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Dr. Chandra Theegala Department of Biological and Agricultural Engineering Louisiana State University.

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Presentation on theme: "Dr. Chandra Theegala Department of Biological and Agricultural Engineering Louisiana State University."— Presentation transcript:

1 Dr. Chandra Theegala Department of Biological and Agricultural Engineering Louisiana State University

2 ARE WE THERE YET ON ALGAL BIOFUELS: WHAT REMAINS TO BE DONE? *Chandra S. Theegala, Ph.D. Associate Professor Biological and Agricultural Engineering LSU AgCenter & LSU Baton Rouge, LA Chandra Theegala*, Adam Dassey, Beatrice Terigar, Javed Iqbal, Ronald Malone

3 3  Biodiesel facts and need for biodiesel lipids  Potential of algae as a biodiesel feedstock  Primary challenges and my research solutions Cost-effective cell harvesting & dewatering* High infrastructure cost* Need for intensification of aerial productivity* Benign and cost-effective lipid extraction # Contaminant mitigation and species dominance (PhD work)  Questions & Answers (slide number will help) * Critical today # Excluded due to time limitations Overview of Presentation

4 4 Biodiesel Facts and Need for Lipids  US diesel needs: ~ 60 billion gal/year  Total US transportation fuel needs ~ 200 billion gal/year  Biodiesel production (2011-12) ~ 1.1 billion gallons/year  Biodiesel production limited by feedstock availability  Biodiesel – Advanced/non-starch fuel. RFS2: 21 billion gallons  Bottomline: Need new and non-food/feed sources of oil  Microalgae has potential to produce 2,000 - 3,000 (or more) gallons/acre/year (compared to ~70-80 gal/acre/year from soybean)  Several limitations exist for microalgal biofuels Reality Snapshot/In a Nutshell: US Navy Contract to Solazyme: ~$425/gal (20,000 gal, heterotrophic direction)

5 5 Biodiesel Economics ~ Approx. Production Figures DescriptionUnit CostCost/gallon Oil (1 gallon, 7.5 lb)$0.53/lb$3.97 Methanol (0.11 gal x 1.5) $1.45/gal$0.24 Catalysts + Chemicals$0.10 Natural gas + Electricity$10/mmbtu; $0.10/Kwh$0.03 Labor + Maintenance $0.10 Interest/Depreciation$0.15 ------------------------ $4.59 = Oil cost + $0.60 Final Cost: Govt. Incentives/Subsidy (-) Distributor/retailer profit (+), Transportation (+)

6 6 Oil Productivities of Various Crops Source: Modified from Chisti, 2007. CropOil Yield [gal / acre] Total Cropping Area Required for Meeting 100% Transportation Fuels Needs Corn181,692% Soybean48652% Canola127244% Jatropha202144% Coconut288108% Oil palm63648% Microalgae (Estimate) 30% lipids 70% lipids 6,275 14,633 5% 2.2%

7 Sustainability – Practicality?? CropOil Yield [gal / acre] Acreage Needed for Average Family (~1200 gallon per year) Soybean4825 acres Canola1279.5 acres Jatropha2026 acres Coconut2884.2 acres Oil palm6362 acres Microalgae Chisti’s Estimate 30% lipids 70% lipids My Estimate 6,275 14,633 2,000 0.2 acres 0.08 acres 0.6 acres 7

8 Microalgal Facts  Several species have up to 40-60 % lipids contents.  Several species can grow at extremely fast growth rates. (think of 1 foot plant going 7 to 10 feet by end of the day)  High biomass productivity & high lipids contents are mutually exclusive  High lipid strains are slow growing and highly susceptible to contamination  Several thousands of recognized species of microalgae.  But less than a handful can be mass produced outdoors (Weeds & predation).  Production from microalgae is not straight forward (several challenges exist).  Low solar energy conversion efficiencies (~2-3%). So surface area and open ponds are important (PBRs????, for biofuels? ) 8

9 9 Primary Limitations for Microalgal Biofuels  High harvesting costs (Think – Removing color in water!)  High infrastructure costs  Need for intensification (70 gal/acre works, but 2000 does not?)  Need for benign and cost-effective lipid extraction #  Species dominance & contaminant control in open cultures (PhD) # Not covered due to time limitations

10 Cost Effective Harvesting & Dewatering  Very challenging task. Think – Removing color in water!  100 mg-dry/L (0.01%) to 20% solids. 2000 times for <$2-3/g-oil  Need 50-100 harvest cycles per year. Why? Low culture density (100-150 mg/L) is key for fast growth Specific growth rates plummet with increasing density  Each cycle - Huge volume to process (660,000 gal). Yield ~22 gal (assuming 150 mg/L density and 20% lipids, 2 ft. depth).  This is a money loser!  Economics will not improve with more harvest cycles (1 cycle loss will project to bigger loss on 100 cycles)  Centrifuges – effective but costly Microscopic & unicelluar~5 microns Marginal density differences (SP ~1) 2000-3000+ g forces > $25/gal oil 10

11 11 Adam, PhD*- Harvesting Beatrice, PhD* Lipid Intensification/ Light Optimization PhD – Species Dominance/ Contaminant Control Javed, PhD – Lipid Extraction Nick, MS*- Species Screening LSU BAE - Microalgal Research Team (Spring 2012) Covering all bases!! Mostafa Jacob

12 Dissolved Air Flotation Prototype 12

13 Electro-flocculation 100 times concentration from 0.01% to 1% But not a complete solution Cost of aluminum (coagulant) released – high Cheaper metal electrodes - promising 13

14 Proprietary 3-stage Harvesting System (Disclosure and Possible Patent) Cheapest way from 0.01% to 20%  Operating at ultra-lean modes  Major synergistic benefits Target price < $2-3/gallon (Final runs this week ! ? ) 14

15 15 High Infrastructure Cost  Pond and raceway construction costs are higher  Ocean based culture systems to lower construction costs  Indirect approach to address high infrastructure costs  Intensify lipid yield from 2,000 to 8,000–15,000/gal/acre/year  Will this effectively lower the burden of high infrastructure costs? Source: Algenol Source: Sapphire Energy Source: Popular

16 Lipid Intensification, Light Optimization, Improved Pond Designs  Full sunlight is PAR ~ 2,000 µmol/m 2 /s. Is this really needed?  Are the current raceways and ponds ideal for high aerial productivity?  DOE’s FOA 0000811, Target for 2018: 2,500 gal/acre/year  We have a developed novel techniques that shows major promise  Already proven at 2 levels (indoor 2 L bench-scale, outdoor 25 L prototype scale)  Awaiting final field-scale test results this summer.  Anticipating lipid yields of 8,000-15,000 gal/acre/year  Operational costs? If proven successful, this will be a major breakthrough for algal biofuels.

17 The Contamination Problem & Species Dominance Facts  Several thousands of microalgal species  But only a handful can be mass cultivated.  High lipid and weaker strains – gets replaced in outdoor ponds Spirulina – high alkalinity Contamination Problem 1) Replacement by faster growing algal species 2) Predation by higher organisms.

18 Ideal Plug Flow CONTAMINANT SLUG (Non-multiplying) CONTINUOUS TIME % WASHOUT IN ONE HRT = 100 % 18

19 Series of CSTRS Mimics Plug Flow Contaminant Contaminant may grow But never displaces the main species Algae Higher Density 10 cells 10 8 Cells 1000 cells 19

20 Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR) : My PhD work. Co-Advisors: Dr. Ronald Malone & Dr. Kelly Rusch TurbidostatSeries of CFSTRs  Outdoor- amplifier   Biomass increases with CSTR  Open to atmosphere  Pure inoculum Inoculum media media water 20

21 Computer Automated 3,000 gallon - HISTAR System 21

22 22

23 Contaminant Washout Demonstrated  Purposefully added 300 million rotifers  System did not collapse  Algal species and predators got flushed out 23

24 Are We There Yet?  Microalgae has lots of potential. 30x soybean yield (200x?) - Yes  Cost-effective harvesting – No (not yet) Reduce frequency of harvesting from 50-100 harvest cycles/year Get more oils per each harvest Economics should be favorable at 1 harvest cycle Bottomline: Lower harvesting/dewatering cost to < $1-2/gallon-oil  Intensification of lipids to 5,000 gal/acre/year – No (not yet)  Species and contamination control - Yes Methods exist for species and contaminant control DOE-ASP report (20 years research) - Grow native species Control is preferable for maximizing yield & lowering harvest frequency

25 Are We There Yet?  Lipid Extraction - Yes Effective methods do exist But need more benign techniques (non-hexane based, biodiesel solvent)  Bio-refinery Model – Not There, But Can Happen Other value added products – critical for industry (say proteins, nutraceuticals, animal feeds, etc.  Genetic/Novel Research – Futuristic (this is all we need!) Can drastically change the bioenergy scenario High lipids in proven and strainable Spirulina! Will be a winner!! No more bioenergy solutions needed

26 Questions? Chandra Theegala Associate Professor Bio & Ag Engineering LSU AgCenter/LSU Email: Phone: (225) 578 1060

27 Dr. Chandra Theegala Department of Biological and Agricultural Engineering Louisiana State University

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