Carbon Capture and Storage - What it is, Applications and Examples

What is Carbon Capture and Storage (CCS)?

Carbon capture and storage is a technology which is being used to store carbon dioxide so that the gas is not released into the atmosphere. This method helps in tackling global warming. Three steps are used in this process which include ?

• Capturing the CO2 emitted from any source
• Transporting the gas
• Storing it underground

Capturing and storing CO2 is necessary so that global warming can be controlled.

How does CCS work?

Three steps are involved in the working of carbon capture and storage and these steps are discussed here in detail ?

1. Capturing carbon dioxide

There are different types of industrial processes that produces various types of gases. Carbon dioxide is separated from these gases and stored.

2. Transportation of the stored carbon dioxide

The stored carbon dioxide is compressed and transported to those sites where there is shortage of the gas. The transportation is done through pipelines, ships, or road transport.

3. Storage of carbon dioxide

Carbon dioxide is stored permanently by injecting it into the rocks deep inside the ground.

Place of storage of carbon emissions in CCS

There are two methods which can be used to store carbon dioxide. These two methods are ?

• Mineral storage
• Deep geological storage

If the carbon dioxide is stored in oceans, it can lead to acidification of the water body as excess gas is already available. It is better to store the gas in the geological formations as the storage space is very large.

1. Deep Geological Formations

Geo sequestration is the name given to the process of storing carbon dioxide in deep geological formations. High pressure is applied to the gas to make it a liquid-like form. This liquid is called supercritical carbon dioxide which can be stored in the sedimentary rocks by injecting the gas.

The places where these rocks can be found are ?

• Old oil fields
• Gas fields
• Saline formations

Other geological sites where the carbon dioxide can be stored are ?

• Unmineable coal
• Volcanic rocks

2. Enhanced Oil Recovery

This is a process in which tonnes of carbon dioxide is stored in the oil fields. It helps to increase the production of oil. The cost of injecting the gas can be partially covered by selling the extra oil.

3. Unmineable Coal

The coal that is available in depth and cannot be mined is known as unmineable coal. So it is also a good place for storing carbon dioxide. If the coal at the extreme depth consists of a lot of pores, a huge amount of carbon dioxide can be absorbed. While storing the coal, methane is released which can be used for different purposes. The released methane can be stored and sold and this will help in partially covering the cost of storing the carbon dioxide.

4. Saline Aquifers

Water with a high content of salt can be found in the pores of the rocks. These pores are called saline aquifers which can be used to store a lot of carbon dioxide.

5. Mineral Storage

Mineral storage is a process in which a reaction of carbon dioxide is performed with different elements like iron, calcium, and magnesium. This process is called mineral carbonation which is a natural phenomenon. The stored carbon dioxide is not released into the atmosphere. It is a slow process but increasing temperature and pressure can increase the pace of carbonation.

Types of carbon capture technology

Many types of carbon capture technologies are available and we will discuss each of them in detail ?

1. Aqueous Amine-Based CO2 Capture

This is a technology in which carbon dioxide released from the industrial processes is absorbed by amines. In the next step, the gas is separated from amine and stored for transportation. This is an expensive technology and consumes a lot of energy.

2. Bioenergy with Carbon Capture and Storage

This is a technology in which carbon dioxide is extracted from biomass energy production and then the gas is stored. Electricity can also be produced through this process.

3. Carbon Capture and Conversion

This is a new technology in which carbon dioxide is captured and converted into products which can be used for various purposes. These products are fuels, polymers, chemicals used in industries, and many more.

4. Carbon Capture at Power Plants

Power plants emit a lot of gases and carbon dioxide has to be captured before the gases are released into the atmosphere. This stored gas is compressed and is made ready for transportation. This technology is being used for reducing carbon emissions.

5. Carbon Capture using Nanotechnology

This is a technology in which carbon dioxide is captured and stored by using nanomaterials. One of these nanomaterials is carbon nanotube. Very little pressure is required to capture and store carbon dioxide.

6. Chemical Looping

This is a process in which carbon dioxide is reacted with particles of different metals. The carbon dioxide is then separated as the metal particles are the catalyst in this process. The carbon dioxide is captured and stored for transportation or further use.

7. Cryogenic Carbon Capture

This is a new technology in which carbon dioxide is separated from the other gases with the help of the cryogenic cooling process. The gas can be stored at a low volume and a high pace. The technology is still under experiment but has a lot of potential.

8. Direct Air Capture

Direct air capture (DAC) is a technology in which air filters are used to capture carbon dioxide from the atmosphere. The carbon dioxide is captured and stored so that it can be transported to the location of storage. It is an expensive technology and is still under research.

9. Enhanced Rock Weathering

Enhanced rock weathering is a process in which crushed silicate minerals are used on the soil. The weathering process starts and continues at a fast pace and the soil captures the carbon dioxide released in the process. The technology is inexpensive and efficient as it also increases the fertility of the soil.

10. Membrane Gas Separation

This is a technology in which carbon dioxide is separated with the help of permeable materials. Low temperature and pressure are required to complete the process and extract carbon dioxide. It is an inexpensive technology and consumes less energy. This technology is still under research.

Benefits of Carbon Capture and Storage

Carbon storage and capture has many benefits which are listed here ?

• Compression of carbon dioxide releases energy when can used in power generation turbines
• More fuel can be created with the help of carbon dioxide
• More strength can be provided to concrete with the help of stored carbon dioxide
• Carbon dioxide emissions will be reduced
• CCS may help in the creation of new job
• The social cost of carbon can be reduced
• Changes in climate can be reduced

Fossil fuels can be converted into a source of renewable energy

Conclusion

Carbon capture and storage is a technology which is used to capture and store carbon dioxide emitted from various sources. The carbon dioxide can be stored in the depths of the earth or can be used as a fuel to generate electricity. Many technologies are being used to capture and store carbon dioxide and some of them are listed below ?

• Aqueous Amine-Based CO2 Capture
• Bioenergy with Carbon Capture and Storage
• Carbon Capture and Conversion
• Carbon Capture at Power Plants
• Carbon Capture using Nanotechnology
• Chemical Looping
• Cryogenic Carbon Capture
• Direct Air Capture
• Enhanced Rock Weathering
• Membrane Gas Separation

Carbon Capture and Storage FAQs

1. How can we differentiate carbon storage and carbon sequestration?

Carbon storage is a technology in which pressurized liquid carbon dioxide is stored in permeable rocks, saline aquifers, oil fields, etc. Carbon Sequestration is a technique in which carbon dioxide is removed from the atmosphere and stored in geological formations.

2. Carbon storage is used by what type of companies?

There are many companies that use carbon storage and some of them are ?

• Fossil fuels
• Fertilizer
• Manufacturing
• Power
• Steel

3. What is carbon cycle?

Carbon cycle is a process in which plants absorb the gas to produce their food through photosynthesis and release oxygen. Animals use oxygen for breathing and release carbon dioxide. The exchange of carbon dioxide also occurs between oceans and the atmosphere.

4. Which gases are termed as greenhouse gases?

The gases which are termed as greenhouse gases include ?

• Carbon dioxide
• Methane
• Nitrous oxide
• Water vapor

5. What trapping methods are being used to store the carbon dioxide underground?

These methods are ?

• Structural trapping
• Residual trapping
• Solubility trapping
• Mineral trapping