Development of Mixed-Salt Technology for Carbon Dioxide Capture from Coal Power Plants


Mixed-salt CO2 capture system
Mixed-salt CO2 capture system
SRI International
Website:  SRI International
Award Number:  FE0012959
Project Duration:  10/01/2013 – 02/28/2018
Total Award Value:  $3,523,649
DOE Share:  $2,817,989
Performer Share:  $705,660
Technology Area:  Post-Combustion Capture
Key Technology:  Solvents
Location:  Menlo Park, California

Project Description

SRI International, in collaboration with OLI Systems, Inc., Aqueous Systems ApS, Politecnico di Milano (POLIMI), and Stanford University, will advance the development of a novel ammonia-based mixed-salt solvent process for carbon dioxide (CO2) capture from coal-fired power plants by designing and testing a bench-scale (approximately 100 kW) CO2 capture system. The mixed-salt technology combines ammonium and potassium carbonates for enhanced CO2 capture efficiency, high CO2 loading capacity, and reduced energy consumption. The high operating pressure of the solvent regenerator also has the potential to reduce the CO2 compression costs. The technology consists of a two-stage absorber system with a single stage regenerator. To improve process performance, the absorber conditions will be optimized using two individual absorbers before testing the single two-stage absorber. Individual absorber and regenerator tests will be performed in a semi-continuous mode to collect data on solvent concentration, CO2 capture efficiency, water usage, and ammonia loss. Bench-scale testing of the continuous, integrated two-stage absorber system will be performed using simulated flue gas. Data collected will be used to complete thermodynamic modeling and a techno-economic analysis for integration of the mixed-salt technology into a full-scale power plant.

Project Benefits

SRI’s mixed-salt process uses known solvents in a new way that increases process efficiency, minimizes energy requirements, and reduces capital and operating costs, which improve the economics of carbon capture. This project will make progress toward the U.S. Department of Energy’s (DOE) overall Carbon Capture Program performance goals of 90 percent CO2 capture rate with 95 percent CO2 purity at a cost of $40/tonne of CO2 captured by 2025.

Contact Information

Federal Project Manager 
Steven Mascaro:
Technology Manager 
Lynn Brickett:
Principal Investigator 
Indira Jayaweera:

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