Dr. Chandra TheegalaDepartment of Biological and Agricultural EngineeringLouisiana State University

ARE WE THERE YET ON ALGAL BIOFUELS: WHAT REMAINS TO BE

DONE?

*Chandra S. Theegala, Ph.D.Associate Professor

Biological and Agricultural EngineeringLSU AgCenter & LSU

Baton Rouge, LA

Chandra Theegala*, Adam Dassey, Beatrice Terigar, Javed Iqbal, Ronald Malone

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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

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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)

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Biodiesel Economics ~ Approx. Production Figures

Description Unit Cost Cost/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 (+)

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Oil Productivities of Various Crops

Source: Modified from Chisti, 2007.

Crop Oil Yield [gal / acre]

Total Cropping Area Required for Meeting 100% Transportation Fuels Needs

Corn 18 1,692%

Soybean 48 652%

Canola 127 244%

Jatropha 202 144%

Coconut 288 108%

Oil palm 636 48%

Microalgae (Estimate) 30% lipids 70% lipids

6,275 14,633

5%2.2%

Sustainability – Practicality??Crop Oil Yield

[gal / acre]Acreage Needed for Average Family (~1200 gallon per year)

Soybean 48 25 acres

Canola 127 9.5 acres

Jatropha 202 6 acres

Coconut 288 4.2 acres

Oil palm 636 2 acres

Microalgae Chisti’s Estimate 30% lipids 70% lipidsMy Estimate

6,275 14,6332,000

0.2 acres0.08 acres0.6 acres

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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

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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

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

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Adam, PhD*- Harvesting

Beatrice, PhD*Lipid Intensification/Light Optimization

PhD – Species Dominance/ Contaminant Control

Javed, PhD – Lipid Extraction

Nick, MS*- SpeciesScreening

LSU BAE - Microalgal Research Team (Spring 2012)Covering all bases!!

Mostafa

Jacob

Dissolved Air Flotation Prototype

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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

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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 ! ?)

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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 Mechanics.com

Lipid Intensification, Light Optimization, Improved Pond Designs

Full sunlight is PAR ~ 2,000 µmol/m2/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.

The Contamination Problem & Species DominanceFacts

Several thousands of microalgal species But only a handful can be mass cultivated. High lipid and weaker strains – gets replaced in outdoor

pondsSpirulina – high alkalinity

Contamination Problem 1) Replacement by faster growing algal species 2) Predation by higher organisms.

Ideal Plug FlowCONTAMINANT SLUG (Non-multiplying)

CONTINUOUS

TIME

% WASHOUT IN ONE HRT = 100 %18

Series of CSTRS Mimics Plug FlowContaminant

Contaminant may grow But never displaces the main speciesAlgae

Higher Density

10 cells

108 Cells1000 cells

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Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR) : My PhD work.Co-Advisors: Dr. Ronald Malone & Dr. Kelly Rusch

Turbidostat Series of CFSTRs

Outdoor- amplifier Biomass increases with CSTR Open to atmosphere

Pure inoculum

Inoculummedia

mediawater

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Computer Automated 3,000 gallon - HISTAR System

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Contaminant Washout Demonstrated

Purposefully added 300 million rotifers

System did not collapse

Algal species and predators got flushed out

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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

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

Questions?

Chandra TheegalaAssociate ProfessorBio & Ag EngineeringLSU AgCenter/LSUEmail: theegala@LSU.eduPhone: (225) 578 1060

Dr. Chandra TheegalaDepartment of Biological and Agricultural EngineeringLouisiana State University