Preparation of Biodiesel from Waste Cooking Oil

Table of Content


The fuel prices are sky rocketing day by day and fossil fuel are at verge of depletion in coming few decades. Since our country is not self-dependent in energy source and every year huge amount is spent in fulfilling these demands.

So, we should focus on finding new alternate source of energy and government have taken initiative and invested money in the research and development in the field of non-conventional source of energy like solar, wind, biogas, biomass biodiesel etc. In the project we focused on the production of biodiesel from waste cooking oil. Biodiesel is an eco-friendly and also renewable in nature . The preparation of biodiesel from waste cooking oil is cheap and the source is conveniently available from restaurant and hotel.

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Biodiesel is prepared from the trans esterification process which involves two step- acidic esterification in which oil (1litre), solution of sulphuric acid and methanol is heated at 60° C for1-2hours at 350 rpm and in second step, trans esterification reaction is carried out in which above obtained mixture is heated at 50° C with additional amount of methanol and catalyst for 1-2 hours at 350 rpm. After completion of reaction it is kept for settling for 8-10 hrs and glycerol is separated from biodiesel. The prepared biodiesel is tested for some important property of fuel like calorific value, viscosity and density.

The above properties are tested from Mahabal Enviro Engineer Pvt. Ltd. Calorific value, viscosity and density obtained for the prepared fuel are 41812 kJ/k (9990kcal/kg), 5. 49 cSt and 870 kg/ respectively. The values of the above properties found for the biodiesel from waste fried oil are near about similar to the properties of conventional fuel like diesel. so it can be said that this biodiesel can be used as an alternate fuel for diesel. The effect on the performance of diesel engines using biodiesel from waste fried oil as a fuel for diesel engine, will be the future scope of project.


The world consumption of fuels is undoubtedly unstable causing world economic crisis; the worst compared to other economic recession that took place at different era. This factor has urged all nations especially the government and the academics to find another alternatives to replace the usage of petroleum. Therefore there is a rising demand to globally provide renewable energy by means of a sustainable and ethical approach.

Sustainable development is a concept that has become significant and increases the awareness of its necessity. There are many alternatives nowadays. There is three generation of bio-fuel. First-generation bio-fuels are bio-fuels made from sugar, starch, vegetable oil, or animal fats using conventional technology. This feedstock could instead enter the animal or human food chain, and as the global population has risen their use in producing bio-fuels has been criticized for diverting food away from the human food chain, leading to food shortages and price rises.

Second generation bio-fuel production processes are in development. These allow bio-fuel to be derived from any source of biomass, not just from food crops such as corn and soy beans but also from waste cooking oil. Algae fuel, or third generation bio-fuel, is a bio-fuel from algae. Biodiesel (fatty acid methyl ester) is a nontoxic alternative fuel that is obtained from renewable sources. A major hurdle in the commercialization of biodiesel from virgin oil, in comparison to petroleum-based diesel fuel, is its cost of manufacturing, primarily the raw material cost.

Used cooking oil is one of the economical sources for biodiesel production. In this thesis trans-esterification method for preparation of biodiesel is discussed.


Energy is the prime mover of economic growth and is vital to the sustenance of a modern economy. Future economic growth crucially depends on the long-term availability of energy from sources that are affordable, accessible and environmentally friendly. India ranks sixth in the world in total energy consumption and needs to accelerate the development of the sector to meet its growth aspirations.

The country, though rich in coal and abundantly endowed with renewable energy in the form of solar, wind, hydro and bio-energy has very small hydrocarbon reserves (0. 4% of the world’s reserve). India, like many other developing countries, is a net importer of energy, more than 25 per cent of primary energy needs being met through imports mainly in the form of crude oil and natural gas. The rising oil import bill has been the focus of serious concerns due to the pressure it has placed on scarce foreign exchange resources and is also largely responsible for energy supply shortages.

The sub-optimal consumption of commercial energy adversely affects the productive sectors, which in turn hampers economic growth. If we look at the pattern of energy production, coal and oil account for 54 per cent and 34 per cent respectively with natural gas, hydro and nuclear contributing to the balance. In the power generation front, nearly 62 per cent of power generation is from coal fired thermal power plants and 70 per cent of the coal produced every year in India has been used for thermal generation. The distribution of primary commercial energy resources in India is quite skewed. 0 per cent of the total hydro potential is located in the Northern and North-eastern regions, whereas the Eastern region accounts for nearly 70 per cent of the total coal reserves in the country. The Southern region, which has only 6 per cent of the total coal reserves and 10 per cent of the total hydro potential, has most of the lignite deposits occurring in the country. On the consumption front, the industrial sector in India is a major energy user accounting for about 52 per cent of commercial energy consumption.

Per capita energy consumption in India is one of the lowest in the world as shown in Fig. 1. But, energy intensity, which is energy consumption per unit of GDP, is one of the highest in comparison to other developed and developing countries. For example, it is 3. 7 times that of Japan, 1. 55 times that of the United States, 1. 47 times that of Asia and 1. 5 times that of the world average. Thus, there is a huge scope for energy conservation in the country. The main raw material for biodiesel in India is non-edible oils obtained from plant species such as Jatropha Curcas and Pongamia Pinnata etc.

While in India is short of petroleum reserves, it has a large arable land as well as good climatic condition with (tropical) with adequate rainfall in large parts of the area to account for large biomass production each year. Since edible oil demand is higher than its domestic production there no possibility of diverting this oil for the production of biodiesel. Fortunately there is a large chunk of degraded forestland and unutilized public land, field boundaries and fallow lands of farmers where non-edible oil-seeds can be grown. There are many tree species, which are rich in oil.

These will be planted in public lands such as along the railway, roads, and irrigation canals. In India it is estimated that the cost of biodiesel produced by process of trans-esterification process of jatropha curcas oil seeds will be approximately the same of diesel. ?

Brief History about Biodiesel

Trans-esterification of vegetable oils has been in use since the mid-1800’s. More than likely, it was originally used to distil out the glycerin used for making soap. The “by-products” of this process are methyl and ethyl esters.

Biodiesel is composed of these esters. Ethyl esters are grain based while methyl esters are wood based. They are the residues of creating glycerin, or vice versa. Any source of complex fatty acid can be used to create biodiesel and glycerin. Early on, peanut oil, hemp oil, corn oil, and tallow were used as sources for the complex fatty acids used in the separation process. Currently, soybeans, rapeseed (or its cousin, canola oil), corn, recycled fryer oil, tallow, forest wastes, and sugar cane are common resources for the complex fatty acids and their by-product, bio fuels.

Research is being done into oil production from algae, which could have yields greater than any feedstock known today. In 1898, when Rudolph Diesel first demonstrated his compression ignition engine at the World’s Exhibition in Paris, he used peanut oil – the original biodiesel. Diesel believed biomass fuel to be viable alternative to the resource consuming steam engine. Vegetable oils were used in diesel engines until the 1920’s when an alteration was made to the engine, enabling it to use a residue of petroleum – what is now known as diesel .

Diesel was not the only inventor to believe that biomass fuels would be the mainstay of the transportation industry. Henry Ford designed his automobiles, beginning with the 1908 Model T, to use ethanol. Ford was so convinced that renewable resources were the key to the success of his automobiles that he built a plant to make ethanol in the Midwest and formed a partnership with Standard Oil to sell it in their distributing stations. During the 1920’s, this bio fuel was 25% of Standard Oil’s sales in that area. With the growth of the petroleum industry Standard Oil cast its future with fossil fuels.

Ford continued to promote the use of ethanol through the 1930’s. The petroleum industry undercut the bio fuel sales and by 1940 the plant was closed due to the low prices of petroleum. Despite the fact that men such as Henry Ford, Rudolph Diesel, and subsequent manufacturers of diesel engines saw the future of renewable resource fuels, a political and economic struggle doomed the industry. Manufacturing industrialists made modifications to the diesel engines so they could take advantage of the extremely low prices of the residual, low-grade fuel now offered by the petroleum industry.

The petroleum companies wanted control of the fuel supplies in the United States and, despite the benefits of biomass fuel verses the fossil fuels, they moved ahead to eliminate all competition. By the 1970’s, we were dependent on foreign oil. Our supply of crude oil, as are all supplies of fossil fuels, was limited. In 1973 we experienced the first of two crises. OPEC, the Middle Eastern organization controlling the majority of the oil in the world, reduced supplies and increased prices. The second one came five years later in 1978.

As was noted in the Diesel Engine section, automobile purchasers began to seriously consider the diesel car as a option. What is more, people began making their own bio fuel. The potential of bio fuels re-entered the public consciousness. The years since have brought many changes. Over 200 major fleets in the United States now run on biodiesel with entities such as the United States Post Office, the US Military, metropolitan transit systems, agricultural concerns, and school districts being major users.

The biodiesel produced today can be used in unmodified diesel engines in almost all temperatures. It can be used in the individual automobile or larger engines and machines. The base biomass comes from soybeans and corn in the Midwest with tallow from the slaughter industries becoming a third source. Sugar cane provides the biomass for Hawaii and forest wastes are becoming a source in the Northwest. The embargo on Cuba halted oil importation depriving it of heating oil. They discovered that recycled fryer oil made a good biomass for fuel.

Today, the fast food industry is the one of the largest and fastest growing industries in the United States and, in fact, the world. This industry can provide a major resource for bio fuels – the recycled fryer oil. The Veggie Van travelled 25,000 miles around the United States on recycled fryer oil as did a group of women. In Europe at this time, there is an option for biodiesel in many gas stations and vehicles that use diesel are readily available. Over 1000 stations in Germany alone offer biodiesel for their customers.

Over 5% of all of France’s energy uses are provided by biodiesel. Journey to Forever, a non-government organization, travelled from Hong Kong to Southern Africa producing their own biodiesel along the way and teaching the people of the small hamlets and villages how to make their own bio fuel for use in their heaters, tractors, buses, automobiles, and other machines they might have. We have the opportunity and the resources to shed our dependence on foreign oil, if we choose. As in the 1930’s, we are faced with tremendous political and economic pressure creating similar challenges.

The enormous influence of the petroleum industries and other industries that might be threatened and/or impacted by a resurgence of the renewable, biomass, and associated industries is being felt on all levels. One only needs to look to Washington to see how that pressure is being played out. It is a time of choice and one in which small actions can lead to greater impact. Biodiesel remains in the political and economic arena and is playing a part in this process as the awareness alternative fuel spreads through the consciousness of the general public.


A variety of oils can be used to produce biodiesel are: 1. Edible oil feedstock such as rapeseed oil, soybean oil, mustard oil, sunflower oil, palm oil etc. can be used. 2. Non-edible oil feed stocks such as Jatropha, Pongamia, castor etc. 3. Waste vegetable oil from restaurant 4. Animal fats including tallow,lad,yellowgrease,chicken,and omega-3fatty acids from fish oils 5. Algae that can be grown using waste material such as sewage and without displacing land currently used for food production The selection of the appropriate biodiesel feedstock is an important issue.

As mentioned earlier, for India, it appears that non-edible oils are the choice feedstock for biodiesel production. Jatropha curcas seems to be the most potential studies, and no pilot project is available to support the data. Some reports indicate that jatropha gives yields varying 1. 5tons/hectare to as high as 12tons/hectare. However, there are some types of genetic species, which produce high yields of suitable oil. Biotechnology tool can be applied for producing high quality elite planting materials. Tissue culture technology helps in mass production of high quality elite planting material.

Tissue culture help in mass production of elite identified clones.


Vegetable oil The vegetable oil used for biodiesel production must be moisture free because every molecule of water destroys a molecule of the catalyst, thus decreasing its concentration. The FFA content of the oil should be less than 1%. It was observed that lesser the FFA in oil, the better is the biodiesel recovery will depend Upon the of type of oil and amount of sodium hydroxide used. Alcohol Methanol or ethanol, as near to absolute as possible can be used.

As with the oil, the water content of the alcohol affects the extent of conversion enough to prevent the separation of glycerol from the reaction mixture. Catalyst Sodium or potassium hydroxide can be used as the catalyst for trans-esterification The corresponding alkoxide also can be used, but it is prohibitively expensive. The best result is obtained, if the catalyst is 85% potassium hydroxide. The best grade of potassium hydroxide has 14%-15% water, which cannot be removed. It should be low in carbonate because carbonate is not a efficient catalyst and may cause cloudiness in stage final ester.


Trans-esterification, also called alcoholysis, is the displacement of alcohol from ester by another alcohol in a process similar to hydrolysis. This process has been widely used to reduce the viscosity of triglycerides. The trans-esterification reaction is represented by the equation RCOOH’+ R”OH =RCOOR”+R’OH If methanol is used in the preparation then it is called methanolysis. The reaction of triglyceride with methanol is represented by the equation given below. Triglyercideare readily trans esterified in the presence of an alkaline catalyst at atmospheric pressure and at a temperature of approximately 60-70 with excess of methanol.

The mixture in the end of reaction is allowed to settle. The layer of glycerol is drawn off while the methyl ester layer is washed to remove glycerol and is then processed further. The excess methanolyis recovered by distillation and is sent to a rectifying column for purification and recycling. The trans-esterification works well when the starting is high. In cases where the FFA content is above 1% in oil there is difficult due to the process of formation of soap which promotes emulsification during the washing stage, and a FFA content above 2% is unworkable.


R= HYDROCARBON GROUP Fig. 2. 1 Trans-esterification reaction


The entire surface transport of India is based on petroleum fuel, but it’s availability is of growing concern. The production of domestic crude has been declining and the transport system has been increasingly dependent on imported crude oil to meet its needs. There is a growing concern that the world may run out of petroleum based fuel resources. All these make it imperative that the search for alternative fuels is taken right earnest. The alternative fuels aspiring to take the place of petroleum are: 2. . 1 Propane Liquefied petroleum gas (LPG) consists mainly of propane, propylene, butane, and butylene in various mixtures. It is produced as a by-product of natural gas processing and petroleum refining. With propane’s simple molecular composition, propane – fuelled vehicles emit significantly lower levels of carbon monoxide, hydrocarbons and nitrogen oxides than gasoline – fuelled vehicles. The level of air – toxic emissions from propane -fuelled vehicles is also low. According to the National Propane Gas Association, U. S. A. spark plugs from a propane vehicle last from 80,000 to 100,000 miles and propane engines can last two to three times longer than gasoline or diesel engines. 2. 3. 2 Ethanol Ethanol (ethyl alcohol, grain alcohol, ETOH) is a clear, colorless liquid with a characteristic, agreeable odour. Two higher blends of ethanol, E-85 and E-95 are being explored as alternative fuels in demonstration programs. Ethanol is also made into ether, ethyl tertiary-butyl ether (ETBE) that has properties of interest for oxygenated gasoline and reformulated fuels Methanol Methanol (CH3OH) is an alcohol fuel.

As engine fuels, ethanol and methanol have similar chemical and physical characteristics. Methanol is methane with one hydrogen molecule replaced by a hydroxyl radical. It is produced from natural gas in production plants with 60% total energy efficiency. Methanol can be made with any renewable resource containing carbon such as seaweed, waste wood and garbage. This is a promising alternative, with a diversity of fuel applications with proven environmental, economic and consumer benefits. It is widely used today to produce the oxygenate MTBE added to cleaner burning gasoline.

Cars, trucks and buses running millions of miles on methanol have proven its use as a total replacement for gasoline and diesel fuels in conventional engines. 2. 3. 4 Bio diesel Biodiesel (mono alkyl esters) is a cleaner-burning diesel fuel made from natural, renewable sources such as vegetable oils. Just like petroleum diesel, biodiesel operates in combustion-ignition engines. The use of biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter.

It also decreases the solid carbon fraction of particulate matter (since the oxygen in biodiesel enables more complete combustion to CO2), eliminates the sulphate fraction (as there is no sulphur in the fuel), while the soluble, or hydrocarbon, fraction stays the same or is increased. Therefore, biodiesel works well with new technologies such as catalysts (which reduces the soluble fraction of diesel particulate but not the solid carbon fraction), particulate traps, and exhaust gas recirculation (potentially longer engine life due to less carbon). 2. 3. 5 Hydrogen

Hydrogen gas (H2) 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 exist for the liquid fuels. Storage systems being developed include compressed hydrogen, liquid hydrogen, and chemical bonding between hydrogen and a storage material(for example metal hydrides) . While no transportation distribution system currently exists, for hydrogen transportation use, the ability to create the fuel from a variety of resources and its clean-burning properties make it a desirable alternative fuel.

Increasing pollution from cars and airplanes has created smog clouds across the country. Hydrogen, on the other hand, emits no toxins, and is also clean and efficient. 2. 3. 6 Natural Gas (CNG / LNG) Natural gas is a mixture of hydrocarbons-mainly methane (CH4)-and is produced either from gas wells or in conguide with crude oil production. The interest for natural gas as an alternative fuel stems mainly from its clean burning qualities, its domestic resource base, and its commercial availability to end-users.

Natural gas is the cleanest burning alternative fuel. Exhaust emissions from NGVs are much lower than those from gasoline-powered vehicles. For instance, NGV emissions of carbon monoxide are approximately 70 per cent lower, non-methane organic gas emissions are 89 per cent lower, and oxides of nitrogen emissions are 87 per cent lower. In addition to these reductions in pollutants, NGVs also emit significantly lower amounts of greenhouse gases and toxins than do gasoline vehicles. Dedicated NGVs produce little or no evaporative emissions during fuelling and use.

For gasoline vehicles, evaporative and fuelling emissions account for at least 50 per cent of a vehicle’s total hydrocarbon emissions. Dedicated NGVs also can reduce carbon dioxide exhaust emissions by almost 20 per cent vehicles. 2. 3. 7 Solar Fuel Solar energy technologies use sunlight to warm and light homes, heat water, and generate electricity. Some research has gone in to evaluating how solar energy may be used to power vehicles; however, the long-term possibility of operating a vehicle on solar power alone is very slim. Solar power, may however, be used to run certain auxiliary systems in the vehicle.

Solar energy is derived from the sun. In order to collect this energy and use it to fuel a vehicle, photovoltaic cells are used. Pure solar energy is 100% renewable and a vehicle run on this fuel emits no emissions. The Indian scenario is however not encouraging. The experimental vehicles supplied by BHEL and Chattered are ling stranded for want of spare parts. The CNG vehicles are languishing with repeated shortages in CNG supplies. In the absence of compressing facilities, natural gas continues to be floored. The prospects of Oman and Iranian pipelines for importing of natural gas have receded.

A brief and isolated experiment with 30% methanol blended petrol has been forgotten. The prospects of solar photovoltaic cells as energy source for vehicles have not even been explored so far. The Indian oil industry and the Government of India should join hands to make future fuels a thing of the near future, and not relegate it to the backseat.


Advantages: One of the key features of biodiesel is that it is environmental friendly than others fuels like petrol or diesel. Most diesel engines work efficiently and last longer with the use of biodiesel.

Biodiesel is a clean fuel and amore economic as it encourages recycling process and can be manufactured from waste oil as well. The most important advantage of liquid biodiesel over gaseous fuels is that can be easily pumped and handled . This is the main reason why almost all vehicles prefer using biofuel for combustion purpose . Using biodiesel is the best way of reducing the emission of greenhouse gases like methane and carbon-dioxide. Biodiesel can also be looked upon as a way to improve energy scenario as compared to fossil fuels that are limited in availability.

The most important feature of biodiesel is that it is a renewable source of energy unlike other natural resources like coal and petroleum. Biodiesel is a booster of rural economy by way of employment and revenue generation. It can also bring wastelands under cultivation. Second generation biodiesel can be produced from algae, which do not require any land resource. Biodiesel vehicle have been developed by all major OEMS throughout the world. The biodiesel engines for passenger cars have developed by GM, Ford, Ferrari, Saab, Daimler Chrysler and Volkswagen. Heavy duty engines for truck and buses have been developed by Scania, Volvo and Nissan.

Indian OEMS like Tata motors, Mahindra, and Ashok Leyland are also developing biodiesel vehicles. Indian railways have been running diesel multiple units. Disadvantages: Biodiesel is known for its reduced oxidation stability. Fuel ageing commences rapidly, which causes deposit formation, build-up of resin and corrosion of fuel injection equipments. New diesel fuel injecting system such as common rail system(CRS) are equipped with material that are compatible with biodiesel(B100) or diesel/biodiesel blends(B5,B20) of good quality. Biodiesel (complying with EN14214) or blends do not attack the materials being used.

Failures amounting to complete destruction of the injection system have been reported by usage of non-standard or contaminated biodiesel. Traces of sodium are frequently found inside the fuel system. Larger quantities of soaps inside injectors cause operational problems. Biodiesel B100 is a nontoxic; however for blend B20, significant toxic fumes are released by benzene and other aromatics present in the base diesel fuel. Biodiesel may cause irritation to the eyes on contact therefore safety glasses or face shield should be used to avoid the fuel from splashing on the eyes and faces.

Fire-fighting measure should be used be followed as per its fire hazard classification. Hot fuels may cause burns. Biodiesel should be handled with gloves as it may cause softening of exposed skin. Bio Diesel Storage Biodiesel can be stored for long period in closed container but it should be protected from direct sunlight, low temperature and weather. Underground storage is preferred in cold climate but can be stored in open. Proper insulation, heating, and other equipments should be installed B20 fuel can be stored in tanks above ground depending upon the pour point and cloud point of the blend.

Low temperature can allow the biodiesel to form gel. The biodiesel or it’s blend should be stored at a temperature 15 higher than the pour temperature of the fuel. While splashing of the biodiesel care should be taken that to avoid very low fuel temperature as the saturated compounds can crystallize and separate out to cause plugging of the fuel lines . Biocides, chemical that kill bacteria and moulds growing in the tank can be added in small amount. It is recommended that biodiesel should be stored for a maximum period of upto six months . Brass, Copper, Zinc etc. xidizes diesel and biodiesel and form sediments which can block the fuel supply. Storage tank made of aluminum, steel etc. should be used.


Biodiesel fuel is a renewable, non-toxic and biodegradable form of fuel produced by an oil press extracting the oils from seeds. Biodiesel can be used in any diesel engine. Unlike traditional petroleum fuel, it does not damage the earth during its production, processing or use. In the late nineteenth century Rudolf Diesel designed his engine to run on biodiesel, and the first automobile made by Henry Ford was also designed to run on plant-based fuels.

Today there is renewed interest in biodiesel due to its low impact on the environment, low production costs and sustainable nature. Biodiesel Compared to Petroleum: The Environment Plant-based fuel obtained with oil presses burns much cleaner than traditional petroleum diesel, emitting from 40% to 60% less dangerous greenhouse gases. Biodiesel can be combined with petroleum fuel, which lowers the creation of pollutants in direct proportion to how much biodiesel is added or it can be used in its pure form. Many people believe this could cause harm to the equipment, but in fact, the opposite has been shown to be true.

Adding biodiesel to petroleum fuel actually increases the lubricating qualities of the fuel, easing the wear and tear on the components and lengthening the lifespan of the engine. A few statistics published by the US Department of Energy and the US Department of Agriculture show that, when compared to petroleum fuel, biodiesel typically produces: – 78% less carbon dioxide – 32% less particulate pollution – 96% less dangerous solid waste Biodiesel Compared to Petroleum: Production Fossil fuels are mined from the earth with invasive and ecologically damaging techniques.

No less damaging is the processing and use of the fuel itself. Biodiesel, on the other hand, can be obtained with oil seed presses from many varieties of plant seeds, including sunflower, canola, linseed, soybean and more. A heated seed oil press is able to extract about 90% – 95% of the oil from the seed. Different seeds yield different amounts of oil, and by running them through the oil screw press multiple times optimum oil extraction is achieved. Growing fuel and extracting it with an oil press is a much cleaner and sustainable process than mining and refining crude oil into useable petroleum fuel.

Biodiesel is gaining in popularity because when compared to petroleum it is cleaner, more sustainable, more efficient and healthier for the environment and all the life it supports. BIODIESELFOSSIL FUEL Renewable in natureNon-renewable in nature Eco-friendlyCause pollution Produced from jatropha, pongamiaExtracted from sea bed Less sulphur contentComparatively more Cetane number greater than 51Cetane number is 41-50 Viscosity at 40 is 3. 5-5 M /s Viscosity at 40 is 2. 6- 4. 6M /s


Oil temperature

The temperature to which oil is heated before mixing with catalyst and methanol affects the reaction. It is observed that an increase in oil temperature marginally increase the percentage oil to biodiesel conversion recovery. However higher temperature may result in methanol loss in the batch process.

Reaction temperature

The reaction rate is strongly influenced by the reaction temperature. Generally the reaction is conducted close to the boiling point of methanol at atmospheric pressure. The maximum yield of ester occur at a temperature of 60-80 at a molar ratio of 6:1. Futher increase will have negative effect. . Ratio of alcohol to oil Another important variable affecting the yield of ester is the molar ratio of alcohol to vegetable oil. A molar ratio of 6:1is normally used in industrial process with higher ratio conversion rate increases but recovery decrease due to glycerol.

Catalyst type and concentration

Alkali metal alkoxide are the most efficient trans-esterification catalyst compared to acidic catalyst. Sodium alkoxide is the most efficient catalyst for this purpose but sodium hydroxide and potassium hydroxide to can also be used. The alkaline concentration in the ratio 0. -1% by weight yields 94%-98% conversion of vegetable oils. Further increase in the catalyst increases the cost and not the conversion rate. 5. Mixing Intensity It is observed that after adding methanol and catalyst to the oil, stirring for 5-10 minutes help in higher rate of conversion and recovery.

Purity of Reactants

Under same condition 67-84%conversion into esters can be obtained, using crude vegetable oils, compared to 94-97% when using refined oil. This problem can be overcome by high temperature and pressure. The FFAs in the originals oil interfere with the production process.


A general understanding of the various properties of biodiesel is essential to study their implication in engine use, storage, handling, and safety. Table 1 shows the typical properties of biodiesel as compared to diesel. Fuel propertiesSoya biodieselRME biodieseldiesel formula to to to Carbon(%wt)788184-87 Hydrogen(%wt)111212-16 Oxygen(%wt)1170 Specific gravity. 87. 88. 81 Pour point-3-15-23 viscosity3. 63. 62. 6-4. 1 Lower heating323735-37 Flash point17974 Cetane number526240-45 Table No. 2. 2 2. 7. 1 Properties of Bio-diesel 1. Density Biodiesel is slightly heavier than conventional diesel fuel(specific gravity0. 8 compared to. 84 for diesel oil). This allow the uses of splash blending by adding biodiesel on top of diesel fuel for making blends. 2. Cetane number Cetane number is indicative of its ignition characteristics. The higher is the cetane number, better is its ignition properties. The cetane number affects a number of engine performance parameters like combustion, stability, drivability, white smoke, nise, noise, emission of HC and CO. Biodiesel has higher Cetane number than conventional diesel fuel. This results in higher combustion efficiency and smoother combustion.


In addition to lubrication of fuel injection system components, fuel viscosity, control the characteristics of the injection from the diesel injector. The viscosity of biodiesel can reach very high level and hence it is important to control it within an acceptable level to avoid negative impact on the performance of the fuel injection system. Therefore the viscosity specifications proposed are the same as that of the diesel. 4. Distillation point The distillation point characteristics of the biodiesel are quite different from that of diesel. Biodiesel does not contain highly volatile components the fuel evaporates only at higher temperature.

This is the reason that sometimes the dilution of sump lubrication oil is observered in many cases . Boiling point of biodiesel is in the range of 330-370 5. Flash point The flash point of fuel is defined as the temperature at which it ignite when exposed to a flame or spark. The flash point of biodiesel is higher than the petroleum product . Thus in storage, biodiesel, and its blend is safer than conventional diesel. The flash point of biodiesel is around 160 but can be drastically reduced if alcohol is used in the production of biodiesel is not removed properly.

Residual alcohol in the biodiesel reduces its flash point drastically. A minimum flash point for biodiesel is specified more from the point of view of restricting the alcohol content rather than a fire hazard . A minimum flash point of 100 is specified in order to ensure that excess alcohol is removed which was used for production of biodiesel. 6. Cold filter Plugging point(CFPP) At a lower temperature the fuel may thicken and not flow properly affecting the performance of fuel lines, fuel pumps, and injectors. The CFPP of biodiesel reflects its cold weather performance . It defines the fuels limit of filterability.

CFPP has a better correlation than cloud point for biodiesel as well as diesel.

Cloud point

Cloud point is the temperature at which a cloud of haze of crystal appears in the fuel which is to be tested and thus it is important for low temperature operations. Biodiesel generally has a higher cloud point than diesel. 8. Oxidation point Poor oxidation stability can cause fuel thickening, formation of gums and sediments, which in turn can cause filter clogging and injector fouling. The iodine number indicates the tendency of a fuel to be unstable as it measures the presence of C=C bonds that are prone to oxidation.

The oxidation stability of biodiesel varies greatly depends upon the feedstock used. 9. Iodine number A high content of unsaturated fatty acids in the esters increases the danger of polymerization in the engine oil. Oil dilution decreases the oil viscosity. A sudden increase in oil viscosity is attributed to oxidation and polymerization of unsaturated fuel parts entering into oil through dilution. The tendency of the fuel to be unstable can be predicted by the iodine number. Thus, iodine number refers to the amount of iodine required to convert unsaturated oil into saturated oil.

It does not refer to the amount of iodine in the sample to presence of unsaturated fatty acids in the fuel. 10. Lubricity The lubricity of the fuel depends on the crude source, the refining process to reduce sulphuric content and type of additives used . Lower the wear scar diameter (WSD) better is the lubricity of the fuel. Even with 2% biodiesel mixed in diesel fuel, the WSD values comes down to around 325 micron and is sufficient to meet the lubricity requirement of the fuel injection pump. B100 perform still better with a about 314micron. 11. Acid number

The acid number reflects the presence of free fatty acids or acids used in manufacture of biodiesel. It reflects the degradation of biodiesel due to thermal effects. 12. Conradson Carbon Residue(CCR) Carbon residue of the fuel is indicative of carbon depositing tendencies of the fuel. The CCR of biodiesel of is more important than that in diesel because it has a high correlation with the presence of FFAs


General method for preparing biodiesel

Considerable efforts have been made to develop derivatives of vegetable and animal fat oils which approximate the physiochemical properties of conventional diesel. Most vegetable and animal oils without proper derivatization would have much higher viscosity than fossil diesel and this renders it impossible to use as fuel in diesel engines without modification. The purpose of basic and acidic trans-esterification is to lower the viscosity of the biodiesel production. In fact trans-esterification is one of the four main methods to reduce the viscosity of vegetable oils.

The various methods used can be summarized as: a) Dilution: viscosity of vegetable oils can be lowered by blending with pure ethanol; 25% of sunflower oil and 75% of diesel were blended as diesel. b) Micro emulsion: the formation of micro emulsion is one of the four solutions for solving high vegetable viscosity and gumming problems. It is quite a simple method of blending various vegetable oils with conventional fuel to decrease the viscosity of biodiesel. c) Pyrolysis: refers to chemical change caused by thermal energy in the presence of air or nitrogen spurge.

Thermal decomposition of triglycerides produce the compounds of shorter chain alkanes, alkenes carboxylic acids etc, which will diminish the viscosity of vegetable oil. d) Trans-esterification (alcoholysis): is the reaction of vegetable oils or animal fats with a short chain alcohol in order to derivatize the triglycerides and fatty acid into esters. These contribute to the low viscosity property of derivatized biodiesel. Alcoholysis can be carried out with or without a catalyst. In catalytic trans-esterification acid base or enzyme catalysis is used to promote the alcoholysis derivative reaction.

Catalysts include sulphuric acid, hydrochloric acid, sodium hydroxide, potassium hydroxide and Candida Antarctica enzyme etc. 3. 2Preparation of Biodiesel through transesterification 3. 2. 1 Preheating of waste cooking oil and filtration The waste cooking oil is collected from various eateries, chips shops, Chinese restaurants etc. For the production of biodiesel 100ml of waste cooking oil is taken in a round bottom glass flask of 1 liter capacity with a tight fitting stopper. The flask is heated at 60°C in a water bath as shown in fig. 3. 1 to remove the water from the waste cooking oil.

The above heated oil is filtered through filter paper to remove the impurities and suspended particles from the oil as shown in fig 3. 2. Fig 3. 1 water bath Figure 3. 2 Filtration Process 3. 2. 2 Acidic esterification The filtered oil then undergoes to a next process i. e. acidic esterification reaction. In this process the solution of methanol and sulphuric acid is prepared and then added to the filtered oil. The concentration of methanol is taken in the range of 8 to 10% by volume ratio with oil, and mix with 1 to 3ml of sulphuric acid (95– 98% pure) by 1 liter of oil.

For 100ml of filtered oil 10 ml of methanol is taken and added to the 0. 3ml of sulphuric acid in a glass beaker. Then, 100ml of filtered oil is taken into a round bottom glass flask and methanol / sulphuric acid solution is poured into the flask. After adding the methanol / sulphuric acid solution to the filtered oil magnetic stirring at 350 rpm and heated at 35° C until it became murky (approximately 1 – 2 hours)as shown in fig. 3. 4. The above mixture is then allowed to settle into the separating funnel for 8-10 hrs as shown in fig 3. 5. H2SO4 (CATALYST)


Acid esterification Reaction

After settling two layers will be formed as shown in fig. 3. 5, the below layer contains small amounts of glycerol and other impurities which is to be separated from the above mixture. The above mixture is taken for the further processing i. e. acidic trans-esterification reaction.

Acidic transesterification

In acidic trans-esterification reaction, the titration process is performed as per the standard titration method as explained further. A titration is necessary if we are using waste cooking oil because the free fatty acids content is different in different samples of waste cooking oil.

The titration will help us to determine how much extra catalyst is needed to neutralize the free fatty acids in the waste cooking oil (The catalyst can either be sodium hydroxide (NaOH) or potassium hydroxide (KOH)). Free fatty acids are created when vegetable oil is heated. The heat excites the molecules so that they bump into each other and break apart. These free fatty acids must be neutralized so that they do not interfere with the reaction of the vegetable oil and alcohol. (Acids are neutralized by reacting with a base. The strengths of acids and bases are measured on the pH scale, which goes from 0-14 with 7 being neutral.

To neutralize a chemical is to bring it to the point that its pH is 7. Acids and bases neutralize each other. ) Because the number of free fatty acids in used waste cooking oil is highly variable, it is important to do a separate titration for every batch of used oil before trying to produce larger amounts of biodiesel from it. This titration should be done just before we are going to make biodiesel because the fatty acid content can change with time. In the Trans esterification reaction, the catalyst will react with the free fatty acids before it breaks apart the vegetable oil molecules to create the esters.

The catalyst is basic and will react quickly with any free fatty acids in the oil. When the catalyst is neutralized, by reacting with the free fatty acids, it will not be able to do its job of breaking apart the vegetable oil molecule into esters that will react with the alcohol to form biodiesel, so we need to add enough extra catalyst to complete the reaction. However, care should be taken not to add too much catalyst, because it will react with the glycerine to produce soap and we will get a thick, gloomy mess.

The catalyst was then mixed with isopropanol for the titration because isopropanol will not react with the oil very quickly, which leaves it to react with the catalyst. By measuring how much catalyst is needed to balance the pH of the oil, we can find out how much extra catalyst is needed to add to the reaction to neutralize the free fatty acids in the oil. Proper care should be taken to measure exactly how much extra catalyst is needed; too little will cause an incomplete reaction and too much will make soap instead of biodiesel. A titration is a process by which the exact amount of reactants for a reaction can be determined.

This is done by adding one reactant to another in small increments until the reaction is complete. You will add increments of one mL of a 1g/L NaOH or KOH solution to a solution of 1 ml oil and 10 ml isopropanol until the oil/ isopropanol solution is no longer acidic. The pH of the oil/isopropanol solution will probably be around 5 before any catalyst is added (remember anything under 7 is acidic). After each ml of catalyst solution is added we will check the pH until it has jumped up to between 8 and 9, which indicates that all of the free fatty acids have been neutralized and the solution has become basic.

The number of millilitres of catalyst solution added to get to this point equals the number of extra grams of catalyst needed to neutralize the free fatty acids in each litre of vegetable oil. 3. 2. 3. 1 Titration Procedure 1. All the apparatus are first washed with water. 2. The burette is rinsed with the 0. 025M NaOH solution and filled with the same solution. (0. 025M NaOH is equivalent to 1 gram of pure NaOH crystals dissolved in 1 litre of distilled water) 3. The burette is clamped on the burette stand. 4. The air gap is removed from the nozzle and the level of the liquid is adjusted upto zero mark. 5.

Filter the waste cooking oil in a 20ml beaker using the filter paper. 6. Measure 1 mL of waste cooking oil into a conical flask using a graduated eyedropper. 7. Add 10 mL of Isopropanol to the conical flask containing 1ml of oil and stir the mixture. 8. 1-2 drops of phenolphthalein indicator is added to it and then titrated with the 0. 025M NaOH solution till the color changes from colorless to pink 9. The burette reading is noted. The process is repeated till we get two consecutive readings constant. Sr. No. Solution of Isopropanol/oil (ml)Volume of 0. 025M NaOH(ml)Constant Burette Reading (ml) InitialFinal 112017. 1 7. 0 212017. 2 Table 3. 1 Titration Table To calculate the number of grams of pure sodium hydroxide required per litre of waste cooking oil. Divide the number of ml solution required to neutralize by 10, and add to 3. 5. From titration process, 17ml of sodium hydroxide solution was used, amount of pure sodium hydroxide required = (17 ? 10) + 3. 5 = 5. 2g NaOH per litre waste vegetable oil (vegetable oil requires 3. 5 g NaOH per litre). 3. 2. 3. 2 Transesterification For acidic trans-esterification reaction, the quantity of methanol required is one fifth the volume of waste cooking oil being used as per the research i. . for 100ml of oil 25ml of methanol is used. In this process, 0. 52g of NaOH (alkaline catalyst) was dissolved in 25ml of methanol for 100ml oil. Fig. 3. 3 Mixtures of methanol and catalyst First the oil was heated to 55 to 60±5°C and mixture of catalyst and methanol was poured into it. The entire mixture was stirred for one hour. After the transesterification reaction was completed, the mixture was allowed for settle in a separating funnel for 8-hours in order to have two layers. CH2 – OOC – R CH2 – OH R – COO – CH3

NaOH (CATALYST) CH – OOC – R + 3CH3OH CH – OH + R – COO – CH2 – OOC – R CH2 – OH R – COO – CH3 TRIGLYCERIDE METHANOL GLYCEROL BIODIESEL OIl Trans-esterification reaction Fig. 3. 4 Trans-esterification setup

Settling Process and biodiesel Separation

Following the acidic trans-esterification process, the mixture was left to lie for at least 8-10 hours. Separating funnels were used to separate the mixture. The reaction solution separates into two obvious layers. The top layer is usually yellow or light brown color methyl ester. The layer is dark brown color and is mostly triglyceride with other minor components such as salts, soap etc. Separate the different layers. The above layer is used for the further process. Fig. 3. 5 Settling Process 3. 2. 5Washing of biodiesel The top methyl ester layer was separated and removed from every production sample.

The biodiesel sample was neutralized with 10% of phosphoric acid. One part water was used with three parts of the top layer (methyl esters) biodiesel for washing. Warm water was used to help combat formation of any solids as the cloud points of the biodiesel samples are high. Then settle the solution for 24 hours in a separating funnel, the biodiesel turns a light yellow color. Separate the two layers obtained. The above layer is of biodiesel and lower layer is discarded as it contains water particles, methanol ions, salts etc. Sodium hydroxide and potassium hydroxide pellets are highly caustic substances.

Methanol can be absorbed through the skin and is a serious contaminant to eyes therefore a lab coat, gloves and protective glasses must be worn when preparing these solutions as well as having a nearby running water supply. ?


The above prepared biodiesel is tested for the standard properties of any fuel like calorific value, viscosity and density from the research laboratories from, Mahabal Enviro Engineer Pvt. Ltd. , as the testing facilities is not available in the college.

The standard methods of testing the properties of fuel are discussed below:

Determination of viscosity using redwood viscometer

2 The Redwood viscometer:-The Redwood viscometer is made in two sizes. The Redwood 1 viscometer is commonly used for determination of viscosity of lubricating oil has an efflux time of 2000 sec or less. Redwood 2 is similar to the type one but the jet for the outflow of oil is of larger diameter, there used for the higher viscous oil. In Redwood viscometer viscosity of oil is measured in time of efflux of 50 ml of oil thought the standard orifice of the instrument Procedure : )Level the instrument with the help of leveling screws on the tripod. 2)Fill the heating bath with water to the height corresponding to the tip of the indicator up to, which the oil is filled in the cylindrical cup. 3)Keep the brass ball in position so as to seal the orifice. 4)Then, pour the oil under test carefully in to the oil cup up to the tip of the indicator. 5)Keep the 50 ml flask in position below the jet. 6)Keep the oil and water well stirred and note their temperatures. 7)When the desired temperature is obtained, raise the valve and suspend it from the thermometer bracket. Simultaneously start the stopwatch. )Note down the time required to flow 50 ml oil. Replace the ball valve in position to seal the cup to prevent the overflow of oil. 9)Repeat the experiment to get reproducible results. Report the mean values as “Redwood no 1 and 2 viscosity at T0C = t seconds. This is the viscosity at room temperature, T0C. 10)Repeat the experiment at five elevated temperatures in decreasing order, say 750C, 650C, 550C, 450C, and note the respective times of efflux as describe above. 4. 3 Determination of density of the biodiesel For all mass measurements, platform balance is used. Volume will either be measured or calculated or both.

Procedure: 1) Collect about 100 mL biodiesel in a beaker; let it sit until its temperature is stabilized. Record its temperature. 2) Weigh a clean, dry 10 mL graduated cylinder and record its mass. 3) Now add biodiesel from the beaker to the cylinder, so that the level is above 5mL, but below 10 mL and record the volume accurately. 4) Wipe off any water droplets adhering to the outside as well as above of the water level inside. 5) Record the mass of the cylinder with water. 6) Now repeat step 2-4 two more times, each time with a different volume, but still between 5-10 mL. ) Now you have 3 sets of data, calculate the average density of biodiesel at this temperature. 8) Calculate the % error, once you know the true value of density of water from literature. % error = (experimental value – true value) X 100 True value The density of the given bio-diesel is found to be 870 kg/ . 4. 4 Determination of calorific value using bomb caloriemeter The heating value of a fuel is defined as the quantity of heat transferred from the calorie meter in order to reduce the temperature of the product to the initial reaction temperature.

Heating value are reported as positive quantities and are widely used in the calculation of the thermal effiency of power system Bomb calorie is a constant volume system is initially charged with oxygen and a small sample of fuel. Subsequent to ignition and combustion, the heat is transferred from the product to the surrounding water bath. The heating value is calculated essentially from the measured temperature increase of the system mass. The calculated result is usually reduced to a standard heating value at 25 0C. A heating value determined by bomb type calorie meter is designated as a constant-volume higher heating value.

Water vapour formed during the reaction is completely condensed especially when few drops of water are placed in the bomb calorimeter prior to sealing in order to saturate the gaseous atmosphere. When the combustion is performed, it generates water in the vapor state. The heat contained in this vapor can be calculated using scientific techniques and is expressed as Higher Heating Value (HHV), Lower Heating Value (LHV), and Gross Heating Value (GHV). A method commonly used in relating HHV to LHV is: HHV = LHV + hv x (nH2O, out/nfuel,in) Procedure: 1. There are many types of calorimeters.

Determine what type would be best suited by the needed accuracy and material being used. The bomb calorimeter is a very common tool for measuring caloric values. 2. Place the biodiesel inside the bomb calorimeter. 3. The bomb calorimeter will combust the biodiesel and vaporizes the water contained within it. As the biodiesel burn, they heat the air inside the calorimeter. 4. The expanded air escapes through a tube from the calorimeter. As the air escapes, it heats up the water outside the tube. This heated water is used for calculating the calorie content. 5.

The heat from the water vapor is calculated and compared against standard benchmarks to achieve the calorific value Fig 4. 1 Bomb Calorie meter

Experimental result of properties of prepared biodiesel

The prepared biodiesel from waste fried oil is tested for calorific value and viscosity from Mahabal Enviro Engineer Pvt. Ltd and the density is tested in the chemistry laboratories and the result obtained are as follows : Calorific value-41812kJ/kg (9990kcal/kg) Viscocity-5. 49 cSt Density- 870 kg/ The comparison of the properties of prepared biodiesel is made with conventional fuels as shown in the table 4. . PropertiesLPGNatural gasHydrogenGobar gasBiodieselCNGDiesel Composition (% Vol)C3H8-30% C4H10-70%CH4-85% C2H6-7% C3H8-2% N2-1% CO2-5%H2 CH4-60% CO2-30% CO-0. 18% H2-0. 18%C- 78% H-11% O-11%CH4-86. 4-95% C2H6-6-3% C3H8-2-3. 5%C-84% H2-15. 2% (By Weight) Lower heating value at 1atm&15oC (MJ/kg)—–45. 75012030325042. 8 Density at 1 atm&15oc (kg/m3)2. 260. 790. 081. 28700. 69840 Flame speed (cm/s)38. 253427525342-8 Stoichiometric A/F (kg of air/kg of fuel)15. 517. 334. 26 m3 air/ m3 gas17. 314. 6 Flammability limits (vol. % in air) Leaner——– Richer——– 2. 15 9. 6 5 15 4 75 7. 14 5. 3 15 6 7. 5 Auto ignition temperature (°C)405-450540585650730315 Latent heat of vaporization kJ/m3 428————–493-549——-509251 Molecular weight55-60—————————-18. 88 – 17. 05144 Table 4. 1 Comparison of biodiesel with other conventional fuel


Biodiesel is produced from waste cooking oil using the transesterification process which involves two steps because the acid value of waste cooking oil is greater than 1. In the first step 1 liter oil is mixed with a solution of 100 ml of methanol and 3ml of sulphuric acid.

In the second step the catalyst is added to the above prepared mixture and the reaction carried out at 350 rpm and 55 to 60±5°C. The fuel property such as calorific value, viscosity and density are tested at research laboratories Mahabal Enviro Engineer Pvt. Ltd. The calorific value is found to be 9990 kcal/kg or 41812 kJ/kg and the viscosity is 5. 49 cSt . The density of the prepared biodiesel is tested in chemistry laboratories of the college and is found to be 870 kg/ . The obtained values for the properties of biodiesel are compared with the properties of conventional fuel.

From the comparison it is observed that the properties of prepared biodiesel are equivalent to the properties of conventional fuel for e. g. the calorific value of the prepared biodiesel is 41812 kJ/kg and that of diesel is 43220 kJ/kg. The other properties like viscosity and density are also similar to that of diesel. Based on the comparison of properties of biodiesel from waste cooking oil it can be said that it can be used as an alternate source of fuel for diesel. The effect on the performance of diesel engines using biodiesel from waste cooking oil as a fuel for diesel engine, will be the future scope of project.


Biodiesel is a popular and promising environment-friendly alternative fuel due to its renewable nature and clean burning characteristics. Apart from biodiesel production from plant species such as Jatropha Curcas and Pongamia Pinnata , waste cooking oil can also reliable source for the raw material for the biodiesel. The by product of biodiesel such as glycerol which can be used in so

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