Utilization of Algae for Biofuels Production

Supervisor: Prof. H. S. GhaziaskarBy: M. Rezayat

Department of ChemistryJun 1, 2010

Outline Introduction Algae

◦ Microalgae◦ As a potential replacement fuel

Large scale production Harvesting and drying Fuel production Oil extraction Economic biodiesel production

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BiofuelsForestryAgricultureAquatic

BiomassesBio-dieselBio-oilBio-gas

1.8-2.2% 6-8%

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BiomassOxygen

AlgaeMicroalgae: Microscopic photosynthetic organismsIn both marine and freshwater environments.

Macroalgae (seaweed):Multicellular plants In both salt or fresh water, They do not have roots, stems and leaves60 m in length

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Applications: Used as food as powder or tablet( Spirulina, Chlorella,…), animal food As a chemical sources Wastewater treatment( heavy metals) Solar energy conversion and biofuel production. As agent for enhanced CO2 fixation.

They should be:

Highly productive Easily harvestable by mechanical techniques Withstand water motion in open ocean( Macroalgae) Produced at a desirable cost

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Adaptable to grow in different conditions Fresh or marine-waters Wide range pH

Why Microalgae?

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Simple structureHigh grow rates

High Photosynthetic efficiency

Advantages: Massive production while using limited land Consuming less water high- efficiency CO2 mitigation Nitrous oxide release could be minimizing More cost effective than conventional farming

50 times more

Disadvantages: Low biomass concentration Small size makes their harvest relatively costly. Drying would be energy-consuming process.

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History : 1950s, the first report on algae

biofuels at MIT.

1970, initial examination on algae.

1980, subsequent studiesAlgae Culture from Laboratory to

Plant (Burlew, 1953)

Potential of Microalgae biodiesel

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Double their biomass within 24 h. Their oil content exceed 80% by weight of dry biomass.

Photosynthetic needs: Light Carbon dioxide Water Inorganic salts ( N, P, Fe) 20-30°C

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CO0.48H1.83N0.11P0.01

50% of dry weight is CarbonProducing 100 tons algae biomass 183 tons

CO2

Large scale productionRaceway ponds

o Cost less to build & operation

Photobioreactorso Provide much greater oilo Recovery cost is less o Biomass concentration is 30

times raceway ponds production

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Raceway ponds Used since the 1950s 440,000 m2(2006) Closed loop channel 0.3 m deep Mixing and circulation by Paddlewheel Cooling by evaporation

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Temperature fluctuation Contamination with unwanted algae and microorganisms Poorly mixed Biomass concentration is low Dark zone

Photobioreactors

Single-species culture Array of straight tube(plastic or glass) ≤ 0.1 m in diameter Parallel to each other and flat above the

ground (Oriented North-South ) The ground painted white or covered

with white plastic Using a pump for maintaining a

turbulent flow (a mechanical or a gentler airlift pump)

Must be cleaned & disinfected

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Oxygen removing 10 g m-3min-1

Inhibit photosynthesis Photooxidative damage Need to a degassing zone Tube length ≤ 80 m

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Biomass concentrationLight intensityFlow rateOxygen concentration (entrance of tube)

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Enhance CO2 Solubility (US2009/0151241 A1)Providing a perfluorodecalin (C10F18) solution.Mixing it with biological growth medium & surfactant.Emulsifying them by circulation in a high-pressure emulsifier.

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Production of algae pigments (US2009/0035835 A1) entering mature algae to a stress bioreactor ( stress tank). Irradiating with electromagnetic waves of mm rang and low

intensity.

Using optical fibers to enhance lighting

Harvesting and Drying

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Microalgae harvesting:Chemical and biological flocculationFiltrationCentrifugationUltrasonic aggregation

long timeDecomposition

More efficientMore costly

Microalgae drying:Sun dryingLow-pressure self dryingDrum dryingSpry dryingFreeze drying

long time, Large surfaceLoss of bioreactive products

More efficientMore costly

Fuel production Direct combustion (boiler & steam turbines),

high moisture contentAnaerobic digestion (Macroalgae), CH4 & CO2

Gasification , Syngas Low temperature catalytic of biomass

Pyrolysis (750 K , 0.1-0.5 Mpa, in absence of air)

Dried mass

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Oil-like liquid ( bio-oil)

Carbon-rich solid (charcoal)

Hydrocarbon rich gas

Pyrolysis:

Liquefaction Low Temp. , high Pressure Using catalyst Recover liquid fuel More expensive than pyrolysis

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Fast-flash (low Temp. & high heating rate) Liquid oil

Slow (low Temp. & heating rate) Char

High Temp. & low heating rate at long residence time Fuel gas

Oil Extraction from Algae Using a mechanical press ( 70% , cheap)

Solvent extraction ( n-hexane)

Enzymatic extraction

Osmotic shock

Ultrasonic assisted extraction

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Supercritical fluids Supercritical carbon dioxide extraction (SFE)

313-323 K, 25-30 MPaWith or without co-solvent (1 mL methanol)Batch or continuous modePretreatment (grounding of dried at 308 K)

Sub- or Supercritical water Hydrothermal conversion of algae to biofuelLipid & free fatty acid5-400 atm, 373-723 K

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Biodiesel production

Trans-esterification process Acid , alkalis and lipase enzyme Non-or mono-unsaturated fatty acids of 16 or 18 carbon

length Rich in polyunsaturated fatty acids with four or more

double bonds

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Economic biodiesel productionMicroalgae bio-refinery

can produce biodiesel, animal feed, biogas and electrical power.

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Power Plant / Energy Source

Flue Gases

NOx + CO2 from combustion flue gas emissions

CleanedGases

Co-Firing

Fermentation

Trans-esterification

Drying

Green Power

Biodiesel

Ethanol

Protein Meal

Integrated pollution control and biodiesel productionMicroalgae farming and CO2 mitigation

◦ Planet, 0.03-0.06% ◦ Chlorella sp. 10-50%

Microalgae farming using wastewater◦ Removing of N, P and heavy metal

Microalgae farming using marine microalgae◦ Red marine algae, green marine algae and marine phytoplankter ◦ CO2 and Nox mitigation

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Enhance algae biologyMolecular level engineering can be used to potentially:

◦ Increase photosynthetic efficiency◦ Enhance biomass growth rate◦ Increase oil contant◦ Improve temperature tolerance◦ Eliminate the light saturation phenomena◦ Reduce photo-inhibition ◦ Reduce sensitivity to photo-oxidation

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References[1] D. Bowle, Micor- and Marco-Algae: Utility for industrial application, Economic

Potential of Sustainable Resources – Bioproducts, 2007.[2] Food and Agriculture Organization of the United Nations (FAO), Algae-based biofuels,

www.fao.org/bioenergy/aquaticbiofuels, 2009.[3] G C. Dismukes, D. Carrieri, N. Bennette, G. M. Ananyev, M. C. Posewitz, Curr. Opin

Biotechnol, 2008, 19:235–240.[4] Y. Chisti, Biotechnology Advances, 2007, 25, 294–306.[5] J.ohn Sheehan, T. Dunahay, J. Benemann, P. Roessler, A Look Back at the U.S.

Department of Energy’s Aquatic Species Program—Biodiesel from Algae, National Renewable Energy Laboratory,1998.

[6] G. Taylor, Energy Policy, 2008, 36, 4406–4409.[7] Y. Li, M. Horsman, N. Wu, C. Q. Lan, N. Dubois-Calero, Biofuels from Microalgae,

10.1021/bp070371k CCC, 2008.[8] F. Lehr, C. Posten, Curr. Opin. Biotechnol. 2009, 20,280–285,[9] L. L Beer, E. S Boyd, J. W Peters, M. C. Posewitz, Curr. Opin. Biotechnol. 2009, 20,

264–271.[10] P. F.F. Amaral, M. G. Freire, M. H. M. Rocha-Lea˜o, I. M. Marrucho, J. A.P. Coutinho,

M. A. Z. Coelho, Biotechnol. Bioeng., 2008, 99 ,588-598.[11] M. Aresta, A. Dibenedetto, G. Barberio, Fuel Processing Technology, 2005, 86, 1679–

1693.

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[12] N. Mitropoulos, WO 2008/151373 A1.[13] C. Keeler, J. D. Stephenson, S. W. Schenk, B. Cloud, M. Bellefeuilie,

WO 2010/017002A1.[14] G. Erb, D. R. Peterson, US 2010/0034050 A1.[15] E. H. Katchanov, US 2010/00118214 A1.[16] J. R. Munford, GB.2447905 A.[17] V. Slavin, US 2009/0035835 A1.[18] L. V. Dressler, US 2009/10151241 A1.[19] R. Downy, WO 2010/027455 A1.[20] T. Merimon, J. McCall, US 2010/0068791.[21] B. Chian-pin Wu, C. A. Deluca, E. K. Payne, US 2010/0050502.

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Thank you

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Bio-hydrogen Steam-reformation of bio-oilsPhotolysis of water catalyzed by special microalgae

species Indirect photolysis,

Cost of the huge bioreactorsCost of hydrogen storage facilities (night or cloudy day)

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starch

Anaerobic Hydrogen