CCS and Power Systems

Carbon Capture - Post-Combustion Capture


Bench Scale Development and Testing of Aerogel Sorbents for CO2 Capture


Performer: Aspen Aerogels Inc.

Project No: FE0013127


Program Background and Project Benefits

The mission of the U.S. Department of Energy Office of Fossil Energy’s (DOE FE) Carbon Capture Research & Development (R&D) Program, implemented through the National Energy Technology Laboratory (NETL), is to develop innovative carbon dioxide (CO2) emissions control technologies for fossil fuel-based power plants. The Carbon Capture R&D Program portfolio of pre- and post-combustion CO2 emissions control technologies and related CO2 compression is focused on advancing technological options for new and existing power plants to enable cost-effective CO2 capture for beneficial use or storage of CO2 and ensure that the United States will continue to have access to safe, reliable, and affordable energy from fossil fuels. The DOE FE/NETL goal is to demonstrate second-generation technologies that can capture 90 percent of the CO2 at less than $40 per metric ton (tonne) in the 2020-2025 timeframe. DOE is also committed to extend R&D support to even more advanced transformational carbon capture technologies that will increase competitiveness of fossil based energy systems beyond 2035.

Post-combustion CO2 capture technologies are applicable to conventional pulverized coal (PC)-fired power plants, where the fuel is burned with air in a boiler to produce steam that drives a turbine generator system to produce electricity. The CO2 is exhausted in the flue gas at atmospheric pressure and a concentration of 10–15 percent by volume. Post-combustion separation and capture of CO2 from PC-fired plants is a challenging application due to the low driving force resulting from the low pressure and dilute concentration of CO2 in the waste stream, trace impurities in the flue gas that affect removal processes, and the parasitic energy cost associated with the capture and compression of CO2. Carbon capture technologies developed by the DOE program may also be applied to natural gas power plants after addressing the R&D challenges associated with the relatively low concentration of CO2 in the flue gas, typically 3-4 percent, of natural gas plants. Advanced adsorption-based capture systems show potential for  reducing the overall costs associated with post-combustion CO2 capture in PC-fired power plants due to a significant reduction in the regeneration energy as compared to conventional aqueous amine technologies.

The advanced aerogel sorbents developed by the project team have previously been shown to have favorable CO2 adsorption capacity and cycle stability. These capabilities take advantage of the unique properties of the solid aerogel materials, including high specific surface area, low density, nanometer pore size, high pore volume, low specific heat, and high thermal insulation value. Further optimization and testing of the aerogel sorbents to increase the scale and improve the resistance to flue gas contaminants is a beneficial step toward development of cost-effective CO2 capture technologies capable of achieving the programmatic goals for carbon capture systems.

Primary Project Goal

The primary project goal is to develop an advanced aerogel sorbent that will improve the performance and economics of CO2 capture technologies and make progress toward meeting the DOE goal to demonstrate second-generation technologies that can capture 90 percent of the CO2 at less than $40 per tonne in the 2020–2025 timeframe.

Objectives

The project objectives are to (1) optimize and test the aerogel formulations for improved CO2 capacity and flue gas contaminant resistance, (2) produce and test the optimized sorbent technology in a pellet form, (3) produce the final pelletized sorbent in larger quantities for fluidized bed testing, (4) assess the sorbent in fluidized bed bench-scale testing, and (5) conduct a final technical and economic assessment of the sorbent technology and process.

Planned Activities

  • Optimize the three most promising formulations from the completed DOE SBIR program.

  • Assess the performance of the optimized sorbents.

  • Develop a coating technology to make the aerogel sorbents further resistant to performance degradation in the presence of flue gas contaminants.

  • Produce the appropriate particle size of sorbents using two different methods: direct bead production and forming the aerogel powders into spherical pellets with custom binder formulations in a post processing pellet fabrication step.

  • Assess the beads and pellets for CO2 capacity, adsorption cycle life, crush strength, resistance to attrition, and flue gas contaminant resistance.

  • Produce larger batches of the best optimized sorbent and confirm consistent quality with analytical testing (surface area, x-ray photoelectron spectroscopy, and particle size measurement) and CO2 capture evaluation (working capacity, energy of regeneration, and CO2 adsorption/desorption stability over 250 cycles).

  • Evaluate the aerogel sorbent performance utilizing cold-flow fluidized beds to determine hydrodynamic properties and heat transfer coefficients.

  • Complete a techno-economic assessment based on the test results using a refined model of the fluidized bed-based capture process.



Project Details