Production of biodiesel from jatropha curcas oil by
using pilot biodiesel plant

D.RAMESH*, A.SAMAPATHRAJAN, P.VENKATACHALAM
Agrl. Engg. College & Research Institute
Tamil Nadu Agricultural University
Coimbatore, Tamil Nadu, India

Introduction

The consumption and demand for the petroleum products are increasing every year
due to increase in population, standard of living and urbanization. Diesel consumption pattern
in India has not varied much and is around 36x106 tonnes as reported by the Ministry of
Petroleum and Natural Gas (Table 1). The increase in crude oil import affects the country’s
economy and its development. The diesel vehicles were banned in New Delhi for serious
problem of air pollution due to higher emissions of polluted gases. The acid rain, global
warming and health hazards are the results of ill effects of increased polluted gases like SOx,
CO and particulate matter in atmosphere.
Today’s diesel engines require a clean burning, stable fuel that performs well under
the variety of operating conditions. Biodiesel is the only alternative fuel that can be used
directly in any existing unmodified diesel engine. Because it has similar properties to diesel
fuel, biodiesel can be blended at any ratio with diesel fuel. In most of the developed
countries, biodiesel is produced from soybean, rapeseed, sunflower, peanut, etc., which are
essentially edible in Indian context. Among the various vegetable oil sources, non-edible oils
are suitable for biodiesel production. Because edible oils are already in demand and too
expensive than diesel fuel. Among the non-edible oil sources, Jatropha curcas is identified as
potential biodiesel source and comparing with other sources, which has added advantages as
rapid growth, higher seed productivity, suitable for tropical and subtropical regions of the
world.
Table 1. Production and import of crude oil in India (MT)
Year Production Import
Total Import
%
1971 6.8 11.7 18.5 63
1981 10.5 16.2 26.7 61
1991 33 20.7 53.7 39
2001 32 57.9 89.9 64
2002 32 73.5 105 70

Biodiesel
Biodiesel is a variety of ester-based oxygenated fuels derived from natural, renewable
biological sources such as vegetable oils. It’s name indicates, use of this fuel in diesel engine
alternate to diesel fuel. Biodiesel operates in compression ignition engines like petroleum diesel

1

---

thereby requiring no essential engine modifications. Moreover it can maintain the payload capacity
and range of conventional diesel. Biodiesel fuel can be made from new or used vegetable oils and
animal fats. Unlike fossil diesel, pure biodiesel is biodegradable, nontoxic and essentially free of
sulphur and aromatics. The estimated biodiesel requirement of India is presented in the table 2.
Table 2. Estimated biodiesel requirement in India
Biodiesel requirement blending, MMT
Diesel requirement,
Year
MMT
5% 10% 20%
2004-05 46.97
2.35
4.70
9.40
2006-07 52.33
2.62
5.23
9.92
2011-12 66.90
3.35
6.69
13.38

Advantages of biodiesel
1. Produced from sustainable / renewable biological sources
2. Ecofriendly and oxygenated fuel
3. Sulphur free, less CO, HC, particulate matter and aromatic compounds emissions
4. Income to rural community
5. Fuel properties similar to the conventional fuel
6. Used in existing unmodified diesel engines
7. Reduce expenditure on oil imports
8. Non toxic, biodegradable and safety to handle

Chemistry of biodiesel production
Biodiesel is produced by transesterification of large, branched triglycerides in to
smaller, straight chain molecules of methyl esters, using an alkali or acid or enzyme as
catalyst. There are three stepwise reactions with intermediate formation of diglycerides and
monoglycerides resulting in the production of three moles of methyl esters and one mole of
glycerol from triglycerides. The overall reaction is:


Alcohols such as methanol, ethanol, propanol, butanol and amyl alcohol are used in
the transesterification process. Methanol and ethanol are used most frequently, especially
methanol because of its low cost, and physical and chemical advantages. They can quickly
react with triglycerides and sodium hydroxide is easily dissolved in these alcohols.
Stoichiometric molar ratio of alcohol to triglycerides required for transesterification reaction is
3:1. In practice, the ratio needs to be higher to drive the equilibrium to a maximum ester yield.
The Jatropha curcas plant and oil
The oil yielding plant Jatropha curcas L. is a multipurpose and drought resistant large
shrub, which is widely cultivated in the tropics as a live fence. The Jatropha plant can reach a
height up to 5 m and its seed yield ranges from 7.5 to 12 tonnes per hectare per year, after
five years of growth. The oil content of whole Jatropha seed is 30-35 % by weight basis.

2

---

Table 3. Problems in use of jatropha oil as fuel in diesel engine
Problems Causes
Coking of injectors on
High viscosity of raw oil, incomplete combustion of fuel. Poor
piston and head of engine
combustion at part load with raw oil
Carbon deposits on piston
High viscosity of oil, incomplete combustion of fuel.
and head of engine
Excessive engine wear
High viscosity of raw oil, incomplete combustion of fuel.
Dilution of engine lubricating oil due to blow-by of raw oil

The above problems can be solved by converting raw jatropha oil in to biodiesel
through transesterification process.
Biodiesel pilot plant

The biodiesel pilot plant consists of a transesterification reactor with heater, a stirrer,
chemical mixing tank, three glycerol settling tanks and washing tank. The capacity of pilot
biodiesel plant is 250 litres/day. The cost of the pilot plant is Rs. 2.5 lakhs. The process
flowchart for biodiesel production and pilot biodiesel plant are shown in figure 1 and 2.


Jatropha curcas
seeds
Oil extraction
Oil cake
Manure
unit
Animal
Jatropha curcas
Detoxification
feed
Lamp/Stoves
Oil
Alcohol &
Transesterification
Crude glycerol
Catalyst
reactor
Refined glycerol
Crude biodiesel
Soap/Candle
Washing tank
Water
Washed water
Pure biodiesel
Diesel engine

Fig. 1. Process flowchart for biodiesel production from
jatropha seeds and by products


3

---

Fig. 2. Pilot biodiesel plant
Pilot biodiesel plant operation
In the pilot biodiesel plant, jatropha oil is blended with alcohol and catalyst mixture in
transesterification reactor. The reactor is kept at reaction temperature for specific duration
with vigorous agitation. After reaction, the biodiesel and glycerol mixture is sent to the glycerol
settling tank. The crude biodiesel is collected and washed to get pure biodiesel. Depending
upon the need, the size of the unit can be scaled up to get higher production capacity. The
fuel properties of jatropha biodiesel produced in the pilot plant are given in the table 4.

Catalyst
Jatropha oil + Alcohol Jatropha biodiesel + Glycerol



















Biodiesel
Glycerol


Fig. 3 Jatropha biodiesel with glycerol samples


4

---

Table 4. Fuel properties of jatropha oil and its biodiesel
Properties Jatropha Oil Jatropha
biodiesel
Diesel
Density, g/ml
0.920
0.865
0.841
Viscosity @ 40oC,
3.5 5.2 4.5
Cst
Calorific value,
39.7 39.2 42.0
MJ/kg
Flash point, oC 240
175
50
Cloud point, oC 16
13
9

Salient features of the pilot biodiesel plant:

Simple in operation
Low
cost
technology
Shorter
reaction
time


Economics of biodiesel production

Cost of raw jatropha oil


=
Rs. 22/litre

Biodiesel processing cost

=
Rs. 9/litre

Cost
of
production

=
Rs.
31/litre

Less return from crude glycerol

=
Rs. 3/litre

Net cost of production


=
Rs. 28/litre

Dealers
margin

=
Rs.
1/litre

Profit

=
Rs.
3/litre

Sale price of biodiesel


=
Rs. 32/litre
Conclusion
Jatropha biodiesel is ideal solution to meet out higher diesel demand and oil imports. By
mixing of 20 per cent biodiesel with diesel will help India to save 7.3x106 tonnes of diesel per year.
In India about 33 million hectares of wasteland is available and can effectively be used for
cultivation of jatropha plants. By installing the developed pilot biodiesel plant at each district,
dependence on diesel fuel for farm operations can be reduced. It offers business possibility to
agricultural enterprises and rural employment.


*Corresponding author :
Dr. D.RAMESH
Assistant Professor
Department of Farm machinery
Agricultural Engineering College and Research Institute
Tamil Nadu Agricultural University
Coimbatore, Tamil Nadu – 641 003
India
1E-mail: ram_tnau@yahoo.co.uk

Dr. A. SAMPATHRAJAN
Dean,
Agricultural Engineering College and Research Institute
Tamil Nadu Agricultural University
Coimbatore, Tamil Nadu – 641 003
India

Dr. P. VENKATACHALAM
Professor and Head,
Department of Bioenergy
Agricultural Engineering College and Research Institute
Tamil Nadu Agricultural University
Coimbatore, Tamil Nadu – 641 003
India

5

---

Jatropha plants
Jatropha seeds
Jatropha oil
Pilot Biodiesel plant
Jatropha Biodiesel and
glycerol
Jatropha Biodiesel fuelled
engine

6

---

Document Outline

• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• ÿ
• • ÿ

---