Carbon capture and storage (CCS) is an emerging technology used to mitigate harmful emissions from power plants and industrial facilities, with excess emissions stored underground as a long-term solution.
To do this, CO2 is compressed and deeply chilled into a liquid-like state before being transported via pipeline to an appropriate geological site and injected into rock formations, similar to those that have stored oil and gas over millions of years.
What is CCS?
Carbon Capture and Storage (CCS) involves extracting carbon dioxide from fossil fuels such as coal, oil or natural gas and storing it underground geological formations for long-term storage. CCS may also be known by other names: CO2 Removal or Negative Emission Technology (NET).
CCS technology has been utilized since the 1970s in industrial processes such as steel and cement production, natural gas processing, ammonia production for refineries, refinery hydrogen production, coal-fired power generation and more recently coal mining operations. According to MIT Climate Portal only 26 commercialized CCS projects worldwide have yet been commercialized worldwide.
Most CCS projects have encountered severe setbacks, from cost overruns and delays to being far too costly relative to alternatives like renewables backed by battery storage. Furthermore, CCS can perpetuate fossil fuel usage and worsen environmental impacts; as a result it should not be seen as a “magic bullet” that locks in fossil fuel power but as part of an arsenal of technologies to drive down emissions.
The Capture Process
CCS involves isolating carbon dioxide from other gases produced at power plants or industrial facilities and then compressing and shipping it either for long-term storage or other uses such as enhanced oil recovery (EOR).
Utilization is another approach to CO2 management that lowers climate impact while still helping reduce emissions, known as carbon capture, utilization and sequestration (CCUS).
RFF supports large-scale CCS projects operating or in development across the US that store about 3 percent of annual CO2 emissions; these projects account for 3 percent of annual emissions storage. But deployment must accelerate significantly for nations to meet climate targets; that’s why RFF advocates for policies that incentivize CCS deployment like California’s Low Carbon Fuel Standard (LCFS), which recently expanded opportunities for projects to generate credits through this technology.
The Transport Process
Carbon capture technologies offer various means for isolating CO2 from other gases emitted by sources like power plants and industrial facilities, so that it may then be transported safely underground storage sites for safekeeping.
Post-combustion carbon capture uses chemical solvents to isolate carbon dioxide from fossil fuel combustion flue gas emissions. It could potentially be retrofitted onto existing power plants using this technology for carbon capture storage (CCS).
Pre-combustion carbon capture requires gasification of fossil fuel into a synthesis gas, or syngas, consisting of both carbon monoxide and hydrogen. A shift reaction then converts this syngas to pure carbon dioxide; such technology would typically be implemented in an integrated gasification combined cycle power plant (IGCC).
Carbon dioxide (CO2) is then stored safely and permanently underground rock formations used to store oil and natural gas over time. Each site is carefully chosen by a team of experts who ensure it will hold on to CO2.
The Storage Process
CO2 collected in an underground geologic formation is then stored, typically through saline aquifers but there may also be options such as basalt formations that react with carbon dioxide to form solid mineral forms that are trapped permanently within its walls.
Noting the process of CCUS takes time; up to seven years may pass between installation of capture and storage plants as well as construction of transportation and storage infrastructure.
CCS deployment must accelerate now for several reasons. Without it, meeting long-term climate targets like limiting global warming to 1.5 degrees Celsius above preindustrial levels may prove challenging. Furthermore, CCS technology plays an essential role in mitigating emissions from fossil fuel power plants and industrial processes like steel and cement production; making investments into its capture, transportation and storage necessary.