Reducing carbon emissions is essential to combating climate change and ensuring future sustainability. However, the world is still very reliant on conventional fossil fuels. So, reducing carbon dioxide emissions while maintaining operations has become a major industry challenge.
Many experts tout carbon capture and sequestration as solutions to reduce emissions. The aim is to capture carbon and inject it back into the ground. But how does it work?
In this article, we will answer this question. We will look into the different types of sequestration that currently exist. We will also break down the complete “capture and sequestration” process.
What is Carbon Capture and Sequestration?
Carbon sequestration and capture is all about capturing and storing greenhouse gases from fossil fuel power plants, energy-intensive industries, and gas fields. The greenhouse gases are stored by injecting them back into the ground.
The capture and sequestration of carbon is proposed in a range of different areas. You can take power stations and enhanced oil recovery (EOR) as examples.
Carbon sequestration and capture proponents argue that it can be used to mitigate the impact of emissions-intensive industries such as cement, steel, and chemical production. However, it will never be a ‘zero-emissions’ solution, especially if it’s linked to highly polluting coal and gas plants.
It is impractical to rely solely on this technology. That’s because it’s a reactive (indirect) rather than proactive (direct) method of dealing with emissions. Long-term, direct methods of reducing carbon footprints are far more effective. Reducing your household, travel, and lifestyle carbon footprints can help fight climate change!
Types of Carbon Sequestration
Carbon is sequestered both naturally and artificially. Naturally, resources like oceans, forests, and soil do the job. Artificially, an approach like putting CO2 underground is another solution. Let’s look at all these types:
Biological Carbon Sequestration
Biologically, carbon dioxide (CO2) is stored in soils, oceans, and forests.
- Oceans: Oceans absorb 25% of human CO2 emissions annually. Like breathing, carbon moves in and out of the ocean. This creates positive and negative fluxes. The polar regions hold great importance here. That’s because their cold, nutrient-rich oceans soak up more CO2. It is estimated that global oceans may become major carbon sinks by 2100. This will change the chemistry of those ocean waters. Since the pH level will drop, the water will become more acidic.
- Soil: Plants can store carbon as soil organic carbon (SOC). Plants sequester carbon in the soil through photosynthesis. Though agroecosystems deplete SOC levels, new land management practices can store carbon. Besides, soil can also store carbon as carbonate. Unlike soil organic matter, inorganic carbonates can store carbon for more than 70,000 years. To store carbon longer, scientists are adding finely crushed silicates to the soil to accelerate carbonate formation.
- Forests: Plant-rich landscapes like forests, grasslands, and rangelands are responsible for capturing about 25% of global carbon emissions. When plants die or their leaves and branches fall off, the carbon they stored either goes into the soil or into the air. However, forests can lose their carbon-storing ability due to wildfires and deforestation.
Geological Carbon Sequestration
Geological carbon sequestration is the method of storing CO2 in underground geologic formations or rocks.
This CO2 is usually taken from an energy-related source. Then, it is placed in porous rocks to be stored for a long time. The source of CO2 could be
- A power plant
- A facility that processes natural gas
- An industrial source, like steel or cement manufacturing
Carbon capture and storage can keep fossil fuels in use until a large-scale switch to a different energy source is possible.
Technological Carbon Sequestration
Scientists are using new technologies and looking for new ways to take carbon out of the air and store it. Researchers are also discovering more uses for carbon dioxide besides just getting rid of it.
- Graphene Production: Graphene is a technological material that is made from carbon dioxide as a raw material. It is used to create screens for smartphones and other tech devices. Graphene production is limited to specific industries. However, it exemplifies how carbon dioxide can be used as a resource and a solution to reduce atmospheric emissions.
- Direct Air Capture (DAC): This is an advanced technology-based method to capture carbon directly from the air. However, this process is energy-intensive and expensive to implement on a large scale.
- Engineered Molecules: Scientists are turning molecules that can change shape into new compounds. These compounds can pick out and capture carbon dioxide in the air. Scientists generated molecules that only pull in the element they were made to find. They filter out everything else.
The Process of Carbon Sequestration and Capture
We have learned the types of carbon sequestrations that exist in today’s world. But how do producers run the whole process of capture and sequestration? The main methods of this operation are gas capture, transportation, and storage. Let’s break down the whole process in more detail:
Capturing and Trapping the Gas
Carbon capture can happen at several points in the process of burning fossil fuels.
- It’s possible for carbon to become trapped after combustion. This means it gets separated from the other gases produced when fuel burns.
- Carbon can also be captured before combustion- it would be removed from the fuel source before it burns.
- A third method involves burning fossil fuel in a power plant filled with pure oxygen. Burning fuel emits carbon dioxide and water. Carbon can then be captured by compressing water and separating it from carbon dioxide.
Transporting the Gas
After capturing carbon dioxide, the company must transport it to a storage facility. Typically, the gas travels through pipelines above, below, or in the ocean. The pipelines may collect gas from multiple sources along the way. Before arriving at its destination, carbon dioxide may be transferred to a tanker.
Storing the Gas
There are a few approaches to storing carbon dioxide.
- One option is to store it in underground reservoirs. When stored underground, carbon is kept at a constant temperature and exists in a state between liquid and gas. Since it has the ability to seep into rock formations, large quantities of the gas can exist in a small area.
- Another option is to store CO2 in the ocean. When stored deep beneath the ocean’s surface, the gas is denser than water. It can remain there for years.
Why is Carbon Sequestration and Capture Important?
Climate change becomes more serious as carbon levels rise in our atmosphere. Carbon and other air pollutants soak up sunlight and solar radiation in the atmosphere. They trap heat and act as insulators for the Earth.
Since the Industrial Revolution, the Earth’s temperature has risen by slightly more than 1 oC or 2 oF. However, this rate has more than doubled since 1981. The current global annual temperature rises by 0.18 °C (0.32 °F) every ten years.
Rising global temperatures can devastate our environment by
- Ice melting
- Sea-level rising
- Extreme weather
- Ocean acidification
Fortunately, reducing, capturing, and sequestering carbon emissions slows down all these scenarios.
When these rates are slowed, Earth’s biodiversity can adapt to temperature and pH changes more easily. Coastal flooding won’t cause any displacement of people. And icebergs will regulate the climate.
Conclusion
Sequestration and capture of carbon is a firm step towards fighting climate change.
Sequestration can be of different types, such as biological, geological, and technological. The whole process begins with capturing the gas and trapping it. Then comes the transportation phase. Finally, the carbon is stored either underground or in the ocean. This process helps mitigate global warming but shouldn’t be solely relied on.
If you are willing to be a small part of this process of reducing carbon emissions, Clima is ready to partner up with you. We assist different industries in reducing their carbon footprint. Contact us today and learn more about our services.