External Cooling Loop

In the External Cooling Loop (CCC-ECL) process, the flue gas is regeneratively cooled so that 99% of the incoming carbon dioxide freezes into solid dry ice. The dry ice is melted and delivered at pipeline conditions, requiring no gas compression.

External Cooling Loop Cryogenic Carbon Capture (CCC-ECL) process flow diagram

1. The flue gas is dried.
2. The flue gas is cooled in a proprietary desublimating heat exchanger.
3. During the cooling, up to 99% 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 CO₂ is pressurized to 70–80 bar.
5. The cold products, supplemented by an external cooling loop, cool the incoming flue gas. The solid CO₂ melts during this step.
6. The warm, liquid CO₂ is pressurized to the final delivery pressure: normally 150 bar.

Demonstrations

SES has demonstrated the CCC-ECL technology on the bench and small pilot scales on several different fuels including Powder River Basin Coal, natural gas, and a mixture of coal and biomass.

CCC-ECL small pilot demonstration unit

Solid CO2, captured from simulated flue gas, is extruded out of a screw press in the CCC-ECL small pilot demonstration.