CCS technologies aim to capture carbon dioxide (CO2) from industrial processes or the atmosphere and store it underground or in geological formations to prevent its release into the atmosphere and mitigate climate change.

Post-combustion capture involves capturing CO2 from the flue gas of industrial plants after the fuel has been burned. This method is widely used due to its compatibility with existing infrastructure and relatively low cost.

Pre-combustion capture requires the conversion of fuel into a hydrogen-rich gas and CO2 prior to combustion. This process is energy-intensive and can result in a decrease in the overall efficiency of the power plant.

Depleted oil and gas reservoirs offer a suitable storage option for CO2 due to their existing infrastructure, well-characterized geology, and the potential for enhanced oil recovery.

Leakage and migration of CO2 from storage sites pose a significant risk, as it can lead to the release of CO2 into the atmosphere, potentially undermining the effectiveness of CCS technologies.

Direct air capture (DAC) technologies aim to remove CO2 directly from the ambient air using various methods, such as chemical absorption, adsorption, or membrane separation.

DAC technologies require significant amounts of energy to capture CO2 from the dilute concentration in the ambient air, making them energy-intensive and potentially costly.

CCU technologies aim to utilize captured CO2 as a feedstock for various industrial processes. One potential application is the production of synthetic fuels, such as methanol or gasoline, which can be used as transportation fuels.

EOR techniques involve injecting CO2 into depleted oil reservoirs to enhance oil recovery. This process not only increases oil production but also provides a means of storing CO2 underground.

EOR using CO2 can potentially lead to groundwater contamination if CO2 or associated fluids leak from the injection site and migrate into aquifers.

The high costs associated with CCS technologies, including capture, transportation, and storage, pose a significant barrier to their widespread adoption. Reducing costs is crucial for making CCS economically viable.

The Paris Agreement, adopted in 2015, includes a goal to limit global warming to well below 2 degrees Celsius, preferably to 1.5 degrees Celsius, above pre-industrial levels. It recognizes the role of CCS technologies in achieving this goal.

The Carbon Capture and Storage (CCS) Research, Development, and Demonstration (RD&D) Program in the United States aims to advance CCS technologies through research, development, and demonstration projects to enable their commercial deployment and contribute to the reduction of greenhouse gas emissions.

CCS technologies can provide additional benefits beyond climate change mitigation. For example, enhanced oil recovery (EOR) using CO2 can increase oil production from depleted reservoirs while simultaneously storing CO2 underground.

The transportation of CO2 for CCS projects poses several challenges, including corrosion of pipelines due to the acidic nature of CO2. Specialized materials and technologies are required to ensure the safe and reliable transportation of CO2.