Producing oil from algae

Producing oil from algae


The main objective of my research is to producing oil from Algae and converting to biodiesel or fatty acid methyl esters continued use of petroleum sourced fuels is now widely recognized as unsustainable in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Biodiesel derived from oil crops is a potential renewable and carbon neutral alternative to petroleum fuels. Unfortunately, biodiesel from oil crops, waste cooking oil and animal fat cannot realistically satisfy even a small fraction of the existing demand for transport fuels. As demonstrated here, microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global demand for transport fuels. Like plants, microalgae use sunlight to produce oils but they do so more efficiently than crop plants. Oil productivity of many microalgae greatly exceeds the oil productivity of the best producing oil crops. Approaches for making micro algal biodiesel economically competitive with petro diesel are discussed.


BIODIESEL as renewable fuel

Biodiesel (or biofuel) is the name for a variety of ester-based fuels (fatty esters) generally defined as the monoalkyl esters made from vegetable oils, such as soybean oil, canola or hemp oil, or sometimes from animal fats OR ALGAL LIPIDS through a simple transesterification process. This renewable source is as efficient as petroleum diesel in powering unmodified diesel engine.

Biodiesel any fuel that is derived from the biomass that is plant material or animal oil.

Biodiesel is an alternative, biodegradable diesel fuel typically made from biological source such as vegetable oil is animal fat. Biodiesel, is made from renewable source it is nontoxic has low emission profile and so environmentally friendly (Krawczyk, 1996).biodiesel is considered as most promising alternative fuel which has similar properties of petroleum based biodiesel fuel.

Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, propyl or ethyl) esters. Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, animal fat (tallow)) with an alcohol.

Continued use of fossil fuel is now widely recognized as UN sustainable in the environment .Due to increasing oil prices depleting resource and the accumulation of green house gases in the environment result in global warming and generation air pollution . Hundred years ago, vegetable oil as fuel for engines was tested by Rudolf diesel (shy 1993).with advent of cheap petroleum ,crude oil fraction were refined to serve as fuel .RECENTLY WITH INCREASE OF FOSSIL FUEL PRICES ,limited resource of fossil fuels and environment concerns due to accumulation of green house gases increasing pollution, energy security raised concerns about use of fossil fuels continued and increasing use of petroleum will intensify local air pollution and magnify the global warming problems caused by co2 (shay 1993) biodiesel fuels has potential to reduce green house gases which is called carbon neutral amount of releasing and amount of use is equal . There has been renewed focus on vegetable oils and animal fats increasingly renewable liquid transportation fuels are being viewed as important, domestically producible alternative to petroleum


Biodiesel becoming alternative fuel to petroleum based biofuel .as the both the fuels have similar chemical structure biodiesel or fatty acid alkyl esters is made by combining the Tag (triglycerides) of any biological fat or animal with an alcohol .the ALKYL IN FATTY ACID ESTERS IS MOST COMMONLY METHLY AFTER THE METHONLA THAT IS USED DURING PRODUCTION THE PRODUCT CAN BE CALLED AS FAME FATTY ACID METHYL ESTERS .ALTHOUGH BIODIESEL PRODUCTION IS COMMONLY DONE WITH A BASE CATALYSED ,ACID CATLYSED OR ENZYME CATALYSED.the production of fame from triglycerides is called transesterification .usually the reaction involves combining oil feedstock with the reactant alcohol and a base or acid catalyst ,most commonly sodium hydroxide(Knothe 2005) THE TRASESTERIFICATION REACTION WHICH PRODUCE BIODIESEL fame and glycerol ,can be seen in fig 1

Fats and oils are primarily water-insoluble, hydrophobic Substances in the plant and animal kingdom that Are made up of one mole of glycerol and three moles of Fatty acids and are commonly referred to as triglycerides (Sonntag, 1979a). Fatty acids vary in carbon chain Length and in the number of unsaturated bonds (double Bonds). The fatty acids found in vegetable oils are Summarized in Table 1. Table 2 shows typical fatty acid Compositions of common oil sources. Table 3 gives the Compositions of crude tallow. In beef tallow the saturated fatty acid component Accounts for almost 50% of the total fatty acids. The Higher stearic and plasmatic acid contents give beef tallow The unique properties of high melting point and high Viscosity. Natural vegetable oils and animal fats are extracted Or pressed to obtain crude oil or fat. These usually Contain free fatty acids, phospholipids, sterols, water, odorants and other impurities. Even reined oils and fats contain small amounts of free fatty acids and water. The Free fatty acid and water contents have signi®cant e€ects On the transesteri®cation of glycerides with alcohols .Biodiesel, defined as the mono-alkyl esters of vegetable oils, animal fats, and oil from algae is alternative diesel fuel accepted around the world. Biodiesel refers to a vegetable oil or animal fat based diesel fuel consisting of long chain alkyl (methyl .propyl or ethyl)esters .biodiesel is typically made by chemical reacting lipids (vegetable oil or animal fat) with an alcoholBiodiesel is clean burning, non -toxic and carbon neutral with respect to global warming, and it is important for air quality, several studies have documented its significant emission improvement over petroleum diesel. Biodiesel can be used in most modern diesel engines with no modifications and can be blend in any proportion with petroleum diesel.




The concept of using vegetable oil as an engine fuel likely dates back when Rudolf Diesel developed the first engine to run on peanut oil, as he demonstrated at the World Exhibition in Paris in 1900.

Rudolf Diesel firmly believed the utilization of a biomass fuel to be the real future of his engine. He wanted to provide farmers the opportunity to produce their own fuel. In 1911, he said "The diesel engine can be fed with vegetable oils and would help considerably in the development of agriculture of the countries which use it".

After R. Diesel death the petroleum industry was rapidly developing and produced a cheap by-product "diesel fuel" powering a modified "diesel-engine". Thus, clean vegetable oil was forgotten as a renewable source of power.

Modern diesels are now designed to run on a less viscous fuel than vegetable oil but, in times of fuel shortages, cars and trucks were successfully run on preheated peanut oil and animal fat. It seems that the upper rate for inclusion of rapeseed oil with diesel fuel is about 25% but crude vegetal oil as a diesel fuel extender induces poorer cold-starting performance compared with diesel fuel or biodiesel made with fatty esters (McDonnel K et al. JAOCS 1999, 76, 539).

Today's diesel engines require a clean-burning, stable fuel operating under a variety of conditions. In the mid 1970s, fuel shortages spurred interest in diversifying fuel resources, and thus biodiesel as fatty esters was developed as an alternative to petroleum diesel. Later, in the 1990s, interest was rising due to the large pollution reduction benefits coming from the use of biodiesel. The use of biodiesel is affected by legislation and regulations in all countries (Knothe G, Inform 2002, 13, 900). On February 9, 2004, the Government of the Philippines directed all of its departments to incorporate one percent by volume coconut biodiesel in diesel fuel for use in government vehicles. The EU Council of Ministers adopted new pan-EU rules for the detaxation of biodiesel and biofuels on October 27, 2003. Large-volume production occurs mainly in Europe, with production there now exceeding 1.4 million tons per year. Western European biodiesel production capacity was estimated at about 2 million metric tons per year largely produced through the transesterification process, about one-half there of in Germany (440,000 and 350,000 MT in France and Italy, respectively). Several studies are now funded to promote the use of blends of biodiesel and heating oil in USA. In USA soybean oil is the principal oil being utilized for biodiesel (about 80,000 tons in 2003.

As many algal species have been found to grow rapidly and produce substantial amounts of triacylglycerols (oleaginous algae), it has long been postulated that they could be employed to produce oils and other lipids for biofuels (see review in : Hu Q et al., The Plant J 2008, 54, 621-639). A very informative review of the prospects of using yeasts and microalgae as source of cheap oils that could be used for biodiesel may be consulted (Ratledge C et al., Lipid Technol 2008, 20, 155).

The promise of algae in the production of biodiesel has been evaluated in the end of 1998.

As the major byproduct of biodiesel production is glycerol, uses for that byproduct have been investigated. Glycerol can be thermochemically converted into propylene glycol (Chiu CW et al., Ind Eng Chem Res 2006, 45, 791), 1,3-propanediol (Gonzalez-Pajuelo M et al., Metab Eng 2005, 7, 329), lipids (Narayan M et al., Int J Food Sci Nutr 2005, 56, 521) and several other chemicals. Among lipids, it was shown that glycerol can be used to produce docosahexaenoic acid (DHA) through fermentation of the alga Schizochytrium limacinum (Chi Z et al., Process Biochem 2007, 42, 1537; Pyle DJ et al., J Agric Food Chem 2008, 56, 3933).


Blends of 20% biodiesel with 80% petroleum diesel can be used in unmodified diesel engines. Biodiesel can be used in its pure form but many require certain engine modifications to avoid maintenance and performance problems.

It was stated that about half of the biodiesel industry can use recycled oil or fat, the other half being soybean, or rapeseed oil according to the origin of these feed stocks.

Biodiesel is nontoxic, biodegradable. It reduces the emission of harmful pollutants (mainly particulates) from diesel engines (80% less CO2 emissions, 100% less sulfur dioxide) but emissions of nitrogen oxides (precursor of ozone) are increased.

Biodiesel has a high cetane number (above 100, compared to only 40 for diesel fuel). Cetane number is a measure of a fuel's ignition quality. The high cetane numbers of biodiesel contribute to easy cold starting and low idle noise.

The use of biodiesel can extend the life of diesel engines because it is more lubricating and, furthermore, power output are relatively unaffected by biodiesel.

Biodiesel replaces the exhaust odor of petroleum diesel with a more pleasant smell of popcorn or French fries.

By developing methods to use cheap and low quality lipids as feedstocks, it is hoped that a cheaper biodiesel can be produced, thus competing economically with petroleum resources.

Source of biodiesel

Plants oil :

Vegetable oil and fats as source of biodiesel is considered as first generation biofuels . vegetable oil represents a alternative fuel for conventional diesel, a non renewable energy source because of their chemical similaraties.

The most commonly used oilseeds for the production of biodiesel are soyabean ,canola ,sunflower ,palm,peanut rapseed ,cottonseed ,cocunutoil, and non-edible jatropha curcas(jatropha oil) (S.P. singh et al.,) since the price of edible vegetable oils are higher than that of diesel fuel ,therefore waste vegetable oils and non edible crude vegetable oils are preferred as low priced biodiesel source

Composition of biodiesel obtained from various source (D.Bajpay et al.,)

Oil or fat

Fatty acid composition wt,%

























































































As plants oil are too viscous for use in modern diesel engines,they are converted to fatty acid esters.This refered as biodiesel .Plants oil is primaraly composed of various triacylglycerols (TAGS),molecules that consist of three fatty acid chains (18 to 16 carbon long) esterified to glycerol . As the most of the TAG molecules are Viscous In nature viscousity range from 17.3 -32.9 mm2s-1 when compared to 1.9-4.1mm2 that is much higher than that of conventional diesel.(Timothy p.durrett et al.,)This higher viscosity results in poor fuel atomization in modern diesel engines ,leading to incomplete combustion results in carbon deposition and coking (Ryan et al.,1984).To reduce the viscous nature of plant oil ,TAGs are converted to less viscous fatty acid esters by esterfication , The fatty acid esters are chemically similar to aliphatic hydrocarbons molecules found in petrol and diesel .

The oil percent and the yield per hecter are important paramaters to consider as biodiesel source .

Comparison of some source of biodiesel


Oil yield L/h

Land area needed

(M ha)

% of existing us cropping area





















Oil palm




The source of biodiesel usually depends on the crops amenable to the regional climate .Source of

Production of biodiesel in different countries from plants


Source of biodiesel






Repeseed oil (>80%) and sunflower


Linseed and olive oil


Sunflower oil


Sunflower oil


Palm oil


Rapseed oil


Guang pi


Rapsid oil


Vegetable oil


Palm oil

Due to increase in crude oil prices and introduction of various subsidies ,the production of biodiesel mainly from vegetable oils in two major ecomonie in world EU and USA has gradualy increased in reacent years from 2002 to 2006 the production of biodiesel increased 15 folds in USA and five folds in EU (Timothy p .Durrett et al.,) soya beans are the second biggest source of of plant oilin the world

Animal fats

Properties of biodiesel

Biodieselis considered as alternative source of energy over conventional petroleum diesel .Biodiesel produced from different feed stocks will in turn have different fuel properties because each feed stock has a unique chemical composition along with presence of the fatty ester composition , contaminants ,and minor components ,dictates the fuel properties of biodiesel .the important properties of biodiesel that are directly influenced by fatty ester composition ,presence of contaminants and minor components include, kinematic viscosity ,low -temperature stability ,oxidative and storage stability ,exhaust emissions, cetane number and energy content .

Kinematic viscosity.

one of the important fuel properties of biodiesel is viscosity ,which is also an important property of lubricants .Increase in kinematic viscosity results in poor fuel atomization in modern diesel ,leading to problems derived from incomplete combustion such as carbon deposition and coking (Timothy P. Durrett et al.,).

Several structural feature influence the kinematic viscosity of FAAE, such as chain length, degree of unsaturation ,double bond orientation and type of ester head group .(Brayan R.moser). As seen from table .factors such as longer chain length and larger ester head group results in increase kinematic viscosity .for example ,methyl esters of lauric ,myristic ,palmitic ,and stearic acids have kinematic viscosities of 2.43, 3.30, 4.38 and 5.85 mm2/s,respectively .furthermore , methyl ,ethyl and butyl esters of stearic acids exhibit kinematic viscosities of 5.85, 5.92, and 7.59 mm2//s. respectively .increasing the degree of unsaturation results in a decrease in kinematic viscosity ,as evidence of comparison of methyl esters of stearic (5.85 mm2/s),oleic (4.51 mm2/s),lineolic (3.65 mm2/s) acids. Double bond orientation also impacts kinematic viscosity, as seen by comparison of methyl elaidate (5.85 mm2/s) and methyl linoelaidate (5.33 mm2/s). (Brayan R. Moser). Ester head group also has a great influence on kinematic viscosity of biodiesel it has by comparison of ethyl and isopropyl esters of tallowate, which have kinematic viscosity of 5.2 and 6.4 mm2/s, respectively (Wu et al.1998).The methyl and ethyl esters of canola oil have kinematic viscosities of 3.9 and 4.4 mm2/s (Kulakarani et al. 2007).The influence of saturated FAME content on viscosity is illustrated by comparison of SME (4.12 mm2/s) and PME (4.58 mm 2/s ; Brayan R. Moser). The influence of double bond orientation is seen by comparison of SME to partially hydrogenated SME (5.0mm2; Brayan R .Moser).

Exhaust emissions.

Exhaust emission is regulated by U.S. code of federal regulation (CFR) includes oxides of nitrogen (NOX), PM (particulate matter), THC (total hydro carbons), and carbon monoxide (co).

ASTM D6751 and EN 14214 contains specification relating to exhaust emissions. In comparison of petrodiesel, combustion of biodiesel (B100) in modern diesel engines results in average increase in NOx emission of 12% and decrease in particulate matter, total hydro carbons and carbon monoxide emission of 48%, 77%, and 48% respectively. (Brayan R. Moser).For B20 (20%Biodiesel and 80% petrodiesel) blend in petrodiesel, NOx emission are increased by 0-4% , but PM,THC and CO emissions are reduced by 10%, 20%, 11% respectively (Hess et al. 2007; EPA 2002).

Cetane number (CN): Cetane number is actually a measure of a fuel's ignition delay time; the time period between the start of injection and start of combustion (ignition) of the fuel. In a particular diesel engine, higher cetane fuels will have shorter ignition delay periods than lower cetane fuels. Cetane numbers are only used for the relatively light distillate diesel oils. CN is determined in accordance with ASTM D613 and is one of the primary indicator of diesel fuel quality. Cetaneis anun-branchedopen chain that ignites very easily under compression, so it was arbitrarily assigned a cetane number of 100. The cetane number of biodiesel exceeds that of conventional fuel which indicates that biodiesel may provide cetane enhancement when used neat or blends, and may provide emission benefits that have been correlated to cetane number. The cetane number of biodiesel mainly depends on the oils or fat feed stock. CN increases with chain length and decreases with number and location of double bonds, and changes with location of carbonyl group. CN number decreases as bonds or carbonyl move towards the centre of the chain. When the number of carbons in the fatty acids in biodiesel increases CN increases from 47.9 to 75.6(D. Baypai and V.K Tyagi ).CN number exceeds 60 when the the number of carbons increase 12 in carbon chain. Knothe et al, reported CN number for methyl esters ranges from 45.8 to 56.9. The variation is due to the distribution of carbon chain lengths in each fuel tested. As seen in the table. CN of various methyl esters is compared to which tells variation of CN.

Flash point: The flash point of a fuel is defined as the temperature at which the fuel becomes a mixture that will ignite when exposed to a spark or flame. All petrodiesel fuel have high flash points (540c, minimum; 710c typically) .the flash point of biodiesel is typically greater than 930c according U.S. Department of transportation considers a material with a flash point of 930c or higher to be non hazardous .from perspective of storage and fire hazard ,biodiesel is much safer than conventional diesel .


Biodiesel derived from plant oils and animal fat is a potential renewable biofuel and carbon neutral alternative to petroleum diesel .But biodiesel from plant oils and animal fat cannot satisfy even a small amount of the existing demand for transport fuels. Because of high feed stock prices, commercialization of vegetable oils for the production of biodiesel results in increasing food prices, in ordered to produce alternative fuel for global demand microalgae appear to be the only source of renewable fuel, like plants microalgae use sunlight to produce oils through the process of photosynthesis, but they do more efficiently than crop plants.

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