What is it?
Carbon capture also known as carbon utilization and sequestration is a process which is captures carbon dioxide emissions from large carbon emitters such power plants and industrial facilities and reuses and/or stores it so that it does not enter into the atmosphere, thereby hindering the process of global warming and curbing the effects of climate change. The process is also referred to as carbon dioxide capture and storage (CCS).
How exactly does it work?
CCS technology is capable of capturing up to 90% of the carbon dioxide emissions which may be produced from the combustion of fossil fuels process and can be built in the fossil fuel plants. Some of the earliest uses of carbon capturing technology was for enhanced oil recovery, which entails pumping carbon dioxide into an oil field to aid oil companies in extracting more oil from the earth.
Factory carbon capture involves sending emissions into a vessel containing a liquid solvent that effectively absorbs the carbon dioxide. The process entails capturing carbon dioxide before transporting it thousands of meters beneath the Earth's surface to be deposited in geological rock formations. Carbon dioxide may be captured at several different stages in the combustion process, that is, after burning fuel, before burning fuel, or burning the fuel in a certain way which makes it easy to catch the carbon.
1. Post Combustion: After the fossil fuel is burned, the CO2 is captured and extracted in a post-combustion process. This is the approach that will be used in natural gas or coal-fired power plants. CO2 makes up about 15% of the gases emitted when these fuels are burned. Absorption towers will need to be built in place of smokestacks to adapt power plants to capture carbon dioxide. Chemicals known as amines can be used to remove CO2 from the towers. Another tower will remove the CO2 from the chemicals, allowing them to be reused.
2. Pre Combustion: fossil fuels are oxidized before being burned to produce syngas, which is made up of carbon oxides and hydrogen, from there, the carbon can be extracted while the hydrogen is burned as fuel.
3. Combusting it in a certain way making the fuel easy to catch: When fossil fuels are burnt in pure oxygen, the air exhaust produced is mainly CO2 and water vapor. The water vapor is condensed leaving almost pure CO2 that can be processed.
Pre-combustion capture, post-combustion capture, or oxy-fuel combustion are used to distinguish carbon dioxide from gasses generated in power generation and industrial processes such as cement or steel manufacturing. The pollutant is then transported via pipeline or ship and then deposited in exhausted oil and gas fields or deep saline aquifer formations. In a method known as "structural storage," carbon dioxide which is pumped into such a structure and trapped by a layer of impermeable rock known as cap rock, is prevented from entering and polluting the atmosphere above. Research states that deep saline aquifers have the greatest long-term storage capacity, but they are still relatively unknown in many areas. Currently, according to the International Energy Agency (IEA), globally, there are twenty-one large scale CCUS (CCS) commercial projects which aids in capturing the carbon dioxide emissions from factory emissions.
There have also been carbon capture technologies developed for in air carbon emissions. However, capturing carbon dioxide from the air has proven to be more difficult then capturing carbon from factory emissions. Scientists have stated that “reversing global climate change” is a difficult job as there has been too much carbon released into the atmosphere.
The term "direct air capture" refers to the method of extracting pollution from the air rather than from a factory smokestack. According to the International Energy Agency, there are currently 15 direct air capture plants in Europe, the United States, and Canada. The IEA however has stated that, “carbon removal is supposed to play a key role in the transition to a net-zero energy system,” but it is currently a very costly technology. The reason for this process being such an expensive one is that due to the fact that carbon dioxide only accounts for 0.04% of the composition of the air, the technical process of removing carbon dioxide from a gas gets more expensive the lower the concentration of the carbon dioxide gets.
Why do we need carbon capture?
The UN Sustainable Development Goals:
Goal 7: Affordable and Clean Energy
Goal 13: Climate Action
The UN Sustainable Development goals listed above encourages the world to practice or put measures in place to achieve clean and affordable energy and make a concerted effort in reducing the effects of climate change in an effort to become a sustainably developed world.
The process of carbon capturing would be able to help achieve both these goals, as installing carbon capturing technology in fossil fuel plants for instance would aid in achieving clean energy as there would be no carbon dioxide emissions in the atmosphere. According to the International Energy Agency, CCUS projects could reduce global carbon dioxide emissions by nearly a fifth while lowering the cost of solving the climate crisis by 70%. At the same time, the use of carbon capturing technology would also put measures in place which would aid in climate action. With a reduction in carbon dioxide emissions, there would also be a reduction in the global warming. As we all should know by now, carbon dioxide is a major greenhouse gas and is one of the major contributors to global warming and as a result climate change. Thus, less carbon dioxide in the atmosphere would suggests that we are taking urgent action to combat climate change and its impacts.
The future of carbon capturing and its effectiveness
Presently as stated above they are twenty-one large scale CCS commercial projects which aids in capturing the carbon dioxide emissions from factory emissions. All of which however are located in the United States, Canada, Europe and China. As of right now, there has not been any governmental initiatives which has propose the use of CCS technologies in Trinidad and Tobago. The problem we are seeing with carbon capturing however, is while the technology exists and has so since 1980s, it is not being used globally. One scientist believes the reason for this is that companies would often find it cheaper to release carbon dioxide into the atmosphere than to invest in the chemical plant on the back of the smokestack which would remove the carbon dioxide from the atmosphere. Furthermore they went on to explain that, in order for there to be a change to this problem would be to put a price on releasing carbon into the atmosphere. Now that's something to consider.
Thank you for reading today's post, I do hope you learnt something from it. Feel free to comment and share your thoughts on carbon capturing below.
Sources:
https://www.un.org/sustainabledevelopment/news/communications-material/