slide 1: ________________________________________
Author for correspondence E-mail: adervenkatesan1970yahoo.com
Int. J. Chem. Sci.: 144 2016 2331-2338
ISSN 0972-768X
www.sadgurupublications.com
DESIGN AND FABRICATION OF LOW COST COMPACT
BIO-DIESEL PRODUCTION PLANT
K. VENKATESAN
Department of Mechanical Engineering S. K. P. Engineering College
THIRUVANNAMALI T.N. INDIA
ABSTRACT
The depletion of fossil fuels and the worst impact on environmental pollution caused of their
burning have led to the search for renewable clean energies. Nowadays there are many sources of
renewable energy. Biodiesel is just one source but a very important one. Biodiesel has been known as an
attractive alternative fuel although biodiesel produced from edible oil is very expensive than conventional
diesel. Therefore the uses of biodiesel produced from non-edible oils are much better option. Biodiesel is
gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources.
Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like
vegetable oils and animal fats. This paper will describe the engineering design for the reactor vessel
development beginning at the stoichiometric equations for the production process and the thermal energy
balance to the detail engineering including the equipment selection and fabrication in order to meet the
design and objective specifications. Biodiesel produced from cashew shell pyro oil coconut shell pyro oil
Kikar seeds pyro oil and velikkathan seeds pyro oil are used in this setup to produce the Bio diesel. The
bio diesel pyro oil properties are very near to diesel fuel and this design system showed close value to the
requirements of diesel standard.
Key words: Cashew nut pyro oil Bio diesel plant Reactor vessel Monoalkyl esters Trans esterification.
INTRODUCTION
Human development towards advanced society will not be possible without energy
recently there have been major advances in the techniques and technologies used to obtain
energy which allowed to improve well-being for most of the world population. However
parallel to this increase in well-being and comfort is a growing demand on the resources
required to get the energy. Morover because energy is affordable people tend to consume
mre than they really need. The overall energy consumption will keep increasing along with
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the increase in world population. This increase in consumption will become a serious issue
as more and more people will have purchasing power the consuming more and more goods.
Such phenomenon will mostly be felt in highly populated cuntries like China and India. For
instance it is believed that the number of car in India will increase from 14 to 48 per 1000
while the number of 2 wheelers from 102 to 393 per 1000 in the next 20 years. The major
concern is that the worldwide oil prduction is expected to peak around 2020. At this time
energy connsumption will still be rising exponentially. Therefore there will be a growing
gap between the energy needs and the energy available which is most likely to result in the
cost of energy becoming outrageously expensive.
The most common way to produce biodiesel is by transesterification which refers to
a catalyzed chemical reaction involving vegetable oil and an alcohol to yield fatty acid alky
esters i.e. biodiesel and glycerol. After the complete conversion of the vegetable oil the
reaction was stopped and the mixture was allowed to stand for phase separation: the ester
mixture formed the upper layer and glycerine formed the lower layer. The outstanding
benefits of pure plant oils are due to their physico ‐chemical properties and by their way of
production which involves few process steps and can be carried out done economically with
small production units.
EXPERIMENTAL
Methods of bio-diesel production
Direct use and blending
Two severe problems associated with the use of vegetable oils as fuels were oil
deterioration and incomplete combustion. Polyunsaturated fatty acids were very susceptible
to polymerization and gum formation caused by oxidation during storage or by complex
oxidative and thermal polymerization at the higher temperature and pressure of combustion.
The gum did not combust completely resulting in carbon deposits and lubricating oil
thickening Winter rapeseed oil as a diesel fuel was studied because of the high yield and oil
content 45 of winter rapeseed and the high 46.7 erucic acid content of the oil. The
rate of gum formation of winter rapeseed oil was 3 times slower than that of high linoleic
75 ± 85 oil. The viscosities of 50/50 and 70/30 blends of winter rapeseed oil and diesel
and whole winter rape oil were much higher 6 ± 18 times than No. 2 diesel. A blend of
70/30 winter rapeseed oil and No. 1 diesel was used successfully to power a small single-
cylinder diesel engine for 850 h. No adverse wear and no effects on lubricating oil or power
output were noted.
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Micro emulsions
To solve the problem of the high viscosity of vegetable oils micro emulsions with
solvents such as methanol ethanol and 1-butanol have been studied. A micro emulsion is
defined as a colloidal equilibrium dispersion of optically isotropic microstructures with
dimensions generally in the 1 ± 150 nm range formed spontaneously from two normally
immiscible liquids and one or more ionic or non-ionic amphiphiles. They can improve spray
characteristics by explosive vaporization of the low boiling constituents in the micelles.
Short term performances of both ionic and non-ionic micro emulsions of aqueous ethanol in
soybean oil were nearly as good as that of No. 2 diesel in spite of the lower cetane number
and energy content. The durabilities were not determined.
Thermal cracking pyrolysis
Pyrolysis is a process of extracting oil from solid waste like cashew nut shell
coconut shell. Pyrolysis is the thermal degradation of carbonaceous materials at
temperatures between 300
o
C and 700
o
C in the absence of oxygen. The process is
endothermic and requires an external indirect input of energy typically through the walls of
the reactor. The heat volatilizes and decomposes the organic matter to produce a pyrolysis
gas liquid and solid char in relative proportions depending on the process parameters of
temperature and pressure.
Bio diesel production systems
The transesterification process can be carried through batch or continues systems.
Continuous systems include techniques such as supercritical alcohol the use of reactive
distillation columns and the use of static mixers. Newer techniques incorporate the use of
microwaves and ultrasounds. Batch production is known to be slow tedious labor intensive
and low in productivity. On the other side production using continuos flow generally
produces more fuel per unit of labor and allows for larger scale projects thus reducing the
overall cost of production.
Supercritical
One of the commonly studies processes is the supercritical method. It is
advantagious due to its short reaction time. On the other hand the alcohol to oil ratio and the
reaction temperature are the highest of all process as showed in table. Because of those two
reasons this method was not considered appropriate to suit the needs of energy situation.
Reactive distillations
Another relatively new and unexplored way of producing is the reactive distillation
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method. It implies simultaneous chemical reactions and distillation processes in a counter
current column. The reaction time is not much longer than for the supercritical method
while the alcohol to oil ratio as well as the reactor temperature are both considerably lower.
Design considerations
Sizing parameters
Another important criterion to consider while sizing the equipment is the alcohol to
oil molar ratio. The general accepted value is six moles of methanol for one mole of oil.
However with this apparatus the students are aiming to decrease the molar ratio. The last
design factor to be fixed is the unit process time. The maximum running time has been fixed
to 1hour: during the first 30min adjustments will be made and the unit is expected to reach
its maximum conversion capacity during that time period during the last 30min the unit
should work under its full potential and samples could be taken. In addition having a
production time set to 1 hour allows separation process to be done.
Gravity
One of the major feature and advantage of the system is that it uses gravity. This
offers many advantages. First using valves is enough to regulate the methanol and oil flows
since they are relatively small. Consequently it decreases material requirement since no
pump or flow meter is required. Secondly it decreases the energy consumption of the
system and makes it more energy efficient. However there are also disadvantages associated
with valve regulated flows: a longer time is required to set-up an experimental run and flows
might be less accurate and fluctuating.
Versatile
Another important point that has been considered is the versatility of the system.
Since this is a research unit many types of experiments must be easily performed and the
unit should be easily modified in order to suit the experimental set-ups. One of the major
features is that every component can be by-passed. Connections and pipes have been
installed for easy redirection of the flow. This enables the study of each component and a
good understanding of its influence on the overall conversion of oil to biodiesel. In addition
the structural frame is done with slotted angles therefore components can easily be moved
or added.
Monitoring
In order to understand the system monitoring of the temperature is essential. Also
the temperatures of reactor are to be constant at all time to 55 to 60 degree Celsius. If any
sound is occurred during the working we must off the reactor.
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Design of biodiesel plant
Design specifications
The stoichiometric equation mentioned the design specifications are set as follows:
a Above 90 of conversion shall be achieved
b Compatible materials must be used
c Atmospheric operation pressure
d Vessel capacity: 2 gallons
e Hot water is used for heat supply
f Ideal mixing in the continuous stirrer reactor vessel
The conversion factor above 90 is determined in a weight percentage of how much
fatty acid methyl ester biodiesel is earned per gallon of palm oil.
Fig. 1: Diagrammatic view of biodiesel plant reactor vessel
The material for the inner vessel and the stirrer is made of stainless steel that is
compatible to the chemical properties of the oil and glycerine. Zink is used for the outer
vessel and a rock wool is utilized as the insulation material preventing a heat loss out the
inner vessel. The heat transfer of the composite walls made of SS 304 at the inner and Zink
at the outer vessel along with the insulation material for reducing heat loss to the
surroundings has been ascertained to select the electrical heater. 1.5 kW and 2.5 kW are
chosen for the esterification and transesterification process heaters respectively. These
different heats sources are selected since the residential time of both processes are various.
The first process takes approximately 30 min and the second ones require two to three hours
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longer for the reaction completeness. As the heat supply to the process is the hot water that
heated by the electrical heater and this mechanism can avoid the temperature fluctuation
especially in the radial direction. It keeps the temperature uniformity during the reaction. A
thermostat is used to set the operating temperature of 65
o
C keeping the methanol at liquid
phase.
Working of biodiesel plant
The vegetable oil is poured in the reactor vessel then the motor is ON then the
reactant methanol is added in to the tank. The oil and stirrer mixes the oil and the reactant
and simultaneously catalyst is added in to the reactor vessel. In order to reduces the time
consumption correct quantity of catalyst is added.
Fig. 2: Photographic view of biodiesel plant
The catalyst we have taken NaOH is more alkalyic and easy for handling and it is
cheaply available. Hot water is supplied at 65
o
C. Hot water is used to speed up the reaction.
After 30 min the motor is kept OFF and it is set ideal for the sedimentation of glycerine.
Glycerine is a byproduct which is formed during the reaction. After 30 min the biodiesel is
extracted out from the vessel.
RESULTS AND DISCUSSION
Quantity of oil obtained
From the bio diesel plant Table 1 show that production of bio diesel from Cashew
shell pyro oil Coconut shell pyro oil Kikar seeds pyro oil and velikkathan seeds pyro oil.
Cashew shell pyro oil more amount of oil extracted from other three pyro oils because of
Cashew shell pyro oil is more viscosity and density when compare to that of other three
fuels.
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2337
Table 1: The quantity of biodiesel and by product
Oil
Quantity
mL
Biodiesel
mL
Glycerine
mL
Wastage oil
mL
Cashew shell oil 1000 750 300 30
Coconut shell oil 1000 650 200 50
Kikarseed oil 1000 550 150 70
Velikkathan seed oil 1000 450 100 80
Properties of biodiesel
Table 2 shows that cashew shell bio diesel properties are very near to diesel fuel
compare to that of Coconut shell pyro oil Kikar seeds pyro oil and velikkathan seeds pyro
oil.
Table 2: Properties of biodiesel
Oil
Viscosity
mL
Density
mL
Flash point
mL
Fire point
mL
Diesel 3.4 860 51 55
Cashew shell oil 4.4 880 58 62
Coconut shell oil 5.5 950 65 70
Kikarseed oil 7.5 990 92 97
Velikkathan seed oil 8.5 1050 87 93
CONCLUSION
Thus bio diesel was prepared from used vegetable oil the properties resembled
closely to that of commercial diesel. Hence it can be used as an alternate for diesel. It is
relatively economic than diesel and emits less pollutants. It can be used for Vehicular use
Railway usage as heating oil when blended with other fuel oil in proportion. The
experimental work carried out in this project shows that bio-diesel of acceptable quality can
be produced on a small scale from a number of low-cost raw materials. However the search
for alternative feed-stocks needs to be continued. More research on the esterification of used
vegetable oil is needed to establish process requirements for high yield and quality and to
find ways of improving its low-temperature properties so that a higher proportion could be
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included in bio-diesel blends. The ester yields obtained from all the oils used in these trials
have been low in comparison with those obtained from refined vegetable oils in existing
large-scale plants. Rising of yields has a significant effect on the economics of bio-diesel
production. Modern technology is giving very high yields it needs to be demonstrated that
the same can be achieved with other raw materials whereas more information is required on
alternative uses for small amounts of glycerol.
REFERENCES
1. W. Sani and K. Hasnan Development of the Mini Scale Biodiesel Reactors
Malaysian Technical Universities Conference on Engineering and Technology 2009.
2. M. Thirumarimurugan V. M. Sivakumar A. Merly Xavier D. Prabhakaran and
T. Kannadasan Preparation of Biodiesel from Sunflower Oil by Transesterification
Int. J. Biosci. Biochem. Bioinformatics 26 2012.
3. R. Hernandez T. Jeffreys A. Marwaha and M. Thomas Plant Design Project:
Biodiesel Production Using Acid-Catalyzed Transesterification of Yellow Grease
Mississippi State University Mississippi State MS 39762 2006.
4. A. S. Chatpalliwar V. S. Deshpande J. P. Modak and N. V. Thakur Issues in
Biodiesel Production: A Review and an Approach for Design of Manufacturing Plant
with Cost and Capacity Perspective Int. J. Indust. Engg. Prod. Res. 243 189-206
2013.
5. A. Abbaszaadeh B. Ghobadian G. Najafi and Ali Motevali Design Fabrication and
Evaluation of a Novel Biodiesel Processor System Int. J. Renewable Energy Technol.
Res. 21 249-255 2013.
6. Thomas Fortin-Chevalier and Peneloppetheriault Design of Continuous Flow
Biodiesel Production Research Unit Tamil Nadu Agricultural University 2007.
7. M. Gomaa A. J. Alimin and K. A. Kamarudin The Effect of EGR Rates on NOX and
Smoke Emissions of an IDI Diesel Engine Fuelled with Jatropha Biodiesel Blends
Int. J. Energy Environ. 23 477-490 2011.
Revised : 18.08.2016 Accepted : 21.08.2016