ISSN 2086-5953
2 MODEL, ANALYSIS, DESIGN,
AND IMPLEMENTATION
The difference in process steps between starch and lignocellulosic feedstocks is that
lignocellulosic biomass hydrolysis requires a more complicated stage. However, innovative methods of
manufacture of bioethanol from lignocellulosic substrate can be easily done by applying the
method of pretreatment Hot Compressed Water and fermentation
methods cellulolytic
bacterium Clostridium thermocellum
can be seen in Figure 1. With this method is expected to optimization of
production efficiency and effectiveness can be improved.
Figure 1. Prodution process of bioethanol from ligoellulosic biomass using pretreatment Hot Compressed Water and
fermentation from
Clostridium thermocellum
2.1 Pretreatment with Hot
Compressed Water Method
Lignin degradation procedure lignification with Hot Compressed Water is started by mixing ±
0.9 grams lignocellulosic material which has been adjusted in size to weight ratio of material weight
of water = 0.05 and then fed into a reactor. Then the water buffer is added as defined variables. Then
the the hydrolysis reactor cover should be closed and reinforcing it with a cap booster. N
v
gas flowed into the reactor until the pressure gauge indicates
the desired pressure, which is 10 bars. Heater is heated and the temperature is set for temperature
control in accordance with the desired temperature and pressure of 2000 C-20 bars. Subsequently, the
stirrer is turned on by connecting it to a power source. After the temperature 200
C is reached and the pressure in the reactor is stable, we then
calculated as t=0, so the hydrolysis reaction is run in accordance with a variable time.
After the reaction is complete, the reactor is cooled by entering into the water at ambient
conditions for several minutes, then pressure is lowered to 1 atm by removing the N
2
gas in the reactor by opening valve gas expenditure. After the
pressure in the reactor reached 1 atm, the reactor was opened, and the material removed from the
reactor which then filtered to separate the hydrolyzate and residues. Hydrolyzate in the form
of glucose pretreatment process expected outcome is minimized, it is expected that the smaller the
likelihood, so as to minimize the occurrence of degradation of monosaccharides into phenol
derivative
compounds, HMF,
and furfural.
Lignified optimum time is 10 minutes after the temperature reached 200
C stable. The residue in the form of cellulose, hemicellulose, lignin and
some will get further treatment.
2.2 Hydrolysis-Fermentation of
Cellulolytic Method for the Conversion of Cellulose and
Hemicellulose into Bioethanol
After the initial treatment, there are two types of processes to hydrolyze celluloce into
ethanol. The process is commonly used by chemical hydrolysis hydrolysis is weak and strong
and the enzymatic hydrolysis. Chemical method was done by cellulose hydrolysis using organic
acids, such as H
2
SO
4
, HCl, and HNO
3
that in fact the prices are still expensive. The result of cutting
by acid is a mixture of dextrin, maltose and glucose
[9]
. The method uses acid hydrolysis has some disadvantages. It produces residues that are
toxic and pollute the environment such as COD in water, requires high temperatures, ie 120-160
C, and relatively produces
small amounts of glucose
[10]
. Therefore, the hydrolysis process using acid is rarely used. Here is the reaction:
CH2O
n
+ H
2
O → mC
6
H
12
O
6
Cellulose hydrolysis method which is more often used is enzymatical hydrolysis with
using enzymes. Enzymes used were cellulase enzymes that can be obtained from the synthesis of
microorganisms such as bacteria. Clostridium thermocellum
synthesizes cellulolytic enzyme complexes, cellulosomes, when grown on medium
containing cellulose. It degrades several forms of cellulose at different rates. This microorganism can
also degrade hemicellulose, cellobiose, and xylose oligomers. Furthuremore, Table 1 describes the
comparison of some hydrolysis process where we can see that enzimatic one has more advantages.
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Table 1. Comparison of Cellulose Hydrolysis Process
Process Input
Temperature Time
Saccharification Diluted Acid
1 H
2
SO
4
21,5 C
3 min 50-70
Concentrated Acid
30-70 H
2
SO
4
40 C
2-6 h 90
Enzymatic Cellulase
70 C
1,5 day
75-95
Additionally, sugars, such as: glucose, fructose, and xylose, are degraded after adaptation
of the culture
[11]
. The enzymes degrade the monomeric sugars that are induced only after a long
adaptation time. The Microorganism grows in complete anaerobiosis and in the thermophilic
temperature range. The optimum temperature for growth is 60-64°C
[12]
and the optimum pH ranges is between 6.1 and 7.5
[13]
, so Clostridium thermocellum
could be easily reproduced by keeping those conditions.
The main
products of
cellulolytic fermentation by using C. thermocellum is glucose,
cellobiose, lactic acid, acetic acid, formic acid, ethanol, CO
2
, and H
2
, and described in Figure 4 Judoamidjojo et al. 1992. Therefore, hydrolysis
of cellulose and hemicellulose into glucose and followed by fermentation of glucose to ethanol can
be done at one stage by using the bacterium Clostridium thermocellum
as hidrolisator and fermenter.
Figure 4. Cellulose Degradation delignification by C. thermocellum
[14]
Examples of reactor model is made from a cylinder with a diameter can be seen in Figure 5.
On a scale reactor experiments can be made from a cylinder with a diameter of 15 cm and 20 cm high.
An extract entrance channel made from metal pipe with a diameter of 2.5 cm and length 40 cm.
Propellers are made of iron plate with a width of 10 cm and height 5 cm, while the player propeller
made of iron wire with a diameter of 1 cm and 20 cm long. Connecting pipe is made from plastic pipe
paralon with a diameter of 2.5 cm and length 50 cm except condenser pipes made of iron pipe with a
diameter of 2.5 cm and length 40 cm. Furnace heating is made from wood-fired clay, charcoal and
or fermentation residue. Cellulose extracts is inserted into the reactor
and the system starts to work with the conditions: stirring speed = 60 rpm, a suction pump power is in
medium stength, the temperature is maintained 65- 70
C. Data derived ethanol is taken every 6 hours, 9 hours, 12 hours, 15 hours, 18 hours, 21 hours and
24 hours. Ethanol produced was analyzed by GC gas chromatography to determine levels of
ethanol produced.
Figure 5. Pretreatment Reactor Design
[15]
The workings of the reactor are as follows: extract the straw is inserted through the appropriate
channels. Straw later in the fermentation to ethanol and CO
2
at temperatures 65-70 C. Ethanol will
evaporate. For maximum evaporation of ethanol in the reactor, the gas is pumped. Ethanol vapor is
cooled by condenser system and liquid ethanol produced. Water in ethanol, react with CaO, then
ethanol liquid is filtered and collected.
Cellulose extracts is inserted into the reactor and the system starts to work with the conditions:
stirring speed = 60 rpm, a suction pump power is in medium stength, the temperature is maintained 65-
70 C. Data derived ethanol is taken every 6 hours,
9 hours, 12 hours, 15 hours, 18 hours, 21 hours and 24 hours. Ethanol produced was analyzed by GC
gas chromatography to determine levels of ethanol produced.
The workings of the reactor are as follows: extract the straw is inserted through the appropriate
channels. Straw later in the fermentation to ethanol and CO
2
at temperatures 65-70 C. Ethanol will
evaporate. For maximum evaporation of ethanol in the reactor, the gas is pumped. Ethanol vapor is
cooled by condenser system and liquid ethanol produced. Water in ethanol, react with CaO, then
ethanol liquid is filtered and collected.
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Table 2. Ethanol Productivity from Different Substrates
Material Cellulo-
ce Hexosan
H Hemicellu
-loce Pentosans
P Lig
nin
Ethanol kg dried
mass Reference
Bagas Molases
33 30
29 0,279
Kuhad and Singh, 1993
Wheat straw
30 24
18 0,239
Kuhad and Singh, 1993
Buckwheat straw
33 18
15 0,240
Kuhad and Singh, 1993
Paddy straw
32 24
13 0,248
Kuhad and Singh, 1993
Oat straw 41
16 11
0,252 Kuhad and
Singh, 1993 Corncob
42 39
14 0,358
Kuhad and Singh, 1993
Cornstalk 35
15 19
0,221 Kuhad and
Singh, 1993 Barley
straw 40
20 15
0,265 Kuhad and
Singh, 1993 Peanut shell
ground 38
36 16
0,25 Kuhad and
Singh, 1993 Alfalfa
stems 48,5
6,5 16,
6 0,252
Shleser, 1994
Rice husk 36
15 19
0,265 Kuhad and
Singh, 1993 Eucalyptus
grandis 38
13 37
0,31 Shleser,
1994 Eucalyptus
saligna 45
12 25
0,322 Shleser,
1994 Pine
44 26
29 0,305
Olsson and Hagerdal,
1996 Poplar
47,6 27,4
19, 2
0,265 Olsson and
Hagerdal, 1996
Sawdust 55
14 21
0,354 Olsson and
Hagerdal, 1996
Willow 37
23 21
Olsson and Hagerdal,
1996 Aspen
51 29
16 0,305
Olsson and Hagerdal,
1996 Spruce
43 26
29 0,288
Olsson and Hagerdal,
1996 Birch
40 23
21 0,291
Olsson and Hagerdal,
1996 Lantana
camara 42,5
22,7 22,
88 0,3
Chandel Unpublish
ed work Prosopis
juliflora 45,5
20,38 24,
65 0,296
Chandel Unpublish
ed work Saccharum
spontaneum 45,1
22,7 24,
65 0,267
Gupta, 2006
Eicchornia crassipis
18,2 48,7
3,5 0,341
Nigam, 2002
Paja Brava 32,2
28,1 24
0,318 Sanchez et
al., 2004 Newsprint
61 16
21 0,248
Olsson and Hagerdal,
1996 Waste
paper 47
25 12
0,291 Olsson and
Hagerdal, 1996
Household Waste
paper 43
13 6
0,3 Olsson and
Hagerdal, 1996
3 RESULT
Bioethanol production has different result if it has been done by using different substrates and
different methods. By using enzymatic method, different substrates will provide different result of
bioethanol production. The result could be seen on the Table 2. Saw dust has the highest productivity
of bioethanol production and comstalk has the lowest productivity.
Then, the different substrates will provide different
percentage of
reduced emissions.
Bioethanol from lignocellulosic also has many advantages because it produces high energy rasio
8.3 to 8.4 and is able to reduce contaminant emissions by 66 -73. Figure 3 shows the energy
ratio of bioethanol from lignocellulosic substrate and non-lignocellulose to produce energy and its
ability to reduce emissions.
Table 3. The Percentage of Avoided Emissions from Several Different Feedstocks
Feedstock Energy Ratio
Avoided Emission Sugarcane
9.3 89
Corn 0.6
– 2.0 -30 - 38
Wheat 0.97-1.11
19 - 47 Beet
1.2 – 1.8
35 - 56 Cassava
1.6 – 1.7
63 Lignocellulosic
Residues 8.3
– 8.4 66 - 73
4 CONCLUSION AND DISCUSSION
There are
some differences
between bioethanol from lignocellulosic biomass production
by using residue as substrate Clostridium
thermocellum and conventional methods. By using
Clostridium thermocellum, the hydrolysis and
fermentation processes can be done at the same time. Therefore, it has significant impact in
increasing efficiency of the processes: it saves energy even better
it lower the production cost it saves the time
it saves the materials needed for the processes since we do not need to add enzymes for more
than once Beside that, the lignocelluloses itself ensures
the high productivity of bioethanol product since it cellulose has very high potent to be converted into
bioethanol by Clostridium thermocellum. The lignin and hemicelluloses can be significantly
removed from the substrates by using pre-treatment method of Hot Compressed Water Method. The
total amount of ethanol produced by using this
ISSN 2086-5953 method is up to 95-100.
Bioethanol from lignocellulosic has many advantages when compared with other ethanol
products. The first is because Indonesia has a high abundance
of lignocellulose.
Second, the
lignocellulosic bioethanol produces high energy rasio 8.3 to 8.4 and is able to reduce contaminant
emissions by 66 -73. The facts has been shown on the Table 3 in result chapter.
Different substrates will also provide different percentage of reduced emissions. From the
table above, we could see that bioethanol from sugarcane residue or molasses can reduce emissions
up to 89. It is the highest number of reduced emissions. Bioethanol from corn, wheat, beet, and
cassava residue can reduce emissions up to 38, 47, 56, and 63 respectively. Bioethanol from
lignocellulosic biomass in average can reduce emissions from 66 up to 73. This number of
reduction is very significant. Therefore, we could say that bioethanol from lignocellulosic materials is
very potential to be developed, and the most important is, it is totally environmental friendly.
Through both these innovations, we can make cost savings for the purchase of enough
bacteria was done once on the first production and for the next production to use a bacterial inoculum
cultivated his own. In delignification so, we do not need to pay for purchases that cost solution kimias
acid acid. Delignification by HCWs can effectively degrade lignin. Another advantage is the production
of bioethanol from lignocellulosic phase becomes shorter due to hydrolysis and fermentation carried
out at once.
Now, we can conclude that bioethanol from lignocellulosic production by using residue as
substrate Clostridium thermocellum has high efficiency in saving energy, cost, time, and
materials used. The total amount of ethanol produced by using this method is up to 95-100.
Beside it, lignocellulosic substrate has significant potent to reduce emissions up to 73. With this
result, it is believed that bioethanol from lignocellulosic biomass substrate that has been
developed by utilizing this method could be a potential solution for the environmental-emission
related problems.
Authors recommend to the next researchers in order to do quantitative and qualitative research
on optimal production results when applying the modified method. It also required a further test of
the maximum limit of ethanol that can be tolerated and how to modify the breeding of bacteria.
Furthermore, the government should publish the results of studies of this scientific work.
REFERENCES
[1] Henniges
and Zeddies
2006 Bioengineering and agriculture: Promises
and challenges. International Food Potollicy Research.
Institute.http:www.ifpri.org2020focusfoc us14 focus1409.pdf. [accessed 20 Oktober
2010]
[2] Knauf, M. and M. Moniruzzaman 2004
Lignocellulosic biomass processing : A perspective. Intl. Sugar J. 1061263:
147−150. [3]
Lynd, L.R. 1996 Overview and evaluation of fuel ethanol from cellulosic biomass:
Technology, economics, the environment, and policy. Ann. Rev. Energy Environ. 21:
403−465. [4]
Seabra, J. E. A. Macedo, I. C. Demanda de energia para a produção de PHB a partir
do açúcar da cana 2006 Report prepared for PHB Industrial S.A., Campinas.
[5] Lacis, L.S. and H.G. Lawford 1985
Thermo anaerobacter ethanolicus in a comparison of the growth efficiencies of
thermophilic and mesophilic anaerobes. J. Bacteriol.
1633: 1275−1278. [6]
L. G. Ljungdahl, L. Carreira, and J. Wiegel. 1981
Production of
ethanol from
carbohydrates using anaerobic thermophilic bacteria. In Ekman-Days, International
Symposium on
Wood and
Pulping Chemistry.
[7] D. Freier, C. P. Mothershed, and J. Wiegel.
1988 Characterization of C thermocellum. AppL Environ. Microbiol., 541:204-211.
[8] L. Carreira and L. G. Ljungdahl 1983
Liquid Fuel
Developments, Chapter
Production of Hanol from Biomass Using Anaerobic Thermophilic Bacteria. CRC
Series in Bioenergy Systems, CRC Press, Inc..
[9] Trifosa, D. 2007. Konversi Pati Jagung
Menjadi Bioetanol. Skripsi Program Studi Kimia
FMIPA ITB. Bandung. [10]
Judoamidjojo, M., A.A. Darwis, dan E.G. Sa‘id 1992 Teknologi Fermentasi. Edisi 1
cetakan 1. Rajawali Press. Jakarta. [11]
L. Carreira and L. G. Ljungdahl 1983 Liquid
Fuel Developments,
chapter Production of hanol from Biomass using
Anaerobic Thermophilic Bacteria. CRC Series in Bioenergy Systems, CRC Press,
Inc.
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L. G. Ljungdahl, L. Carreira, and J. Wiegel. 1981
Production of
ethanol from
carbohydrates using anaerobic thermophilic bacteria. In Ekman-Days, International
Symposium on
Wood and
Pulping Chemistry, June.
[13] D. Freier, C. P. Mothershed, and J. Wiegel
1988 Characterization of C thermocellum. AppL Environ. Microbiol., 541:204-211.
[14] Ben-Bassat et al. 1980 Metabolic control
for microbial
fuel production
during thermophilic fermentation of biomass. In
Energy from biomass and wastes IV, pages 275-301, Institute Gas Technology.
[15] Pahlevi,
Reza 2009
Pretreatment Saccharum spontaneum Linn
dengan Metode Hot Compressed Water
[skripsi]. Surabaya : Fakultas
Teknologi Industri,
Institut Teknologi Sepuluh Nopember.
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135 ISSN 2086-5953
CHLORELLA SP. CULTURE AS A SOURCE OF PROTEIN FOR FISH LARVAE
Dina Silvia Dewi
1
, Denny Wahyudi
1 1
Aquatic Resources Management, Fisheries and Marine Science Faculty, Bogor Agricultural University 16680 Email: dinasilviadewiyahoo.co.id
1
, masakan_ibuku_yahudyahoo.com
2
ABSTRACT
Human population growth is increasing every year. It needs a healthy source of food for
nutrition one with fish and other aquatic organisms. One source of water that has high protein is
Chlorella sp. It can be used as a natural source of
food for larval fish and do not produces toxins. The reason for the importance of culture Chlorella sp. is
a high protein content of microalgae, especially chlorella. Chlorella has a fairly high growth rate.
From the observations, the density culture of Chlorella
sp. during culture has fluctuated up and down in nearly all replications. The level of
penetration of chlorella sp. high happened on day 8 must be in plankton growth through several phases,
adaptation, logarithmic phase, stationary phase and phase of death. Harvesting can be done when the
plankton reached logarithmic phase.
Keywords: Culture, Chlorella sp., growth phases
1 INTRODUCTION
In the last two centuries, the worlds population growth rate is 6 per annum to reach
2.5 billion in 1950. Five decades of the worlds population growth rate is twice as much as 18 to
6 thousand million in the 21st century. In September 2008, the worlds population has been
6720 million people. The worlds population with experience in the number of 1.2 per cent
14
It requires a healthy food and feeding high protein and other necessities of life are quite good
quality. one food product that requires a few fish and other aquatic organisms, which were very
useful for the organism. a great opportunity for the fishing industry to meet food needs is through the
development of aquaculture. One of the biological capacity of water, which still developed a culture of
microalgae Chlorella sp. Chlorella sp has many benefits for human beings as raw material for
pharmaceuticals, cosmetics, beverages as a source of protein for humans, as a food source for fish
larvae and purification of wastewater. Election chlorella sp. As an object of study is based on the
consideration that chlorella sp. Relatively easy in a culture in a short time.
This potential in Indonesia is not working optimally. because of the fishery resources remain
identical to the water in the form of fish, shrimp, shellfish and seaweed biota. Aquaculture the latter
is limited to commodities. with the effort to develop the culture of Chlorella to address the challenges in
the development of aquaculture, taking into account that these agencies have a very high value to
humans.
2 MATERIALS AND METHODS
2.1 Time and Place Research
