jatropha final3

Faculty of Engineering Final Report Galle

CHAPTER 01

1. INTRODUCTION

1.1 Background

The undergraduate project which is to be done within the period of the final year as the part of

Bachelor of Science of Engineering Program in Mechanical and Manufacturing field, which

gives an excellent opportunity to ourselves to apply theoretical knowledge, practical

experience etc to understand a real world problem and analyze it to find a better solution. Also

undergraduate project helps us to improve our analytical and design skills, written and oral

communication skills and presentation skills that are very helpful for our future engineering

career.

Relative to the final year undergraduate project in Department of Mechanical and

Manufacturing, Faculty of Engineering, University of Ruhuna, we decided to “Design and

fabrication of a Jatropha oil extractor” as our undergraduate project in year 2006/2007.

The fast pace of economic development consequent with ever increasing consumption of

fossil fuel and petroleum products has been a matter of concern for the country as it is related

to huge outgo of foreign exchange on one hand and increasing emission causing

environmental hazards on the other. Public at large are raising their concerns over the

declining state of environment and health. With domestic crude oil output stagnating, the

momentum of growth experienced a quantum jump since 1990s when the economic reforms

were introduced paving the way for a much higher rate of development leading the demand

for oil to continue to rise at an ever increasing pace. The situation offers us a challenge as well

as an opportunity to look for substitutes of fossil fuels for both economic and environmental

benefits to the country.

Petroleum resources are finite and therefore search for alternative is continuing all over the

world. Development of bio-fuels as an alternative and renewable source of energy for

transportation has become critical in the national effort towards maximum self-reliance. Bio-

fuels like bio-diesel being environment friendly, will also help us to conform to the stricter

emission norms.

Department of Mechanical & Manufacturing Engineering 1


Jatropha is a quick maturing plant species that starts bearing fruits within a year of its planting

and following the extraction of the oil can be blended with petroleum diesel for use. It is a

very hardy plant and grows in a wide variety of agro-climatic conditions from arid to high

rainfall areas and on lands with thin soil cover to good lands. It is also not browsed by cattle

and so its plantation can be easily under taken in the farmers’ fields and their boundaries,

under-stocked forests, public lands and denuded lands facing increasing degradation. Its

plantation, seed collection, oil extraction etc. will create employment opportunities for a large

number of people, particularly the poor, and will help rehabilitate unproductive and

wastelands and save precious foreign exchange by substituting imported crude.

The capacity of Jatropha and similar other oil seeds bearing plants to rehabilitate degraded or

dry lands, from which the poor mostly derive their sustenance, by improving their water

retention capacity, makes it an instrument for up-gradation of land resources and especially

for helping the poor. Thus, grown on a significant scale, they can clean the air and green the

country, add to the capital stock of the farmers and the community and promote crop

diversification which is imperative in agriculture. The chain of activities from raising

nurseries, planting, maintaining, primary processing and oil extraction is labor intensive and

will generate employment opportunities on a large scale, particularly for the rural landless and

help them to escape poverty.

1.2 Objectives

The Jatropha already grows widely in many rural villages in Sri Lanka where it is used as a

‘live fence’ to protect crops from livestock (the leaves are inedible). Its nuts are not currently

used for anything and have no commercial value.

To design Jatropha oil extractor with easy operation than the existing oil extractor.

To meet the higher oil yield than the existing oil extractor.

Provide higher production rate and lower cost than the existing oil extractor.

To avoid the difficulty of removing the husk of the Jatropha seed by crushing the

seeds with the husk.

To minimize the size of oil extractor and provide easy moving in domestic areas.



To provide Jatropha oil in meeting domestic needs of energy services including

cooking and lighting;

To provide rural communities with a new, cheaper, 100% renewable and 100%

locally produced fuel to substitute for diesel fuel.

Potential of Jatropha as an additional source of household income and employment

through markets for fuel, fertilizer, animal feed medicine, and industrial raw material

for soap, cosmetics, etc.



CHAPTER 02

2. LITERATURE REVIEW

2.1 Introduction

Jatropha is a tall bush or small tree (up to 6 m hight) and belongs to the euphorbia family. The

genus Jatropha contains approximately 170 known species1. The genus name Jatropha derives

from the Greek jatrós (doctor), trophé (food), which implies medicinal uses. The seeds are

toxic and they contain about 35 % 11of nonedible oil. The plant is planted as a hedge (living

fence) by farmers all over the world around homesteads, gardens and fieldes, because it is not

browsed by animals

Jatropha originates from Central America. From the Caribbean, Jatropha was probably

distributed by Portuguese seafarers via the Cape Verde Islands and former Portuguese Guinea

(now Guinea Bissau) to other countries in Africa and Asia.

The wood and fruit of Jatropha can be used for numerous purposes including fuel. The seeds

of Jatropha contains (. 50% by weight) viscous oil11, which can be used for manufacture of

candles and soap, in the cosmetics industry, for cooking and lighting by itself or as a

diesel/paraffin substitute or extender. This latter use has important implications for meeting

the demand for rural energy services and also exploring practical substitutes for fossil fuels to

counter greenhouse gas accumulation in the atmosphere.

Jatropha is not browsed, for its leaves and stems are toxic to animals, but after treatment, the

seeds or seed cake could be used as an animal feed. Being rich in nitrogen, the seed cake is an

excellent source of plant nutrients. Various parts of the plant are of medicinal value, its bark

contains tannin, the flowers attract bees and thus the plant has honey production potential.

Like all trees, Jatropha removes carbon from the atmosphere, stores it in the woody tissues

and assists in the build up of soil carbon.



2.2 Possible Uses of the Jatropha

Traditionally the Jatropha plant is used as a medicinal plant.

Jatropha is planted in the form of hedges around gardens and fields to protect the

crops against roaming animals like cattle or goats.

Jatropha hedges are planted to reduce erosion caused by water and/or wind.

Jatropha is planted to demarcate the boundaries of fields and homesteads.

Jatropha plants are used as a source of shade for coffee plants (on Cuba).

In Comore islands, in Papua New Guinea and in Uganda, Jatropha plants are used as a

support plant for vanilla.

The seeds can be processed (oil, press cake) or sold directly as seed or for industrial

use.

Because of its mineral content, which is similar to that of chicken manure, it is

valuable as organic manure. In practical terms an application of 1 ton of Jatropha press

cake is equivalent to 200 kg of mineral fertilizer.

2.2.1 Jatropha as an Energy Source


Fig. 2.2. Jatropha oil lamp & Cooking using jatropha oil

Fig. 2.1. Jatropha press cake & Jatropha oil


Jatropha oil is an important product from the plant for meeting the cooking and lighting needs

of the rural population, boiler fuel for industrial purposes or as a viable substitute for diesel.

Substitution of firewood by plant oil for household cooking in rural areas will not only

alleviate the problems of deforestation but also improve the health of rural women who are

subjected to the indoor smoke pollution from cooking by inefficient fuel and stoves in poorly

ventilated space. Jatropha oil performs very satisfactorily when burnt using a conventional

(paraffin) wick after some simple design changes in the physical configuration of the lamp.

About one-third of the energy in the fruit of Jatropha can be extracted as oil that has a similar

energy value to diesel fuel. Jatropha oil can be used directly in diesel engines added to diesel

fuel as an extender or trans-esterised to a bio-diesel fuel. In theory, a diesel substitute can be

produced from locally grown Jatropha plants, thus providing these areas with the possibility

of becoming self sufficient in fuel for motive power. There are technical problems to using

straight Jatropha oil in diesel engines that have yet to be completely overcome. Moreover, the

cost of producing Jatropha oil as a diesel substitute is currently higher than the cost of diesel

itself that is either subsidized or not priced at "full cost" because of misconceived and

distorted national energy policies. Nevertheless the environmental benefits of substituting

plant oils for diesel provides for make highly desirable goals.


Table 2.1. The chemical analysis of Jatropha oil


Specification Standard specification of

Jatropha oil

Standard specification of

Diesel

Specific gravity 0.9186 0.82/0.84

Flash point 240/110°C 50°C

Carbon residue 0.64 0.15 or less

Cetane value 51.0 > 50.0

Distillation point 295°C 350°C

Kinematics Viscosity 50.73 cp > 2.7 cp

Sulpher % 0.13 % 1.2 % or less

Calorific value 9,470 kcal/kg 10,170 kcal/kg

Pour point 8°C 10°C

Colour 4.0 4 or less

Department of Mechanical & Manufacturing Engineering

ITEM VALUE

Acid value 38.2

Iodine value 101.7

Viscosity (31oC) cp 40.4

Fatty acids composition

Palmitic acid % 4.2

Stearic acid % 6.9

Oleic acid % 43.1

Linoleic acid % 34.3

Other acids % 1.4

7

Table 2.2. The comparison of properties of Jatropha oil and standard specifications of diesel oil

Table 2.3. Physical and chemical properties of diesel fuel and Jatropha

oil

(Source: www.svlele.com)



Property Jatropha Oil Diesel Oil

Viscosity (cp) (30°C) 5.51 3.60

Speciflc gravity (15°C/4°C) 0.917/ 0.923(0.881) 0.841 / 0.85

Solidfying Point (°C) 2.0 0.14

Cetane Value 51.0 47.8 to 59

Flash Point (°C) 110 / 340 80

Carbon Residue (%) 0.64 < 0.05 to < 0.15

Distillation (°C) 284 to 295 < 350 to < 370

Sulfur (%) 0.13 to 0.16 < 1.0 to 1.2

Acid Value 1.0 to 38.2

Iodine Value 90.8 to 112.5

Refractive Index (30°C) 1.47

2.3 Features of Jatropha

2.3.1 Botanical Features

It is a small tree or shrub with smooth gray bark, which exudes whitish colored, watery, latex

when cut. Normally, it grows between three and five meters in height, but can attain a height

of up to eight or ten meters under favorable conditions.

2.3.2 Leaves

It has large green to pale-green leaves, alternate to sub-opposite, three-to five-lobed with a

spiral phyllotaxis.


Fig. 2.3. Leaves



2.3.3 Flowers

The petiole length ranges between 6-23 mm. The inflorescence is formed in the leaf axil.

Flowers are formed terminally, individually, with female flowers usually slightly larger and

occur in the hot seasons. In conditions where continuous growth occurs, an unbalance of

pistillate or staminate flower production results in a higher number of female flowers. More

number of female flowers are grown by the plant if bee keeping is done along with. More

female flowers give more number of seeds.

2.3.4 Fruits

Fruits are produced when the shrub is leafless, or it may produce several crops during the

year if soil moisture is good and temperatures are sufficiently high. Each inflorescence yields

a bunch of approximately 10 or more ovoid fruits.


Fig. 2.4. Flowers

Fig. 2.5.Fruits


2.3.5 Seeds

The seeds become mature when the capsule changes from green to yellow, after two to four

months from fertilization. The blackish, thin shelled seeds are oblong and resemble small

castor seeds.

2.3.6 Ecological Requirements for Production of Jatropha

Jatropha is a fast growing plant and can achieve a height of three meters within three years

under a variety of growing conditions. Seed production from plants propagated from seeds

can be expected within 3-4 years2. Use of branch cutting for propagation is easy and results in

rapid growth; the bush can be expected to start bearing fruit within one year of planting.


Fig.2.6. Seeds


Whilst Jatropha grows well in low rainfall conditions (requiring only about 200 mm of rain to

survive) it can also respond to higher rainfall (up to 1200 mm) particularly in hot climatic

conditions. Jatropha does not thrive in wetland conditions. The plant is undemanding in soil

type and does not require tillage. The recommended spacing for hedgerows or soil

conservation is 15cm - 25cm x 15cm-25cm in one or two rows respectively and 2m x 1.5m to

3m x 3mm for plantations. Thus there will be between 4,000 to 6,700 plants per km 2. for a

single hedgerow and double that when two rows are planted. The number of trees per hectare

at planting will range from 1,600 to 2,200. 2

In equatorial regions where moisture is not a limiting factor (i.e. continuously wet tropics or

under irrigation), Jatropha can bloom and produce fruit all year. A drier climate has been

found to improve the oil yields of the seeds, though to withstand times of extreme drought,

Jatropha plant will shed leaves in an attempt to conserve moisture which results in somewhat

decreased growth.

Seed production ranges from about 0.4 tons per hectare per year to over 12 t. /ha. /y after five

years of growth2. Although not clearly specified, this range in production may be attributable

to low and high rainfall areas... The practices being undertaken by the Jatropha growers

currently need to be scientifically documented along with growth and production figures. The

growth and yield of wood may be in proportion to nut yield and

Jatropha grows almost anywhere – even on gravelly, sandy and saline soils. It can thrive on

the poorest stony soil. It can grow even in the crevices of rocks. The leaves shed during the

winter months form mulch around the base of the plant. The organic matter from shed leaves

enhance earth-worm activity in the soil around the root-zone of the plants, which improves

the fertility of the soil. Climatically, Jatropha is found in the tropics and subtropics and likes

heat, although it does well even in lower temperatures and can withstand a light frost. Its

water requirement is extremely low and it can stand long periods of drought by shedding most

of its leaves to reduce transpiration loss. Jatropha is also suitable for preventing soil erosion

and shifting of sand dunes.

Analysis of the Jatropha seed shows the following chemical composition7:

Moisture 6.20 %

Protein 18.00 %



Fat 38.00 %

Carbohydrates 17.00 %

Fiber 15.50 %

Ash 5.30 %

The oil content is 25 – 30%7 in the seeds and 50 – 60%7 in the kernel. The oil contains 21%7

saturated fatty acids and 79%7 unsaturated fatty acids. There are some chemical elements in

the seed, which are poisonous and render the oil not appropriate for human consumption.

2.4 Analysis of national energy availability and consumption (Source:www.energy.g

ov.lk)

INDICATOR 2000 2001 2002 2003 2004Primary Energy Supply (thousand TOE)

Biomass 4,469.81

4,291.84

4,310.57

4,371.83

4,513.25

Petroleum 3,577.13

3,498.21

3,652.53

3,955.76

4,131.90

Hydro 767.28 746.30 646.10 791.33 710.71Non-conventional 1.92 1.87 2.34 3.15 3.60

TOTAL PRIMARY ENERGY SUPPLY

8,816.1 8,538.2 8,611.5 9,122.1 9,359.5

Share of Biomass in Primary Energy 50.7% 50.3% 50.1% 47.9% 48.2%Share of Renewable Energy in Primary Energy

59.4% 59.0% 57.6% 56.6% 55.9%


Table 2.4. Primary Energy Supply (kTOE)

Fig. 2.7. Pie chart of primary energy supply in 2003


Department of Mechanical & Manufacturing Engineering

2002 % 2003 %

Industry 1,681.38 23.39 1,799.61 24.41

Transport 1,737.91 24.18 1,848.66 24.80

Household, Commercial & Others 3,767.03 52.48 3,806.50 51.10

Total 7,186.32 100.00 7454.77 100.00

2002 2003

Hydro 1,137.45 1,207.45

Diesel 4,135.60 4,320.00

Fuel Oil 711.90 588.32

Residuel Oil 1,365.40 1,354.70

Naptha 219 539.60

Non-conventional, CEB 3.60 3.40

Self-generation by Customers 140.80 -

Off-grid, Conventional 105.10 16.70

Off-grid, Non-conventional 9.70 10.90

Gross Generation Sri Lanka 7,087.00 7,661.40

2002 2003

Crude Oil 2,281.01 1,995.71

LPG 137.00 141.61

Super Petrol 56.21 117.41

Jet A-1 174.56 144.40

Kerosene 19.68 3.14

Auto Diesel 1,081.46 1,055.43

Fuel Oil 96.82 37.28

Total Refine Products 1,565.73 1,499.28

2002 % 2003 %

Domestic (LPG, Kerosene) 377.28 11.60 337.45 11.85

Transport (Gasoline, Auto Diesel,

Super Diesel, Furnance Oil)

1,530.53 47.12 1,608.18 50.50

Commercial (Auto Diesel, Super

Diesel, Furnance Oil)

46.71 1.44 44.76 1.41

Power Generation (Naphtha, Auto

Diesel, Super Diesel, Furnance Oil)

986.99 30.83 918.73 28.85

Industry (Kerosene, Auto Diesel,

Super Diesel, Furnance Oil)

306.31 9.43 275.33 8.64

Total 3,247.82 100.00 3,184.45 100.0013

Table 2.5. Energy Consumption by Sector (kTOE)

Table 2.6. Electricity Generation by Resource (GWh)

Table 2.7. Petroleum Product Imports (Thousand Metric Tonnes)

Table 2.8. Sectorial Consumption of Petroleum Products (Thousand Metric Tonnes)

TOTAL GRID ELECTRICITY SALES BY SECTOR

0%

20%

40%

60%

80%

100%

1990

1993

1996

1999

2002

Year

(%)

STREET LIGHTINGCOMMERCIALINDUSTRIALRELIGIOUSDOMESTIC

Fig. 2.8. Total grid electricity sales by sector


2.5 Current Status in the world

Oil extraction is isolation of oil from animal by-products, fleshy fruits such as the olive and

palm, and oilseeds such as cottonseed, sesame seed, soybeans, and peanuts. Oil is extracted by

three general methods: rendering, used with animal products and oleaginous fruits;

mechanical pressing, for oil-bearing seeds and nuts; and extracting with volatile solvents,

employed in large-scale…

Presently the edible oil is extracted through traditional oil extractors. The recovery of oil in

traditional oil extractors is lesser and of inferior quality. The capacity is also much less as

compared to the improved expellers. Oil extraction can be more effectively carried out by the

Pre-pressing of seeds lightly which can precede oil milling resulting higher capacity; lower

power consumption, lower wear & tear and maintenance and two-stage pressing. Different oil

expellers for Jatropha seed are build in many countries.

2.5.1 The Sayari Oil Expeller

The Sayari oil expeller has been developed by FAKT consulting engineers Dietz, Metzler,

Zarrate for the use in Nepal. Therefore it was designed out of iron sheets instead of cast iron

to limit the weight of the heaviest parts to 40 kg12 .It is now built in Tanzania by VYAHUMU

Trust, Morogoro, and in Zimbabwe by POPA, Harare


Fig.2.9. Front View of Sayari oil expeller


2.5.2 The Yenga press

The piston creates the pressure to force the oil out of the press cake. Sometimes the piston

gets stuck and is difficult to move. Then the press has to be taken apart and the piston and its

cylinder have to be cleaned thoroughly.

The cage is welded from iron bars with a fine gap between them. Before starting the pressing,

make sure that the gaps are free.

The outlet is the regulation part of the ram press. The more it is closed, the more difficult it is

to press the cake through the gap, the more oil is extracted (higher extraction rate). The outlet

should be regulated in such a way that one person can push down the lever without too much

force (not "hanging" on the lever).

Department of Mechanical & Manufacturing Engineering 15Fig.2.10.Yenga Press


2.5.3 Komet Oil Expellers

Komet Vegetable Oil Expellers are manufactured in Germany, whose range of products

covers small hand operated as well as industrial machines. According to the product literature,

Komet oil expellers feature a special cold pressing system with a single conveying screw to

squeeze the oils from various oil-bearing seeds. The machines operate on a gentle mechanical

press principle that does not involve mixing and tearing of the seeds. Virtually all oil-bearing

seeds, nuts, and kernels can be pressed with the standard equipment without adjusting the

screws or oil outlet holes.


Fig. 2.11. Sectional view of KOMET oil expeller


CHAPTER 03

3. CURRENT OIL EXTRACTION PROCESS IN SRI LANKA

As our main target is designing and fabrication of jatropha oil extractor, first we have studied

about the purpose and steps involving in oil extraction process. This was more beneficial at

the stage of the designing the maximum torque of the machine and determining the yield of

the oil. The brief description of oil extraction process is described as in the following section.

Oil can be extracted mechanically with an oil press, an expeller. Presses range from small,

hand-driven models that an individual can build to power-driven commercial presses.

Expeller pressing is the most popular method of jatropha oil extraction. Expellers have a

rotating screw inside a horizontal cylinder that is capped at one end. Jatropha seeds are fed

into a cylinder, and pressure is added as the screw turns and gradually increasing the pressure.

This forces the separate the liquid oil and vegetation water from the solid seed. Then oil

escapes from the cylinder through small holes or slots, the oil can be collected. Percentage oil

extraction form the current machine is approximately 18%. The major disadvantages of


Fig.3.1: Current jatropha oil extractor


available machine are hard operation and less oil extraction. Also the husk of the seed wanted

to remove before fed into the machine that is more time consuming and hard work for

labours. By doing this project we hope to minimize the current difficulties and develop the

machine into a high yield oil extractor.

Preparation of the raw material often includes removing husks or seed coats from the seeds

and separating the seeds from the chaff. For successful pressing, the seed must be:

Dry. Moist seed will lead to low yields and clog the cage (a part of the press). Moist

seed may also get moldy.

Clean. Fine dust in the seed may clog the cage. The seed will absorb some of the oil

and keep it from getting squeezed out of the cage. Sand in the seed will wear the press

out. Stones badly damage the piston.

Warm. Warm seed will yield the most oil for the least effort.

Seed that is slightly too damp may feel dry but will not press well. If it is too damp, but not

yet moldy, it can be dried in the sun. (Never press moldy seed. It is not safe for human

consumption.) Spread the seed out thinly on the ground, on plastic, or on roofing tin. At the

end of the day, pile the seed up to keep it from absorbing moisture in the cool night air, and


Fig.3.2: Removing the jatropha husk


spread it out again in the morning. If there is any chance of rain, or if the morning dew is

heavy, need to bag all the seed in the evening and put it back out the following morning. After

two or more sunny days, the husks will be dry. Then bag the seed and store it for a week. In

that time, the moisture in the seed will be drawn into the dry husk, and the entire seed will

become evenly dry.



CHAPTER 04

4. EXPERIMENTS

4.1 Experiment 01

DATE : 14 / 12 / 2006

TITLE : Performance of existing oil extractor.

INTRODUCTION :

Percentage of weight of the oil extracted from Jatropa seeds is the most

critical factor in our project. Because our main objective is to increase

the yield, there fore at the beginning we do a small practical using

existing oil extractor to identify its performance.

RESULT :

Table 4.1. Performance of existing machine

Parameter Weight(g)Test 01 Test 02 Test 03 Average %

Seeds total weight

450 450 450 450.00 -

Husk 180 195 186 187.00 41.55Core(Useful) 270 255 264 263.00 58.44Disposal 218 205 210 211.00 80.23Oil 47 44 48 046.33 17.61

4.2 Experiment 02

DATE : 18/12/2006

TITLE : Moisture Test for Jatropha

INTRODUCTION :

The moisture content of jatropha seed is very much important for oil

extraction process. High moisture level will lead to low yields and clog

the cage. First take the weights of the samples Then jatropha seeds kept

inside an oven under 100°C for 24 hours. Finally measure the weight

again. The difference gives the weight of the water content in jatropha

seed.



RESULT :

Table 4.2. Moisture test details

Parameter Sample 01 Sample 02 Sample 03 Sample 04 Sample 05Weight of the container/(g)

9.592 9.690 26.550 9.451 26.554

Weight (Before) /(g)

50.262 50.124 50.120 50.290 50.760

Weight(After) /(g)

44.916 44.659 44.885 44.976 45.33

Weight of Moisture/(g)

5.346 5.465 5.235 5.314 5.43

Percentage of moisture

content/(%)

10.64 10.90 10.44 10.57 10.70

Average percentage of moisture = 10.65%



CHAPTER 05

5. PROPOSED MODEL

Fig.5.1. shows the proposed model for the Jatropha oil extractor. It is a simple manual

operated machine for domestic uses. Here we mainly consider the increase of the yield from

jatropha seed and the easy operation.

5.1 Operation

When the shaft is rotated by means of the handle, the helical gear wheel that’s connected to

the shaft is rotated. Due to that, the other gear wheel which meshed with the drive gear also

begins to rotate in the opposite direction. The gear ratio between two gears is one. When

prepared Jatropha seeds put into the hopper as they slide through the hopper and fallen

between two meshing gears, which are in motion. When gears are rotating they catch Jatropha

seeds and then these seeds will move toward the exit side. Meanwhile due to the shear and

compression actions generated by the meshing gears Jatropha seeds are crushed and squeezed.

Because of these crushing and squeezing actions oil will expelled from the Jatropha seeds.

Mixture of this extracted oil and crushed Jatropha particles are then collected to a strainer

which has been placed outside of the main extractor. The collection will keep on the strainer

for some time to extract the oil and then put in to the secondary extractor.

Then the remaining is put in to the secondary extractor. After that crushed Jatropha particles

compressed by means of a screw attachment. When the screw is rotated the plate attached to

the end of this shaft will move downward and create squeezing action on the Jatropha

particles. Due to this squeezing action oil will extracted and strained through the strainer to

the collector


Fig.5.1. Proposed model


5.2 Part list of proposed model

Table 5.1. Part list

Part Function

Main Extractor.

Hopper To put Jatropha seeds into the extractor.

Helical gears To crush & squeeze seeds.

Bearings To create friction less rotation of shafts.

StrainerTo separate oil from crushed Jatropha particles

Handle To rotate the driving gear.(To input power)

Bearing capes To mount bearings

Shaft For power transmission

End covers To cover two ends of the machine

HousingExist two gears and generate shearing action on Jatropha seeds

Clamping plates To clamp the extractor

Secondary extractor (Screw press)

Cylinder Provide space for squeezing operation

Screw To generate squeezing action

Plate To prevent escaping of particles

Stand To retain the extractor

5.3 3D modelling of proposed model




Fig.5.2. Front view of the proposed model

Fig.5.3. Plan view of the proposed model



Fig.5.4. Inside view of the proposed model

Fig.5.5. Helical gear wheel

Fig.5.6. Hopper



Fig.5.7. Gear housing

Fig.5.8. Clamping plate



Fig.5.9. Screw press


CHAPTER 06

6. MATERIAL SELECTION

An important aspect of design for mechanical, electrical, thermal, chemical or other

application is selection of the best material or materials. Systematic selection of the best

material for a given application begins with properties and costs of candidate materials. For

example, a thermal blanket must have poor thermal conductivity in order to minimize heat

transfer for a given temperature difference.

Systematic selection for applications requiring multiple criteria is more complex. For

example, a rod which should be stiff and light requires a material with high Young's modulus

and low density. If the rod will be pulled in tension, the specific modulus, or modulus divided

by density E / ρ, will determine the best material. But because a plate's bending stiffness

scales as its thickness cubed, the best material for a stiff and light plate is determined by the

cube root of stiffness divided density .

6.1 Cost issues

Cost of materials plays a very significant role in their selection. The most straightforward way

to weight cost against properties is to develop a monetary metric for properties of parts.

However, the geography- and time-dependence of energy, maintenance and other operating

costs, and variation in discount rates and usage patterns between individuals, means that there

is no single correct number for this. Thus as energy prices have increased and technology has

improved, automobiles have substituted increasing amounts of light weight magnesium and

aluminium alloys for steel, aircraft are substituting carbon fiber reinforced plastic and

titanium alloys for aluminium, and satellites have long been made out of exotic composite

materials.



6.2 Materials for Gear Wheels

The material used for the manufacture of gears depends on the strength and service conditions

like wear, noise etc. the gears may be manufactured from metallic or non-metallic materials.

The metallic gears with cut teeth are obtainable in cast iron, steel and bronze. The non-

metallic materials like wood, rawhide, compressed paper and synthetic resins like nylon are

used for gears, especially for reducing noise.

The cast iron is widely used for the manufacture of gears due to its good wearing properties,

excellent machinability and ease of producing complicated shapes by casting method. The

cast iron gears with cut teeth may be employed, where smooth action is not important.

6.3 Some Benefits and Advantages of Cast Irons

A family of materials capable of meeting a wide variety of engineering and

manufacturing requirements (the "family" includes Gray Iron, Ductile Iron,

Compacted Graphite Iron, Malleable Iron, and White Iron)

Available in a wide range of mechanical/physical properties, i.e. tensile strength from

20 KSI to over 200 KSI, hardness from 120 to about 300 Brinell in standard grades

and up to about 600 Brinell in special abrasion resistant grades

Good strength to weight ratio

Typically lower cost than competing materials and relatively low cost per unit of

strength than other materials

Lower density and higher thermal conductivity than steels at comparable tensile

strength levels

Excellent machinability, allowing for high speeds and feeds and reduced (minimal)

energy due to the presence of free graphite



Many iron castings can be used without heat treatment (as-cast) but, when needed, can

be heat treated to enhance overall properties or localized properties such as

Surface hardness

Excellent damping capacity, especially in Gray Irons

Chemical analysis can be modified to provide improved special properties such as

corrosion resistance, oxidation resistance, wear or abrasion resistance, etc.

Rapid transition from design to finished product

Capability of producing highly complex geometries and section sizes in a wide range

of sizes, from ounces to over 100 tons

Flexibility in design and ability to optimize appearance for sales appeal

Possibility of casting intricate shapes as well as very thin to very thick section sizes

Capability of redesigning and combining two or more components from other

materials into a single casting, thus reducing assembly cost and time

Capability of casting with inserts of other materials

Variety of casting processes for low, medium or high production

Reduced tendency toward residual stresses and warpage than some competitive

materials

CHAPTER 07


Fig. 7.1. Gear Terminology


7. DESIGN

Concerning our proposed machine, two helical gears are the most important component. So

that in our designing process we give special attention on designing a helical gear, Apart from

that there are few another parts to be design. They are;

a) Shaft

b) Bearings

c) Keys

7.1 Design of the helical gear

A helical gear has teeth in form of helix around the gear. Two such gears can be used to

connect two parallel shafts in place of spur gears. The helixes may be right handed on one

gear and left handed on other gear. The pitch surfaces are cylindrical as in spur gear, but teeth

instead of being parallel to the axis, wind around the cylinders helically like screw threads.

The teeth of helical gears with parallel axis have line contact, as in spur gearing. This

provides gradual engagement and continuous contact of the engaging teeth. In our design to

extract maximum amount of oil from ‘Jatropha’ seeds it required to generate better crushing

and continuous squeezing action by using two gear wheels. Due to that reason we select two

helical gears to obtain these actions because it can generate gradual engagement and

continuous contact of the engaging teeth.

7.1.1 Gear Terms Used in Gears

Pitch circle : The intersection of the pitch surface with a plane perpendicular the

axis of rotation



Addendum circle : It is the circle which bounds the outer ends of the teeth.

Addendum : The radial distance between the pitch circle and the addendum

circle.

Dedendum circle : The circle which bounds the bottom of the teeth.

Dedendum circle. : The radial distance between the pitch circle diameter and the

addendum

Total depth of tooth : The sum of addendum and addendum.

Clearance : The difference between the dedendum and the addendum of mating

gear teeth.

Base circle : A circle from which the tooth profile curve is generated.

Tooth thickness : The chord length measured along the pitch circle between the

opposite faces of the same tooth.

Module : The ratio of the pitch circle diameter to the number of the teeth, i.e.

the reciprocal of the diametral pitch (DP).

Diametral pitch : The ratio of the number of teeth to the pitch circle diameter.

Backlash : The space between two consecutive teeth, measured along the

pitch circle.

Circular pitch : The distance measured along the pitch circle from a point on one

tooth to the corresponding point on the adjacent tooth.

P = d1/Z1

Where;

d1 : the pitch circle diameter of the pinion.

Z1 : is the number of the teeth of the pinion.

Helical angle : It is a constant angle made b the helices with the axis of rotation.

Axial Pitch : It is the distance, parallel to the axis, between similar faces of

adjacent teeth.

Normal Pitch : It is the distance between similar faces of adjacent teeth along a

helix on the pitch cylinder normal to the teeth.

7.1.2 Strength of Helical Gears



In helical gears contact between mating teeth is gradual, starting at one end and moving along

the teeth so that at any instant the line of contact runs diagonally across the teeth. therefore in

order to find the strength of helical gears, a modified Lewis equation is used. It is given by;

Where;

= Tangential tooth load

= Allowable static stress

= Velocity factor

= Face width.

= Module

= Tooth form factor or Lewis factor

The values of the velocity factor ( ) are given as follow:

, for ordinary cut gears operating at velocities up to 12.5 m/s.

, for carefully cut gears operating at velocities up to 12.5 m/s.

, for very accurately cut and ground metallic gears operating at

velocities up to 20 m/s.

, for non-metallic gears

7.1.3 Assume Data for the Design



By doing some experiments we have identify that the maximum force required to crush and

squish the ‘Jatropha’ seeds in order to extract maximum amount of oil is about 2600N.

Considering a helical gear this force represents the Tangential Tooth Load ( ).

There fore take;

But considering the safety of the gear teeth take safety factor as 3

Then take;

Since our machine is designed for domestic use, it is prefer to operate it manually. Therefore

maximum speed of the gear wheel cannot be a large value. So that we take that as 30 rpm.

Then;

Also we select our material as ‘Cast Iron’. Ten from Table 11.1

Take the optimal length of the axel which used to introduce the torque as 400mm (0.4m)

7.1.4 Gear Design Calculations

From data we know

Then the peripheral velocity (v);

Since we use ordinary cut gear and having < 12.5 m/s

(1)

Also;



But equivalent number of teeth in spur gear ( );

For 200 Stub teeth;

(2)

Take;

Then from Lewis equation

There fore;

But considering over extracting process it should have lengthy process to extract oil

Take;

Because maximum face width bm

20 m < bm < 30 m

Then face width = 90 mm

Number of teeth =

Since required =2600 N

Torque =

Force required to rotate =

Force required to rotate axel in order to extract maximum amount of oil from ‘Jatropha’ seeds

is = 195 N



Axial thrust ( ) =

=

=

=

Normal Force ( ) =

=

=

Dynamic Tooth Load (Wd)

Wear load

But;

,

Therefore;

But



Then;

=

Gear Parameters.

Addendum =0.8m = 2.4 mm

Dedendum = 3mm

Working depth =1.6m = 4.8 mm

Tooth thickness = 1.5708m = 4.7124 mm

Minimum Clearance = 0.2m = 0.6 mm

Fillet radius at root = 0.4m =1.2 mm

7.2 Designing the Shaft

Shaft design is another important task in our project. Though shaft is a rotating machine

element which is used to transmit power from one place to another, it required various

members such as pulley, gears etc... in order to transmit power from one shaft to another. In

other words, we can say that a shaft is used for the transmission of torque and bending

moment. Here there are two shafts to support two gear wheels.



Shaft can be divided in to two major parts.

Transmission Shaft : These shafts transmit power between the source and the machines

absorbing power.

Machine shaft : These shaft form an integral part of the machine it self. (crank shaft)

7.2.1 Standard sizes of Transmission shaft.

The standard sizes of the transmission shaft are;

25mm to 60mm with 5mm steps

60 mm to 110 mm with 10 mm steps



7.2.2 Design methods

Shafts can be designed on the basis of

a) Strength

b) Rigidity and stiffness

In designing shaft on the basis of strength, the following cases may be considered;

Shaft subjected to twisting moment or torque only.

Shaft subjected to bending moment only.

Shaft subjected to combined twisting and bending moments.

Shaft subjected to axial loads in addition to combine torsional and bending

load.

Shaft subjected to axial loads in addition to combine torsional and bending load

In our case the main shaft is subjected to an axial force (due to helical gear) in addition to

torsional and bending loads. There fore we used following method to calculate shaft diameter.

From Maximum shear stress theory



Where;

M = Bending moment

T = Torsion

d = Diameter of the shaft

= Maximum shear stress

= Equivalent twisting moment

For failure,

According to the maximum normal stress theory,

Maximum normal stress in the shaft

=

Finally if is maximum allowable bending stress

When shaft is subjected to an axial load( F ) in addition to torsion and bending loads, then the

stress due to axial load must be added to the bending stress ( )

The stress due to axial load

Then resultant stress

=

Department of Mechanical & Manufacturing Engineering 3965 65

R

R/2 R/2


Fig 7.2. Bearing arrangement

Take;

Considering the gear width and operational feasibility, in our design we decided to fix two

bearings, 130mm apart. As shown in Fig.7.2.

Then;

Assumption: Since compare to the load applied due to squishing action self weight of the

gear wheels is very much small, self weight of the gear is neglected.

Then;

Maximum torque transmit = 78 Nm

Maximum Bending Moment = 274.95 Nm

Equivalent Bending Moment =



=

= 280.37 Nm

For Mild Steel ( )

=280.37+562.5.d

=.0380 m

= 38.00 mm

Select Mild steel shaft with diameter = 40 mm

7.3 Bearing Selection

Since in our design it has to handle radial force and little amount of axial thrust we select

single raw deep grove ball bearing to mount two helical gears.

Data

Axial thrust = =4500N

Radial Load =

Since we are designing this machine for domestic use, we assume that people will prefer to

extract oil per day by operating this machine maximum two hours. Also we predict that the

machine will last for minimum five years which are having maximum 300 operating days.

Then bearing life in hours ( ) given as;

Life of the bearing in revolution (L)

L =

=

=



Basic dynamic equivalent radial load (W),

Where;

V = A rotational factor

= 1, for all type of bearings when the inner race is rotating

= 1.2 for all types of bearings except self aligning, when inner race is stationary.

X = Radial load factor

Y = Axial load factor

Then;

Take ;( we don’t know )

Then from data sheets (Table 10.4)

&

Also V= 1; because for all type of bearings when the inner race is rotating V=1

=

=

= 6868.8

= 6.869 KN

For uniform & steady load, service factor (From Table 11.3)

Basic dynamic load rating,

=

= 12686.08 N

= 12.7 KN



In this point we have to consider about both bearing loads as well as shaft diameter. Because

if the shaft diameter is much lesser value than bearing bore then it gives designing failure.

there fore in our case we have to select bearing which is having its bore closer to 30mm or

less than that. By considering these two factors with Table 11.5 and Table 11.6.

Select bearing number as 205 which gives following values

, C = 11

Then

But using Table.11.1 we have to select

This gives same X & Y values as in our first case

There fore we select deep groove ball bearing which is having bearing number 205

7.4 Designing of Key -Way

7.4.1 Force acting on a Sunk Key

When a key is used in transmitting torque from a shaft to a rotor or hub, the following two

type of force act on the key:

1. Force (F1) due to fit of the key in its keyway, as in a tight fitting straight key or in a

tapered key driven in place. These forces produce compressive stresses in the key

which are difficult to compute in magnitude.

2. Forces (F) due to the torque transmitted by the shaft. These forces produce shearing

and compressive (or crushing) stresses in the key.

The distribution of the forces along the length of the key is not uniform because the forces are

concentrated near the torque-input end. The non-uniformity of distribution is caused by the

twisting of the shaft within the hub.

The forces acting on a key for a clockwise torque being transmitted from a shaft to hub are

shown in Fig.7.3



In designing a key, forces due to fit of the key are neglected and it is assumed that the

distribution of forces along the length of key is uniform.

7.4.2 Strength of a Sunk Key

Let

Little consideration will show that due to power transmitted by the shaft, the key may fail due

to shearing or crushing.

Considering shearing of key, the tangential shearing force acting at the circumference of the

shaft,

Considering crushing of the key, the tangential crushing force acting at the circumference of

the shaft,


T = Torque Transmitted by the shaft

F = Tangential force acting at the circumference of the shaft

d = Diameter of shaft

l = Length of key

w = Width of key

t = Thickness of key

Fig.7.3. Forces acting on a sunk key


The key is equally strong in shearing and crushing, if

The permissible crushing stress for the usual key material is at least twice the permissible

shearing stress. Therefore from equation (iii), we have w = t. In other word, a square key is

equally strong in shearing and crushing.

In order to find the length of the key to transmit full power of the shaft, the shearing strength

of the key is equal to the tensional shear strength of the shaft.

We know that shearing strength of the shaft,

and tensional shear strength of the shaft,

In our design the shaft diameter is 60mm then from the table 11.7 we select width and

thickness as 20 mm and 12 mm. In our case we select material as mild steal then permissible

shear ( )and crushing stresses( c) are 56N/mm and 112 N/mm

Then considering shearing of the key. From equation iv

And torsion shearing strength of the shaft. From equation v



Solving above two equations we get

Now considering crushing of the key. We know that shearing strength of the key

From equation (b) and (c)

Taking larger of these two we select the length of the key-way used at gear wheel as

Say 90 mm

There Fore the two key-ways have following dimensions

CHAPTER 08

8. Fabricating of Oil Extractor



8.1 Main Shaft

Manufacturing of the main shaft is the most important part of the manufacturing process

because the gear wheel, bearings and handle are mounted on this shaft. To manufacture the


Fig.8.1. Front View of Main Shaft


shaft we have to use the lathe machine. There we can use the turning, facing & parting

operations to make the main shaft to the required dimensions as shown in the Fig.8.1.

Then we have to prepare the driven shaft also, there the machining operation is similar to the

main shaft only difference is dimensions.

8.2 Helical Gear

Manufacturing of helical gear is somewhat difficult but using CNC milling machine can make

the gear wheel according to the required profile as given in the design. We have chosen the

material as Cast iron so the casting operation also can use to manufacture the gear wheel

because this operation does not need very carefully cut teeth.

8.3 Gear housing


Fig.8.2. Helical Gear Wheel


Manufacturing of gear housing is somewhat easier comparing with earlier manufacturing

parts because this needs only drilling & boring operations. First we need to cut a metal piece

and shaped into required dimensions. Then using CNC milling machine can drill & bore the

holes as shown in the Fig.8.3.

8.4 Clamping Plate


Fig.8.3. Gear Housing


By using metal plates we can prepare clamping plate to required dimensions as shown in

Fig.8.4. This requires welding & drilling operations. First we have to cut two metal plates to

required dimensions & then we can drill to make the holes need. After that we can weld the

two plates to finish the part.

8.5 Hopper


Fig.8.4. Clamping Plate

Fig.8.5. Hopper


Hopper can be made by using alluminium sheet. There we can draw the development of

hopper on alluminium sheet. Then cut the development and revert it to a hopper.

8.6 Other Parts

Manufacturing of key is very simple because it need only cut a metal piece & sized it. Handle

can be made using two metal pieces & casing by using alluminium sheet. Metal mat can be

placed below the machine to collect the crushed seed particles.

CHAPTER 09

9. CONCLUSION AND RECOMMENDATION

Designing of a Jatropha Oil Extractor is very important task because here we were

concern mainly about poor people in domestic areas. In those areas jatropha planted in their

fences. These jatropha seeds not used for any purposes because there poisonous. So by doing

this kind of project we can encourage people living in rural areas to cultivate jatropha plant as

an energy crop.

Finding an alternative fuel to petroleum is world’s trend in these days so jatropha oil

also one of a bio-fuel using & researching in nowadays. Some of non- government

organizations also make their concern about this area in Sri Lanka. In last few months we had

contact with people who are interested in this field and got very important information about

the future projects which will be implemented in Sri Lanka.



In our design some assumptions were made. Actually the testing of existing machine

was very difficult because there were no any facilities to test the performance at

Thanamalwila area. How ever we were able to get the some measurements relating to the

design from that machine.

There are more methods of oil extracting available in world. Here we have considered

about mechanical method. We hope that in our design we could obtain more oil yield than the

existing oil extractor in Sri Lanka also we reduce the size and weight of the extractor which

would be very easy for operators. Most importantly we have avoid the removing of husk in

our extractor but we couldn’t test the conditions with and without husk as we fail to fabricate

the complete oil extractor because of no any fund provided by the university.

Our design can develop up to the industrial level by introducing suitable electric

motor. Finally we were disappointed because we have no enough money for fabricate the oil

extractor which we have design and check whether the performance of our machine.

CHAPTER 10

10. BIBLIOGRAPHY

10.1 Web

1. http://home.t-online.de/home/320033440512-0002/downloads/jcl-manual,30.07.2006

2. www.jatropha.de/zimbabwe/rf-concept-paper.doc,30.07.2006

3. www.jatropha.org,24.07.2006

4. www.wikipedia.org/wiki/Jatropha ,24.07.2006

5. www.jatrophaworld.org/,24.07.2006

6. www.biodieseltoday.com,24.07.2006

7. www.hort.purdue.edu/newcrop/duke_energy,28.07.2006

8. www.svlele.com,28.07.2006

9. www.energy.gov.lk,02.08.2006

10. www.ceb.lk,02.08.2006



11. www.oregonstate.edu/international/outreach/rlc/resources/Jatropha.pdf,04.08.2006

12. www.jatropha.de/documents/jcl-booklet.pdf,04.08.2006

10.2Books

1. R.S.Khurmi & J.K.Guptha, A Textbook of Machine Design, 1st ed. (S.Chand &

Company Ltd, 2004), Ch 28 & 29.

CHAPTER 11

11. ANNEXURE

Table 11.1.Values of Allowable Static Stress

Material Allowable static stress ( ) MPa or N/mm2

Cast iron, ordinary 56

Cast iron, medium grade 70

Cast iron, highest grade 105

Cast steel, untreated 140

Cast steel, heat treated 196

Forged carbon steel-case hardened 126

Forged carbon steel-untreated 140 to 210

Forged carbon steel-heat treated 210 to 245

Alloy steel-case hardened 350

Alloy steel –heat treated 455 to472



Phosphor bronze 84

Non-metallic materials

Rawhide, fabroil 42

Bakellite, Micarta, Celoron 56

Table 11.2.Minimum no. of teeth on the pinion in order to avoid interference

S. No System of gear teeth. Minimum no. of teeth on the pinion

1.

2.

3.

4.

14 1/20 composite

14 1/20 Full depth involutes

200 Full depth involutes

200 stub involutes

12

32

18

14

Table 11.3.Values of Service Factor (Ks)

S.No

.

Type of service Service Factor (Ks) for radial ball

bearing

1 Uniform and steady load 1.0

2 Light shock load 1.5

3 Moderate shock load 2.0

4 Heavy shock load 2.5

5 Extreme shock load 3.0

Table 11.4.Vales of X and Y for Dynamically Loaded Bearing

Bearing

type

Specification

s< e >e

e



Deep

groove

ball

bearing

X Y X Y

= 0.025

1 0 0.56

2.0 0.22

= 0.04 1.8 0.24

= 0.07 1.6 0.27

= 0.13 1.4 0.31

= 0.25 1.2 0.37

= 0.50 1.0 0.44

Table 11.5.Principal Dimensions for Radial Ball Bearing

Bearing No. Bore(mm) Outside diameter(mm) Width(mm)

200 10 30 9

300 35 11

201 12 32 10

301 37 12

202 15 35 11

302 42 13

203 17 40 12

303 47 14

403 62 17

204 20 47 14

304 52 15

404 72 19

205 25 52 15



305 62 17

405 80 21

206 30 62 16

306 72 19

406 90 23

207 35 72 17

307 80 21

407 100 25

208 40 80 18

308 90 23

408 110 27

209 45 85 19

309 100 25

409 120 29

210 50 90 20

310 110 27

410 130 31

Table 11.6.Basic Static and dynamic capacities of various types of radial ball bearing Bearing

No.Basic Capacities in kN

Single row deep groove ball bearing

Single row angular contact ball bearing

Double row angular contact ball bearing

Self-aligning ball bearing

(1)

Static(Co)(2)

Dynamic(C)(3)

Static(Co)(4)

Dynamic(C)(5)

Static(Co)(6)

Dynamic(C)(7)

Static(Co)(8)

Dynamic(C)(9)

200300

2.443.60

46.3

--

--

4.55-

7.35-

1.80-

5.70-

201301

34.3

5.47.65

--

--

5.6-

8.3-

2.03.0

5.859.15

202302

3.555.20

6.108.80

3.75-

6.3-

5.69.3

8.314

2.163.35

69.3

203303403

4.46.311

7.510.618

4.757.2-

7.811.6

-

8.1512.9

-

11.619.3

-

2.84.15

-

7.6511.2

-204304404

6.557.6515.6

1012.524

6.558.3-

10.413.7

-

1114-

1619.3

-

3.95.5-

9.814-

205305

7.110.4

1116.6

7.812.5

11.619.3

13.720

17.326.5

4.257.65

9.819



405 19 28 - - - - - -206306406

1014.623.2

15.322

33.5

11.217-

1624.5

-

20.427.5

-

2535.5

-

5.610.2

-

1224.5

-207307407

13.717.630.5

202643

15.320.4

-

21.228.5

-

2836-

3445-

813.2

-

1730.5

-208308408

1622

37.5

22.83250

21.634-

2535.5

-

32.545.5

-

3955-

9.1516-

17.635.5

-209309409

18.33044

25.541.260

21.634-

2845.5

-

37.556-

41.567-

10.219.6

-

1842.5

-210310410

21.235.550

27.54868

23.640.5

-

2953-

4373.5

-

47.581.5

-

10.824-

1850-

211311411

2642.560

345678

3047.5

-

36.562-

4980-

5388-

12.728.5

-

20.858.5

-

212312412

324867

40.56485

36.555-

4471-

6396.5

-

65.5102

-

1633.5

-

26.568-

Table 11.7.Proportions of Slandered parallel, tapered and gib head keys.

Shaft Diameter (mm) up to

and including.

Key cross-section

With(mm) Thickness(mm)

6 2 2

8 3 3

10 4 4

12 5 5

17 6 6

22 8 7

30 10 8

38 12 8

44 14 9

50 16 10

58 18 11

65 20 12



75 22 14


jatropha final3

Documents

oil extraction

engineering program

public lands

oil seeds

jatropha oil extractor

denuded lands

dry lands

good lands