Research Institute for Climate Change

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Research Institute for Climate Change
SustainabilityClimate2030 Clean Energy
TechnologiesBiofuelsDr David Lewis Dr Peter
AshmanMicroalgal Engineering Research Group
(MERG)School of Chemical Engineering
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What are Biofuels?

• Fuels produced from renewable organic sources
• Fuels for electricity generation biomass,
  forestry residues, black liquor
• Transport fuels biodiesel, bioethanol

What Biofuels are not!

• A one-shot magic bullet
• Life-cycle greenhouse gas emissions can vary
  widely
• Resource (labour, land, water) intensive
• Supportive of regional and developing economies

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What is biodiesel?
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• Renewable diesel
• A transport fuel produced from crude or recycled
  vegetable oils, oilseed crops and/or animal fats
  which is "equivalent" to petroleum-derived diesel
• A mixture of fatty acid methyl esters (FAME)
• "Legal definition" in Australia Fuel Standard
  (Biodiesel) Determination 2003
• Specifies min. ester content, max. impurity
  levels physical properties

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Why Biodiesel, Why now?

• Drivers for biodiesel
• Increased oil/diesel prices
• Efficient, lower cost manufacturing plant
• Government support (oil cost/supply or GHG?)
• Capital grants
• Mandated 350 ML renewable fuels by 2010
• Low-sulphur diesel
• Threats for biodiesel
• Cost of feedstock
• Fuel excise
• Quality education

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Advantages of biodiesel

• Uses in existing vehicles with existing
  distribution infrastructure
• Blendable with mineral diesel
• Much smaller greenhouse footprint than mineral
  diesel
• Lower combustion emissions than mineral diesel
• High lubricity compared to ULSD
• Non-toxic biodegradable (storage issues)
• Socio-economic advantages
• Proven technology utilising a range of feedstocks
• Growing international market

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Disadvantages of biodiesel

• Storage stability
• Cold flow properties
• Rapeseed Methyl Ester Pour Point 15oC
• Soybean Methyl Ester 3oC
• Tallow Methyl Ester 16oC
• High cost of production
• Competition for agricultural resources (labour,
  arable land, fresh water)

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Australian Production Capacity
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Biodiesel Economics

• Feedstock accounts for 65 90 of biodiesel
  production costs
• "Typical" feedstock prices
• Canola Oil 800/t
• Palm Oil 1000/t
• Tallow 950/t
• Excise subsidies
• Value of by-products??

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Changing excise landscape

• Pre-2006
• Excise duty (38/L) offset by Energy Grants
  (Cleaner Fuel) Credit Scheme (38/L)
  Alternative Fuels Grant (14.8/L)
• Net Eligible biodiesel subsidised by 14.8/L
• Post-2006
• 2006-2010 AFG reduces to zero
• 2010-2015 EGCS reduces to 19/L
• 2015 Net Eligible biodiesel taxed at 19/L
• But from 1 July 2006, off-road users and large
  on-road users (gt 4.5 tonnes) are exempt from
  38/L excise provided fuel meets Australian
  diesel standard

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Does the Australian Biodiesel industry have a
future?

• Maybe
• Significant Capex has been committed
• Clarification of excise uncertainty and
  acceptance as a genuine fuel necessary to ensure
  profitability
• Access to low-cost feedstock required for survival

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Biodiesel from Microalgae?
As feedstock for existing plant
A dedicated production facility
Integrated Algal-biodiesel Production Facility
incorporating production, harvesting, extraction,
reaction and separation
Inputs
Biodiesel
B100 B20 B5 ??
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Background AP6 project

• Proposed to produce an algal oil feedstock for
  the production of biodiesel using microalgae
  growing in saline water.
• Uses elite strains of microalgae isolated from
  Australian saline water habitats
• Screened for their suitability for large-scale
  production under Australian conditions,
• ease of harvesting
• high lipid productivity while in the active (log
  phase) stage of growth
• Optimisation of the whole production process
• algal culture
• biomass harvesting
• ease of oil extraction from the biomass
• effective use of the biomass remaining after
  extraction
• The process proposed is based on proven open-air
  raceway pond culture systems

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Microalgae

• Cultures are dilute
• 500 mg/l dry wt
• Very small (3 30 mm)
• For bio-diesel need paste 15 solids
• HRAP 0.5 to 1 solids
• Typically centrifuge 20 solids
• Require pre sedimentation 3 solids
• Centrifuge 15 solids

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Current systems
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Conceptual system
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Cyanotech production plant at Kona, Hawaii.
Reddish ponds Haematococcus other ponds
Spirulina
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Haematococcus plant operated by Algatech Ltd,
Kibbuz Ketura, Israel
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Harvesting

• Algae can be harvested using
• Micro-screens
• Centrifugation
• Flocculation
• Froth flotation
• Auto-flocculation
• Ultrasound

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Auto-flocculation and bio-flocculation

• considered to be the most promising means for the
  economical harvesting of microalgae
• produce extracellular polymers during ageing
• can initiate bio-flocculation
• algae sediment more readily upon ageing, possibly
  as a result of increased ceil density

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Extraction

• Chemical solvents Algal oil can be extracted
  using chemicals
• Enzymatic extraction
• Expression/Expeller press
• Osmotic shock
• Supercritical fluid
• Ultrasonic-assisted extraction

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Economics

• Current (June 2007) prices for oils used in the
  manufacture of biodiesel (FOB)
• Crude US60 70 per barrel.
• Current cost of production of microalgae is
  greater than about AUS 8 kg-1 dry weight. At an
  oil content of 40 this would mean an algal oil
  price of about AUS 20.kg-1 or about AUS 17 l-1.
  
• The US Defence Department is estimating that the
  current production cost of algae oil exceeds 20
  (13) a gallon. Despite this, algae-based
  research and development is increasing
• For comparison crude oil (at US100 per barrel)
  costs about AUS 0.94 l-1 and vegetable oil (at
  US700 t-1) costs about AUS 0.69 l-1 i.e. the
  algal oil is about 10x more expensive than
  alternative feedstocks!!

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Acknowledgements

• The MERG team

Special Thanks

• Michael Borowitzka
• Peter Ashman