Oxy-combustion involves the use of oxygen, with a purity of 95 to 99 percent oxygen assumed in most current designs, to combust coal and produce a highly concentrated CO2 stream. The CO2 is separated from water vapor by condensing the water through cooling and compression. Further treatment of the flue gas may be needed to remove pollutants and non-condensed gases (such as nitrogen) from the flue gas before the CO2 is sent to storage.
Oxy-combustion cannot be simply substituted for air combustion in existing fossil-fueled power plants due to differences in combustion characteristics. For oxy-combustion to be utilized in existing plants, a thermal diluent is required to replace the nitrogen in air. The oxygen produced from air separation would be mixed with recycled flue gas to approximate the combustion characteristics of air.
For oxy-combustion to be a cost-effective power generation option, a low-cost supply of pure oxygen is required. In the most frequently proposed version of this concept, a cryogenic air separation unit is used to supply high purity oxygen to the boiler. This commercially available technology is both capital- and energy-intensive and could raise the cost of electricity from coal-fired plants considerably, in addition to degrading the overall plant efficiency. However, novel technologies currently under development, such as oxygen and ion transport membranes, have the potential to reduce the cost of oxygen production.
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Another breakthrough oxy-combustion concept under development is the chemical looping combustion process. Chemical looping splits combustion into separate oxidation and reduction reactions. A metal (e.g., iron, nickel, copper, or manganese) oxide is used as an oxygen carrier which then releases the oxygen in a reducing atmosphere and the oxygen reacts with the fuel. The metal is then recycled back to the oxidation chamber where the metal oxide is regenerated by contact with air. The advantage of using two chambers for the combustion process is that the CO2 is concentrated once the water is removed and not diluted with nitrogen gas. The benefit of the process is that no air separation plant or external CO2 separation equipment is required.
DOE/NETL is funding multiple oxy-combustion CO2 emission control projects within each of the above mentioned approaches. These R&D efforts are being performed both externally by research organizations and academic institutions, as shown in the table below, and internally through NETL’s Office of Research and Development (ORD), specifically the Separations and Fuels Processing Division and the Office of Computational Dynamics.
The In-House Oxy-combustion CO2 Control webpage provides detailed information regarding NETL’s internal R&D.
Click on a project title in the table for more information.
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Oxy-Combustion
Active and completed projects researching oxy-combustion CO2 control.
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Active Oxy-combustion Projects |
Optimization of Pressurized Oxy-Combustion with Flameless Reactor NEW!
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Unity Power Alliance
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DE-FE0009478 |
Laboratory/ bench scale |
Demonstration of a Novel Supercritical Carbon Dioxide Power Cycle Utilizing Pressurized Oxy-Combustion in Conjunction with Cryogenic Compression NEW!
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Southwest Research Institute
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DE-FE0009395 |
Laboratory/ bench scale |
Oxy-Fired Pressurized Fluidized Bed Combustor (Oxy-PFBC) NEW!
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Pratt and Whitney Rocketdyne
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DE-FE0009448
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Laboratory/ bench scale |
Staged, High-Pressure Oxy-Combustion Technology: Development and Scale-up NEW!
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Washington University
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DE-FE0009702 |
Laboratory/ bench scale
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High Efficiency Molten-Bed Oxy-Coal Combustion With Low Flue Gas Recirculation NEW!
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Gas Technology Institute
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DE-FE0009686 |
Laboratory/ bench scale
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Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion
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The University of Texas at El Paso |
DE-FE0002402 |
Laboratory/ bench scale |
Characterization and Prediction of Oxy-combustion Impacts in Existing Coal-fired Boilers
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Reaction Engineering International |
DE-NT0005288 |
Pilot scale |
Near-Zero Emissions Oxy-combustion Flue Gas Purification
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Praxair, Inc. |
DE-NT0005341 |
Laboratory scale |
Oxy-combustion Technology Development for Industrial-Scale Boiler Applications
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Alstom Power, Inc. |
DE-NT0005290 |
Pilot scale |
Jupiter Oxy-combustion and Integrated Pollutant Removal for the Existing Coal-Fired Power Generation Fleet
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Jupiter Oxygen Corporation |
FC26-06NT42811 |
Laboratory scale |
Completed Oxy-combustion Projects |
Oxy-combustion Boiler Material Development |
Foster Wheeler NA, Corp. |
DE-NT0005262 |
Laboratory scale |
Flue Gas Purification Utilizing SOX/NOX Reactions During Compression of CO2 Derived from Oxyfuel Combustion |
Air Products and Chemicals, Inc. |
DE-NT0005309 |
Laboratory scale |
Development of Cost-Effective Oxy-combustion Technology for Retrofitting Coal-Fired Boilers |
Babcock & Wilcox Company |
FC26-06NT42747 |
Pilot scale |
Oxygen-Fired CO2 Recycle for Application to Direct CO2 Capture From Coal-Fired Power Plants |
Southern Research Institute |
FC26-05NT42430 |
Pilot scale |
Evaluation of CO2 Capture/Utilization/Disposal Options |
Argonne National Laboratory-IL |
FWP49539 |
Laboratory scale |
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Alstom Power, Inc. |
FC26-04NT42205 |
Pilot scale |
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Foster Wheeler NA, Corp. |
FC26-04NT42207 |
Study scale |
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Foster Wheeler NA, Corp. |
FC26-03NT41736 |
Study scale |
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Alstom Power, Inc. |
FC26-01NT41146 |
Study scale |
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Praxair, Inc. |
FC26-01NT41147 |
Laboratory scale |
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Natural Resources Canada-CANMET |
IEA-CANMET-CO2 (International Agreement) |
Pilot scale |
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Oxygen Production
Active and completed projects researching oxygen production for oxy-combustion CO2 control.
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Chemical Looping
Active and completed projects researching chemical looping for oxy-combustion CO2 control.
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