Algae as a Feedstock for Biofuels

164 Pages·2011·7.66 MB·English

DISCLAIMER
The IA-AMF, also known as the Implementing Agreement on Advanced Motor Fuels,
functions within a framework created by the International Energy Agency (IEA). Views,
findings and publications of IA-AMF do not necessarily represent the views or policies of
the IEA Secretariat or of all its individual member countries.

Neither the authors nor the participating organizations nor the funding organizations
makes any warranty or representations, expressed or implied, with respect to use of any
information contained in this report, or assumes any liabilities with respect to use of or
for damages resulting from the use of any information disclosed in this document.

About the Cover:
Photos from left to right: (1) microalgae Haematococcus pluvialis, vegetative (Palmella-)
stage, are shown under light microscope (Image Source: Fraunhofer IGB:
http://www.igb.fraunhofer.de/start.en.html); (2) cyanobacteria often grow in long
filaments resembling algae (Image Source: biotechnologie.de); (3) macroalgae are
mulitcellullar, photosynthetic marine organisms with plant-like features (Image Source:
The Scottish Association for Marine Science); an aerial view shows Cyanotech’s outdoor
algae pond cultivation facility in Kailua Kona, Hawaii (Image Source: Cyanotech Corp.).
For details, see Chapter 4 in text.

Notice:
The IEA Advanced Motor Fuels Implementing Agreement, also known as the
Implementing Agreement for a Programme on Research and Demonstration on
Advanced Motor Fuels, functions within a framework created by the International
Energy Agency (IEA). Views, findings and publications of the IEA Advanced Motor Fuels
Implementing Agreement do not necessarily represent the views or policies of the IEA
Secretariat or of all its individual member countries.
Preface
Recently, a worldwide reemergence of interest in pursuing research and development
of algae as a feedstock for biofuels has occurred, and many R&D initiatives are
underway around the world as researchers, governments, and policy-makers become
aware of the considerable potential that algae possess. It can be expected that these
various initiatives will go in many different directions as researchers look for answers to
the challenges that algae-derived fuels face. Some pathways will be deemed
unsuccessful for large scale production while others will produce high-quality results. It
is important at this point to make an inventory and an assessment of the many various
activities and to try to develop recommendations about the most promising pathways
to success in making large quantities of transportation fuels from algae, which may help
policy-makers reach wise decisions about which areas of effort to support.

Specifically, the project team has been tasked under the International Energy Agency
(IEA) Implementing Agreement on Advanced Motors Fuels (AMF) with conducting a
study that assesses the state of the technology and opportunities associated with algal
fuels. Since the AMF Agreement focuses on end-use fuels, the focal point of this report
will be on the downstream activities (e.g., dewatering, oil/biomass extraction, and
conversion of algae and algal components to energy products). However, limited
investigation of upstream activities (e.g., strain selection, cultivation) was also
conducted to help identify promising lifecycle pathways. For more detail on upstream
activities, the IEA Implementing Agreement on Bioenergy Task 39 report entitled
“Current Status and Potential for Algal Biofuels Production” should be accessed (Darzins,
Pienkos, & Edye, 2010).

The authors would like to acknowledge several individuals and organizations for their
support throughout the preparation of this report. Specifically, the authors would like to
extend gratitude to:

• Cost sharing provided by International Energy Agency Advanced Motor Fuels
Implementing Agreement member countries Canada, Finland, Japan (LEVO),
and United States.

• Stephen O’Leary (Research Officer) and Patrick McGinn (Scientific Leader) at
the National Research Council (NRC) Canada Institute for Marine Biosciences
for extensive property data on algal strains housed at the Institute’s Research
Facilities and Ketch Harbour Research Facilities located in Nova Scotia, Canada.

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Table of Contents
Preface ................................................................................................................. iii
Acronyms and Abbreviations ................................................................................ x
Executive Summary .............................................................................................. xiii
1. Allure of Algae as Feedstock for Biofuels ........................................................ 1
2. Algal Fuel Industry Overview ......................................................................... 5
2.1. Existing Industry .......................................................................................... 5
2.1.1. Current Market Size ........................................................................ 5
2.1.2 Current Production Volumes ........................................................... 5
2.1.3. Current Algal Biofuel Prices ............................................................. 6
2.2. Projected Industry ....................................................................................... 7
2.2.1. Projected Market Size ..................................................................... 7
2.2.2. Projected Production Volumes........................................................ 8
2.2.3. Projected Algal Biofuel Prices .......................................................... 10
3. Government Support ..................................................................................... 11
3.1. North America ............................................................................................. 11
3.1.1. United States ................................................................................... 11
3.1.2. Canada ............................................................................................. 12
3.2. Europe ......................................................................................................... 13
3.2.1. European Union .............................................................................. 13
3.2.2. France .............................................................................................. 14
3.2.3. Germany .......................................................................................... 14
3.2.4. The Netherlands .............................................................................. 14
3.2.5. United Kingdom ............................................................................... 15
3.3. Australia and New Zealand ......................................................................... 15
3.4. Asia .............................................................................................................. 16
3.4.1. Thailand ........................................................................................... 16
3.4.2. Philippines ....................................................................................... 17
3.4.3. South Korea ..................................................................................... 17
3.4.4. Indonesia ......................................................................................... 17
3.5. South America ............................................................................................. 17
3.5.1. Brazil ................................................................................................ 17
3.5.2. Chile ................................................................................................. 17
3.6. Africa ........................................................................................................... 18
4. Algal Biofuels Production Spectrum ............................................................... 19
4.1. Algal Strain Selection ................................................................................... 19
4.1.1. Microalgae ....................................................................................... 20
4.1.2. Cyanobacteria.................................................................................. 22
4.1.3. Macroalgae ...................................................................................... 24
4.1.4. Summary of Algal Strains ................................................................ 26
4.2. Algae Cultivation ......................................................................................... 28
4.2.1. Open Ponds / Raceways .................................................................. 28
4.2.2. Photobioreactors ............................................................................. 30
4.2.3. Heterotrophic Fermenters .............................................................. 32
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4.2.4. Marine Systems ............................................................................... 34
4.2.5. Summary of Algae Cultivation Methods.......................................... 35
4.3. Harvesting and Dewatering ......................................................................... 38
4.3.1. Filtration / Microscreening .............................................................. 39
4.3.2. Centrifugation ................................................................................. 41
4.3.3. Flocculation ..................................................................................... 42
4.3.4. Flotation .......................................................................................... 43
4.3.5. Off-shore Methods .......................................................................... 44
4.3.6. Other ............................................................................................... 46
4.3.7. Summary of Algae Harvesting and Dewatering Techniques ........... 47
4.4. Oil / Biomass Separation ............................................................................. 50
4.4.1. Physical Extraction .......................................................................... 50
4.4.2. Chemical (Solvent) Extraction ......................................................... 52
4.4.3. Enzymatic Extraction ....................................................................... 54
4.4.4. Wet Extraction ................................................................................. 54
4.4.5. Summary of Oil / Biomass Separation Methods ............................. 56
4.5. End-Use Fuel Production ............................................................................. 59
4.5.1. Transesterification ........................................................................... 61
4.5.2. Hydroprocessing .............................................................................. 63
4.5.3. Fermentation ................................................................................... 66
4.5.4. Anaerobic Digestion ........................................................................ 68
4.5.5. Gasification ...................................................................................... 71
4.5.6. Pyrolysis/Liquefaction ..................................................................... 72
4.5.7. Biophotolysis ................................................................................... 73
4.5.8. Purification of SVO .......................................................................... 76
4.5.9. Summary of Methods for Producing End-Use Fuels from
Algal Biomass ................................................................................... 77
5. Feasibility Assessment ................................................................................... 81
5.1. Production Capacity .................................................................................... 82
5.2. Total Energy Balance and GHG Emissions ................................................... 86
5.3. Competition with Food Supply .................................................................... 91
5.4. Environmental Impacts ............................................................................... 91
5.5. Biodiversity and Ecosystems ....................................................................... 92
5.6. Production Cost ........................................................................................... 93
5.7. Future State of the Energy Industry ............................................................ 93
5.8. Adaptability among Markets ....................................................................... 94
5.9. Overall Assessment ..................................................................................... 94
6. Recommendations for Policy Makers ............................................................. 97
SPECIAL FOCUS: Investigation of How Algal Species-Specific Properties
Drive End-Use Fuel Properties .............................................................................. 99
Background on Biodiesel Process Inputs .............................................................. 99
General Approach and Collaborative Efforts ........................................................ 102
Preliminary Analysis and Findings......................................................................... 103
Anticipated Future Steps ...................................................................................... 111
References ........................................................................................................... 113
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List of Tables
1 Oil yields from common feedstocks. .................................................................... 1
2 Estimated growth of algal biofuel companies between 2001 and 2010
(Oilgae Estimates) ................................................................................................. 5
3 Oil content as a percent of cell’s dry weight (dw) for select
microalgal species. ................................................................................................ 21
4 Selection of seaweeds that are suitable for marine farms and
feedstock for biofuels. .......................................................................................... 25
5 Summary of the three primary algae strain categories reviewed
in this report. ........................................................................................................ 27
6 Summary of the four primary algae cultivation settings reviewed
in this report. ........................................................................................................ 36
7 Summary of the five primary algae harvesting and dewatering
techniques reviewed in this report. ...................................................................... 48
8 Comparison of common values for gases, liquids, and supercritical fluids. ......... 54
9 Summary of the primary techniques used to separate oil and biomass
within algal cultures. ............................................................................................. 57
10 Indications of methane yields of seaweeds. ......................................................... 69
11 Energy productivity in the form of hydrogen for biophotolysis by
microalgae and cyanobacteria, obtained in laboratory experiments.
The energy is expressed per liter liquid volume of the culture in the
bioreactor, and per hour. ..................................................................................... 75
12 Summary of the primary techniques used to convert algal biomass into
transportation fuels and energy products. ........................................................... 78
13 Estimates of biomass and/or oil yield from micro- and macroalgae,
based on small-scale production data and extrapolation from results
of experiments in laboratories. ............................................................................ 84
14 Comparison of energy in crop and photovoltaic electricity production. .............. 86
15 Common feedstocks for biodiesel production...................................................... 100
16 Variation of finished biofuel properties with feedstock composition
(NREL, 2009) ......................................................................................................... 102
17 Fatty acid profile for Botryococcus braunii (Race A) ............................................. 103
18 Fatty acid profile for Chlorella vulgaris ................................................................. 104
19 Fatty acid profile for Neochloris oleoabundans .................................................... 105
20 Fatty acid profile for Nannochloropsis granulata ................................................. 106
21 Fatty acid profile for Phaeodactylum tricornutum ............................................... 107
22 Fatty acid profile for Isochrysis galbana ............................................................... 108
23 Summaries of Fatty Acid Profiles Algal Strains provided by NRC Canada’s
Institute for Marine Biosciences ........................................................................... 108
24 EN 14214 standards for FAME biodiesel (Stanhope, 2010). ................................. 110

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List of Figures
1 Forecasted algal biofuel production through 2025 based on the
anticipated commercial scale-up by five major algal biomass producers
(Emerging, 2009). .................................................................................................. 9
2 Microalgae Haematococcus pluvialis, vegetative (Palmella-) stage, under
ight microscope (Image Source: Fraunhofer IGB:
http://www.igb.fraunhofer.de/start.en.html). .................................................... 20
3 Cyanobacteria often grow in long filaments resembling algae
(Image Source: biotechnologie.de). ...................................................................... 23
4 Macroalgae are mulitcellullar, photosynthetic marine organisms with
plant-like features (Image Source: The Scottish Association for
Marine Science). ................................................................................................... 24
5 Single algae raceway with two motorized paddles. ............................................. 29
6 Aerial view of Cyanotech’s outdoor algae pond cultivation facility in
Kailua Kona, Hawaii (Image Source: Cyanotech Corp.) ......................................... 29
7 Various designs of PBRs used in industry. From top to bottom: Brite Box
PBR (Source: Natural Resources Canada); Tubular PBR (Image
Source: Bioprodukte Prof. Steinberg); Wrapped PBR
(Source: The University of Georgia); High Density Vertical Bioreactor
(Source: Vertigro Products, Inc.). .......................................................................... 31
8 Heterotrophic fermenter (Source: Wageningen University, 2010). ..................... 33
9 Schematic of a full-grown Seaweed Carrier designed by Seaweed Energy
Solution (Seaweed, n.d.). ...................................................................................... 35
10 Schematic of AlgaeVenture's harvesting model (AlgaeVenture, 2009). ............... 40
11 In flocculation, free-floating cells clump to form easily harvestable
algal masses (Wageningen, 2010). ....................................................................... 42
12 Biomagnetic separation of algae from water using finely ground iron
oxide, at the bottom of a flask (Image Source: Siemens AG). .............................. 47
13 Schematic of a Soxhlet extractor (Image Source: Alex Tan). ................................ 53
14 Carbon dioxide pressure-temperature phase diagram ........................................ 53
15 OriginOil's Single-Step Oil Extraction combines microbubbles, pulsed
electromagnetic waves, and pH modification in their patent-pending
extraction process (OriginOil, n.d.) ....................................................................... 56
16 Summary of fuel options attainable with algae .................................................... 60
17 Primary byproducts of transesterification are biodiesel on the top half
and glycerol on the bottom half
(Image Source: www.AlgaeForBiofuels.com). ..................................................... 62
18 Four-Step Centia™ Biofuels Production Process developed by
Diversified Energy Corporation and North Carolina State University
(Diversified, n.d.) .................................................................................................. 64
19 Algenol’s proprietary PBRs do not require harvesting or dewatering of
algal cultures (Algenol, n.d.). ................................................................................ 68
20 Common anaerobic digestion process (Vergara-Fernandez et al., 2008). ............ 69
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