Features - May 2015

Testing the Technology of Tomorrow: The National Carbon Capture Center

The Department of Energy (DOE) regards addressing climate change—from the development of new, clean energy technology to the mitigation of the effects of greenhouse gases—as a top priority. And, as part of the DOE’s national laboratory system, the National Energy Technology Laboratory (NETL) is deeply committed to furthering the department’s mission, and thereby advancing the security and energy future of our nation. This is why the Laboratory joined forces with the private sector to create a testing facility dedicated to bringing new technologies to bear on the climate change challenge.

Traditional power generation that uses fossil fuels emits what is known as a greenhouse gases, or a gas that remains in the atmosphere, absorbing infrared radiation and trapping heat. The primary greenhouse gas produced by power generation is carbon dioxide (CO2). According to the Environmental Protection Agency, in 2013, CO2 accounted for about 82 percent of all U.S. greenhouse gas emissions from human activities.

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The National Carbon Capture Center serves as an important testing ground for some of NETL's most promising pre- and post-combustion carbon capture technologies.

Addressing climate change without drastically disrupting our energy systems requires development of ways to capture and store CO2 before, during, and after power generation. NETL is involved in extensive research and development efforts to create and implement carbon capture technologies. An essential element of the development process is testing new technologies under realistic power plant conditions. NETL partnered with Southern Company Services to establish the National Carbon Capture Center (NCCC) at the Power Systems Development Facility (PSDF) in Wilsonville, Alabama.

Launched in late 1990, with an agreement between DOE and Southern Company Services, the PSDF is a unique testing facility. Designed to mimic a variety of process conditions, the facility is capable of evaluating carbon capture technologies at multiple scales, allowing results to be applied directly to commercial applications. The site is large enough to provide commercially relevant data, yet small enough to be cost-effective and adaptable. These capacities give the PSDF the flexibility to demonstrate a wide range of advanced power generation technologies that are critical to developing highly efficient power plants that capture CO2.

A new NCCC effort at the PSDF will concentrate specifically on developing cost-effective, commercially viable carbon capture technologies for coal-fueled power plants. Testing and developing new CO2 capture technologies in commercially representative conditions is critical before the technologies can be deployed at full scale, and the NCCC continues to be an invaluable partner in those efforts.

Multiple NETL technologies, from solvent to membrane to sorbent, have harnessed the testing capabilities offered through the NCCC.

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    Linde’s post-combustion CO2 capture pilot plant

  • A solvent currently being tested at the NCCC is a pilot-scale, post-combustion CO2 capture process developed by Linde LLC and their partners, which is expected to capture 30 tons of CO2 per day. The technology being evaluated integrates an advanced aqueous amine-based solvent (OASE® blue) with novel CO2-capture process and engineering innovations being developed by Linde. OASE® blue chemically absorbs CO2 from the power plant flue gas. The CO2-rich solvent is then transferred to a stripping column where heated steam triggers a reversal of the chemical reaction, releasing high-purity CO2 for compression and pipeline transport. The CO2-lean solvent is recycled and reused to capture additional CO2.

    Following pilot testing at the NCCC, data analysis will be performed to confirm that the technology meets key performance targets and that plant systems are stable during long term operation. The data will be used to confirm the benefits of the post-combustion CO2 capture technology, leading to larger-scale testing, and, ultimately, full-scale commercialization.

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    MTR’s high-permeance CO2 selective membranes

  • The NCCC is partnering with Membrane Technology and Research, Inc. (MTR) to test a new type of membrane that can selectively separate CO2 from a flue gas stream. The PolarisTM system is ten times more permeable to CO2 than conventional gas-separation membranes and has a surface area of 500 square meters, 20 to 25 times larger than that of current modules used for CO2 capture. The membrane uses less water than other capture technologies, and does not use hazardous chemicals, which eliminates emissions and disposal issues. These unique features mean the PolarisTM membrane has a reduced membrane area, lower capital costs, and a smaller footprint in the capture system.

    The MTR membrane separation process has already completed 7,500 hours of small-scale testing using actual flue gas. Data from the pilot testing will provide insights into the next steps required for industrial application including further scale-up and field tests. The feasibility of using the membranes system in several different hybrid process designs is being evaluated for future development potential. This project is the largest-scale CO2 membrane technology in the DOE’s research portfolio and has the potential to support the reduction of greenhouse gas emissions from coal-fired power plants while minimizing the increase in electricity price.

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    SRI International’s carbon microbead solid sorbent

  • SRI International, in cooperation with the NCCC, is running tests on an innovative, low-cost, low-energy sorbent for post-combustion carbon capture. Manufactured by ATMI, Inc., the novel sorbent developed for the project is composed of carbon microbeads. Sorbent-based technologies, which adsorb CO2  onto a solid support material, have the potential to effectively reduce the energy penalties and costs associated with post-combustion CO2  capture for industrial facilities, as well as for both new and existing PC-fired power plants.

The SRI sorbent was tested first in a small boiler unit at the University of Toledo, and the promising results prompted testing at the NCCC. Operational data from the NCCC tests will be used for further process scale-up. 

The overall goal of these, and all, projects at the NCCC is to advance the development of carbon capture technologies that will reduce the energy penalty and cost for CO2 capture. Successful testing of technologies at pilot scale represents a major step for a technology. The DOE’s carbon capture program objective is to develop and demonstrate second-generation capture technologies that can capture more than 90 percent of fossil fuel power plant generated CO2 by 2025, and the NCCC has proven itself as an invaluable resource in pursuit of this goal.