Carbon Capture and Storage [CCS] is a process that reduces carbon emissions so that global warming can be tackled. The three stages in the process are capturing the carbon dioxide that power generation or industries produce, transporting it, and finally storing it. The carbon dioxide is captured before it can enter the atmosphere.
Chemical or biomass power plants and coal-fired plants are the largest sources of carbon dioxide. Underground geological formations are used for the storage of this gas. While injecting geological formations with CO2 has been practised for several decades, long-term Carbon Capture and Storage [CCS] is a recent concept.
Significance of Carbon Capture and Storage [CCS]
Carbon emissions are responsible for global warming and Carbon Capture and Storage [CCS] aids in the prevention of global warming by capturing and storing it.
Prevention of Global Warming Through Carbon Capture and Storage [CCS]
Here are the details of the actual working of Carbon Capture and Storage [CCS]:
CO2 is captured using the following technologies:
- Post-Combustion Capture: After the fossil-fuel combustion, there is the removal of CO2. This technology is used in fossil-fuel power plants. This method is popular in research.
- Pre-Combustion Capture: Power, chemical, and fertilizer industries use this technology. There is partial oxidation of fossil fuel in a gasifier.
- Oxy-Fuel Combustion: In this method, there is burning of fuel in pure oxygen, not air.
- Absorption: The carbon capture technology used by industries is absorption or carbon scrubbing. The primary cost of Carbon Capture and Storage [CCS] is the capture stage which takes up two-thirds of the total cost.
- Chemical Looping Combustion: A metal oxide is used in this process where the end products after combustion are solid metal particles, CO2, and water vapour. After condensation, pure CO2 is sequestered.
☛ Also Read: Current Affairs Today
The next step in the Carbon Capture and Storage [CCS] process is transportation, where the CO2 reaches the proper storage site. The cheapest mode of transport is pipelines, and where this facility is not available, ships are utilized. Using rail or tankers would double the cost of transport.
Storage (Sequestration) -
There are various forms of storage ranging from gaseous form to solid-state. CO2 is stored in gaseous form in deep geological formations. CO2 and metal oxides react, producing stable carbonates.
Here are some of the different forms of storage:
- Geological Storage: CO2 is injected into underground geological formations in supercritical form. Other alternatives include unmineable coal seams, saline formations, gas fields, and oil fields. Leakage risks are reduced with trapping mechanisms like residual trapping, structural trapping, and more.
- Enhanced Oil Recovery: This is not a carbon-neutral method since CO2 is released on burning the oil.
- Algae/Bacterium: Degradation of CO2 by supplying it to algae or bacteria
- Mineral Storage: Stable carbonates are produced with the exothermal reaction of CO2 with metal oxides.
Possibility of Leakage from CCS Storage Sites
Retention over the Long-Term -
The storage sites can retain about 99% of the CO2 over a period of 1000 years. Evidence of the efficacy of geosequestration can be found in the Sleipner Gas Field in Norway, and it was proved after an environmental assessment of 10 years.
Sudden Leakage -
Ruptured pipelines would lead to leakage of CO2. To prevent leakage, remotely-controlled valves can be used to regulate these pipelines.
Carbon Capture and Storage [CCS] is an important tool for controlling carbon emissions in the atmosphere and preventing global warming. It is achieved through a 3-stage process, and there is sufficient evidence to prove that there are minimal chances of leakage.
FAQs on Carbon Capture and Storage [CCS]
Q.1. Where are the First Carbon Capture and Storage [CCS] facility located?
More than 200 MT of CO2 has been stored in Texas in the US since 1972, which is the first Carbon Capture and Storage [CCS] facility.
Q.2. Is Carbon Capture and Storage [CCS] a Reliable Storage Method for CO2?
Yes, Carbon Capture and Storage [CCS] has been considered a proven technology for CO2 storage for more than 45 years.
Q.3. How Many Carbon Capture and Storage [CCS] Facilities are There Globally?
As of 2019, there are 51 large-scale Carbon Capture and Storage [CCS] facilities globally.
Q.4. What Are the Three Stages of Carbon Capture and Storage [CCS]?
The three stages of Carbon Capture and Storage [CCS] are captures, transportation, and storage.
Q.5. Where is CO2 stored in Carbon Capture and Storage [CCS]?
In Carbon Capture and Storage [CCS], CO2 is stored in depleted oil and gas reservoirs and saline aquifers.