Carbon capture utilisation technologies                                                                                

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Context: Indian Scientists under Mission Innovation program, have discovered a strategy to synthesize novel solid adsorbents for CO2 capture and utilization.

Need for such technologies:

• Mitigate global warming by reducing CO2 emissions.
• Existing technologies are not economical viable
• Existing critical materials fails to capture and utilize CO2 completely.

About New strategy:

• Scientists have discovered special types of nanoparticles or microparticles, which can capture CO2 in their micro and mesoporous voids.
• The novel materials has distinct physical properties on its surfaces that have been synthesized include porous Covalent organic frameworks like COF-graphene Janus thin films.
• The newly designed COF-coated zeolites could be an excellent candidate for CO2 storage in the industry due to their high surface area and increased chemical stability.

What is carbon sequestration?

• Carbon dioxide is the most commonly produced greenhouse gas.
• Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide.
• It is one method of reducing the amount of carbon dioxide in the atmosphere with the goal of reducing global climate change.
• Aim: stabilizing the amounts of the greenhouse gas concentration in the atmosphere and reducing the human ‘carbon footprint’.
• Carbon sequestration is both a natural and artificial process by which carbon dioxide is removed from the Earth’s atmosphere and then stored in liquid or solid form.

Types of Carbon Sequestration

1. Biological Carbon Sequestration: storage of carbon dioxide in vegetation like grasslands and forests, as well as in soils and oceans.

• In oceans: Naturally, oceans absorb about 25% of the carbon dioxide emitted through human activities each year.
• In forests: plant-rich landscapes like forests, rangelands and grasslands absorb about 25% of the global carbon emissions. When the trees, branches and leaves die and fall to the ground, they release the carbon they had stored into the soil.
• In soils: carbon can be sequestered in soil by plants through photosynthesis. Soil can also store carbon as carbonates.
• In grasslands: grasslands and rangelands are more reliable areas of storing carbon than forests due to the rapid wildfires and deforestation affecting forests.

2. Geological Carbon Sequestration: This is where carbon dioxide is stored in underground geologic formations, such as in rocks. Industrial sources of carbon dioxide such as steel or cement production companies or energy-related sources like power plants or natural gas processing facilities will release their carbon dioxide, which is then injected into porous rocks for long-term storage.
3. Technological Carbon Sequestration: This is a relatively new way of capturing and storing carbon dioxide. This method uses innovative technologies for removing CO2 from the atmosphere.
4. Graphene production: Technology is being used to produce graphene from carbon dioxide as its raw material. Graphene can be used as a viable resource and solution in reducing carbon’s emissions from the atmosphere.
5. Engineered molecules: engineering molecules can act as filters and only attract the element they are engineered to seek.
6. Direct air capture (DAC): this is a means of capturing carbon dioxide from the air using advanced technology plants. It is an effective technological method of sequestrating carbon but it is energy-intensive.
7. Industrial Carbon Sequestration: This is not a widely renowned method, that can capture the carbon in three ways a. Pre-combustion: the carbon is captured in power plants before the fuel is burned. The aim is to remove the carbon from coal before it is burned. The coal is reacted with oxygen to produce synthesis gas, a mixture of carbon monoxide and hydrogen gases.
8. Post-combustion: carbon is removed from a power station’s output after the fuel has been burned. This means waste gases are captured and scrubbed clean of their carbon dioxide before they travel up smokestacks.
9. Oxyfuel or oxy-combustion: the point is to burn fuel in more oxygen and the process traps the entire output from the smokestacks and stores it all. Pure oxygen is blown into the furnaces to purify the exhaust, so the fuel burns completely, producing relatively pure steam and carbon dioxide gas.

Examples of Carbon Sequestration

1. Photosynthesis: This is the process where plants and trees absorb and store carbon dioxide during growth, releasing oxygen in turn.
2. Century Plant: This is the single biggest carbon capture and storage plant in the world.

How Does Carbon Sequestration help the Environment?

• Forests and vegetation have been identified to be key players in capturing and storing carbon dioxide, capturing about 25% of all carbon emissions.
• It helps reduce global warming
• It reduces ocean acidification
• Helping mitigate carbon dioxide emission

https://www.pib.gov.in/PressReleasePage.aspx?PRID=1804748