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Challenges and Opportunities for Biological Capture of CO2 from
Power Plant Flue Gases
Richard L. Axelbaum
Dept. Energy, Environmental & Chemical Engineering Director, Consortium for Clean Coal Utilization
Washington University in St. Louis
Sept 2, 2009
World annual CO2 emissions from power generation (Stationary Power Plants)
Source Data: IEA World Energy Outlook, 2008
Land Use Projected 2015 U.S. CO2 emissions from power generation sources:
2,000 Mton CO2 fixation rate : 40 g_CO2 m-2 day-1
Land Surrounding Power Plant (Labadie, MO)
•! 2 GW of continuous power (three train-loads of coal per day •! CO2 production rate = 43,000 metric tons/day •! 7% Capture •! Fixation rate = 40 gCO2 m-2 day-1
1 mile
29 sq. miles (75 km2)
Coal Land Use
Source: ACI, Frank Clemente at Penn State
The red dot (6 square miles) depicts the size of the area mined in the PRB each year, which supplies over 40% of America’s coal (20% of the US power)
Cooling pond
Wisconsin Power & Light Columbia Plant
photo by :Louis J. Maher Jr., University of Wisconsin
Flue Gas Composition: Case Studies AmerenUE Labadie, MO
TVA Cumberland, TN
Coal Type Sub-bituminous, PRB, Wyoming
Bituminous, Illinois
Annual Output (billion kW-hr) 18.6 16.4
CO2 emission rate (metric tons per day) 4,300 4,200
NOx control low-NOx burners, overfire-air
low-NOx burners, SCR
SO2 control none wet scrubber
CO2 (v%) 13 – 15% 13 – 15%
NOx (ppm(v)) 100 - 115 350 - 410
SO2 (ppm(v)) before FGD 265 - 310 3,300 – 3,800
after FGD N/A 105 - 125
PM10 (mg/m3) 25 – 30 8 - 10
Labadie, MO
Cumberland, TN
Estimated flue gas composition:
Considerations when using Flue Gas for Biofixation with Microalgae
Composition of flue gas varies with type and moisture content of coal operating conditions type of plant
High CO2 concentration has been shown to increase growth rates of certain microalgae
Concentration of CO2 can vary and be as high as 95% Temperatures can be high ~ 250°F Low pH (as low as pH = 2) due to presence of SO2 and
NOx in flue gas Low concentrations of heavy metals
Historical Activities: Effects of flue gas Simulated Flue Gas: • High CO2 concentration and temperature:
Hanagata et al., (1992) Appel et al., (1994) Sakai et al. (1995) Sung et al., (1999)
• SO2 and NOx: Negoro et al., (1991-1992) Brown, Zeiler, et al. (1995-1996) Hauck et al. (1996) Nagase et al., (1997-2001) Lee et al., (2000) Olaizola, (2003)
Actual Flue Gas: • Oil:
Hamasaki et al (1994) Matsumoto et al. (1995 & 1997) Kurano et al. (1995)
• LNG & Diesel Lee et al. (2002)
• Propane Nakamura, Olaizola et al. (2004-2005)
• Natural gas: Pedroni et al. (2002) Doucha et al. (2005)
• Kerosene: Chae et al. (2006)
• Coal: Hamasaki et al (1994), Maeda et al., (1995) Nakamura, Olaizola et al. (2004-2005) Israel et al. (1995) (red seaweed)
Effects of Culture Temperature
30 oC 25 oC
40 oC 35 oC
45 oC
Scenedesmus Chlorella
Hanagata et al. (1992)
Optimum temp in the range of 25–35 °C (77–95 °F)
Effects of NO and SO2
• Productivity is not inhibited, as long as pH is maintained
Lee et al 2002 Matsumoto et al 1997
NO capture by microalgae
1. NO dissolution in the aqueous phase (slow)
2. NO oxidation in medium to NO2
-
OR
Direct uptake of NO by algae cells (dominant) (Nagase et al 2001)
(Nagase et al 1997)
Dunaliella culture cell-free medium fresh medium DI water
• Dunaliella preferentially used NO as its source of N over nitrates in the medium (Nagase et al 2001)
• With proper reactor design to allow time for NO dissolution, > 95% capture efficiency can be achieved (Nagase et al. 1998)
• Additives may be used to improve NO dissolution rate (Jin et al 2008)
Process:
Heavy Metals, Toxic Organics, and Hg Douskova et al. (2009)
Concentrations in Chlorella after cultivating in control gas (CO2 + air) and flue gas from waste incineration
Recent Demonstrations with Flue Gas
Onsite powerplant supplies 188 kg CO2/hr to the ponds. (Pedroni et al. 2001)
CO2 scrubber Cyanotech Corp., HI
Seambiotic, Ashkelon Israel • Uses flue gas from Israeli Electric coal-fired power station • up to 20 g algae/m2/day
Carbon Capture Corp., CA Uses flue gas from two 30kw microturbines
photos: Pedroni et al . (2001) http://www.cyanotech.com/
photo: www.seambiotic.com
Companies Involved in Microalgae R&D Name Location Notes
Algae Production Systems (APS) Houston, TX Developing bioreactor and processing technology
Algenol Biofuels Bonita Springs, FL Working with BioFelds in large site in Sonora desert, Mexico, under construction 40 bioreactors installed in FL
Aquatic Energy Lake Charles, LA 4 hectare pilot facility, 100 m raceway ponds,
Aurora Biofuels Hq:Almeda CA Pilot facility in FL
Small pilot scale facility in operation, 20 acre facility finished by end of 2009
Carbon Capture Corp. Imperial Valley, CA Total pond capacity 2.7 M gal, 7 – 150gal photobioreactors Cyanotech HI, Kona coast 80-acre facility Exxon Mobile Committed $600 million to develop biofuels from algae Infinifuel Corp Dayton, NV Ingrepro Netherlands Operates three large production sites, Kent BioEnergy Palm Springs, CA 160 acre open pond facility existing, Purchased 350 acre site LiveFuels San Carlos, CA Exploring extracting oil from aquatic feedstock PetroAlgae Fellsmere, FL Several acre facility with raceway and still ponds PetroSun Rio Honda, TX 1,100 acres of ponds Seambiotic Israel 1,000m2 (0.25 acres) ponds at a power plant Shell-Cellana & HR Biofuels HI, Kona coast 2.5 hectare under construction, intends to use powerplant flue gas
Solix Biofuels Fort Collins, CO 2-acre facility, using CO2 captured from coal-bed methane XL Renewables AZ 2.5 acre facility in operation, 40-acre facility to come online
Benefits of microalgal CO2 flue gas capture
• Potential for multi-pollutant flue gas scrubbing: CO2, NO, SO2, Hg,
• Flue gas provides high CO2 concentration for improved algae production
• Waste heat from power plant can be utilized to maintain algae at optimum temperature
• CO2 is converted into a value product for sale / utilization
• Reduced carbon emissions and possibly other emissions that can offset costs to the power plant
• Algae is stored solar energy, unlike energy from PV
Costs Stepan et al (2002): Raceway ponds Algae production costs: $110/ton dry algae $55/ton CO2
Chisti, (2007): Photobioreactor Algae production cost:
$500/ton_dry algae $250/ton CO2
Buhre et al. (2005)
Cost of other carbon capture technologies
Needs & Recommendations
• low-cost technology to produce microalgae
• stable cultivation at high productivity
• co-products such as nutraceuticals
• co-processes such as flue gas capture, waste water treatment
• Collaboration between utilities and algae/biofuel producers
• Collaboration between biologists, engineers and utilities • to improve reactor designs for newly engineered organisms • to develop novel uses of algae for energy production
CO2
coal
biomass
CO2
solar
storage
bioreactor liquid fuels
wind
steam turbine
O2 oxy‐fuel combustor
Conceptual Drawing of a Future Power Plant
Present U.S. CO2 Sequestration Activities
1. Report: DOE/NETL-402/1312/02-07-08
CO2 stored by EOR: (natural and anthropogenic)
51 MMt/yr
CO2 saved in 2007 by using wind and solar for electricity instead of coal
30 MMt/yr
compare to
Currently more than 3,500 miles of CO2 pipeline in place
In perspective…
Algae to Liquid Fuels
!!Cultivation!!Harvesting
"! concentration by chemical flocculation "! drying
!!Extraction!!Use in Internal Combustion Engine
"! efficiency <20%, compared to >45% for modern power plant)
Combustion Characteristics of Chlorella
NIES culture collection http://mcc.nies.go.jp/images/100images/nies-0642.jpg
Proximate Analysis
Chlorella pr. Demirbas (2006)
PRB coal Sawdust
HHV (daf) 23.6 MJ/kg 29.9 MJ/kg 19.7 MJ/kg
Fixed C (dry) 39.6% 48.0% 14.9%
Volatiles (dry) 54.6% 45.3% 84.5%
Ash (dry) 5.8% 6.7% 0.6%
Chlorella can be grown in waste water treatment plants
Direct Combustion of Algae in Power Cycle for Electricity
Eliminates losses from Drying Extraction 50% of algae is not converted into fuel
Eliminates low efficiency IC Engine (20%) Replaces it with high efficiency Power Cycle (45%)
and PHEV or EV.
} >30% of cost of algal fuels
! Vision"! Dedicated to addressing the scientific and technological challenges
of ensuring that coal can be used in a clean and sustainable manner.
!! Mission"! A resource to industry for the advancement of technologies that
foster clean utilization of coal by creating an international partnership between universities, industries, foundations, and government organizations.
!! Goals"! State-of-the-art clean coal facilities that are unprecedented on a
university campus "! Support of advanced research projects at Washington University in
collaboration with the McDonnell Partner Universities around the world.
Consortium for Clean Coal Utilization
screwfeeder
primaryoxidizer(O2 / N2 /CO2)
Oxy-fuel combustor
secondaryoxidizer, swirl (O2 / N2 /CO2)
eductor
refractory
combustionzone
mixing /char burnout
zone
35 kW, self-sustaining oxy/coal/biomass combustor
coal
screwfeeder
biomass exhaust
Research facility under development • 0.5-1.0 MW Combustion Facility • Oxy-coal and Air-coal • Co-firing with Biomass • Steam generation for Campus• 4000 sq. ft Research Facility • Designed for flexibility
DryScrubber
Fly Ash Silo Stack
ID Fan
Booster Fan Wet Scrubber (optional)
FabricFilter
BoilerCombustor
Pulverizer
CoalStorage Bin BucketElevatorCoal Chute
Feeder
CO2 Compressions Skid
Bioreactor