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Our earth has permanently crossed a dangerous threshold. Humans continue to burn fossil fuels regardless of the consequences, with the result that our atmosphere now contains 400 parts per million (ppm) of carbon dioxide (CO2). Unfortunately, 350 ppm was the last safe level of atmospheric CO2.

James Hansen, former head of NASA’s Goddard Institute for Space Studies and climate change expert, said in an interview in Rolling Stone that the Paris Agreement, which targets limiting warming to 2 degrees Celsius, is only barely possible and would lead to a sea level rise of 20 to 30 feet. A target of 1.5 degrees Celsius is better, but as he said, “…that would require a six-percent-a-year reduction in emissions, which may be implausible without a large amount of negative emissions – that is, developing some technology to suck CO2 out of the atmosphere.”

While this means that our situation is worse than we would like to believe, we are very close to having that kind of technology.

Net-Zero Fuel: Mobilizing the Future?

Even if we do not yet have the technology to remove more emissions from the atmosphere than we create, we are very close to having the ability to create carbon neutrality, or being able to balance the amount of carbon released by limiting, sequestering, or offsetting emissions. One company, located in unassuming Squamish, British Columbia, is successfully testing the idea that carbon itself can become a net zero fuel.

Carbon Engineering has built a small-scale plant that sucks in air and forces it through corrugated sheets covered in a capture liquid. CO2 is captured when it comes in contact with the liquid, and this is extracted and compressed into a pure CO2 pellet. The capture liquid is recycled, and the entire process works as a closed-loop system.

carbon engineering process

While this process isn’t going to save the earth by sucking CO2 from the air, (the rate that it removes CO2 from the air is too small to make a difference), it does have huge implications for limiting harmful emissions. We asked Geoff Holmes, Business Development Manager at Carbon Engineering, what the company hopes to achieve with their technology. His response was simple and realistic: “Our goal is to develop and commercialize air capture, in order to enable production of low-carbon-intensity transportation fuels.”

While carbon fuels already exist, they have typically been created from carbon that comes out of the earth, rather than the sky. In the future, these low-carbon fuels may be used mostly for heavy vehicles that can’t be converted to electricity, such as shipping trucks. Currently, this process is too expensive to be feasible, but with investors like Bill Gates who have heavily supported the idea, the company hopes to drive progress forward and pave the way for a carbon-neutral fuel source for an industry that currently creates 17% of all CO2 emissions. The next step for Carbon Engineering is to install a fuel-synthesis operation at the end of the plant that would combine carbon with hydrogen gas, creating synthetic gasoline.

Low-Energy Carbon Capture Strategies

One of the biggest challenges of capturing carbon is the tremendous amount of energy needed to gather it from the air and turn it into something solid, and this energy output has previously made the process impractical. Until now, direct air capture of carbon involved a pipe system transporting carbon dioxide deep into the ground after it has been heated to 900 degrees Celsius in order to release it from the air capture material. The process of heating the material usually created more carbon dioxide than was removed from the air. This is why Carbon Engineering’s process is so revolutionary, but it still requires enough energy that the fuel created would be double the cost of traditional fuel.

Scientists at the Oak Ridge National Laboratory run by the US Department of Energy recently captured carbon dioxide from ambient air, without the need for high-powered fans or intense heat. They came upon this accidentally when studying ways to remove environmental contaminants from water by using a compound to bind with negatively charged ions. This compound is called guanidine, and it forms insoluble crystals that can be lifted out of the water, taking the toxins along with it. Surprisingly, when the liquid form of guanidine was left in the air, it also created crystals containing carbonate forming from a reaction between water and carbon dioxide. The scientists were able to release the carbon dioxide by heating it to only 80-120 degrees Celsius, an energy output far less than the 900 degrees needed before, and with the possibility of using solar energy as a heat source.

We’ve Captured Carbon – Now What?

It is easy to see that while the idea of carbon capture seems like it could be a simple process, it isn’t, even though there is a huge market for CO2 as a raw material for industrial purposes. Even Carbon Engineering hasn’t quite successfully processed the carbon they’ve captured. But, a company called Carbon Clean Solutions in southern India has managed to harvest carbon dioxide cheaply enough to use it to create baking soda, and they say that they will be able to store 60,000 tons of CO2 a year with their technology. Rather than pulling it from the air, they are capturing it from flue gas using a new chemical that makes the process of stripping CO2 from coal-fired emissions cheaper and more efficient. In Carbon Clean’s project, the flue is from the plant’s own boiler. The company says its technology “enables more than 90% CO2 capture from coal/gas fired power stations.” The potential of this technology is that fertilizer plants, factories, steel and iron refineries, power plants, and other large CO2 emitters can become net zero operations and sell baking soda to boot.

Another recent breakthrough has come in the realm of carbon storage. While carbon storage previously required piping gas deep into the earth, usually at exhausted oil fields that require constant monitoring for leaks, a new project in Iceland called Carbfix has successfully turned CO2 into rock. Originally scientists thought this process would be impractical because they predicted the gas would take thousands of years to turn into a solid. Instead, CO2 reacts with basalt to form carbonate minerals (the chief makeup of limestone) within only two years. This project is able to bury 10,000 tons of CO2 a year, and thankfully, basalt rocks can be found anywhere in the world. The one drawback is that it takes 25 tons of water to bury one ton of CO2, but proponents might be able to solve this issue by using ocean water.

Iceland’s Hellisheidi power plant is the world’s largest geothermal plant. It pumps volcanically heated water into turbines to generate electricity, but it also brings up carbon dioxide. The researchers at Carbfix took this gas, dissolved it in water, and pumped it over 1500 feet into the earth at the basalt deposit. Obviously this wouldn’t work for everyone, but it’s an ingenious design that helps push ideas forward.

While these discoveries will not solve climate change individually, they can be used together to help stop CO2 emissions and possibly mitigate some of the damage. With a net-zero fuel source, a way to turn factory emissions into baking soda, and the possibility of safely storing CO2 in the earth, we can have hope that there is a path to a cleaner future.

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