Carbon dioxide: the most infamous of greenhouse gases, the product of combustion of fossil fuels, and a structure students struggle to draw in gen chem. The United States produces the most carbon dioxide of any country besides China, and makes almost five and a half thousand million metric tons each year. This has a huge impact on the climate and environment. So, what can be done?
One option is carbon capture and sequestration (CCS), in which CO2 is collected and stored in a stable, undegrading form. The CO2 can be gathered from the atmosphere or prevented from being released from emitters like factories and power plants, but either way it is not an easy process. A lot of work is being done to take CCS from a theory to a working solution. Here we highlight three emerging technologies in the fields of energy, construction, and biology.
Climeworks, Iceland: The world’s first net negative emissions plant
A power plant that generates energy and simultaneously cleans the air seems too good to be true, but after many years of work it is a reality. Since October 2017, a geothermal energy plant in Iceland has been proving just how far green technology has come.
The Swiss company Climeworks outfitted the plant with a direct-from-air CO2 capture system which runs on excess heat energy from the plant. The captured CO2 is then dissolved in water and injected underground, using technology from another company called CarbFix. Once underground, the carbon is mineralized by the basaltic rock and will stay put for millions of years.
CarbonCure: Injecting cement with CO2
As civil engineers may know, concrete is the most abundant human-produced material on earth. Production of its main ingredient, cement, is the second largest industrial source of CO2. However, this might be about to change.
CarbonCure, a Canadian startup, has developed a method of injecting captured CO2 into cement as it is being prepared. There the CO2 reacts with the material and mineralizes, so that even when the concrete degrades it will continue to be sequestered rather than being released. The best thing,though, is that this does not compromise the strength of the concrete; instead, it actually improves it. It also decreases the amount of cement needed for projects. While not yet widely adopted, CarbonCure offers an economical option for companies to decrease their carbon emissions and become more sustainable.
Dr. Chory of the Salk Institute: Engineering plants to sequester CO2
Plants use sunlight to convert CO2 into other products, but in most cases they release this carbon back into the atmosphere when they die. This is not always true, though, such as in the case of suberin, or cork. It is a compound that is not biodegradable and can last for a few thousand years before breaking down, making it the perfect natural CO2 sink. And while it is mostly produced by cork trees, it is also produced in the roots of many plants.
Dr. Joanne Chory decided to exploit this fact for the good of the planet. Her lab has been developing plants that will produce a greater-than-average amount of cork. On a small scale, the difference is not huge; however, if expanded to 5% of the world’s agricultural land these slight modifications could remove half of the CO2 emissions currently being produced. With more work, this could be a very cost effective technique for carbon capture.
Ultimately, necessity drives innovation, and climate change may just be humanity’s greatest need yet. The incredible progress being made by people from all disciplines highlights that there are always opportunities to make a difference, if you are just willing to look.
-- Evelyn Byrd
Lord, B. (2018, July 6). This concrete (yes, concrete) is going high-tech. CNN Business. Retrieved March 3, 2019, from https://money.cnn.com/2018/06/12/technology/concrete-carboncure/index.html
Rathi, A. (2017, October 12). The world’s first “negative emissions” plant has begun operation—turning carbon dioxide into stone. Quartz. Retrieved March 3, 2019, from https://qz.com/1100221/the-worlds-first-negative-emissions-plant-has-opened-in-iceland-turning-carbon-dioxide-into-stone/
Thompson, A. (2017, December 4). The new plants that could save us from climate change. Popular Mechanics. Retrieved March 3, 2019, from https://www.popularmechanics.com/science/green-tech/a14000753/the-plants-that-could-save-us-from-climate-change/