By Jericho Rajninger
Direct Air Capture:
Direct air capture (DAC) refers to the process of extracting large quantities of carbon dioxide from the atmosphere using man-made technologies. Methods vary, and some are more energy efficient than others. Most DAC technologies function like mechanical trees: through a sequence of chemical reactions, they consume air rich in CO2, suck out the carbon dioxide and then release clean air back into the environment. The extracted carbon dioxide is expelled in a stream of gas to be stored or used. Recently, Massachusetts Institute of Technology developed a machine that extracts carbon dioxide from the air by passing the air through a series of electrochemical plates, releasing a pure stream of carbon dioxide out the other end.
Carbon Capture and Utilization:
There are a multitude of ways in which carbon dioxide in the atmosphere can be stored and used to create synthetic materials — materials that would otherwise require the removal of more carbon from the earth. While significant research remains to be done to understand the true environmental impact of artificial sequestration, carbon capture, utilization and storage (CCUS) technologies have the potential to significantly reduce the level of emissions in the atmosphere.
One promising method for CCUS lies in building materials, namely concrete. The recipe for concrete requires a number of ingredients, some of which can be replaced with carbon dioxide. For example, carbon dioxide can be used in place of steam to cure concrete, and aggregates added to the concrete mixture can be made using mineralized CO2. These substitutions achieve two goals: they remove CO2 from the atmosphere while simultaneously avoiding the extraction of more natural resources from the earth.
CCUS can also be achieved through carbon-neutral synthetic fuels, which are created by removing one of the oxygen atoms from carbon dioxide and bonding the remaining carbon monoxide molecule to a hydrogen molecule. This fuel, known as syngas, could help decarbonize fields of industry that cannot be electrified. Similar combinations of recycled carbon monoxide and hydrogen can also produce low-carbon plastic.
Today, some companies are even experimenting with ways to turn carbon dioxide emissions into food.
Tags: carbon capture, concrete, cement, sequestration, carbon dioxide, syngas, CCUS
Further Reading:
- MIT Engineers Develop a New Way to Remove Carbon from the Air
- The Status of Carbon Capture Projects in the U.S.
- These Startups are Turning CO2 Pollution into Something Useful
- This Carbon Negative Vodka is Made From Captured CO2
- Would You Eat a Burger Made out of CO2 Captured from the Air?
- Capturing Carbon’s Potential: These Companies Are Turning CO2 into Profits
Transcript
Ethan: Can carbon dioxide emissions be put to good use? This is Ethan Elkind of Climate Break. We’re joined today by Noah Deich, Director of Carbon 180, a nonprofit that promotes carbon sequestration initiatives. Removing carbon dioxide from the atmosphere could help reverse the effects of climate change. Once captured, recycled carbon can replace fossil carbon in products like fuels and plastic.
Mr. Deich: There’s a wide range of things that are made with fossil carbons today that are really the building blocks of everything that we have, from the clothes that we wear to the consumer goods that we use. All of this can be shifted so that we’re using the feedstock from carbon in the air instead of fossil oil and gas in the ground.
Ethan: Noah offers some other opportunities for society to become carbon negative by capturing more gasses than we produce.
Mr. Deich: There are a handful of companies today that are commercializing cement and concrete products that sequester CO2. In the future, I think we’ll be able to take CO2 and make a wide range of fuels and chemicals that we make from fossil carbon today.
Ethan: For more information on Carbon 180’s carbon capture initiatives, and for more climate solutions, go to climatebreak.org or wherever you get your podcasts.