 5.5 10.3 10.2 3.7
Therefore, four pre-treatments are provided to
lower decomposition period of biomass material
as follows:
(1). Biomass at aerobic condition: Biomass
specimen is chopped into sizes less than 10 mm.
Water is added to biomass. Biomass and water
ratio is maintained at 1:4 ratios all the time. The
mixture is kept in sun with a transparent cover.
(2). Biomass with cow dung at aerobic condition:
Cow dung is added to chopped biomass in
requisite form in 1:9 ratios. Mixture and water
ratio is maintained at 1:4 ratios. The mixture is
kept in sun with a transparent covering.
(3). Biomass at anaerobic condition: The mixture of
chopped form biomass (less than 10 mm sizes)
and water is kept in sealed polythene bags.
Biomass and water ratio is maintained at 1:4.
(4). Biomass with cow dung at anaerobic condition:
Cow dung is added with biomass in required sizes
in 1:9 ratios. Biomass mixture to water is
maintained at 1:4 ratios. Whole mixture is kept in
sealed polythene bags.
Three sets of pre-treatments are prepared for rice
straw, banana leaves and teak leaves.
Suitability of decomposed biomass is
assessed by some tests based on visual observation
and feeling 17, 18
. These are given below:
(1) The "ooze" test: If the material oozes
through fingers on squeezing with fist, it is too
―ripe‖. This indicates that fibers are insufficient or
they have been destroyed due to over
decomposition. Adding more fibers helps to retain
its desired composition
(2) The "spring back" test: If after squeezing
wet biomass, the material expands by more than
10% of its original diameter or length, then the
material requires more pounding or mixing with
better material.
(3) The "shake" test: A good briquette
material will not fall apart when held over the
upper 1/2 portion and shaken vertically a few
times as one would move a salt shaker. Samples
that fall apart during such shaking will require
more fibrous material (chopped grasses/straws,
stems, fibrous leaves, choir fibre etc.).
Apart from low lignin and ash content in
biomass material, calorific value also plays an
important role in choosing a biomass feedstock for
briquetting. Calorific values of rice straw, banana
leaves and teak leaves are 13.57 MJ/kg, 14.98
MJ/kg, and 11.78 MJ/kg respectively. However,
when nahar seed cake is used as binder with the
biomass materials, calorific values of briquettes
are bound to increase in each case due to combine
effect. Calorific value of Mesua ferrea L. seed
cake is 19.6 MJ/kg. In earlier studies, it has been
come to know that Nahar added rice straw, banana
leaves and teak leaves briquettes have calorific
values of 19.76 MJ/kg, 19.21 MJ/kg and 19.10
MJ/kg respectively[11].
2.2 Wet Briquette making Technique
After passing the hand tests,
decomposed biomass material undergoes
following steps:
1. Suitable biomass mixture up to brink of piston
cylinder is pressed for 40 sec in a piston press of
45 mm diameter and 100 mm length in which dies
pressure can be varied from 200kPa to 1 MPa.
2. Carefully remove from die
3. Dried for two week in the sun
4. Briquettes
For current investigation, briquettes are
made both by addition of binder (Mesua ferrea L.

3. Seed cake) or without binder in order to
investigate the effects of the binder on the
briquettes made from rice straw, teak and banana
leaves.
2.3 Determination of physical characteristics of
briquettes
Physical characteristics such as initial
density and final relaxed density of briquettes
were determined. Durability, shear strength and
impact resistance of briquettes were also
determined to assess the quality of briquettes in
terms of handling and transportability.
2.3.1 Determination of density
Initial density: Immediate after ejection from
die, initial density of briquette is recorded from
the ratio of mass to the volume of briquette.
Final relaxed density: Relaxed density is the
ratio of the briquette’s weight to the new volume
after two weeks of sun drying. Relaxed density
can be defined as the density of the briquette
obtained after the briquette has become stable. It is
also known as spring back density [8].
2.3.2 Durability
Durability of briquettes gives the
mechanical handling of the solid fuel. This is
measured by standard procedure ASAE S269.4
[9]. To measure durability, 100 g of sample is
taken and sample is tumbled at 50 rpm for 10
minutes in a dust tight enclosure of size
300mm×300mm. Metal cloth of aperture size
4mm is used to retain crumbled briquettes after
tumbling.
Durability index in % given by =
×100
2.3.3 Shear strength test
To measure shear strength, a simple test
is done. Briquette is sheared between two planes
and shear force developed is the shear strength of
briquette [8].
2.3.3.1 Shear strength test set up
To measure shear strength, shearing test
set up has been fabricated. The instrument consists
of three wooden plates. The middle plate with a
central cylindrical hole of 45 mm diameter and 30
mm thickness slides over the bottom plate. In the
top plate, a cylindrical hole of same diameter as
that of moving plate with 20 mm thickness is
being provided in such a way that it coincides with
the one that is provided in the movable plate when
this plate is fully inserted between top and non
moving bottom plate. The movable plate is
connected to dead weights.
Shear strength, kPa =
Where F= Force causing shear in briquette, kN
D= diameter of briquette, m
2.3.4 Impact resistance test
This test simulates the forces encountered
during emptying of densified products from trucks
onto ground, or from chutes into bins. Drop tests
can be used to determine the safe height of
briquette production during mass production.
ASTM D440-86 method is used to determine
impact resistance index [9]. In the drop test,
briquettes are dropped twice from a height 1.83 m
onto a concrete floor. An impact resistance index
(IRI) is calculated.
IRI =
where, N= Number of drops, n= Total number of
pieces. The upper limit of IRI is 200 which would
result if the briquettes are not broken even after
dropping twice.
3. RESULTS AND DISCUSSIONS
3.1 Optimum pre-treatment for decomposition
Biomass material takes months for
normal decomposition. But we want
decomposition in biomass up to that level at which
it can be compressed to briquettes. The
decomposition level of biomass is regularly
checked by shake and spring back tests. It is found
that biomass samples at aerobic condition are first
to reach desired level of decomposition as defined
by shake and spring back test. Rice straw and teak
leaves take 19 days each to reach the desired
decomposition stage while banana takes 28 days.
3.2 Density as a function of applied pressure
The decomposed biomass materials are
subjected to varying pressure levels from 200 kPa
to1 MPa with the help of piston press. Initial
densities of freshly prepared briquettes are
recorded. Again, densities of dried briquettes are
measured after an interval of two weeks when
they become stable in weight. Figs. 1, 2 and 3
show the variation of final relaxed density with
applied die pressure for rice straw, banana leaves
and teak leaves. Final relaxed densities of
briquettes from various biomasses in the given
pressure range are rice straw (151.29-257.98
kg/m3
), teak leaves (231.58-343.70 kg/m3
) and
banana leaves (167.88-213.38 kg/m3
).

4. Fig.1 Variation of final relaxed density of rice
straw briquettes with increasing applied die
pressure
Fig.2 Variation of final relaxed density of
banana leaves briquettes with increasing
applied die pressure
Fig.3 Variation of final relaxed density of teak
leaves briquettes with increasing applied die
pressure
In order to raise density in briquettes,
biomass materials are added with Mesua ferrea L.
(Nahar) seed cake at the time of pressurization in
4: 1 ratio. A density variation of final relaxed
density of nahar added briquettes is found in the
range of: rice straw (316.198-499.70 kg/m3
),
banana leaves (288.22-384.44 kg/m3
) and teak
leaves (289.13-417.27 kg/m3
). Figures 4, 5 and 6
show the variation of final relaxed density with
applied die pressure for nahar added rice straw,
banana leaves and teak leaves briquettes
respectively.
Fig.4 Variation of final relaxed density of
Mesua ferrea L. added rice straw briquettes
with increasing applied die pressure
Fig.5 Variation of final relaxed density of
Mesua ferrea L. added banana leaves briquettes
with increasing applied die pressure
140
160
180
200
220
240
260
280
200 400 600 800 1000
Finalrelaxed
density,kg/m3
Applied Die pressure, kPa
160
170
180
190
200
210
220
200 400 600 800 1000
Finalrelaxed
density,kg/m3
Applied die pressure, kPa
220
240
260
280
300
320
340
360
200 400 600 800 1000
Finalrelaxeddensity,kg/m3
Applied die pressure, kPa
300
350
400
450
500
550
200 700
Finalrelaxed
density,kg/m3
Applied die pressure, kPa
270
290
310
330
350
370
390
200 400 600 800 1000
Finalrelaxeddensity,kg/m3
Applied die pressure, kPa

5. Fig.6 Variation final relaxed density of Mesua
ferrea L. added teak leaves briquettes with
increasing applied die pressure
3.3 Physical characteristics of briquettes
3.3.1 Shear strength
It is one of the characteristics to assess
the quality of briquette. Higher shear strength
means higher quality. Fig.7 shows that rice straw
briquettes having higher shear strength followed by
teak and banana leaves briquettes. Rice straw
briquettes showed shear strength in the range of
41.76- 62.99 kPa while teak and banana leaves
briquettes in 27.67-37.00 kPa and 22.34-32.49 kPa
respectively.
Fig.7 Variation of shear strength of rice,
banana leaves and teak leaves briquettes with
increasing applied die pressure
Fig.8 Variation of shear strength of Mesua
ferrea L. added rice, banana leaves and teak
leaves briquettes with increasing applied die
pressure
Fig.8 shows the variation of shear strength of
nahar and added rice straw, banana and teak
leaves briquettes with applied die pressure. Nahar
added rice straw briquettes have the highest shear
strength 44.28 to 64.48 kPa in the given pressure
range.
3.3.2 Durability of briquettes
Fig.9 shows clearly variation of durability of
briquettes with increase in pressure. High pressure
causes well binding of material. Durability index
above 90 is considered to be good for
transportation and handling purposes. Therefore,
briquettes produced pressure above 600 kPa for
rice straw, 500 kPa for banana leaves and 700 kPa
for teak leaves have above 90 durability indexes.
Fig.9 Variation of durability index with
increasing applied die pressure for rice straw,
banana and teak leaves briquettes
280
300
320
340
360
380
400
420
440
200 400 600 800 1000
Finalrelaxed
density,kg/m3
Applied die pressure, kPa
20
30
40
50
60
70
200 400 600 800 1000
Shearstrength,kPa
Applied die pressure, kPa
Rice straw
Banana
Teak
25
35
45
55
65
200 400 600 800 1000
Shearstrenth,kPa
Applied die pressure, kPa
Rice
Teak
banana
82
84
86
88
90
92
94
200 400 600 800 1000
DurabilityIndex,%
Applied die pressure, kPa
Rice
straw
Banana
leaf
Teak
leaf

6. Fig.10 shows the variation of durability index of
nahar added briquettes against applied die pressure.
Nahar added rice straw briquettes show above 90
durability index at 800 kPa applied die pressure
while banana and teak leaves show at 700 kPa each
for 45 mm diameter of briquette production. It is
observed that an increase amount of applied die
pressure is required for nahar added rice straw
briquettes to get optimum quality briquettes while
the pressure requirement is same for banana and
teak leaves.
Fig.10 Variation of durability index with
increasing applied die pressure for Mesua
ferrea L. (Nahar) seed cake added rice straw,
banana and teak leaves briquettes
3.3.3 Impact resistance
Highest impact resistance index (IRI) 200
is obtained for all types of biomass briquettes.
Generally IRI is measured to identify safe height
of briquette production in mass production units
run by extruder and other high compaction
technology. In wet briquetting method, briquettes
produced after removal of water from decomposed
biomass are needed to remove from die carefully.
Even though in wet briquetting method, impact
resistance index of briquettes could generate
valuable information regarding loading and
unloading on and from trucks if the briquettes are
to be transported by trucks. For coal briquettes
acceptance level of impact resistance index is 50.
Therefore, briquettes obtained by wet briquetting
method are highly impact resistant compared to
coal briquettes.
4. CONCLUSIONS
From the present study, we came to know
that for all the selected biomass types,
decomposition in aerobic condition without any
kind of additive is the fastest pre-treatment. Rice
straw and teak took 19 days for desired level of
decomposition while banana leaves took 28 days
for the purpose.
Densities of briquettes are obtained in the
ranges 151.29-257.98 kg/m3
for rice straw,
231.58-343.70 kg/m3
for teak leaves and 167.88-
213.38 kg/m3
for banana leaves within applied die
pressure range of 200 kPa to 1Mpa. Similarly,
densities of nahar added briquettes are obtained in
the ranges 316.198-499.70 kg/m3
for rice straw,
288.22-384.44 kg/m3
for banana leaves and
289.13-417.27 kg/m3
for teak leaves for the same
applied die pressure range .Optimum density for
rice straw, banana leaves and teak leaves
briquettes are determined for quality briquettes.
Similarly, for nahar added rice straw, banana
leaves and teak leaves optimum densities are
determined.
Physical characteristics are determined
for 3 types of locally available biomass within
200-1000 kPa. Shear strength and durability
increase with applied die pressure while impact
resistance is constant at 200 impact resistance
index for all types of briquettes. Physical
characteristics are improved on addition of nahar
seed cakes. It has raised overall density of
briquettes. Applied die pressure above 600 kPa for
rice straw, 500kPa for banana leaves and 700 kPa
for teak leaves yields durable briquettes in 45
diameter sizes where 45 mm diameter size is
optimum diameter for a briquette. Similarly, for
Mesua Ferrea L. Seed cake added briquettes,
applied die pressure above 800 kPa for rice straw,
700 kPa for banana leaves and 700 kPa for teak
leaves is required for durable briquettes for the
studied set up. In order to produce, optimum
quality briquettes at low applied die pressure,
Mesua Ferrea L. added rice straw at 800 kPa is a
good option among the other two biomass options.
It has higher density, durability index, shear
strength and impact resistance as compared to
other optimum ones described earlier.
5. REFERENCES
1. Ponnamperuma. (1973). ―The Chemistry of
Submerged soil‖, Advan. Agron. , 24, 29-96.
2. Campbell C A; Zentner R P; Gameda S; Blomert
B; Wall D D (2002).Production of annual crops on
the Canadian prairies: trends during 1976–1998.
Canadian Journal of Soil Science,82, 45–57.
3. Sokhansanj S; Mani S; Stumborg M; Samson R;
Fenton J (2006). Production and distribution of
cereal straw on the Canadian prairies. Canadian
Biosystems Engineering, 48, 3.39–3.46.
4. Kishore V.V.N., Bhandari P.*, Gupta P. (2004).
―Biomass energy technologies for rural
infrastructure and village power—opportunities
andchallenges in the context of global climate
change concerns‖ Energy Policy, vol 32 , pp801-
810.
82
84
86
88
90
92
94
96
200 400 600 800 1000
DurabilityIndex,%
Applied die pressure, kPa
Rice straw
Banana
Teak

7. 5.Singh J. and Gu S., Biomass conversion to energy
in India- A critique. Renewable and Sustainable
Energy Reviews 2010; Vol 14, pg 1367-1378.
6. Zohar k. And Hadar Y. (1995).Effect of
Manganese on Preferential Degradation of Lignin
by Pleurotus ostreatus during Solid-State
Fermentation, Applied And Environmental
Microbiology, Vol 65, pg 3057–3062.
7. Han Y. W. and Lee J.S. (1975).Chemical
Composition and Digestibility of Ryegrass Straw,
J. Agric. Food Chem., Vol. 23, pg 931.
8. Chin Ooi and Siddiqui K.M. (2000).
Characteristics of some biomass briquettes
prepared under modest appliied die pressures,
Biomass and Bioenergy, Vol 18, pg 223 to 228.
9. Wenger (1984). Forestry Hand Book.
10. The legacy foundation 2003 — fuel briquettes:
a trainer’s manual.
11. Talukdar A. and Saikia M. (2013). ―Study of
Combustion Characteristics of Fuel
Briquettes‖,International Journal of Computational
Engineering Research Vol, 0 4,Issue 3