Carbon Capture

Capturing Carbon for Use or Storage

From Flue to Blue Hydrogen

Global warming and climate change concerns are intensifying global efforts to reduce the concentration of greenhouse gases such as carbon dioxide (CO₂) in our atmosphere. Increasingly, attention is focusing on the need to remove CO₂ from the flue gases released by several processes in countless industries including power, chemicals and steel. Carbon capture is a key strategy in meeting today’s CO₂ emission reduction targets.

Carbon Capture Strategies

There are three different carbon capture strategies to choose from, depending on the source of the gas:

Pre-combustion technologies separate CO₂ before the combustion process. Reforming and gasification processes react fossil fuels with air or pure oxygen to create a synthesis gas comprised of hydrogen (H₂), carbon monoxide (CO), and carbon dioxide (CO₂). The CO₂ molecules are separated out of the syngas stream before combustion or further downstream chemical use of the syngas takes place.
Oxy-fuel combustion technologies burn fuel in an almost purely oxygenated environment. Oxygen is separated from air and then combusted with a fossil fuel to produce CO₂ and water vapor. This combustion, for example, drives turbines and generates electricity, then the water vapor is cooled, condensed, and removed while the CO₂ is captured, purified and piped away.
Post-combustion technologies separate CO₂ from the exhaust after the combustion process. This is the most widely used CCS technology for retrofitting industrial and power generating facilities. During the post-combustion process, flue gas resulting from burning fossil fuels passes through an absorber column with circulating liquid solvent, which absorbs the CO₂ molecules. A heating medium like steam enables the adjacent regeneration column releases the CO₂ from the solvent, and the CO₂is captured and piped away before it reaches the atmosphere.

Many chemical applications rely on CO₂ scrubbing. Oxyfuel technology is an ideal way to increase the efficiency of combustion processes in new power plants. And post-combustion capture (PCC) is targeted specifically at flue gas in existing power plants, typically using a solvent to chemically absorb the CO₂from the flue gases after the combustion process.

Tomatoes ripening on hanging stalk in greenhouse

The captured gas can be further purified and liquefied for commercial use - for example, as food-grade CO2 for the production of food and beverages, as a feedstock for the production of commodities like methanol or urea or in greenhouses. Alternatively, it can be stored underground (sequestered) as a carbon abatement measure.

Blue Hydrogen is produced by applying a carbon capture step into the production of hydrogen via steam methane reforming. With this additional step, up to 95% of the carbon can be captured, resulting in low-carbon hydrogen.

Capturing CO₂ in Heavy Industries

Industries face the challenge to decarbonize their value chains. Implementing carbon management technology into industrial processes helps future-proof businesses. Watch the video below to find out more.