Understanding CCUS: A Cornerstone in Climate Change Mitigation
Carbon Capture is the process of capturing CO 2 before it escapes into the atmosphere, then routing it for either reuse (utilization) or long-term containment (storage). In CCUS programs, carbon capture is paired with utilization and storage to help reduce greenhouse gas emissions from major industrial sources such as power plants, refineries, and natural gas processing. CCS is the storage-focused pathway within these carbon capture programs, concentrating on injecting captured CO 2 deep underground into suitable geological formations so it remains isolated from the atmosphere for the long term.
The CCUS process has three main stages:
- Capture: In a carbon capture system workflow, CO2 is collected before it reaches the atmosphere. Depending on the source and plant design, capture can be done through post-combustion capture (removing CO2 from exhaust flue gas), pre-combustion capture (converting fossil fuels into a gas mixture so CO2 can be separated more easily), or oxy-fuel combustion (burning fuel with oxygen to produce a stream dominated by CO2 and water vapor, which can then be separated).
- Utilization: After capture, the CO2 can be routed for utilization — turning emissions into a usable input. For example, captured CO2 may be used in manufacturing materials such as concrete and plastics, or it can support enhanced oil recovery (EOR). In EOR, CO2 is injected into oil fields to help extract additional oil, keeping the carbon out of the atmosphere while creating practical value that can encourage broader CCS and CCUS adoption.
- Storage: When utilization is not the goal, the workflow moves to storage — the core of CCS and carbon capture storage. CO2 is injected deep underground into suitable geological formations, such as depleted oil and gas fields or deep saline aquifers, where it is intended to remain isolated long term. CCS programs also include ongoing monitoring of storage sites to help verify that the stored CO2 remains secure.
With these steps, CCUS and CCS technologies are a big part of moving towards a future with less carbon. In many regions, CCS and carbon capture storage are planned alongside renewable energy as part of a broader development pathway to limit the buildup of CO2 and CO 2 in the atmosphere. They let industries keep running while cutting down on how much they affect the environment. This supports other clean energy and sustainability efforts, all working together to address climate change.
