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Utilization of Algae for Biofuels Production. Supervisor: Prof. H. S. Ghaziaskar By: M. Rezayat Department of Chemistry Jun 1, 2010. Outline. Introduction Algae Microalgae As a potential replacement fuel Large scale production Harvesting and drying Fuel production Oil extraction
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Utilization of Algae for Biofuels Production Supervisor: Prof. H. S. Ghaziaskar By: M. Rezayat Department of Chemistry Jun 1, 2010
Outline • Introduction • Algae • Microalgae • As a potential replacement fuel • Large scale production • Harvesting and drying • Fuel production • Oil extraction • Economic biodiesel production
Biofuels • Forestry • Agriculture • Aquatic • Bio-diesel • Bio-oil • Bio-gas Biomasses • 6-8% • 1.8-2.2% Biomass Oxygen
Algae • Microalgae: • Microscopic photosynthetic organisms • In both marine and freshwater environments. • Macroalgae (seaweed): • Multicellular plants • In both salt or fresh water, • They do not have roots, stems and leaves • 60 m in length • 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 • Adaptable to grow in different conditions • Fresh or marine-waters • Wide range pH
Why Microalgae? 50 times more • Simple structure High 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
Disadvantages: • Low biomass concentration • Small size makes their harvest relatively costly. • Drying would be energy-consuming process. • History : • 1950s, the first report on algae biofuels at MIT. • 1970, initial examination on algae. • 1980, subsequent studies Algae Culture from Laboratory to Plant (Burlew, 1953)
Potential of Microalgae biodiesel • 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 • CO0.48H1.83N0.11P0.01 • 50% of dry weight is Carbon • Producing 100 tons algae biomass 183 tons CO2
Large scale production • Raceway ponds • Cost less to build & operation • Photobioreactors • Provide much greater oil • Recovery cost is less • Biomass concentration is 30 times raceway ponds production
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 • Temperature fluctuation • Contamination with unwanted algae and microorganisms • Poorly mixed • Biomass concentration is low • Dark zone
Photobioreactors • Single-speciesculture • 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
Oxygen removing • 10 g m-3min-1 • Inhibit photosynthesis • Photooxidative damage • Need to a degassing zone • Tube length ≤ 80 m Biomass concentration Light intensity Flow rate Oxygen concentration (entrance of tube)
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. • 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 long time Decomposition • Microalgae harvesting: • Chemical and biological flocculation • Filtration • Centrifugation • Ultrasonic aggregation More efficient More costly long time, Large surface Loss of bioreactive products • Microalgae drying: • Sun drying • Low-pressure self drying • Drum drying • Spry drying • Freeze drying More efficient More costly
Fuel production • Direct combustion (boiler & steam turbines), • high moisture content • Anaerobic 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 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
Oil Extraction from Algae • Using a mechanical press ( 70% , cheap) • Solvent extraction ( n-hexane) • Enzymatic extraction • Osmotic shock • Ultrasonic assisted extraction
Supercritical fluids • Supercritical carbon dioxide extraction (SFE) • 313-323 K, 25-30 MPa • With or without co-solvent (1 mL methanol) • Batch or continuous mode • Pretreatment (grounding of dried at 308 K) • Sub- or Supercritical water • Hydrothermal conversion of algae to biofuel • Lipid & free fatty acid • 5-400 atm, 373-723 K
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
Cleaned Gases Economic biodiesel production Microalgae bio-refinery can produce biodiesel, animal feed, biogas and electrical power. Co-Firing Green Power Power Plant / Energy Source Biodiesel Trans-esterification Flue Gases Ethanol Fermentation Protein Meal Drying NOx + CO2 from combustion flue gas emissions
Integrated pollution control and biodiesel production • Microalgae 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 Noxmitigation
Enhance algae biology • Molecular 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
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. OpinBiotechnol, 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.
[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 2010/027455A1. [20] T. Merimon, J. McCall, US 2010/0068791. [21] B. Chian-pin Wu, C. A. Deluca, E. K. Payne, US 2010/0050502.
Bio-hydrogen • Steam-reformation of bio-oils • Photolysis of water catalyzed by special microalgae species • Indirect photolysis, • Cost of the huge bioreactors • Cost of hydrogen storage facilities (night or cloudy day) starch Anaerobic Hydrogen