PRODUCTION OF BIODIESEL FROM ALGAE-Soumya kittur
Contents What is biodiesel? Characteristics Production of algae oil Production of biodiesel from algae Photobioreactor Large scale production Copmanies Producing biodiesel Developments Researches Advantages and disadvantages Applications References
What is Biodiesel ? Biodiesel is a nontoxicand biodegradable alternative fuel that is obtained from renewable sources.
Biodiesel is
biodegradable, less CO2 and NOx emissions.
Biodiesel production is
the act of producing the biofuel, biodiesel, through either transesterification or alcoholysis of oils.
Characteristics of Algal BiodieselNo sulfur content. It has superior lubricating properties. Cloud point about 32 0F Flash point 266 0F. Biodiesel reduces particulate matter by about 47percent as compared to petroleum diesel. Biodiesel has less dangerous particulate matter Algae biodiesel has more aggressive solvent properties than petro diesel.
PropertiesDensity Kg l-1 Viscosity Pa s Flash point C Solidifying point C
Biodiesel fromMicroalgal Oil 0.864 5.210-4 (40 C) 65-115 -12
Diesel Fuel0.838 1.9 - 4.1 10-4 (40 C) 75 -50 - 10
Cold filter plugging point C Acid value mg KOH g-1Heating value MJ kg-1 HC ratio
-110.374 41 1.18
-30.5 40-45 1.18
Production of Algae oilSteps involved in the production of Algae oil:
Selection of algae and site Cultivation Harvesting Biomass Processing Oil extraction
Selection of Algae and SiteSpecies
Some of the species
Yield (in g/m2/day)20 (~ 30% lipids)10.3
which are being used in Marine Nannochloro psis the production of Biodiesel are given in the Spirulina plantesis table.Dunaliella salina
12.013.4
Production sites can be
selected according to the production scale and other factors.
Scenedesmus species Ankistrodesmus Haematococcus plu vialis
18 3.8
CultivationAlgae can be Cultivated in:
Open ponds Closed ponds Photobioreactors
HarvestingSeparating algae from its medium is known asharvesting. Harvesting methods depends primarily on the type of algae. whereas.
Macroalgae harvesting employs manpower microalgae can be harvested using
microscreens, centrifugation, flocculation or by froth flotation. energy-efficient and relatively inexpensive so selecting easy-to harvest strains is important.
The processes used for harvesting must be
Extraction of algal oilTwo methods:
Mechanical method Chemical method
Extraction of Algal Oil by Mechanical MethodsMechanical methods includes:-Expression/Expeller press -Ultrasonic-assisted extraction In case of Expression press method algae is dried itretains its oil content, which then can be "pressed" out with an oil press. create cavitation bubbles in a solvent material, when these bubbles collapse near the cell walls, it creates shock waves and liquid jets that causes those cells walls to break and release their contents into the solvent.
Using an ultrasonic reactor, ultrasonic waves are used to
Extraction of Algal Oil by Chemical MethodsThree types: Hexane Solvent Method Soxhlet extraction Supercritical fluid Extraction Hexane is used for extraction in case of hexane solvent Method. It can be used along with oil press method to get more efficiency. soxhlet extraction is an extraction method that uses chemical solvents. Oils from the algae are extracted through repeated washing, or percolation, with an organic solvent such as hexane or petroleum ether, under reflux in a special glassware. In supercritical fluid/CO2 extraction, CO2 is liquefied under pressure and heated to the point that it has the properties of both a liquid and a gas, this liquified fluid then acts as the solvent in extracting the oil
Production of Biodiesel from algae oil Algae oil is highly viscous.So to reduce viscositytransestrification, pyrolysis, micro Emulsion, blending and thermal depolymerization methods can be used.
Transestrification: Transesterification of algal oil is
normally done with Ethanol and sodium ethanolate serving as the catalyst.
End products are biodiesel, sodium ethanolate andglycerol.
This end-mixture is separated as follows: Ether and salt
water are added to the mixture and mixed well. After sometime, the entire mixture would have separated into two layers, with the upper layer containing a mixture of ether and biodiesel. This layer is separated. under a high vacuum. As the ether vaporizes first, the Biodiesel will remain.
Biodiesel is in turn separated from ether by a vaporizer
Working of a Photobioreactor
Advantages of PBR:High Biomass Productivity and cell density. Less contamination, water use, & CO2 losses.Better light utilization & mixing.
Controlled culture conditions.
Disadvantages of PBR: High capital cost associated with construction costs,circulation pumps, and nutrient-loading systems. high temperatures
Absence of evaporative cooling, which can lead to very
Accumulation of high concentration of photosyntheticallygenerated O2 leading to photooxidative damage them
Biofouling of interior surfaces and difficulty of cleaning Cell damage by shear stress Deterioration of materials
Large scale Production Theoretically, Biodiesel produced from algae appears to be the onlyfeasible solution today for replacing petro-diesel completely.
In practice however, biodiesel has not yet been produced on a widescale from algae, though large scale algae cultivation and biodiesel production appear likely in the near future (4-5 years).
In order to produce biodiesel from algae on a large-scale, the following conditions need to be met, logically speaking: Ability to sustainably produce high-oil-yielding algae strain on a large-scale Ability to extract the oil from the algae on a large scale Capability for large-scale conversion of algal oil into
biodiesel
Some of the Companies which are trying to produce Biodiesel:OriginOil PetroSun PetroAlgae SolixBiofuel
DevelopmentsOriginOils recent breakthrough can extract up to 97% of the oil from algae cells. This level of efficiency is astonishing for a process that requires less than a tenth of the energy of conventional processes, and without needing chemicals,
-Riggs Eckelberry, OriginOils CEO.AlgaeLink,have developed a new way to extract oil out of wet algae paste. Valcent Products - Has developed a high density vertical bio-reactor for the mass production of oil bearing algae while removing large quantities of carbon dioxide (CO2) from the atmosphere
Research on Biodiesel from AlgaeEnhancing lipid production rates by increasing Through nitrogen & phosphorus deprivation Si Depletion - research into diatom lipidaccumulation by silicon depletion
the activity of enzymes via genetic engineering
Advantages of Biodiesel From Algae High Yield According to some estimates, the yield (per Acre yield say) of oil from algae is over 200 times the from the best-performing plant/vegetable oils. Algae can grow practically in every place where there is enough sunshine The biodiesel production from algae also has the beneficial by-product of reducing carbon and NOx Emissions from power plants, if the algae are grown using exhausts from the power plants. Algae produces lot of polyunsaturated oils, so it can work good in the cold weather also.
DisavantagesAglal oil is highly viscous.Stability problem Technical problems for large scaleproduction
Applications Biodiesel can be blended with petroleumdiesel. Vehicular use Railway usage Aircraft use As a heating oil
References:www.wikipedia.com www.olgae.com www.science.howstuffwork.com www.originoil.com
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