Pre-Treatment for Carbon Dioxide Capture

Pre‑treatment for carbon dioxide (CO₂) capture

ERG designs and supplies flue gas pre‑treatment packages to condition combustion exhaust streams upstream of amine‑based carbon capture systems. These pre‑treatment stages remove residual SO₂, particulates and excess moisture so the gas meets the inlet quality requirements for amine solvents such as monoethanolamine (MEA), protecting the carbon capture plant and supporting stable, efficient operation.

Flue gas pre‑treatment duty and CCS experience

ERG has direct experience of CO₂ capture pre‑treatment on a coal‑based power station as part of a large‑scale pilot plant treating approximately 2% of the total flue gas. At this UK site, the main flue gas line was already treated using limestone De‑SOx and ESP particulate removal, but the gas was still too contaminated for direct amine scrubbing and required additional conditioning.

ERG’s skid‑mounted pre‑treatment packages treated a total of around 30,000 m³/hr of flue gas at 55 °C and were installed upstream of the amine absorption column as a side‑stream pilot plant.

Pre‑treatment stages supplied by ERG

The pre‑treatment system comprised the following elements:

Tray tower scrubbing – a tray tower with caustic‑dosed scrubbing solution to capture residual SO₂ and particulate fly ash, reducing acid gas loading and fine solids carry‑over into the amine system.
Booster fan package – a dedicated booster fan providing the pressure drop required to draw flue gas from the main duct, drive it through the complete side‑stream pilot plant and return the conditioned gas to the main flue gas stack.
Packed tower sub‑cooler – a packed tower sub‑cooler to reduce flue gas temperature and condense water vapour, bringing temperature and humidity into the desired range for the downstream amine contactor.

Together, these stages conditioned the flue gas to meet the quality and stability requirements of the amine‑based CO₂ capture system. The pilot plant was a success, and ERG’s package worked effectively as the pre‑treatment section ahead of the amine column, demonstrating the feasibility of integrating such conditioning trains on coal‑fired power flue gases.

If you are assessing carbon capture options or planning a pilot plant, contact ERG’s sales team.