abio diesel first report

7/28/2019 Abio Diesel First Report

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ABSTRACT

Bio-diesel has become more attractive recently because of its environmental benefits

and the fact that it is made from renewable resources. There are four primary ways to use

vegetable oil: direct use and blending; micro emulsions; thermal cracking (pyrolysis); and

bio diesel production by trans-esterification. The most commonly used method is trans

esterification of vegetable oils and animal fats into bio-diesel. Trans-esterification converts

the vegetable oil into methyl or ethyl esters, which will be used as diesel engine fuels. In the

current work, bio-diesel was processed from used and un-used palm oil. The various

properties of bio diesel and blends of diesel and bio-diesel were estimated. Performance were

conducted on a Twin cylinder diesel engine using diesel, bio-diesel and there blends. The

main hurdle to commercialization of bio-diesel is its cost. Usage of used cooking oils as

raw material adaptation of continuous trans-esterification process, and recovery of high

quality glycerol as by product may be options to be considered to lower the cost of bio-diesel.


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INTRODUCTION

The global pollution situation is worsening day by day. One of the major

causes for this condition is the overwhelming consumption of fossil fuels as power source.

Automotive sector is the major consumer of fossil fuels - mainly petroleum based products.

The fossil fuel resources are depleting at a faster rate and this has lead to a grave situation

because of greater dependence on fossil fuel resources. Automobiles and other industries

pollute the atmosphere with 'green house' gases CO2 and H2O these gases in turn lead

to the increase in global temperature, which ultimately results in melting of the polar ice

caps. This phenomenon is called global warming. Global warming results in the change

of global weather pattern

In addition to the change in global weather phenomenon, fossil fuel pollution is

also the reason for many major health problems. Major health risks due to pollution are

respiratory problems and skin ailments. For example, the Ozone (Os) gas, produced

when the sun acts on hydrocarbons and nitrogen oxides (byproducts of fuel combustion), is

a respiratory irritant that reacts chemically with our body tissues. The short term effects of

ozone are harmful: shortness of breath, chest pain, wheezing and coughing. In the long

term, ozone will lead to lung disease and long term respiratory problems. The American

Lung Association adds that as many as 60,000 premature deaths annually can be

attributed to air pollution. Furthermore about 20% of the total population is annually

exposed to the harmful effects of ozone. Amongst younger children, as many as 27.1 million

children (age 13 and under) are exposed to dangerous levels of ozone. This makes it even

more imperative that responsible citizens look into other alternative sources of fuel for

our automobiles.


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1.1 ALTERNATIVE FUELS

Alternative fuels are environmentally beneficial alternatives to

conventional fuels. The fuels most commonly used for transportation are gasoline and

diesel. The combustion of these hydrocarbon fuels results in the formation and release of

carbon dioxide into the atmosphere. Incomplete combustion results in carbon monoxide.

As mentioned above, the mixture of hydrocarbon and nitrogen oxides with heat and

sunlight results in ground level ozone. All the gases produced are harmful. Carbon

dioxide (CO2), one of the greenhouse gases, contributes potentially to global warming.

Carbon monoxide (CO) can cause harmful effects on the cardiovascular and central

nervous system, and can contribute to the formation of urban smog. Ground level Ozone

damages human health, vegetation and is a key component of urban smog.

The Clean Air Act, established by the US Environmental Protection Agency

(EPA), sets the acceptable levels called the National Ambient Air Quality Standard. This

standard sets the measures to control the air concentrations and emissions of these

common air pollutants. These controls are falling behind with the increasing number of

automobile usage especially in the larger cities. Therefore, in an effort to make the

environment free from these toxic by-products (carbon-dioxide, carbon-monoxide and ground

level ozone), we must look into alternative fuels.

Different types of alternative fuels are:

Compressed Natural Gas (CNG)

Liquefied Petroleum Gas (LPG)

Liquefied Natural Gas (LNG)

Hydrogen - 1C engines and Fuel Cells

Hybrid Energy Systems

Vegetable oils


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Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG)

became the first choice as clean fuels for implementation in metropolitan cities, where the

pollution from conventional fuels was intolerable and proved to be a serious health

hazard. But storage, distribution infrastructure and safety considerations are more in

this case. Leakage of these fuels causes fire accidents.When leaks occur, CNG and LPG

will be in gaseous state and readily forming a combustible mixture.

Another alternative fuel is Hydrogen. It is being explored for use in

combustion engines and fuel-cell electric vehicles. It is a gas at normal temperatures

and pressures, which presents greater transportation and storage hurdles than the

existing liquid fuels. Storage systems being developed include compressed hydrogen,

liquid hydrogen, and metallic hydride storage material. Hylhane, a combination of 15

percent hydrogen and 85 percent natural gas, is being tested in metal lattice storage

systems.

Hydrogen can be admitted into the engine cylinder in three ways; -

Carburetion or valve controlled flow into the intake manifold directly from hydrogen

cylinder or hydride storage

Manifold hydrogen injection

Direct in-cylinder injection.

Since hydrogen is a low density gas it occupies a significant volume

proportion in the intake manifold thus reducing the volumetric efficiency and hence the

output decreases by about 25% relative to liquid gasoline. Back firing is an important

drawback of hydrogen.

A fuel cell is controlled chemical- electro energy conversion device that

continuously converts chemical energy into electrical energy. A fuel cell requires

continuous supply of a fuel and an oxidant and generates DC electric power

continuously. Unlike a battery, a fuel cell does not run down or require recharging. They


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have an efficient, inherently clean option for generating electricity and can be

fabricated in a wide range of sizes. No air pollutants are produced in this process.

The word hybrid means something that is mixed together from two things.

Hybrid energy systems combine different power generation devices or two or more fuels for

the same device. When integrated, these systems overcome limitations inherent in either

one. Hybrid energy systems may feature lower fossil fuel emissions, as well as continuous

power generation for times when intermittent renewable resources, such as wind and

solar, are unavailable. Hybrid systems can be designed to maximize the use of renewable,

resulting in a system with lower emissions than those of traditional fossil fueled

technologies. Hybrid energy systems can offer solutions to customers that individual

technologies cannot match. Hybrid systems offer market-entry strategies for technologies

that currently cannot compete with the lowest-cost traditional options.

Vegetable oils are one of the most important alternative fuels for diesel

engines having possibility to use as decentralized energy. The engine running on

vegetable oils emits non-toxic gases into atmosphere, which is a very important advantage.

Vegetable oils provides a complete energy package for all categories of consumers and

can be used as an alternative to diesel, kerosene, coal, LPG and firewood. The direct use

of vegetable oils as engine fuels create problems due to there high viscosity and density.

An alternative lucrative solution that has come up is to produce bio-diesel out of them which

could be used directly or blended with diesel in various proportions.

1.2 BIO-DIESEL

Bio-diesel is an alternative fuel formulated exclusively for diesel engines. Bio-diesel is made

from renewable biological sources such as vegetable oil, animal fats and other agricultural

products. It is biodegradable, non-toxic and possesses low emission profiles. Bio-diesel ismuch cleaner than fossil fuel diesel. It can be used in any diesel engine with no major

modifications - in fact diesel engines run better and last longer with bio-diesel. Bio-diesel fuel

burns up to 75% cleaner than conventional diesel fuel made from fossil fuels. It

substantially reduces unburned hydrocarbons, carbon monoxide and particulate matter

in exhaust fumes. Bio-diesel contains no Sulphur. It is plant-based and adds no COzto the

atmosphere. The ozone-forming potential of bio-diesel emissions is nearly 50%


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less than conventional diesel fuel. Nitrogen oxide (NOX) emissions may

increase or decrease but can be reduced to well below conventional diesel fuel levels by

adjusting engine timing and other means. The fuel economy is same as the diesel fuel.

High cetane rating improves the engine performance. According to a comparative life-cycle

study by the US Department of Energy's National Renewable Energy Laboratory, bio-

diesel requires only 0.31 units of fossil energy to make 1 unit of fuel.

Bio-diesel can be mixed with petroleum diesel in any percentage, from 1 to

99, which is represented by a number following a B. For example, B5 is 5 percent bio-diesel

.with 95 percent petroleum, B20 is 20 percent bio-diesel with 80 percent petroleum, or B100 is

100 percent bio-diesel.

Bio-diesel is one of the many alternative fuel options that can help reduce oil

dependence and global warming pollution. Using high percentage blends of bio-diesel

in an existing diesel vehicle offers clear green-house-gas benefits and reductions in most

criteria air pollutants and air toxics compared with petroleum based diesel. Using B20 in all

highway diesel engines would reduce highway petroleum fuel use less than 5%. To

make a significant impact on petroleum use and global warming emissions, bio-diesel

needs to be used in higher blends.

To make bio-diesel fuel efficiently from used vegetable oils and animal fats

we have to avoid one major problem: soap formation. Soap is formed during base-

catalyzed trans-esterification, when sodium ions combine with free fatty acids present in

used vegetable oils and animal fats. The soaps diminish the yield because they bond the

methyl esters to water. The bonded esters get washed out at the washing stage but make

water separation more difficult and increase water consumption. This process takes care of

the free fatty acids.

Pure bio-diesel (B100) has a solvent effect, which may release deposits

accumulated on tank walls and pipes from previous diesel fuel use. With high blends of bio-

diesel, the release of deposits may clog filters initially and precautions should be taken to

replace fuel filters until the petroleum build-up is eliminated.


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The main operating issues are cold weather operability, engine and fuel system

compatibility, and the solvency properties of bio-diesel. B100 does not flow as well as

petroleum diesel in cold temperatures, and requires special additives or fuel heating

systems to operate in colder climates. B100 may cause rubber seals and gaskets from

engines wear faster or fail. Bio-diesel also acts as a solvent, which can dissolve sediments

in diesel fuel tanks and clog fuel filters during an initial transition from petroleum diesel.

Despite these issues, some fleets are successfully using B100.

Many standardized procedures are available for production of bio diesel. The

commonly used methods are:

1. Blending

2. Micro Emulsification

3. Trans-esterification

4. Thermal Cracking (Pyrolysis)

1.2.1 Blending

Vegetable oil can be directly mixed with diesel fuel and may be used for

running an engine. The blending of vegetable oil with diesel fuel were experimented

successfully by various researchers. A diesel fleet was powered with a blend of 95%

filtered used cooking oil and 5% diesel in 1982. In 1980, Caterpiller Brazil Company used

pre-combustion chamber engines with a mixture of lO% vegetable oil to maintain total

power without any modification to the engine. A blend of 20% oil and 80% diesel was

found to be successful. It has been proved that the use of 100% vegetable oil was also

possible with some minor modifications in the fuel system. The high fuel caused the

major problems associated with the use of pure vegetable oils as fuel viscosity incompression ignition engines. Micro-emulsification, pyrolysis and trans-esterification are

the remedies used to solve the problems encountered due to high fuel viscosity.

1.2.2Micro Emulsification:


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To solve the problem of high viscosity of vegetable oil, micro emulsions

with solvents such as methanol, ethanol and butanol have been used. A micro emulsion is

defined as the colloidal equilibrium dispersion of optically isotropic fluid micro structures

with dimensions generally in the range of 1-150 nm formed spontaneously from two

normally immiscible liquids and one or more ionic or non-ionic amphiphiles. These can

improve spray characteristics by explosive vaporization of the low boiling constituents in

the micelles. All micro emulsions with butanol, hexanol and octanol will meet the maximum

viscosity limitation for diesel engines. Czerwinski prepared an emulsion of 53% sunflower oil,

13.3% ethanol and 33.4% butanol. This emulsion had a viscosity of 6 .3 centistokes at

40 C, a cetane number of 25. Lower viscosities and better spray patterns were observed

with an increase in the percentage of butanol

1.2.3Trans-Esterification

Trans-esterification (also called alcoholysis) is the reaction of a fat or oil with

an alcohol to form esters and giycerol. A catalyst is usually used to improve the reaction

rate and yield. Because the reaction is reversible, excess alcohol is used to shift the

equilibrium to the products side. Among the alcohols that can be used in the trans-

esterification process are methanol, ethanol, propanol, butanol and amyl alcohol.

Methanol and ethanol are used most frequently, especially methanol

because of its low cost and its physical and chemical advantages. The reaction can be

catalyzed by alkalis, acids, or enzymes. The alkalis include sodium hydroxide (NaOH)

and potassium hydroxide (KOH). Sulfuric acid, sulfonic acids and hydrochloric acid are

usually used as acid catalysts. Alkali-catalyzed trans-esterification is much faster than

acid-catalyzed trans-esterification and is most often used commercially. Low free fatty acid

content in triglycerides is required for alkali-catalyzed trans-esterification. If more water and

free fatty acids are present in the triglycerides, acid catalyzed trans-esterification can be

used.

Trans-esterification is a multi-step process. The overall reaction is:


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Rl, R2, and R3 are fatty acid alkyl groups (could be different, or the same), and depend on

the type of oil. The fatty acids involved determine the final properties of the bio-diesel

(cetane number, cold flow properties, etc.)

1.2.4 Thermal Cracking (Pyrolysis)

Cracking is the process of conversion of one substance into another by means of heat or

with the aid of catalyst. It involves heating in the absence of air or oxygen and cleavage

of chemical bonds to yield small molecules. The pyrolyzed material can be vegetable

oils, animal fats, natural fatty acids and methyl esters of fatty acids. The pyrolysis of fats

has been investigated for more than 100 years, especially in those areas of the worldthat lack deposits of petroleum [5]. Since World War I, many investigators have studied

the pyrolysis of vegetable oil to obtain products suitable for engine fuel application. Tung

oil was saponified with lime and then thermally cracked to yield crude oil, which was refined

to produce diesel fuel and small amounts of gasoline and kerosene.

1.2.5 Factors Affecting Bio-diesel Production

In trans-esterification of vegetable oils, a triglyceride reacts with three

molecules of alcohols in presence of catalyst, producing a mixture of fatty acid alkyl

esters and glycerol. The overall process is a sequence of three consecutive reactions,


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in which die and mono-glycerides are formed as intermediates. Trans-esterification is a

reversible reaction; thus excess alcohol is used to increase the yields of the alkyl esters

and allow its phase separation from glycerol formed. Conversion of vegetable oil to bio-

diesel is affected by several parameters namely,

Reaction temperature, Reaction ratio (molar ratio of alcohol to vegetable oil), Catalyst, Reaction time,

Presence of free fatty acid and moisture

Reaction Temperature

The rate of reaction is strongly influenced by the reaction temperature. However,given enough time the reaction will proceed to near completion even at room temperature.

Reaction Ratio

Another important factor affecting the yield of ester is molar ratio of alcohol to

vegetable oil. The stoichiometric of the trans-esterification requires three moles of alcohol

per mol of triglyceride to yield three moles of fatty esters and one mole of glycerol. To shift

the trans-esterification reaction in forward direction, it is necessary to use either an

excess amount of alcohol or to remove one of the products from the reaction mixture.

The second option is preferred where ever feasible, since the reaction can drive towards

completion. A molar ratio of 6:1 is normally used in industrial processes to obtain methyl

ester yields higher than 98 % by weight.

Catalyst

Catalysts are classified as alkali, acid or enzyme. Alkali-catalyzed trans-

esterification is much faster than acid-catalyzed trans-esterification. However a

triglyceride has higher free fatty acid content and more water,pretreatment is required.


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Base catalyzed trans-esterification is commonly used due to faster esterification and partly

because alkaline catalysts are less corrosive to industrial equipments than acidic catalysts.

The alkaline catalyst concentration in the range of 0.5 to 1% by weight yields 94 to 99% conversion of vegetable oil into esters. Further, increase in catalyst concentration does not

increase the conversion and it adds costs because it is necessary to remove it from the

reaction medium at the end.

Reaction Time

The conversion rate increases with reaction time. The reaction was very slow

during the first minute due to the mixing and dispersion of methanol into the vegetable oil.

From one to five minute the reaction proceeded very fast.

Presence of Moister and Free Fatty Acid

Starting materials used for alkali trans-esterification of triglycerides must

meet certain specifications. The glyceride should have an acid value less than 1 and should

be substantially anhydrous. If the acid value is higher than 1, more catalyst is required for

neutralize the fatty acid. Presence of water causes soap formation, which consumescatalyst and reduces catalyst efficiency. The resulting soap causes an increase in viscosity,

formation of gels and makes separation of glycerol difficult,

1.3 PROPERTIES OF BIO-DIESEL

The important fuel properties are viscosity, flash point, fire point, density,

cloud point, pour point, and calorific value.

1.3.1 Viscosity


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Viscosity of a fluid is a measure of resistance to flow. Standard measuring

instruments like the Redwood viscometer, and the Saybolt viscometer and standard

procedure are used to measure the time required for a fixed volume of fluid to flow through

an orifice of fixed dimensions at a certain temperature .The result is usually expressed as

the number of seconds required for the flow.

Viscosity is one of the most important criteria of fuel oils. This property

directly affects the engine's operation and combustion process, whose efficiency depends

on the maximum power developed by the engine. The purpose of controlling viscosity is to

allow for the good atomization of the oil and for the preservation of its lubricating

characteristics. Alterations in the viscosity may lead, among other things, to excessive

wear of the self-lubricated parts of the injection system, leaking of the fuel pump,

incorrect atomization in the combustion chamber, and damage to the pistons

1.3.2 Flash and Fire Point

The flash point of a flammable liquid is the lowest temperature at which it can

form an ignitable mixture with oxygen. At this temperature the vapor may cease to burn

when the source of ignition is removed. A slightly higher temperature, the fire point, is

defined at which the vapor continues to burn after being ignited. Neither of these

parameters is related to the temperatures of the ignition source or of the burning liquid,

which are much higher. The flash point is often used as one descriptive characteristic of

liquid fuel, but it is also used to describe liquids that are not used intentionally as fuels.

The flash point can be used to determine the transportation and storage temperature

requirements for fuel

1.3.3 Cloud and Pour Point

The pour point is defined as temperature 3C higher than that at which the

oil ceases to flow when cooled and tested according to prescribed conditions. The

cloud point of the fuel is the temperature at which crystals of paraffin wax first appear.

1.3.4 Calorific Value


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The quantity of heat evolved by the combustion of unit quantity of

the fuel is its calorific value or heating value. If the calorific value of the fuel is high, power

output of the engine will be high and the fuel economy can be achieved.

1.4 LITERATURE REVIEW

Milford A Hanna et. al. [1] reviewed many standardized procedures available

for the production of bio-diesel fuel oil Considerable research has been done on

vegetable oils as diesel fuel. That research included palm oil, soybean oil, sunflower oil,

coconut oil, rapeseed oil and tung oil. Animal fats, although mentioned frequently, have not

been studied to the same extent as vegetable oils. Some methods applicable to vegetable

oils are not applicable to animal fats because of natural property differences.

A. S, Ramadhas et.al. [2] had reviewed the production and

characterization of vegetable oil as well as the experimental work carried out in various

countries in this field. In addition, the scope and challenges being faced in this area of

research are clearly described. In this paper he described the different methods of bio-

diesel production and the important characteristics of good vegetable oil required to

substitute diesel fuel. He concluded that the thermal efficiency was comparable to that

of diesel with small amounts of power losswhile using vegetable oils. The particulate

emission of vegetable oils is higher than that of diesel fuel with a reduction in NOX

A Duran et.al [3] studied the impact of bio-diesel chemical structure,

specifically fatty acid composition on particulate matter formation, particularly on the

retention of hydrocarbons by soot due to the scrubbing effect and absorption processes.

The values of parameters related to the scrubbing effect and the absorption process were

evaluated.

Mohamad I. Al-Widyan et.al. [4] Investigated the potential of ethyl ester used as

vegetable oil (VO; bio-diesel) to substitute oil-based diesel fuel. The fuels tested were

several ester/diesel blends including 100% ester in addition to diesel fuel, which served as

the baseline fuel. Variable-speed tests were run on all fuels on a standard test rig of a


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single-cylinder, direct-injection diesel engine. Tests were conducted to compare these

blends with the baseline local diesel fuel in terms of engine performance and exhaust

emissions. The results indicated that the blends burned more efficiently with less specific

fuel consumption, and therefore, resulted in higher engine thermal efficiency.

X Lang et.al. [5] prepared methyl, ethyl, 2-propyl and butyl esters from Canola

and Linseed oils through trans-esterification using KOH as catalyst. In addition methyl and

ethyl esters were prepared from rapeseed and sunflower oils using the same method.

Chemical composition of the esters was determined. The bio-diesel esters were

characterized for their physical and fuel properties including viscosity, iodine value,

acid value, cloud point, pour point, heat of combustion and volatility.

Ulf Schuchardt et.al. [6] studied the trans-esterification of rapeseed oil with

methanol in the presence of eight substituted cyclic and acyclic guanidines and

compared with un substituted guanidine. Give the gas chromatographic analysis of

rapeseed oil and investigate the conversion of bio-diesel from rapeseed oil as a function of

time.

A.S. Rarnadhas et.al. [7] developed a two-step trans-esterification process to

convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification

reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed

trans-esterification process converts the products of the first step to its mono-esters and

glycerol. The major factors affect the conversion efficiency of the process such as

molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed.

The two-step esterification procedure converts rubber seed oil to its methyl esters. The

viscosity of bio-diesel oil is nearer to that of diesel and the calorific value is about 14% less

than that of diesel. The important properties of bio-diesel such as specific gravity, flash point,

cloud point and pour point are found out and compared with that of diesel.

M.A. Kalam, et.al [8] carried out experimental work to evaluate the exhaust

emissions characteristics of ordinary Malaysian coconut oil blended with conventional

diesel oil fueled in a diesel engine. The results showed that the addition of 30%


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coconut oil with conventional diesel produced higher brake power and net heat release

rate with a net reduction in exhaust emissions such as HC, NOx, CO, smoke and polycyclic

aromatic hydrocarbon (PAH). Above 30% blends, such as 40 and 50% blends, developed

lower brake power and net heat release rate were noted due to the fuels lower calorific

value.

Herchel T.C. Machacon et.al [9] experimentally studied the effects of pure

coconut oil and coconut oil/diesel fuel blends on the performance and emissions of a

direct injection diesel engine. Operation of the test engine with pure coconut oil and

coconut oil/diesel fuel blends for a wide range of engine load conditions was shown to be

successful even without engine modifications. It was also shown that increasing the amount

of coconut oil in the coconut oil/diesel fuel blend resulted in lower smoke and NOx

emissions. However, this resulted in an increase in the BSFC. This was attributed to the

lower heating value of neat coconut oil fuel compared to diesel fuel.

Ming Zheng et. al. [10] briefly reviewed the paths and limits to reduce

NOx emissions from diesel engines and highlighted the inevitable use ofEGR. The paths

and limits to reduce NOX emissions from Diesel engines are briefly reviewed, and the

inevitable uses of EGR are highlighted. The impact of EGR on Diesel operations is

analyzed and a variety of ways to implement EGR are outlined. Thereafter, new concepts

regarding EGR stream treatment and EGR hydrogen reforming are proposed.

Deepak Agarwal et. al. [11] investigated on the usage of bio-diesel and EGR

simultaneously in order to reduce the emission of all regulated pollutants from diesel engine.

A two-cylinder, air-cooled, constant speed direct injection diesel engine was used for

experiments. HCs, NOx, CO, and opacity of the exhaust gaswere measured to estimate

the emissions. Various engine performance parameters such as thermal efficiency, brake

specific fuel consumption (BSFC), and brake specific energy consumption (BSEC), etc.

were calculated from the acquired data. Application of EGR with bio-diesel blends resulted in

reductions in NOx emissions without any significant penalty in PM emissions or BSEC,


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Shay E G [12] investigated oil from algae, bacteria and fungi. This report will

review some of the results obtained from using vegetable oils and their derivatives as fuel in

compression ignition engines and examine opportunities for their broader production and

use. It will include some historic background, as well as current and potential yields of

candidate crops, the technology and economics of vegetable oil conversion to diesel fuel,

the performance of various oils, the potential inherent in diesel fuel co production,

environmental considerations, and other research opportunities. Vegetable oils will not

entirely displace petroleum as a source of diesel fuel. There are, however, technical,

economic, and environmental considerations that can lead to their wider use in this

application.

A.S. Ramadhas et.al, [13] experimentally investigate the important properties of methyl

esters of rubber seed oil and are compared with the properties of other esters and diesel.

Pure rubber seed oil, diesel and bio-diesel are used as fuels in the compression ignition

engine and the performance and emission characteristics of the engine are analyzed. The

lower blends of bio-diesel increase the brake thermal efficiency and reduce the fuel

consumption. The exhaust gas emissions are reduced with increase in bio-diesel

concentration. The experimental results proved that the use of bio-diesel (produced from

unrefined rubber seed oil) in compression ignition engines is a viable alternative to diesel.

In this paper he explained the demerits of direct use of vegetable oil as fuel and

Ayhan Demirba [14] investigated different methods for bio-diesel production and compared

the results other methods like micro emulsions of vegetable oil. The methods used were

microemulsion, pyrolysis, catalytic trans-esterification and Supercritical methanol trans-

esterification method. Also gave comparison of methyl and ethyl esters, and discussed about

bio-diesel economy. He concluded that, direct

use of vegetable oil as a fuel is not economical. Specific weight is higher for bio-diesel,

heat of combustion is lower and viscosities are higher. The esters all have

higher levels of injector coking than diesel fuel.


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From the above literature survey it was found that trans-esterification is the

best method for bio-diesel production. The bio-diesel production from unused oil is not

economical. So bio-diesel from used oil is most economical and the most common oil used in

restaurants is palm oil. Pre-treatment with hexane is a new method. So the pre-treatment

was opted for in this project.

OBJECTIVE AND METHODOLOGY

2.1 OBJECTIVE

The main objective of the project is to process bio-diesel from used and unused

palm oil. It also aims at determination of properties of the bio-diesel produced. Further the

project also aims to experimentally analyze the performance of bio-diesel and blends in a twin

cylinder diesel engine. Also this project aims at the fabrication of bio-diesel processing setup

for producing 1L bio-diesel

2.2 METHODOLOGY

Production of Bio-diesel from Pure Palm Oil

Production of Bio-diesel from Waste Palm Oil.

Determination of Properties

Performance Test

Comparision of performance with blend


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CHAPTER-3

BIO-DIESEL PRODUCTION AND PROPERTY DETERMINATION

The current work was aimed at producing bio-diesel from pure and used palm oil.

The method for bio-diesel production is described below. The basic method is alkali based

trans-esterification. But in the case of used oil this method gave fewer yields. So an

alternative method was used. After production the samples' properties were tested.

Crude Palm Oil and Refined Palm Oil are the most traded vegetable oil in the

world today. Pure palm oil contains low free fatty acid so base catalyzed trans-esterification is

the best method. This process has high efficiencies and produces high quality fuels, after

removal of excess methanol, base catalyst and glycerin.


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The basic chemistry of the reaction requires three molecule of methanol for

every molecule of triglyceride. The catalyst ratio is roughly 10% of the methanol mass.

Small amounts of free fatty acids are converted into soaps. These soaps are typically

removed with the glycerin. The typical trans-esterification process is run at standard

atmosphere and temperatures around 60C. The fatty acid composition in palm oil is:

Lauric 0.1

Myristic 1.

Palmitic 42.8

Stearic 4.5

Oliec 40.5

Linoleic 10.1

Linolenic 0.2

3.1 BIO-DIESEL PRODUCTION FROM PURE PALM OIL

MethanolCatalystWaste Oil Processor

Heat

Mixing

Chamber

Mixing

Chamber

Processor

Allow

Oil to separate

Bio-diesel

Glycerin

Bio-dieselGlycerin


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In the present work bio-diesel is produced by base catalyzed trans-esterification

of pure palm oil. Potassium Hydroxide (KOH) is used as catalyst. For 100 ml of palm oil

about 15 ml methanol and Igm KOH is used. Palm oil is first heated about 50C. KOH is

dissolved in methanol and then added to the heated oil. The process is done in a

magnetic stirrer with heater. The above solution is heated and stirred for 30 minutes. The

temperature should be 50-60 C. About 3 to 4 hours is needed for separation for bio-diesel

and glycerin. The bio-diesel is separated from glycerin. The yield of bio-diesel from pure

palm oil is about 90%. After washing it in water, it could be used directly in diesel engine.

3.2BIO-DIESEL PRODUCTION FROM USED PALM OIL

Used oil has high free fatty acid content. Due to high free fatty acid content and

water content normal alkali based trans-esterification is not feasible. The conventional method

used is acid based trans-esterification. Sulfuric acid and hydrochloric acid are commonly used

catalyst for acid based trans-esterification. For acid based trans-esterification processing

time is about 5 hours. A settling time of about 6 hours is required. Ethanol is mixed with

used oil in acid based trans-esterification. But the cost of ethanol is higher than that of

methanol and the yield is also less in this case. The quality of bio-diesel is also less. So this

is not economical. So the conventional method was modified for increasing the yield and

quality of bio-diesel from used oil.

3.2.1 Pre - Treatment Method

Bio-diesel is produced from used palm oil by trans-esterification after pre-

treatment. Normally an acid is used for pretreatment. Acid trans-esterification is not

economical. Since hexane is a solvent for fatty acid, pretreatment by hexane is a suitable

method. The water content in used oil can be removed by using a suitable adsorbent. Silica

gel is the best adsorbent for this. Percentage of hexane added for pretreatment is an important

factor in this case.


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abio diesel first report

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