Aspen Aerogels, along with ADA Environmental Solutions (ADA-ES) and the University of Akron, will optimize and test an innovative aerogel sorbent for post-combustion CO2 capture from coal-fired power plants. Aerogels are synthetic porous materials formed by replacing the liquid component of a gel with air while retaining the pore structure. Under a previous DOE Small Business Innovation Research (SBIR) project, the research team developed aerogel sorbents with very promising CO2 adsorption capacities and excellent stability over thousands of adsorption-desorption cycles. The aerogel sorbents have high surface area and porosity, unique and tailored pore size distribution, highly-stable functionality, and excellent hydrophobicity for resisting degradation from moisture and contaminants in the flue gas over long-term use. This project will focus on scaling up and testing advanced aerogel sorbents for CO2 capture with exposure to flue gas contaminants. Aspen Aerogels will optimize the most promising aerogel formulations for maximized working capacity and robust cyclic stability in flue gas conditions. The University of Akron will develop binder formulations, pellet production methods, and post treatment technology for increased resistance to flue gas contaminants. ADA-ES will assess the performance of the powdered and pelletized sorbent formulations by analyzing sorption isotherms, selectivity to flue gas contaminants, crush strength, attrition, fluidized bed properties, and heat transfer coefficients for the adsorption/desorption process. The hydrodynamic and heat transfer properties of the pelletized sorbent will be evaluated in a bench-scale cold flow fluidized bed reactor. A techno-economic assessment of the aerogel sorbent technology for CO2 capture from coal fired power plants will be performed. The aerogel sorbent will be optimized through engineering models and tested with simulated flue gas. The team will assess the CO2 capture process for the pelletized sorbent, including a temperature swing adsorption reaction where the aerogel is cycled between ~55 degrees Celsius (°C) and a regeneration temperature of 100–130 °C. The bench-scale evaluation will be conducted at Aspen Aerogels, ADA-ES, and the University of Akron. High level assessments will be conducted to estimate the cost of the process at larger scales.
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.
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