CCS and Power Systems
Carbon Capture - Post-Combustion Capture
Bench-Scale Development and Testing of Rapid Pressure Swing Absorption for Carbon Dioxide Capture
Project No: FE0007639
W.R. Grace & Company (Grace) has teamed with the University of South Carolina (USC), Battelle Memorial Institute, and Catacel Corporation to develop a unique rapid PSA process for cost-effective post-combustion CO2 capture from coal-fired power plants. The rapid PSA process could enable CO2 capture from a 550 megawatt (MW) power station with no more than a 35 percent increase in the cost of electricity (COE). PSA is a favorable process for CO2 capture as adsorption and desorption are achieved with electrical energy rather than with the extraction of steam from the power plant’s steam cycle, which is important for retrofitting into existing plants.
This project will build on promising results from a previously developed proprietary PSA cycle configuration for CO2 capture from a coal-fired power plant that demonstrated a total separation energy of 25 kilojoules per mole (kJ/mol) compared to 39 kJ/mol for a monoethanolamine system. The new PSA cycle is capable of achieving over 90 percent CO2 recovery and over 95 percent CO2 purity using commercial 13X zeolite pellets. Although this CO2 capture technology could be retrofitted to a coal-fired power plant, the adsorption columns would be exceedingly large and thus capital intensive. The project team will develop a rapid version of the proprietary PSA process, taking advantage of a much shorter cycle time—30 seconds compared to 300 seconds for a conventional PSA cycle. This would increase the feed throughput, a measure of the size of the adsorption columns, by a factor of 10 or more, concomitantly decreasing the column size by an order of magnitude or more. The new process could significantly reduce both the capital costs and plant footprint, while also reducing the operating costs.
The rapid PSA concept is conceptually simple but difficult to implement. The key to the success of this project is finding a suitable match between the adsorbent and the PSA cycle configuration for a full-scale rapid PSA process. A select team of experts has been assembled to demonstrate the feasibility of the rapid PSA concept for CO2 capture at the bench scale, and their research will focus on the materials, structure, and PSA cycle.