#01 Direct Air Capture (DAC)

One of the fastest growing carbon removal technologies

Oct 29, 2022

Read time: 4.5 minutes

In this week’s issue you will learn about one of the fastest growing carbon removal technologies: Direct Air Capture.

“The UN's latest climate report made clear that removing legacy carbon pollution from the air through direct air capture and safely storing it is an essential weapon in our fight against the climate crisis” - U.S. Secretary of Energy Jennifer M. Granholm

Top Direct Air Capture News 🗞️

The US wants to become a DAC superpower: The Biden administration has launched a $3.5 billion program to build large-scale DAC hubs across the country.

First certification methodology in the world: Climeworks and Carbifx have developed the world's first certification methodology dedicated to carbon dioxide removal via direct air capture and underground storage.

Big brands are jumping in: Earlier this year Stripe, Meta, Google, Shopify, and McKinsey created Frontier, an advance market commitment to spend $1 billion buying carbon removal over the next 9 years to help scale DAC and other carbon removal tech faster.

Let’s dive in 🧠

To meet the target limit of 1.5ºC of warming by the end of the century, bringing our emissions all the way down to 0 is not enough.

Since the 18th century we have been adding A LOT of CO2 into the atmosphere, and we need to remove it.

Reducing our emissions is key to keep us from going up in the graph. In order to go back down to that safe level point we need to remove CO2, it doesn’t just go away into space.

There are many ways to remove CO2 from the atmosphere. Some solutions are nature-based (not just planting trees) and others are tech-based.

There are so many ways to remove carbon from the atmosphere and all of them are so crucial that Elon Musk even launched a $100 million competition to scale them!

But anyways, today I will focus on Direct Air Capture, one of the tech-based solutions to get CO2 out of the air.

How does it work?

Think of Direct Air Capture machines basically as huge fans that suck large amounts of polluted air directly out of the atmosphere, and just get the CO2 out of it.

Here are the steps:

The fans suck the air into the system.
Some filters get rid of impurities.
The air passes through chemical substances, the CO2 gets stuck in them, the rest goes through.
The captured CO2 can be released from the chemicals that trapped it simply by applying heat to the mix.
You’re left with a high concentration of CO2 on one side and chemical substances that can be reused again on the other.

It's kind of how human lungs extract oxygen.

Actually, there are two main ways DAC works. There’s solid sorbent DAC (the steps and image I just showed) and there’s liquid solvent DAC.

You can check out the technical differences at the end, but both work under the same premise:

Get CO2 from the ambient air, make it contact some chemicals, apply some heat and electricity to separate the CO2.

Once we have the CO2 captured there are 2 main things to do with it:

Store it: This is called carbon sequestration. Keeping it safely deep underground to make sure it never goes back out. Sell carbon credits for every tonne of captured and stored CO2 to companies that want to offset their emissions.

Use it to make stuff: This is called carbon utilization. If you think about it, most of the things we use have carbon in them! Diamonds, cement, fuels, rubber, Coca Cola, etc.

If you are more of a video learner, here's a short explanation to understand DAC better (liquid DAC), since I already showed you solid DAC above.

Pros of DAC

Great measurability: It’s very easy to know exactly how much CO2 was captured, not the case in nature-based solutions. This is key for reporting impact and then selling carbon credits to companies.
Adaptable: In theory, a DAC plant can be situated in any location that has low-carbon energy and a CO2 storage resource or CO2 use opportunity.
Efficient: It uses very little land and water and it’s quite quick to implement.

Cons of DAC

Price: Currently really expensive. Between $250 and $1000 per tonne of CO2 captured. It won’t scale fast until prices go under $100 per tonne.
Misusage: Some companies are using these offsets as an excuse to pollute more. Besides, old oil wells are ideal for placing the storage of carbon and that builds up pressure that gets oil out more easily (enhanced oil recovery).
Huge challenge: We need to capture 60 Mt CO2/year by 2030, we are currently capturing 0.01 Mt CO2/year.
Source: International Energy Agency

Top Direct Air capture companies 💰

Climeworks: Based in Switzerland. They own 15 out of the 18 currently running DAC plants in the world. They raised a record $650 million in 2022. Uses solid DAC.
Carbon Engineering: Based in Canada. Operating since 2009. They are building the world’s largest DAC facility and are building several others worldwide. Uses liquid DAC.
Heirloom: A startup combining engineering and nature to offer the most cost-effective and scalable DAC solution. They have huge clients and investors despite being so young.

❗Extreme knowledge area❗

What you just read is a simple DAC overview. Here you have some additional resources if you want to become a pro in the subject.

Direct Air Capture Coalition: An organization that brings together global innovators to mobilize society for Direct Air Capture. Everything you need explained in plain English.

International Energy Agency DAC report: Document addressing the main points in tech, investment, innovation and policy in a technical but very clear way.(September 2022)

DAC venture space in Europe and North America: Sector insights, funding insights, tech overview, compiled in a very complete and organized document (June 2022).

DAC is for sure promising but we can’t forget about the big picture: Reduce emissions as much as possible and remove the rest.

That’s it for today, 1 climate tech topic in under 5 minutes.

Next week… Agrivoltaics! 🤯

This is the first issue of the newsletter, I will improve, I promise. Any feedback is welcome to help me make it better for you!

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