Carbon: a simple element that represents very deep problems for us.
The excess of carbon dioxide (CO2) in the atmosphere contributes to global warming, with the threat of irreversible climate collapse.
However, carbon is also the essential building block of all life. It makes up the food that sustains us and provides the energy that fuels the economy.
So, if there is so much carbon in the air and we need this element for our daily lives anyway, why not use it to our advantage?
That is the idea behind several projects that aim to capture greenhouse gas emissions directly from the atmosphere and use them productively.
Climeworks from Switzerland and Carbon Engineering from Canada are two such companies that use Direct Air Capture (DAC) technology to extract CO2 from the atmosphere and use it to make everything from pants to diamonds.
But these jewels, of course, come at a cost.
First of all, it is worth noting that DAC is not a “silver bullet” — and the sector representatives themselves admit this.
The process of capturing and extracting CO2 will likely release some carbon into the air. Furthermore, the technology is still very expensive, and its current contribution to removing pollutants from the air is minimal.
However, many experts believe that carbon dioxide removal (CDR) technology — which includes DAC — is one of the crucial tools we need to use to avoid a climate catastrophe in the coming decades.
The Intergovernmental Panel on Climate Change (IPCC) — the United Nations body that assesses the science related to the issue — concluded in its April 2022 report that “deploying CDR to counterbalance residual emissions is inevitable.”
This need is recognized by the market. Much of the captured CO2 will simply be stored underground or at the bottom of the sea, but a growing sector seeks to use this essential element in production chains.
Data released by Reuters in 2021 showed that several startups involved with this technology raised about $800 million from investors that year to manufacture a variety of products using CO2 emissions. This amount is three times what was invested in 2020.
Here are some interesting things that can be made from polluted air.
Diamonds from ‘thin air’
Diamonds are essentially an extremely condensed piece of carbon. Aether, a New York-based jewelry company in the USA, produces diamonds from CO2 extracted from the atmosphere and ensures that all stages of the process are done with sustainable energy.
According to Aether, these lab-grown diamonds are chemically and visually identical to mined diamonds. The only way to tell the difference is through a deeper chemical analysis. They are even certified by the International Gemological Institute, just like “original” diamonds.
But how are diamonds made from pollution? First, in partnership with Climeworks, giant vacuums pull air from the atmosphere. Then, a special filter captures the carbon dioxide and other pollutants.
The CO2 is then sent to a facility in Europe, where it is converted into hydrocarbon methane, which serves as raw material.
This, in turn, is sent to Aether’s reactor in Chicago, USA, where extreme heat and pressure allow the diamonds to “grow.”
Essentially, the million-year heat and pressure process needed to create a natural diamond is done in a lab in about three to four weeks.
And Aether is not the only company investing in this idea — several others around the world are producing similar lab-grown diamonds.
Vrai, backed by actor Leonardo DiCaprio, says its diamonds are created in a zero-emission foundry in the Pacific Northwest, using 100% hydroelectric power from the Columbia River in the USA — the foundry has been certified since 2017 by Natural Capital Partners for not producing excess carbon.
SkyDiamond, based in the UK, uses a similar process to make diamonds with only renewable energy, carbon, and rainwater.
Yoga pants and more…
LanzaTech, based in Chicago, USA, is also a carbon transformation startup, whose “product” is used to make everything from yoga pants to food containers and laundry detergent.
LanzaTech specializes in converting carbon released by industrial ethanol plants. This material is used to feed a type of genetically modified anaerobic bacteria.
These bacteria — first identified decades ago in rabbit feces — metabolize the gas and produce sustainable ethanol, which can be used to make a variety of synthetic materials.
In partnership with sportswear retailer Lululemon — famous for its yoga pants — the company created the world’s first fabric thread made from recycled carbon emissions.
Stronger concrete
Unlike CO2 capture that relies on giant fans, Heirloom, based in California, USA, uses limestone to capture carbon directly.
The company then stores this material permanently and securely underground or in materials such as concrete.
The technology works as follows: limestone, composed of calcium oxide (CaO) and CO2, is one of the planet’s most vital carbon deposits.
When ground and heated, the CO2 is released, and the remaining CaO acts like a “sponge” that absorbs some of this CO2 — which can return to its natural limestone state.
Heirloom places these CO2-hungry rocks in large trays stacked on top of each other like mini-buildings. This accelerates the limestone’s natural property, reducing the CO2 absorption time from several years to just three days.
In partnership with Canadian concrete company CarbonCure, the technology serves as an attempt to “mineralize” the gas in concrete.
When recycled CO2 is mixed into the concrete manufacturing process, it makes the mixture much stronger — which the partnership says is a win-win scenario for both the climate and the construction industry.
Concrete itself has been part of the climate problem, accounting for about 8% of global carbon emissions. Therefore, using it to permanently store recycled CO2 is an attractive solution.
The fact that concrete is so widely used and currently has no real substitute is also an advantage. Adding CO2 to concrete reduces the need to add more cement to the mixture (and this is the ingredient with the largest carbon footprint).
Heirloom says it aims to use limestone’s natural power to remove one billion tons of CO2 by 2035, using the “world’s most cost-effective” DAC technology.
Can we trust DAC?
While we can make many things with CO2 captured from the air, DAC is still a very nascent — and extremely expensive — technology.
According to a May 2022 report by the World Resources Institute, there are 18 DAC plants of varying sizes that capture just under 8,000 tons of CO2 per year. This is equivalent to the annual emissions of about 1,740 cars.
The cost of DAC ranges from $250 to $600 per ton of CO2 extracted — therefore, it is much more expensive than reforestation, which typically costs less than $50 per ton.
Part of the reason DAC is so difficult and expensive is that CO2 is very diluted in the atmosphere, at about 400 parts per million (ppm) in the air. To compare, if there were 5,000 tennis balls representing air molecules, only two of them would be CO2.
But Peter Psarras, an assistant research professor in chemical and biomolecular engineering at the University of Pennsylvania, USA, says it is important to start and study the subject.
“The problem is that we are running out of time. That is why DAC and other CDR need to take on such an important role to achieve climate goals,” he told the BBC. “We have to start today; otherwise, we won’t be able to scale the technology in time.”
He adds that DAC is one of the simplest technologies to study and verify results because the scientific community has a “solid understanding of engineering.”
“DAC is happening in real-time, and you can see it in practice. You can observe the CO2 through a [system] into the ground. [DAC is] durable, easy to monitor and verify, but it comes at a cost.”
“Compare this to a forest, which has a series of variables that can impact the amount of CO2 that comes in and out of there. Measuring that is infinitely more complex,” the expert concludes.
Source: BBC