An Overview of CO2 Utilization in Biofuel Production

Ron ChanceSchool of Chemical & Biomolecular Engineering

School of Chemistry & Biochemistry

Strategic Energy Institute

Georgia Institute of Technology

Green Chemistry and Engineering Conference

June 23-25,2009

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OutlineBackground/Drivers – near term outlook for fuels and emissions

Cellulosic Biofuels – vision and challenges

Algae to Hydrocarbon fuels

Algae to Ethanol

Research challenges for algae to biofuels

Comparisons – Carbon impact

– Climate Change

+ Can be carbon neutral or even carbon negative

+ Potentially a low risk carbon mitigation strategy

+ But must compete economically with fossil fuels, with a little help perhaps

– Energy Supply

Biofuels – the Drivers

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+ Can add another significant component to energy portfolio

+ From a US perspective, adds energy diversity and less dependence on unfriendly

sources for oil and gas

– Environment

+ Oxygenates in gasoline

+ Potential to be cleaner than fossil fuels

+ Must not compete with food

–Energy demand growth to 2030 will be dominated by developing (non-Kyoto, non-OECD) countries.

–There are sufficient resources, including oil, to meet the demand to

Short Term Energy Outlook

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–There are sufficient resources, including oil, to meet the demand to 2030 and well beyond0 but not clear at what price.

– With business as usual:

+ Fossil fuels will supply the bulk of the demand growth

+ CO2 emissions will continue to grow

CO2 Emission Trends and Mitigation Strategies

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30BILLION METRIC TONS

60% of CO2 Emissions Growth in Developing World

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Continued use of fossil fuel in a carbon constrained world will

require most of the following:

+ Moderating demand (e.g., by improving energy efficiency)

+ Implementing large scale CO2 capture and sequestration

+ Developing low/no carbon energy resources

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2003 2010 2015 2020 2025 2030

BILLION METRIC TONS

Non-OECDOECD

Cellulosic Biofuels

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– Biochemistry/Plant Science

+ Increase capture of light energy

+ Increase cellulose/lignin ratio

– Characterization (cellulose, hemicellulose, lignin, small molecules)

+ Chemical composition

+ Physical structure

+ Mimic oil refineries

–

Research Challenges: Cellulosic Biofuels

Ethanol Water Separations

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Fuel Energy Content of Ethanol

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– Separations

+ Extraction of high value chemicals and materials

+ Fuel production (e.g. ethanol-water separations)

– Conversion

+ More efficient depolymerization of cellulose and hemicellulose to sugars

+ Improved fermentation processes (CO2 capture?)

+ Better options for lignin

+ New gasification processes

– Life Cycle Analysis

+ Environmental, economic, and technical optimization

+ Full consideration of Bio-refinery concept

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Ethanol Concentration (%)

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corncellulose

– Microalgae+ Photoautotrophs—carry out photosynthesis (sunlight,

CO2, and water to organic molecules)

+ Much higher productivity than larger plants

+ 10’s of thousands of known species including blue

green algae (cyanobacteria)

– Aquatic Species Program (NREL 1980-95)+ Favored Open Pond vs. Closed Systems Open Ponds (Raceway)

Microalgae to High Value Products

Microalgae to Fuels

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+ Focus on bio-diesel production

+ Pilot plant in New Mexico

+ John Benemann, reference for economics and project

history

– Microalgae to Fuels—Major Players+ Sapphire Energy

– Diesel, jet fuel, and gasoline

– Open (raceway) ponds

+ Algenol Biofuels

– Ethanol

– Closed photobioreactors

Microalgae to High Value Products

Cyanotech, Big Island, Hawaii

Closed Photobioreactors (PBR)

Blue Green Algae to Ethanol

Algenol Biofuels, Florida

Life Cycle Analysis Reported by Sapphire Energy (2009)

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CO2 into SUGARS into ETHANOL

via Cyanobacteria, Salt Water, Nutrients, Sunlight, and Desert Land

Algenol links photosynthesis with

the natural enzymes that convert

sugars directly into ethanol.

The ethanol diffuses out of the

cell into the closed

photobioreactor (PBR) medium.

Algenol Biofuels Direct to EthanolTM Technology

Ethanol is collected from the

medium, the head-space, or

condensate in the PBR.

Cyanobacteria are collected

infrequently (less than once per

year).

Productivity (>6000 gal/acre-yr)

achieved via enhanced CO2.

No competition with food.

– Biology+ Enhanced photosynthetic growth/productivity

+ Robustness under growth conditions

+ Resistance to competition/contaminants

+ Better products (e.g. higher alcohols)

– System Management+ Low cost, low energy collection of biofuel (capital and operation)

+ Minimization of carbon footprint

Research Challenges: Algae-Based Biofuels

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+ Minimization of carbon footprint

– Open Pond vs. Closed Photobioreactor (PBR) + CO2 management (+ for PBR)

+ O2 management (+ for Open Pond)

+ Water management (+ for PBR)

+ Temperature management (some issues for both)

+ Contamination/Competition (+ for PBR)

+ Productivity (+ for PBR)

+ Costs (+ for Open Pond)

Biofuel Options and Their CO2 Mitigation Impact

Green House Gas Emission

Fuel Source Description From Life Cycle Analyses Reference

g CO2 (equiv)/MJ

Gasoline Fossil Fuel Status Quo 93

Diesel Fossil Fuel Status Quo 95

Ethanol Corn 1st Gen Biofuel 50 - 110 Various

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Ethanol Corn 1st Gen Biofuel 50 - 110 Various

Ethanol Sugar Cane 1st Gen Biofuel 50 DeOliveira (2005)

Ethanol Cellulosic Biomass 2nd Gen Biofuel 20 - 60 Delucchi (2009)

Diesel Soybeans 2rd Gen Biofuel 20 - 190 Delucchi (2009)

Diesel Microalgae 3rd Gen Biofuel 30 Sapphire (2009)

Ethanol Microalgae 3rd Gen Biofuel 20 - 25 Georgia Tech (2009)