Algae Biofuel Research at the University of Texas at Austin

Cost-Effective Production of Biodiesel from Algae

Mike Werstm.werst@cem.utexas.edu

February 9, 2010

Algae is the Clear Choice“Biofuels Made from Microalgae Hold the Potential to Solve Many of the

Sustainability Challenges Facing Other Biofuels Today” (US DOE)

• Highest Productivity – Currently, algae can yield more than 2,000 gallons of fuel per acre, compared with 50 gallons for

soybean oil and 650 gallons for palm oil

• Continuous Harvesting – Growing algae is a continuous process, compared with the production of plants such as corn,

which are typically harvested annually and stored for later use

• Bypasses the “Food or Fuel” Fight – Algae can be cultivated in large open ponds or in closed photobioreactors located on non-arable

land in a variety of climates including deserts

• Flexible on Water Quality – Since algae growth does not require fresh water, it can thrive in brackish or salt water. Even

treated waste water can be used, as the water itself acts as a nutrient to foster growth

• Strongest CO2 Advantage– During photosynthesis, algae use solar energy to fix CO2 into biomass, which presents an

opportunity to make productive use of the CO2 from other sources

• Value-Added Byproducts – The remaining biomass residue is not waste and can be used as organic fertilizer, animal or fish

food, and biomass for power generation

Sources: US Department of Energy; The Lamp 2009, ExxonMobil

MARKET OPPORTUNITY

• The technical feasibility demonstrated years ago– Present cost to produce 1 gallon of algae oil—$20-30/gal

• Issues…production scale-up and cost reduction– Strain selection - oil yield, growth rates, stability– Production systems - ponds or photobioreactors– Oil content & consistent definition of oil– CO2 and nutrient sources– Harvesting– Oil extraction– Capital costs– Energy and water usage

The Problem – Production Cost

The UT Effort is• Large

– ≈ 30 faculty, researchers, and students– Plus larger group of researchers in associated, related fields

• Multidisciplinary– Biologists, biochemists, physicists, mechanical engineers, electrical

engineers, chemical engineers, and environmental engineers• Focused on fuel

– Complete process • Algae selection – Key driver of economics• Growth• Harvesting• Dewatering• Lysing• Separation• Metrology – Without good process measurements, there is no process control• Biodiesel production – As needed, anticipate relatively small research need• Life cycle analysis – Regulatory acceptance

Research is on reducing process cost

HarvestingFiltrationSettling

Water

BiofuelsProcessingConcentration

PreparationLysing

Extraction

Biomass Co products

Algae Production

BiodieselBiogasJP-8Ethanol

FeedsFertilizersEnergy

Sunlight

TimeMake-up water

UT Program

Simplified Algae Oil Process

Nutrients

CO2

Algae Selection• Culture Collection of Algae--UTEX

– About 3000 strains available– Expertise in growth and identification

• Cellular engineering– Optimize triglyceride production in existing species

• Genome analysis

GrowthCenter for Electromechanics

• Growth primarily to support process development effort• Helping us understand species selection impact on

processing• Control of nutrient levels and light intensity to maximize

triglyceride production• Identification and control of predators• Maintenance of healthy growth ecology

Harvesting/ConcentrationEnvironmental and Water Resources Engineering—Lynn Katz/Kerry Kinney

• Challenges: • Dilute concentrations of micron size

algae• Varying water composition• Harvesting economics preclude

excessive water pumping• Maintaining water quality essential for

discharge, recycling and reuse• Investigating wide range of low cost

harvesting methods for algae grown in a variety of source waters

• Developed harvesting process that yields algae concentrate suitable for proprietary oil extraction process.

• Current testing at bench and pilot-scale

• Electromechanical cell lysing verified by:– EM Analysis - good correlation with wave theory– Spectrophotometer chemical and chlorophyll assays– Biodiesel and algae oil quantities produced– Released triglyceride, protein and enzymes analyses– Fluorescent imaging– High speed camera imaging– Scanning electron microscope

– Also use Dounce homogenizer, bead beater, ultrasonic and French press for comparison

0

1

2

3

LysingCenter for Electromechanics

SeparationsSeparation Research Project—Frank Siebert

• Selective solvent• Primary extraction process

– Novel, enhanced solvent contactor—modified commercial process

• Two promising alternative extraction processes– May eliminate distillation and

stripping

• Alternative distillation approaches

Process CharacterizationMolecular Cell Biology—Martin Poenie

Center for Electromechanics—Rhykka Connelly

Mass SpecNMR

HPLC

Analytical methods provide– Molecular identification– Accurate quantitation of oils– Guidance on algae selection – Feedback on algae health– Data for process mass balances– Information on oil quality

TLC

12

UT Algal Oil ProcessingFluidic Concentrate (89-99% Removal; up

to 100X concentration factor)

Cultivation:Outdoor Pond

CEM

Extraction:Enhanced Contactor

ProcessSRP

Lysing:Electro-

MechanicalCEM

Harvest:Sweep

Coag/Defloc*EWRE

Growth Volume

Discharge Water

Concentrate

LysedConcentrate

Biomass Outlet Algal Oil*centrifugation used when quantity insufficient for sweep coag/defloc equipment

Economic Target

• Threshold– $2.00/gal algal oil– Assumed entry level for jet fuel, particularly for

DOD• Stretch Goal

– $0.50/gal algal oil– Economical for most existing markets

Algal Oil Processing Economics-Projection for 50MM gal/yr algal oil production--Based on integrated pilot scale demonstrations-

Process Description Installed Capital Cost ($M)

Operating Cost/Gal Algae Oil ($/gal)*

Cost/Gal Algal Oil ($/gal oil)

Concentration Sweep coagulation- deflocculation

305 0.06 0.56

Lysing Electromechanical 18 0.06 0.08Oil Separation Enhanced contactor

w/distillation37 0.21 0.38

TOTAL $1.02/gal algal oil

• Assumptions:– Oil content—20% (Triglycerides)– Media conductivity—18 ms/cm– Algae growth density—1g/L– Lysing/separation algae density—5% dw– 50 MM gal/yr production (algae oil)

– Installed capital cost—3-4 times cost of equip.– Depreciation—10-15 yr life, 6.7-10% of installed

cap costs– Maintenance—4-6.7% of installed capital costs– $0.10/kWhr– Extraction efficiency—71%

• Oil content & growth density must be improved• Alternative concentration methods or low water growth methods must be developed

• Modular pilot plant demo planned (2010)• Initial plant sized to fit 18-wheeler to evaluate a

variety of algae sources• UT resources engaged to meet challenge

Commercialization Plan

Commercialization

EM Oil ExtractionPilot Plant

Demonstration

OptimizedElectrodistentionDose Response

OptimizedPower Supply Design

Design/Demo ofFlow Through

Distention Process

Subscale ExtractionPlant & Pond Design

Oil Quantification &Analysis

Algae Inoculation &Growth

Algae Dewatering

Post Oil Separation

• Oil producing algae growth capability up to 2,500 gal

• Dewatering process demonstrated at 5000 gal/day

• Flow-through EM lysing apparatus built; used to process dewatered algae.

• Novel version of commercial separation process demonstrated

• Mass and energy balance performed on integrated system of processes

• Mobile extraction pilot plant design in-progress

Commercialization Moving Forward

Research to Support Commercialization

• Research to reduce commercialization costs includes– Enhanced growth techniques– Species improvement– Minimization of water usage– Return water purification– Alternate technologies for dewatering, lysing, and

separation to further reduce cost– Process measurement technology– Process automation– Integration of algal oil production with complementary

processes

Summary

• The solution is multidisciplinary• Optimization of the process requires

understanding at the process level, not just the individual process step level

• Significant progress is being made in driving down cost