Carbon Capture

Carbon Capture, Utilisation & Storage (CCUS) is essential in the energy transition as it plays a critical role in CO2 removal from the atmosphere. CCS technologies aim to store the CO2 underground, and CCU technologies aim to utilize CO2 as feedstock in other industrial processes such as enhanced oil recovery, or e-fuels production.

Capture: CO2 can be captured from fuel gas (pre-combustion) or flue gas (post-combustion) in many industrial sectors (such as oil & gas, LNG, biofuels, steel, cement), or even by direct air carbon capture (DAC) in the atmosphere. A common capture technique is CO2 absorption, which is similar to the H2S scrubber in refineries, and consists of following equipment:

• Pre-scrubber to cool down the flue gas and remove particles
• Absorber (or scrubber) to bond CO2 to a chemical amine (at 30-50°C/ 85-120°F)
• Desorber (or stripper) to release the CO2 from the amine (at 110-130°C/230-260°F)
• Reboiler: 3-4 bar steam required to heat up the desorber

Utilization: CO2 can be injected in existing oil wells for enhanced oil recovery (EOR), converted with green hydrogen to e-methanol transport fuel, or utilized as feedstock in other industrial processes.

Storage: First, CO2 is dried in a dehydration unit to eliminate acid corrosion in pipes. Then it’s pressurized to 72bar/1050psi, and injected underground below the critical depth where the temperature exceeds 32°C/90°F. In these conditions the CO2 is a supercritical fluid and storage volume is drastically reduced.