CO2 Extraction Plants for Boiler Systems - Extraction Based Unit - EBU

The Extraction-Based Unit (EBU) converts boiler flue gas into ultra-pure, beverage-grade CO₂ through a series of controlled steps:

1. Flue Gas Conditioning
Source: Flue gas from boilers fired with diesel, heavy fuel oil, kerosene, natural gas, LPG, or LNG.
Cooling & Scrubbing: The gas is cooled to condense water and scrubbed to remove impurities.S
O₂ Removal: Sodium carbonate (soda ash) is automatically dosed via pH control to neutralize sulfur compounds.

2. CO₂ Absorption
The conditioned flue gas enters an absorber column, flowing counter-current to a 9% MEA (monoethanolamine) solution.
The MEA solution chemically binds to CO₂ from the flue gas, creating a rich solution while minimizing corrosion risk.

3. Contaminant Removal (NOxFlash)
The rich MEA solution passes through the NOxFlash column, where oxygen, nitrogen, and NOx are removed without using potassium permanganate.
This patented process also reduces benzene and other hydrocarbons, ensuring product safety.

4. CO₂ Stripping
Heat from a steam-driven reboiler releases CO₂ from the MEA solution.
The lean MEA is cooled and recycled back to the absorber for continuous operation.

5. Gas Polishing & Purification
After-scrubber: Removes any MEA carry-over.
Compression: CO₂ is compressed in two stages to ~15–18 barg.
Drying: Achieves a dew point of −60 °C (≤10 ppm v/v H₂O).
Activated Carbon Filter: Eliminates trace odors and acetaldehyde.

6. Final Purification (PUR-D)
CO₂ passes through a distillation column to remove non-condensable gases.
Result: O₂ ≤ 5 ppm (v/v) and CO₂ purity ≥ 99.999% (v/v).

7. Liquefaction & Storage
CO₂ is condensed at −27 °C to −21 °C and stored in insulated tanks at ~15–18 barg.
A refrigeration unit maintains temperature and pressure, even during idle periods.