By December 2021, we just exceeded the carbon dioxide (CO2) threshold of 416 ppm. CO2 levels in the atmosphere are already excessive. As a part of the solution, we are transitioning to renewables, recycling, reusing. However, we must now do more than just reduce emissions to properly ensure a sustainable climate for future generations: We must also remove CO2 from the atmosphere.
As the most known removal technique, photosynthesis captures the CO2 in the air and releases it into the atmosphere as oxygen. Per contra, we have neither an adequate bunch of trees nor the time for planting to eliminate the current carbon emissions we produce in nature before it is too late. In this respect, we may consider artificial ways for photosynthesis under carbon-negative technologies. The most popular one is carbon capture.
Carbon capture is not a new technology, the usage has been dating back to the 1970s. The main purpose of inventing this technology was to enhance oil production by injecting captured CO2 into existing oil fields. The procedure could be briefly explained as injecting CO2 increases the overall pressure in an oil reservoir and pushes more oil to a production wellbore. Nowadays, carbon capturing has been glimpsed as a way out to meet up reducing and removing carbon emissions.
The current extensively used technology mainly prevents the disperse of CO2 into the atmosphere from power stations and industrial plants which are the main sources of greenhouse gas emissions. This method helps with stopping putting CO2 into the air to great extent during industrial production. The most advanced and adopted capturing method is done with chemical absorption that grabs CO2 by reacting it with a chemical solvent. Other processes include physical separation, oxyfuel separation, membranes and looping cycles. Then, the CO2 is compressed so that it could be transported via pipeline. Where the captured carbons could be held and for what purpose the stored could be used are still open questions. The entire procedure is called carbon capture, utilisation and storage (CCUS).
CO2 in the air could also be directly captured through the Direct Air Capture (DAC) technology. The target of DAC is low concentration CO2 in the atmosphere. Nonetheless, this capturing method is currently not widespread in usage since it is a reasonably expensive proposition. There are plenty of startups that run direct air capture and share openly their licenses that technology anywhere. One of them, Carbon Engineering, expects to capture 1 million tonnes of atmospheric CO2 per year which is equal to the carbon removal work of approximately 40 million trees with a cost of 200$ per ton.
Carbon capture is an important part of the cycle of energy. The cycle occurs as, shortly, the captured CO2 from mainly power stations turns back as the fuels or energy to be used. That cycle could bring carbon neutrality into reality if all emitted CO2 could back into the atmosphere without producing new. In this sense, it has a huge potential to make a big difference regarding greenhouse gas emissions. Also, the International Energy Agency (IAE) underlines the importance of the technology by a warning that meeting climate targets without capturing and storing emissions from factories, power plants, transportation, and other sources will be "virtually impossible."
There are currently 21 CCUS plants and 19 DAC plants operating across the world, with the capacity of capturing up to 40 Million tonnes and 11 thousand tonnes CO2 per year, respectively. The majority of the projects are implemented in the United States and Europe, but there are also new plant plans in Australia, China, Korea, the Middle East, and New Zealand. Unfortunately, carbon capturing has a low share at present when compared to overall emissions, which are 33 billion tons per year. IAE reports indicate that if the new projects could be embarked, global CO2 capture capacity would be reaching roughly 1150 Mt CO2 from CCUS and 85 Mt CO2 from DAC per year by 2030.
In my opinion, carbon capture technology can really help us to tackle climate change and reduce greenhouse gas emissions in a great manner if the tech grows up all around the world. It may indeed not absolve the world of the need to reduce and remove emissions, but it may ease the path to net zero emissions by 2050 and a global temperature rise of less than 2 degrees Celsius, as the main purpose of the Paris Climate Agreement. In other words, it is only a part of the solution, and we need to find the other pieces of the puzzle of the carbon issue as well.
Additionally, be kindly aware of the contest of Carbon Removal X which is funded by Elon Musk and the prize is $100 million dollars for those who build CO2 removal solutions at 1000 tonnes per year and present a model for billion tonnes in the future.