Direct Air Capture – what is it? and how does it work?
With many different types of carbon projects out there, we know it can be overwhelming to understand what they do and evaluate which your company should buy carbon credits from.
Next up: Direct Air Capture – featuring example projects 1PointFive and Noya.
Since the Industrial Revolution, we’ve pumped billions of tonnes of carbon dioxide into the air – over 34 billion tonnes every year, in fact.
Now, we need to get it out.
The IPCC has made it crystal clear that to have a chance of keeping within the acceptable level of 1.5 degrees of warming, we need to remove 10 billion tonnes of existing CO2 per year – alongside deep reductions to prevent further emissions as much as possible.
Direct Air Capture is one method for enabling this.
In Direct Air Capture (DAC), technology is combined with chemical processes to remove CO2 directly from the ambient air around us.
The process looks like this:
1. Air is drawn into the Direct Air Capture plant using large fans
2. Carbon dioxide is then extracted from the air. There are several ways to do this, with the most promising methods being:
3. Finally, the air (minus CO2) is re-released back into the atmosphere.
So, we’ve successfully removed carbon dioxide from the air.
Well, there are two options:
Carbon Capture and Storage (CCS) and Direct Air Capture (DAC) are, understandably, often mixed up. But, what is the difference between the two?
In Carbon Capture and Storage projects, carbon emissions are captured at their source – for instance the carbon emitted through burning fossil fuels at power plants, or through industrial processes at manufacturing facilities (e.g. steel or cement). Similarly to DAC, the technology relies on chemical processes to extract the carbon dioxide from the exhaust gases produced. But, unlike DAC, the technology is retrofitted onto existing infrastructure to capture carbon at source e.g. the chimney of a power plant.
So, the big difference between Direct Air Capture and Carbon Capture and Storage is:
As we mentioned at the start of this article, we desperately need to remove existing carbon emissions from the atmosphere ASAP – at a rate of 10 billion tonnes per year.
But, we don’t currently have the means to reach that goal.
At the start of 2022 the amount of CO2 we’d ever removed from the atmosphere totalled less than 10,000 tonnes. We need to be doing that a million times over, every year.
There are several technologies and techniques in development for increasing our capacity for carbon removal, and Direct Air Capture is one of them.
DAC is particularly exciting because:
Whilst the potential for scale is what makes Direct Air Capture particularly exciting, it’s also what’s currently holding it back – the technology just doesn’t exist at scale yet.
As of 2022, there are currently 19 Direct Air Capture plants in operation globally, with the capacity to capture almost 10,000 tCO2 per year (0.01 megatonne). There are further plants in development, including 1PointFive’s design for a DAC plant that captures 1 megatonne of CO2 every year. But, even with this, we’re still not close to what’s needed – the Net Zero Emissions by 2050 Scenario (NZE) by the International Energy Agency requires 60 megatonnes removed by Direct Air Capture every year, for instance.
So, what’s stopping the technology reaching that scale? Current question marks around scaling up Direct Air Capture are:
If you’re truly committed to making a real difference as an organisation, then we’d definitely recommend buying carbon credits from Direct Air Capture projects.
Because, as we outlined above, Direct Air Capture could hold the key to permanently removing vast amounts of CO2 from the atmosphere – which is desperately needed to curb climate change. But, to do that DAC needs to scale up quickly, and that requires funding.
And businesses have the ability to provide that funding and enable that potential to be reached through using their revenue to buy carbon credits – it’s one of the most important actions needed today.
But, you do need to be aware of:
These factors are why we always recommend building a portfolio of projects to buy carbon credits from.
A portfolio approach enables you to balance out your company purchases in terms of cost, emissions avoidance vs carbon removal, impact made now vs impact made in the future, established techniques vs innovative new technologies etc – and we especially recommend creating a portfolio aligned with the Oxford Offsetting Principles.
And, of course, if you are considering buying carbon credits from a Direct Air Capture project, you need to be confident that it’s a high-quality, credible carbon project.
We’d suggest taking a look at both 1PointFive and Noya – both trusted, credible projects with different approaches but a shared goal of scaling up the supply of Direct Air Capture to meet climate targets.
As we’ve seen, for Direct Air Capture to work we need to prove it’s actually possible to scale up and capture vast amounts of carbon dioxide straight from the air around us.
The good news? 1PointFive is working on exactly that – aiming to ramp up Direct Air Capture in a major way.
Construction of their first DAC plant in the Permian Basin, USA is currently underway. The design uses arrays of ‘air contactors’ that take in the air and absorb the CO₂, all feeding into one industrial-scale processing facility for increased efficiency – enabling the commercial scale that we need to see in Direct Air Capture.
1PointFive’s DAC plants will be connected to ‘geological sequestration hubs’: sites where the extracted CO₂ can be safely injected deep underground for permanent storage.
1PointFive is planning to develop multiple sequestration sites across the Gulf Coast, including at the King Ranch in South Texas, where 1PointFive has secured enough acreage to enable the potential development of a mega hub with up to 30 DAC plants.
This represents a massive increase in global DAC capacity. The first plant alone aims to remove 500,000 tCO₂ per year, compared to our current total capacity of 10,000 tones per year.
At Lune we always put quality first to ensure real climate impact is made through the carbon projects in our library.
So what are the markers of quality in 1PointFive’s Direct Air Capture project? Here’s a few of the key ones:
As we’ve seen, high energy use is one of the main barriers for Direct Air Capture technology currently.
Ensuring close proximity to renewable energy sources (as 1PointFive are doing) is one way to address that. But we also need to find innovative ways to reduce the energy use of DAC in the first place – and Noya is doing just that.
Noya was initially exploring how to retrofit existing cooling towers with Direct Air Capture technology. Part of this exploration included how to reduce energy consumption, so that the technology could use the energy sources already set up for existing buildings.
Now, Noya has shifted focus to standalone DAC units co-located with renewable energy and geological storage for permanent carbon removal – but still using their methodology for reduced energy use.
Noya’s DAC method uses activated carbon monoliths coated with the CO₂ adsorbing chemicals to separate CO₂ from air. Increased temperatures are then needed to ‘desorb’ the CO₂ from the monolith to give a stream of pure CO₂ – the energy intensive part of DAC. But, because the activated carbon monoliths are electrically conductive, electricity can be applied directly to the monolith to provide heat. This allows for rapid heating and minimises any energy lost in the process, resulting in significantly lower energy use.
It’s early days for Noya’s approach, but signs of quality include:
To buy carbon credits from 1PointFive or explore our full library of high-quality carbon projects, log-in or sign-up to the Lune dashboard to get started.
Or, if you’re interested in building an impactful offsetting portfolio that includes Direct Air Capture but want to discuss the best way to go about this for your company, get in touch with our team first – we’d love to chat.