Global warming is a matter of great concern for life on Earth. As the industrial revolution is progressing, the global temperature increases. As a result, Earth’s temperature has increased, and the climate has been imbalanced; these climatic changes are leading to the loss of habitats of several plants and animals.
Global warming occurs when carbon dioxide and other gaseous pollutants accumulate in the atmosphere and absorb sunlight and solar radiation emitted from the Earth’s surface. This results in the planet getting hotter and increasing climate changes.
To control this condition, capturing air pollutants such as carbon dioxide, methane, nitrous oxide, water vapor, and synthetic fluorinated gasses is important. These air pollutants are also known as greenhouse gasses. However, capturing all these gaseous pollutants may not be possible, but CO2 can be captured easily from various industrial sources. Hence capturing and storing CO2 is convenient and helps protect Earth from global warming.
Which Methods are Playing Vital Role in Carbon Capture and Storage?
Different options are being investigated to reduce overall CO2 emissions, but from all of them, carbon capture and storage (CCS) is the central way to reduce CO2 emissions from a wide range of industrial sources.
Even the Ministry of Petroleum and Natural Gas, Government of India, has taken the initiative to lower the greenhouse effect on climate change by implementing the CCS process.
CCS involves capturing carbon dioxide (CO2) from emissions and transporting sources before releasing it into the atmosphere and storing CO2 in deep underground locations. CCS means direct or indirect removal of CO2 from the atmosphere. CO2 can be captured from various sources such as natural gas processing facilities, power plants, and some industrial activities like steel or cement making. Open atmosphere capture of CO2, also known as direct air capture (DAC), is also an option.
Three techniques are used to remove or ‘scrub’ CO2:
- Pre-combustion
- Post-combustion
- Oxyfuel combustion
Pre-combustion
This process happens before fossil fuel is burnt at power plants. In the pre-combustion process, first, synthetic gas is produced by partially burning fossil fuels in a ‘gasifier’. This procedure produces a relatively pure exhaust mixture of gasses. In this process, CO2 can be captured safely by fuel gasification with oxygen, and hydrogen can be isolated and used as fuel.
The pre-combustion process is widely used in the production of fertilizer, power production, and chemical gas fuel. It is an inexpensive alternative to post-combustion but cannot be retrofitted in older power plants.
Post-combustion
In this process, CO2 is captured (‘scrubbed’) from the exhaust gasses after burning the fossil fuel. Scrubbing of CO2 is done by using chemical absorption, physical adsorption, membrane separation, or chemical loop process.
Post-combustion method would be used in most conventional power plants as it can be retrofitted. The technology is well-known and is currently popular in several industrial applications.
Oxyfuel combustion
In this process, the fossil fuel is burned using oxygen rather than air. The resultant flue gas mainly consists of CO2 and water vapor. The cooling technique causes the water to condense, producing nearly pure CO2 that may be transported and stored.
In electricity plant processes based on oxyfuel combustion, almost all the CO2 is captured, hence it is referred to as ‘zero emission’. However, condensed water may contain some CO2, so the water must be further treated.
Oxygen combustion may be the most efficient method of the three, but the initial oxygen-burning process is energy-intensive.
What are the Emerging Innovations and Advancements in Carbon Capture and Storage Technology?
It has been decades, and numerous researchers are exploring the most effective ways for carbon capture and storage to lower the climate change and global warming.
Some of the latest innovations in the realm of carbon capture and storage technology are mentioned below.
MOFs and Porous Polymers for Carbon Capture and Storage
One of the most promising innovations in carbon capture and storage is the advancement in new processes and materials for CO2 capturing.
CCS has been using amine-based solvents for decades to capture CO2 from industrial flue gasses. Although these solvents can be energy-intensive and expensive to maintain, researchers are exploring alternative materials.
Metal-organic frameworks (MOFs) and porous polymers are effective viable options for industries worldwide and can capture CO2 more efficiently and with lower energy requirements.
Artificial Intelligence and Machine Learning for Carbon Capture and Storage
Another emerging technology in the carbon capture and storage field is the use of artificial intelligence and machine learning. This advanced technology will optimize the CCS capture process by analyzing huge data on industrial activities.
AI algorithms have the potential to improve the efficiency of CO2 capture by identifying patterns and trends that can help. For example, AI can significantly save energy by operating temperature and pressure requirements for CO2 capture systems. Additionally, with the help of machine learning, accurate models, better materials, and design systems can be developed for CCS.
Carbon Mineralization for Long Storage of Carbon
In addition to innovations in carbon capture technology, significant progress has been made in the storage aspect of CCS. Carbon mineralization is one such breakthrough, which includes converting CO2 into stable, solid minerals that can be stored permanently. This process can take a long time to occur naturally, but researchers are working on ways to speed it up, making it a more viable choice for large-scale CO2 storage. By injecting CO2 into subsurface rock formations rich in minerals like olivine and serpentine, the CO2 can react with the minerals to generate stable carbonates, thus removing carbon from the atmosphere.
Renewable Energy Integration with Carbon Capture and Storage
Another innovative way is CCS integration with renewable energy sources such as solar and wind power. It is conceivable to develop a closed-loop system by integrating CCS with various clean energy technologies. This will collect and store CO2 emissions while providing electricity with low environmental impact.
How the Government is Taking Care of Carbon Emission and Climate Change?
- The U.S. Department of Energy (DOE), the Biden-Harris Administration, has announced earlier the launch of four programs funded with $3.7 billion by President Biden’s Bipartisan Infrastructure Law. This program will help build a commercially feasible and responsible carbon dioxide removal industry in the United States. It will also grant local and state governments to procure and use products developed from captured carbon emissions.
- S. Senators Shelley Moore Capito (R-W.Va.) and Heidi Heitkamp (D-N.D.)—along with Senators John Barrasso (R-Wyo.) and Sheldon Whitehouse (D-R.I.)—has announced in 2017, a bipartisan bill with the FUTURE Act. This bipartisan bill encourages technological innovation in carbon capture utilization and storage (CCUS) to reduce carbon emissions. This bipartisan budget deal was signed into law by President Donald J. Trump.
- In 2018, the Low Carbon Fuel Standard (LCFS) of California was amended to encourage carbon capture and storage projects. To generate LCFS credits, CCS is associated with the production of transport fuels sold in California. As the only exception to the norm, it also allowed DAC projects to create credits regardless of their location, even if they did not include a fuel component. These modifications went into effect in January 2019.
Summing up
Carbon capture and storage allow the industry to continue to operate while emitting fewer greenhouse gasses (CHGs). CCS addresses the mitigation of anthropogenic CO2 in the atmosphere. However, carbon storage must be safe, environmentally sustainable, and cost-effective. The examination of CCS industry trends is currently impacting the industry’s growth.
The advancements in CCS technologies and applications have the potential to play a vital role in lower climate change. By improving the efficiency and costliness of CCS, developing new storage methods, and combining it with renewable energy sources and carbon utilization, these advancements could help pave the way for a more sustainable future.