CCS and Power Systems

Carbon Capture - Post-Combustion Capture


Combined Pressure, Temperature Contrast and Surface-Enhanced Separation of Carbon Dioxide for Post-Combustion Carbon Capture


Performer: William Marsh Rice University

Project No: FE0007531


Program Background and Project Benefits

The mission of the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL) Carbon Capture Research & Development (R&D) Program is to develop innovative environmental control technologies to enable full use of the nation’s vast coal reserves, while at the same time allowing the current fleet of coal-fired power plants to comply with existing and emerging environmental regulations. The Carbon Capture R&D Program portfolio of carbon dioxide (CO2) emissions control technologies and CO2 compression is focused on advancing technological options for new and existing coal-fired power plants in the event of carbon constraints.

Pulverized coal plants burn coal in air to generate steam and comprise 99 percent of all coal-fired power plants in the United States. Carbon dioxide is exhausted in the flue gas at atmospheric pressure and a concentration of 10 to 15 percent by volume. Postcombustion separation and capture of CO2 is a challenging application due to 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. Post-combustion CO2 control technologies include the use of solvents, solid sorbents, and membranes, alone or in beneficial combinations. Improvement in the performance of these technologies as well as the development of novel cost-effective processes using these technologies are key to affordable carbon capture for coal-fired power plants.

Primary Project Goal

The primary project goal is to develop, test, and optimize (at bench scale) a novel gas separation process with the potential to reduce the cost of CO2 capture from coal-fired power plants and meet the DOE goals of capturing 90 percent of the CO2 with less than a 35 percent increase in the cost of electricity.

Objectives

Project objectives are to (1) develop a CO2 capture process that uses a single integrated unit that combines both the absorber and desorber columns, (2) use waste heat for absorbent regeneration instead of low-pressure steam by operating the desorber section of the integrated unit under vacuum, (3) functionalize the ceramic gas-liquid contactors for enhanced gas absorption and desorption, and (4) develop a 2-D model to simulate the CO2 absorption process and optimize the material properties (i.e., pore-size distribution, aspect ratio, etc.) to attain the best process performance.

Planned Activities

  • Perform an initial techno-economic analysis.

  • Design and fabricate a bench-scale stainless steel prototype for the combined absorber/desorber CO2 separation process.

  • Implement and demonstrate the bench-scale CO2 capture process using simulated flue gas.

  • Conduct studies to measure the heat and mass transfer characteristics of the ceramic foam.

  • Conduct experiments to functionalize the absorption and desorption substrates.

  • Evaluate the impact of functionalization on the mass transfer behavior of the ceramic foam.

  • Complete development of a 2-D model to simulate gas and liquid flow in the capture process and compare simulation results with experimental measurements.

  • Perform a sensitivity analysis and process optimization.

  • Complete an exergy (available energy) and techno-economic analysis.

  • Perform an EH&S assessment of the process.


Project Details