Compressed Flue Gas

In the Compressed Flue Gas (CCC-CFG) process, the flue gas is moderately compressed, cooled, then expanded, to remove 99% of carbon dioxide with only minimal refrigeration required.

Compressed Flue Gas Cryogenic Carbon Capture (CCC-CFG) process flow diagram

Compressed Flue Gas Cryogenic Carbon Capture (CCC-CFG) process flow diagram

  1. The flue gas is dried and compressed to 5–7 bar.
  2. The flue gas is cooled in a proprietary desublimating heat exchanger.
  3. During the cooling, up to 75% of the CO2 forms a solid and is separated. Pollutants such as mercury, SO2, NO2, Hg, and HCl are also removed at this point.
  4. The gas is expanded and cooled in a turbine, causing more CO2 to solidify. At this point, 99% of the original CO2 has been captured.
  5. The captured CO2 is pressurized to 70–80 bar.
  6. The cold products are used to cool the incoming flue gas. The solid CO2 melts during this step.
  7. The warm, liquid CO2 is pressurized to the final delivery pressure: normally 150 bar.

Demonstrations

The first demonstration of CCC-CFG was a small pilot unit. This unit has been tested successfully at two on-site locations and has accumulated hundreds of hours of run time.


Interior of the small pilot unit showing the flue gas compressor

Interior of the small pilot unit showing the flue gas compressor

The CCC-CFG small pilot bubbling desublimating heat exchanger

The CCC-CFG small pilot bubbling desublimating heat exchanger

View inside one of the heat exchangers in the CCC-CFG small pilot. The white smoky substance is solid CO2.

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