Biodiesel is an alternative fuel made from vegetable oils, methanol, and a catalyst through a chemical process called transesterification. It can be used in unmodified diesel engines and provides benefits over petroleum diesel such as being cleaner-burning, producing lower emissions, and being more biodegradable. However, biodiesel also has some disadvantages like being less stable during long storage periods. The production of biodiesel involves selecting feedstocks, pre-treating oils to remove contaminants, mixing the oils with alcohol in the presence of a catalyst, separating and purifying the biodiesel and glycerin products to meet fuel standards. Jatropha is a promising biodiesel feedstock due to its

1. What Is Biodiesel
 Biodiesel is a diesel fuel made from vegetable oil, methanol and a catalyst.
 Biodiesel is the only alternative fuel that has passed all of the EPA clean air fuel requirements.
 Biodiesel is fully compatible with any diesel engine. It has been tested more thoroughly than
any other alternative fuel.
 Biodiesel is safe to handle and is biodegradable.
 Best of all, Biodiesel can be made quite easily using recycled waste vegetable oil.
ADVANTAGES OF BIODIESEL
Biodiesel benefits compared to petroleum diesel
 Using a waste product as an energy source
 Clean burning: lower in carbon monoxide, and carcinogens
 Lower in sulfur compounds
 Significant carbon dioxide reductions: less impact on global climate change
 Domestically available: 30 million gallons of waste restaurant grease are produced annually in
US
Biodiesel benefits compared to petroleum diesel
 Biodiesel can be readily mixed with diesel fuel in any proportion. For example B100 contains
100% biodiesel, B20 contains 20%
 Biodiesel can be run in any unmodified engine
 Biodiesel is less flammable than diesel. It will get at a higher temperature (typically around 20F)
and thus should be mixed with petroleum fuel in cold weather
DISADVANTAGES OF BIODIESEL
• Cold handling and storage of B100
• soybean based biodiesel start to crystallize at 0
C
• Oxidative stability
• old fuel can become acidic and form sediments and varnish
• Excellent solvent
• replace natural rubber components
Combustion Testing Of B-20 Blend In Burning Equipment
1. NOx reductions
2. Combustion stability with the Biodiesel blend is as good as conventional oil
3. Sulfur Oxide emissions reduced by 83%, (blended 20%)
4. Smoke numbers are lower with Biodiesel blend than the home heating oil when the
same burner air setting is used
5. Fuel oil and combustion odors are improved with the biodiesel blend
What will happen when I use Biodiesel
•At 20% Biodiesel your vehicle will not create smoke or soot.
•You will feel a power boost up because Biodiesel will clean up your injectors and
because it is oxygenated

2. •You will get better mileage because the smoke created by a diesel engine is unburned
fuel with Biodiesel there is little unburned fuel
Clean Power
•Biodiesel Contains Virtually No Sulfur
•Biodiesel Contains No Polycyclic Aromatic Hydrocarbons
•Biodiesel Is Carbon Negative and results in reducing Carbon Dioxide in the Atmosphere
•Biodiesel Contains Virtually no Halogens
Renewable Energy
•Biodiesel is made from Soybeans and are a big part of Agricultural America
•The Market for Soy Bean Oil is reducing because of the elimination of Trans Fats in
American Diets.
•We and Increase the rate of growth of the Biodiesel Market for the next five years and
not impact the Soy market
Bio diesel Production Basics
 Three basic routes
 Base catalysed transestrification
 Acid catalysed transestrification
 Conversion of oil to fatty acids and then to Easter by acid catalysis
CH2
CH OOC R2
CH2
3R'OH
Catalyst
60-700
C
R1
CH2
CH
CH2
OH
OH
OOC R1
OOC R3
COO R'
R3 COO R'
R2 COO R'
OH
Titration
 When oil is fried too hot too long, the fatty acids break off, acidifying the oil.
 Titration is necessary to determine the acidity of oil.
 Use a stock solution of known strength, and phenolphthalein indicator.
 Creates a 1/1000 scale reaction.

3. Typical Biodiesel Generation
Problem associated with Bio-diesel Production
1. Conventionally, biodiesel is produced using homogeneous mineral acid or alkali catalysts.
2. In addition to the corrosion problems, these homogeneous catalyst-based processes involve elaborate
process steps for removal of FFAs and water from the feedstock and catalyst from the products.
3. When FFAs are present, they react with the homogeneous alkali catalysts, form unwanted soap by-
products and deactivate the catalyst.
4. In addition, water, sometimes present in non-edible, unrefined or waste vegetable oils also leads to
the deactivation of homogeneous catalysts.
5. It has been reported that water should be kept below 0.06% and FFAs should be kept below 0.5 wt%
to get the best conversions.
Difficulty with Basic catalysts
Vegetable oils and fats may contain small amounts of water and free fatty acids (FFA). For an alkali-
catalyzed transesterification, the alkali catalyst that is used will react with the FFA to form soap.

4. Soap lowers the yield of the biodiesel and inhibits the separation of the esters from the glycerol. In
addition, it binds with the catalyst meaning that more catalyst will be needed and hence the process will
involve a higher cost.
Difficulty Involves with Acid Catalysts
Water, originated either from the oils and fats or formed during the saponification reaction, retards the
transesterification reaction through the hydrolysis reaction. It can hydrolyze the triglycerides to
diglycerides and forms more FFA.
However, the FFA can react with alcohol to form ester (biodiesel) by an acid-catalyzed esterification
reaction. This reaction is very useful for handling oils or fats with high FFA.
Normally, the catalyst for this reaction is concentrated sulphuric acid. Due to the slow reaction rate and
the high methanol to oil molar ratio that is required, acid-catalyzed esterification has not gained as
much attention as the alkali-catalyzed transesterification.
Quality control
1. To ensure safe operation in diesel engines, the most important aspects of the biodiesel
product are the completion of the reaction, the removal of the free glycerol, residual catalyst
and alcohol, and the absence of free fatty acids.
2. If the transesterification reaction is not complete then triglycerides, diglycerides, or
monoglycerides may be left in the final product. Chemically, each of these compounds contains
a glycerol molecule. Fuel with excessive free glycerol may plug the fuel filters and cause
combustion problems in the diesel engine. Therefore, the ASTM standard requires the total
glycerol to be <0.24% of the final biodiesel product.

5. Storage of biodiesel product
1. The temperature of stored biodiesel should be controlled so as to avoid the formation of
crystals which can plug fuel lines and fuel filters. For this reason, the storage temperature of
most pure biodiesel is generally kept between 7 and 10 C. Even in extremely cold climates,
underground storage of pure biodiesel
usually provides the storage temperature necessary for preventing
crystal formation.
2. Stability of biodiesel is an important property when it is to be stored for a prolonged period.
Poor stability can lead to an increased acid value and fuel viscosity and to the formation of
gums and sediments. Therefore, if the duration
of storing biodiesel or biodiesel blends is more than 6 months,
it should be treated with an antioxidant additive.
3. Water contamination will lead to biological growth in the fuel, it should be minimized in the
stored fuel by using biocides.
Main factors affecting the yield of biodiesel
Alcohol quantity: (1:6)
1. Theoretically, the ratio for transesterification reaction requires 3 mol of alcohol for 1 mol
of triglyceride to produce 3 mol of fatty acid ester and 1 mol of glycerol.
2. An excess of alcohol is used in biodiesel production to ensure that the oils
or fats will be completely converted to esters and a higher alcohol
triglyceride ratio can result in a greater ester conversion in a shorter
time.
3. The yield of biodiesel is increased when the alcohol triglyceride ratio is raised beyond 3 and
reaches a maximum. Further increasing the alcohol amount beyond the optimal ratio will not
increase the yield but will increase cost for alcohol recovery
4. When the percentage of free fatty acids in the oils or fats is high, such
as in the case of waste cooking oil, a molar ratio as high as 15:1 is needed when using acid-
catalyzed transesterification.

6. JATROPHA THE ANSWER?
• Jatropha (Jatropha curcas, Ratanjyot, wild castor) thrives on any type of soil
◦ Needs minimal inputs or management. Has no insect pests, not browsed by cattle
or sheep
◦ Can survive long periods of drought, Propagation is easy
◦ Rapid growth; forms a thick live hedge after only 9 months of planting.Yield from
the 3rd
year onwards and continues for 25-30 years
◦ Yield from established plantations in Brazil, 1.5 to 2.3 tons per hectare, 25% oil
from seeds by expelling; 30% by solvent extraction.The meal after extraction an
excellent organic manure (38% protein)
Fe
C
C
C
C
C
N
N
N N
N
H2O
Fe
C
C
C
C
C
N
N
N N
N
H2O
Zn
Zn
Zn
OH2
H2O
H2O
t
BuOH
Bio-Fuel from Renewable Feedstock Vegetable Oil
Margarine oil and ethanolysis products fatty acid ethyl ester and colorless by-
product glycerol