Algae Biofuel Research at the University of Texas at Austin

Cost-Effective Production of Biodiesel from Algae

Dr. Rhykka Connelly

What are Algae?

• Algae range from small, single-celled organisms to multi-cellular organisms, some with fairly complex and differentiated form.

• Like plants, algae require primarily three components to grow: sunlight, carbon-dioxide and water. Photosynthesis is an important bio-chemical process in which plants, algae, and some bacteria convert the energy of sunlight to chemical energy.

H2O

O2

CO2

energy

nutrients

oildroplets

Micro-algae make and store many types of energy: lipids and fatty acids as membrane components, sugars/starches, and other metabolites

(~2% - 40% of lipids/oils by weight).

Overview

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

Large-scale Cultivation of Algae in Open Ponds

Open ponds can be categorized into natural waters (lakes, lagoons, ponds) and artificial ponds or containers.

Large-scale Cultivation of Algae in Photobioreactors

Cultivation

Visual/Molecular Identification

Strain Selection and Growth Optimization

1

Ankistrodesmus falcatus

Botryococcus braunii

Chlorella vulgaris

Chlamydomonas debaryana

Coelastrum proboscideum

Dictyosphaerium pulchellum

Neochloris cohaerens

Scenedesmus dimorphus

Nannochloropsis oculata

Oil Contentunder various

growth conditions

Protein Contentunder various

growth conditions

HPLC/MS(high performance

liquid chromatography/mass spectrometry)

Characterize andOptimize Growth

2Analyses

3

• HPLC - quantify lipids, e.g. triacylglycerols (TAGs), diacyglycerols (DAGs), free fatty acids (FFAs), phospholipids (PLs) in a sample

• MS – confirm identify of lipid species by molecular weight

TLC(thin layer chromatography)

• TLC – easily visualize changes in lipid composition over time or between different samples

GC(gas chromatography)

• GC – identify lipid species by chain length

Peak identification in GC profile above: (1) caprylic acid (C8:0); (2) capric acid (C10:0); (3) lauric acid (C12:0); (4) myristoleic acid (C14:1); (5) myristic acid (C14:0); (6) pentadecanoic acid (C15:0); (7) palmitoleic acid (C16:1); (8) palmitic acid (C16:0); (9) heptadecanoic acid (C17:0); (10) linoleic acid (C18:2n-6c); (11) oleic acid (C18:1n-9c); (12) -linolenic acid (C18:3n-3); (13) stearic acid (C18:0); (14) arachidonic acid (C20:4n-6); (15) eicosapentaenoic acid (C20:5n-3); (16) eicosenoic acid (C20:1); (17) arachidic acid (C20:0); (18) docosahexaenoic acid (C22:6n-3); (19) erucic acid (C22:1); (20) behenic acid (C22:0); (21) nervonic acid (C24:1); (22) hexacosanoic acid (C26:0); (23) octacosanoic acid (C28:0); (I.S.) tricosanoic acid (C23:0).

Total Protein• track total protein over growth cycles or changes

in protein content due to cultivation or genetic modifications

Protein Isolation

• isolate specific industrially-relevant proteins

lake harvester

NASA Uses Algae to Turn Sewage into Fuel

Belt harvester

flocculation

filtration

Algal Lysis Techniques

apply high pressure sonication

15 psi = 1 atmneed ~20,000 psi

UT/CEM-developed and -patentedElectromechanical Forces

CEM Algae Lysis Validation

lyse• patented technology

employing electromechanical forces strip cell walls and expose lipid droplets

• solventless system maintains the integrity of the algal biomass

• works on fresh, brackish, and marine algae

• extremely cost efficient

microscopicimaging

chlorophyllrelease

lipid release

• cell walls are stripped• Nile Blue staining reveals extruded lipids

• High power images of intact Chlorella (left) show compact, well-ordered cellular structures.

• In contrast, pulsed algae (right) are disordered. The nucleus (N), chloroplasts (C), and Golgi (G) are compromised. The cell is in disarray and is likely initiating cell death mechanisms.

• chlorophyll molecules released into the supernatant are quantified spectrophotometrically at 436nm, the wavelength associated with chlorophyll a

• neutral lipids released into the supernatant are quantified fluorometrically at 520nm with Nile red or BODIPY493/503. On the left, Nile red fluoresces green indicating lipid droplets in Chlorella. Chorophyll molecules autofluoresce in red.

Development of aspecies-specificpulse scheme

• The CEM-developed standard pulsing scheme lyses most algae species tested

• Pulsing schemes are optimized for specific algae by systematically changing pulse parameters:

• electrical pulse amplitude• pulse width• frequency of pulses

Evaluation of a

pulsing scheme

• each time a parameter is changed, the pulsed algae are evaluated by:

• microscopic imaging

• chlorophyll release into the surrounding media

• lipid release

• parameters are adjusted until maximal chlorophyll and lipid release is achieved

• all experiments are performed with negative (unpulsed) and positive (French press-lysed) controls

Director: Dr. Robert Hebner. Algae Biofuels Program Manager: Mike Werst.Center for Electromechanics (CEM), 10100 Burnet Rd., Austin, TX 78758

solvent extraction supercritical fluid extraction

Algal Oil Extraction Methods

expeller press

UT Separations – Extracting the Oil

• Patented membrane technology• Primary extraction process

– Novel, non-dispersive, solvent contactor—modified commercial process

• Two promising alternative extraction processes– May eliminate distillation and

stripping

• Alternative distillation approaches

UT Mass Balance: Track the Oil

HPLCUT’s Mass balance approach:

– Sample from each step in the process– Identify and quantify important lipids/oils– Track the changes in the oil throughout processing– Unique in the field

Thin Layer Chromatography (TLC)

According to an article published in May 2007 by the Nature magazine, Algae can also be picky:

• too much direct sunlight can kill them,

• temperature must be held steady,

• overcrowding will inhibit their growth,

• oxygen that they produce must be continually removed from the water,

• open algal ponds are subject to evaporation and rainfall, which cause salinity and pH imbalances, and

• local species of algae can overgrow the desired strain.

Challenges in Algaculture

• The technical feasibility demonstrated years ago– Present cost to produce 1 gallon of algae oil—$20-30/gal– Threshold is $2.00/gal– Stretch goal is $0.50/gal

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

Another Challenge– Production Cost

At present most companies in the sector are early stage start-ups and involved in R&D rather than commercialization. To date, none has launched full commercialization/industrialization of biodiesel from algae oil on a large scale.

Main obstacles to realization Besides the challenges in Algaculture, there are some other obstacles to the realization of Algae oil projects:

Financing. Although specialized VC firms in this sector are rare, there have been some interesting developments recently.

Technology. Most companies only conduct R&D and are only nearing commercialization in years to come.

Competition. There are many small start-up companies in the sector. We can assume that some bigger companies will emerge out of the group of early-stage businesses – potentially making market-entry more difficult.

Intellectual property. Patents are beginning to play a key role, especially when the technology becomes mature and the companies are nearing commercialization,

• UT has partnered with VC firm to establish a start-up company, OpenAlgae

• UT synergizes its R&D with cost-effective scale-up strategies

• UT is developing partnerships with other start-ups to maximize strengths

• UT is innovative – several technology patents and patents pending

• 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

main advantages of deriving biodiesel from algae oil include:

• rapid growth rates

• a high per-acre yield (between 5000 – 20,000 gal/acre/yr) • certain species of algae can be harvested daily

• algae biofuel contains no sulphur, is non-toxic, and is highly biodegradable

• algae consume carbon dioxide as they grow, so they could be used to capture CO2 from power stations and other industrial plant that would otherwise go into the atmosphere.

According to U.S. Department of Energy:

Currently most research into efficient algal oil production is being done in the private sector, but if predictions from small scale production experiments bear out then using algae to produce biodiesel may be the only viable method by which to produce enough automotive fuel to replace current world gasoline usage.

The Algae Advantage

Summary

• The solution is multidisciplinary• UT has organized a highly competent, multidisciplinary team• OpenAlgae supported

• Optimization of the process requires understanding at the process level, not just the individual step level• UT is an end-to-end operation• Mass balance analyses have yielded critical information…and more

questions

• Significant progress is being made in driving down cost• UT innovation has generated patented and patent-pending

technologies