Direct Air Capture

Direct Air Capture: Climate Tech for a Post-Fossil World

By tapping into the CO₂ in our atmosphere, direct air capture technology offers a powerful tool for reversing climate change and quitting fossil fuels. Understandably, it’s causing quite a stir.

Suddenly, the world is talking about direct air capture — a type of sci-fi-sounding technologies that promise to pull gigatonnes of historic CO₂ emissions out of the atmosphere in the coming decades.

‍

The hype is intense. The Intergovernmental Panel on Climate Change (IPCC) has called direct air carbon capture a critical Net Zero technology; big tech and climate investors are investing heavily; the US government is already incentivising a rapid build-out; and big oil is figuring out whether to woo or crush it.

‍

As scientists and engineers developing DAC technology, we’ve created this high-level guide to navigate you through the excitement and noise, as we see it — hopefully giving a taste of what this transformational climate technology is all about.

DAC BasicsLet’s get technicalPutting DAC in contextThe biggest DAC questionsDive deeper
DAC Basics

What is DAC direct air capture?

Direct air capture (DAC) refers to a broad range of technologies which strip carbon dioxide (CO₂) from the atmosphere. When connected with other processes, that CO₂ can then either be permanently removed or used to decarbonise valuable products, like building materials, chemicals, sustainable fuels, and even vodka.

As a concept, direct air carbon capture has been kicking around for quite a while. First suggested in 1999, the early noughties witnessed the first pilot tests of nascent direct air capture technology. Yet, it is only in the last few years that the emerging direct air carbon capture industry has started to gather the technological momentum, political urgency, and policy incentives to truly scale.

DACronyms you can’t avoid

The world of direct air capture is peppered with uninspiring acronyms, some of which we’ve already encountered. Here are the main ones you’ll get used to seeing:


‍

  • CDR – ‘carbon dioxide removal’. An umbrella term for nature-based and engineered solutions which remove CO₂. Reforestation is nature-based; DAC is engineered.
  • DAC/DACC – ‘Direct air (carbon) capture’. Any engineered solution that removes carbon dioxide directly from the atmosphere.
  • DAC(C)S – ‘S’ for ‘storage’. Combining a DAC system with a storage solution (e.g. an underground well).
  • DAC(C)M – ‘M’ for ‘mineralisation’. Combining a DAC system with a process that permanently stores CO₂ in rock.
Let's get technical

How direct air capture works

Direct air capture describes any technology which separates carbon dioxide from the air through a chemical or physical process. While there are several, very different ways to do that, every direct air capture technology effectively boils down to two steps: capturing atmospheric carbon in a material and then getting it back out of that material.

Capture

Air is brought into contact with a reactive (chemical process) or adsorbent (physical process) material that selectively binds CO₂. This is usually either a liquid (solvent) or a solid (sorbent).

Release

That material is subjected to a process which forces it to release the captured carbon as pure CO₂ — often by applying temperature, pressure, moisture, or electric voltage shifts.

This all results in a pure stream of CO₂ — which can either be used as a feedstock to displace fossil carbons in products and processes, or permanently stored.

Different types of direct air capture technology

Despite direct air carbon capture sounding like a singular technology, the term actually houses a huge breadth of different ones. This makes it difficult to make neat apples to apples comparisons, but if you really pressed us to generalise, we’d break the biggest distinction down to the capture method and regeneration (release) mechanism.

Liquid capture DAC

Liquid-capture DAC

In liquid capture direct air capture technologies, CO₂ from the air dissolves into a solution which is then heated to regenerate CO₂. Carbon Engineering has created a system based on this approach. The high temperatures required by this route means natural gas is sometimes burned in the process.

Solid-capture DAC

Solid-capture DAC

In solid capture technologies, CO₂ from the air clings to the surface of a solid material which is then heated to release the carbon as CO₂. Climeworks and Heirloom have both created systems based around this approach. Solid direct air capture technologies tend to use lower temperatures than liquid ones, but are more energy intensive overall.

CO2 regeneration in direct air capture

The regeneration process is what extracts the CO₂ that has been trapped in either the solid or liquid capture medium, releasing it in its pure form for sustainable use or permanent removal.

‍

The different regeneration methods can be split into four categories; low- grade heat (<200°C), high- grade heat (~800°C), humidity and electrochemical.

‍

At Mission Zero, we’ve pioneered a new, heat-free electrochemical direct air capture process to overcome these challenges. In our process, carbon in the air is dissolved in a solution and passed through a selective membrane, before having renewable electricity dynamically applied to it to regenerate CO₂.

What isn’t direct air capture?

As excitement around direct air capture takes off, the technology is already being widely misunderstood. Here are a few things that DAC is definitely not:

1. Point-source carbon capture technology

Point-source technologies capture new CO₂ emissions from industrial processes before they enter the atmosphere. These sit on smokestacks of things like cement factories and bioenergy plants, often capturing carbon recently generated from fossil sources. In contrast, direct air capture technology recovers historic CO₂ emissions already in our atmosphere.

This is some text inside of a div block.

2. Carbon capture and storage (CCS)

CCS is an umbrella term for solutions that permanently store point-source CO₂, for example capturing a waste CO₂ gas stream from a steel factory and piping it into an underground well. While the CO₂ recovered by direct air capture technologies can also be permanently stored, the climate value achieved is fundamentally different to that of traditional CCS projects.

This is some text inside of a div block.

1. Point-source carbon capture technology

Point-source technologies capture new CO₂ emissions from industrial processes before they enter the atmosphere. These sit on smokestacks of things like cement factories and bioenergy plants, often capturing carbon recently generated from fossil sources. In contrast, direct air capture technology recovers historic CO₂ emissions already in our atmosphere.

2. Carbon capture and storage (CCS)

CCS is an umbrella term for solutions that permanently store point-source CO₂, for example capturing a waste CO₂ gas stream from a steel factory and piping it into an underground well. While the CO₂ recovered by direct air capture technologies can also be permanently stored, the climate value achieved is fundamentally different to that of traditional CCS projects.

Why do we need direct air capture?

According to the world’s leading climate scientists, reducing carbon emissions is no longer enough for the world to meet its 1.5°C obligations. Carbon-intensive human activities — including deforestation and the burning of fossil fuels — have simply overwhelmed the natural mechanisms which absorb carbon from our atmosphere, causing excessive amounts of the planet-warming gas to hang around in the air.

To address this, the world needs to eliminate masses of historic CO₂ emissions from our atmosphere in the coming decades, in addition to immediately reducing carbon emissions to stop the problem from growing even larger. Alongside natural carbon removal solutions — like reforestation and restoring coastal wetlands — engineered solutions like direct air carbon capture will be critical to realising this at scale.

Direct air capture’s role in fighting climate change

Eliminating CO₂ from the atmosphere

Direct air capture’s obvious climate value lies in its potential to permanently remove the masses of CO₂ that humans have released into the atmosphere for the last 150 years of industrial activity. Mineralising atmospheric CO₂ in rock and storing it in underground reservoirs are just two methods currently being explored, since they promise “high permanency” — locking CO₂ out of our atmosphere for hundreds of years.

‍

At Mission Zero Technologies, we believe that mineralising CO₂ into rock offers the gold standard for high-impact carbon removals, which is why we’re partnering with carbon removal developers to accelerate this pathway.

Displacing the use of fossil carbon

Carbon capture from air is also set to completely reinvent our relationship with carbon. Almost any carbon-based product you can think of that’s currently made from oil — fuels, high-value chemicals, and materials — can be made from CO₂. If we can use the mass of CO₂ that’s already in our atmosphere, we can stop digging up ‘new’ fossil sources of it.

‍

By scaling direct air capture infrastructure to turn our atmosphere into the world’s default carbon source we can quit fossil fuels for good and establish a truly sustainable carbon economy — where we recycle carbon for the carbon-based products we still need. The University of Sheffield has bought our first direct air capture plant to do precisely this — pioneering sustainable aviation fuel made from air instead of oil.

Eliminating CO₂ from the atmosphere

Direct air capture’s obvious climate value lies in its potential to permanently remove the masses of CO₂ that humans have released into the atmosphere for the last 150 years of industrial activity. Mineralising atmospheric CO₂ in rock and storing it in underground reservoirs are just two methods currently being explored, since they promise “high permanency” — locking CO₂ out of our atmosphere for hundreds of years.

At Mission Zero Technologies, we believe that mineralising CO₂ into rock offers the gold standard for high-impact carbon removals, which is why we’re partnering with carbon removal developers to accelerate this pathway.

This is some text inside of a div block.

Displacing the use of fossil carbon

Carbon capture from air is also set to completely reinvent our relationship with carbon. Almost any carbon-based product you can think of that’s currently made from oil — fuels, high-value chemicals, and materials — can be made from CO₂. If we can use the mass of CO₂ that’s already in our atmosphere, we can stop digging up ‘new’ fossil sources of it.

By scaling direct air capture infrastructure to turn our atmosphere into the world’s default carbon source we can quit fossil fuels for good and establish a truly sustainable carbon economy — where we recycle carbon for the carbon-based products we still need. The University of Sheffield has bought our first direct air capture plant to do precisely this — pioneering sustainable aviation fuel made from air instead of oil.

This is some text inside of a div block.
Putting DAC in context

Other carbon removal solutions

Carbon capture from air is not a ‘silver bullet’ for solving the climate crisis; no single carbon removal solution can be. We need a diverse mix of different ones — nature-based and engineered — to mitigate the worst impacts of human-made climate change as quickly as possible. This gives us a variety of tools to draw on for different situations and acts as insurance for any one climate solution failing.

‍

A few prominent carbon removal solutions you may have heard of include:

Reforestation and afforestation

Restoring and further expanding coastal and inland natural carbon sinks

Enhanced rock weathering

Restoring and further expanding coastal and inland natural carbon sinks

Micro- and macro-algae cultivation

Restoring and further expanding coastal and inland natural carbon sinks

Burying biomass

Restoring and further expanding coastal and inland natural carbon sinks

Reforestation and afforestation

Restoring and further expanding coastal and inland natural carbon sinks

This is some text inside of a div block.

Enhanced rock weathering

Accelerating a natural process of drawing carbon down into rock

This is some text inside of a div block.

Micro- and macro-algae cultivation

Increasing the formation of ocean biomass creation which stores carbon

This is some text inside of a div block.

Burying biomass

Locking the carbon from agricultural and forestry waste products into the soil

This is some text inside of a div block.

It’s also worth stressing that, in the global green energy transition, direct air capture should be a companion — not a competitor or replacement — to critical emissions reduction solutions. We believe that the immediate mass build-out of renewable energy infrastructure is key to this, which is why we have designed our electrically-powered direct air capture technology to thrive off intermittent renewable grids to help facilitate the development of such projects.

The benefits of direct air capture

Direct air carbon capture offers a wealth of unique benefits which stand to make it one of the world’s most effective solutions for delivering credible, high-quality carbon removals.

Versatility

Land efficiency

Carbon negativity

Measurability

Location flexibility

Permanence

The biggest DAC questions

Making direct air capture affordable

As a young climate technology, direct air capture is currently more expensive than a lot of the more readily-available carbon removal solutions. Yet, this is not altogether surprising. Wind and solar energy were also expensive when they were first being rolled out, but in just ten years the cost of renewable energy dropped rapidly, with the price of electricity from solar and onshore wind power from new power plants in the US dropping by a massive 89% and plummeting below the cost of both coal and gas. In the UK, the cost of renewables has repeatedly fallen faster than predicted, with solar dropping from over £200 per MWh to around £50 per MWh between 2014 and 2022.

Though it’s true that economies of scale will play a part in making carbon capture from air more affordable, it’s vital that we put in the work to bridge the gap between pilot plant and gigatonne-scale carbon removal now.

‍

For us, actually working with renewable energy is key to this. Currently, direct air carbon capture’s biggest cost is tied to the energy required to do it, since moving large volumes of air and chemical separation processes require a lot of electrons. That’s why we have decided to develop an electric-only direct air capture technology designed to work flexibly with cheap and abundant sources of intermittent renewable energy.

Renewable energy

Efficiencies in the tech alone won’t deliver affordable DAC: early investment and policies — whether through government incentives, accelerators or regulatory mandates — are critical for growing the markets for direct air capture to scale. That’s why we’ve focused on putting first-of-a-kind demonstrations of our technology on the ground as quickly as possible. By proving cost-efficiency and mass manufacturability from the smallest scale, we seek to quickly reduce the financial risks investors and governments take when scaling new climate technology.

MZT Modularity

Designing our technology for modularity and affordable maintenance and servicing is also intrinsic to bringing down the cost of direct air capture. This allows for easier upgrades, repairs, and scalability — which dramatically reduce downtime and operational costs, not to mention system sustainability.

Is direct air capture energy efficient?

One of the biggest questions around scaling direct air capture is the amount of energy it requires. The reason this technology can be energy intensive is due to the low concentration of CO2 in the atmosphere (about 0.04%). This means that in order to capture a meaningful amount of CO2, a large volume of air needs to be processed.

As a nascent technology, research and development is an ongoing priority for direct air capture companies. Every month, new milestones in materials and process optimisation take us closer to reduced energy consumption and costs. Evolving direct air carbon capture away from processes that require high temperatures to separate CO2 is just one example of this.

Our heat-free electrochemical process offers one of the most energy-efficient approaches to DAC. Heating and cooling is the easiest way to burn through power during the capture and release of CO₂. Whilst other approaches to DAC require heating everything in the system to release captured carbon, our DAC process selectively targets just the CO₂ molecules.

Although direct air capture technologies are still being refined to lower power consumption where possible, energy savings can be made across the process as a whole. Thanks to the minimal geographic requirements of DAC, recovered CO2 doesn’t have to travel far. Situating direct air capture plants near to mineralisation or utilisation facilities means negligible energy usage during the movement of carbon from sky to storage.

‍

We’ve said it (more than) once, and we’ll say it again – the key to energy-efficient direct air capture starts with combining it with cheap, abundant renewable energy sources.

DAC’s greenwashing potential

It’s completely understandable why some environmentally-conscious groups are nervous about what direct air capture technology will enable. This has not been helped by the disappointing example the carbon capture and storage industry has historically demonstrated, with the majority of CO₂ captured from industry flue stacks being used to enable enhanced oil recovery — and only around 10% of projects sending carbon to permanent storage.

‍

While DAC and point-source CCS are very different things (with fundamentally different climate values), we see how scaling technology which can pull CO₂ out of the air could potentially play into the hands of the world’s biggest carbon polluters, to avoid, delay, or distract from immediate, deep industrial decarbonisation.

‍

We didn’t form Mission Zero to enable ‘pollution as usual’ — which is why we are being extremely careful about the end use of our technology. We believe our technology’s greatest climate impact lies in eliminating historic carbon emissions and displacing the use of fossil carbons in the harder-to-abate products and processes which currently depend on them. This is what we are developing direct air capture technology to deliver — and are working to build the frameworks, processes, checks, and standards to ensure we deliver responsible, climate-first DAC.

Scaling direct air capture sustainably

What does scaling a new technology sustainably mean? At Mission Zero, we believe that social, environmental, and climate considerations should be baked into every decision. Quality direct air capture is low-carbon, environmentally regenerative, and socially empowering.

Creating social and economic value

Creating sustainable local benefits and opportunities, and working collaboratively with communities to guide the planning and deployment of new direct air capture projects, is vital for an equitable build-out.

‍

While we're still small, we're trying to integrate social and economic benefits into our tech early, taking care to positively shape our own ways of working, as well as ensuring our customers and partners are on the same page. We have already created 40 quality, sustainable jobs in-house and enabled the creation of at least 20 further ones in our partner organisations through our ongoing projects in the UK, EU, and Canada. Over the last 12 months, we have also lectured at leading UK universities to engage 100+ students with relevant science or engineering backgrounds on the increasing career opportunities available within the energy transition sector — highlighting the abundant alternatives to the traditional path into oil and gas jobs.

Working with the global renewables build-out

It simply doesn’t make sense to burn fossil-based fuels to run machines that recover historic fossil fuel emissions from the atmosphere. Climate-first direct air capture at scale also requires renewable energy infrastructure to scale. We’ve purposely designed our electric-only direct air capture technology to work flexibly with intermittent renewable sources, allowing renewables developers to monetise curtailed energy to increase the profitability of renewable infrastructure.

Ensuring a net negative carbon impact

In our current fossil-based economy, producing hardware still comes with a carbon cost — meaning, certain carbon emissions are ‘embodied’ in the technology due to materials used, and the manufacturing and installation process. Operational maintenance and end-of-life processing also need to be navigated with care. Conducting comprehensive life cycle analyses (LCA) takes into account the total environmental impact of a DAC project, ensuring that the right decisions are made to put the planet first. We work with third party providers to guarantee that we’re actively improving our LCA, alongside building a bank of real-world data from our three, on-the-ground projects.

Policies and partnerships for progress

Achieving gigatonne-scale carbon removal requires robust environmental policies. Access to renewable electricity, on-site or proximate geological storage (paired with affordable CO2 transport infrastructure), onsite shared utilities, and the efficient permitting of appropriate land are all essential components of the infrastructure required to keep the scaling of DAC on track.

Creating social and economic value

Creating sustainable local benefits and opportunities, and working collaboratively with communities to guide the planning and deployment of new direct air capture projects, is vital for an equitable build-out.

While we're still small, we're trying to integrate social and economic benefits into our tech early, taking care to positively shape our own ways of working, as well as ensuring our customers and partners are on the same page. We have already created 40 quality, sustainable jobs in-house and enabled the creation of at least 20 further ones in our partner organisations through our ongoing projects in the UK, EU, and Canada. Over the last 12 months, we have also lectured at leading UK universities to engage 100+ students with relevant science or engineering backgrounds on the increasing career opportunities available within the energy transition sector — highlighting the abundant alternatives to the traditional path into oil and gas jobs.

This is some text inside of a div block.

Working with the global renewables build-out

It simply doesn’t make sense to burn fossil-based fuels to run machines that recover historic fossil fuel emissions from the atmosphere. Climate-first direct air capture at scale also requires renewable energy infrastructure to scale. We’ve purposely designed our electric-only direct air capture technology to work flexibly with intermittent renewable sources, allowing renewables developers to monetise curtailed energy to increase the profitability of renewable infrastructure.

This is some text inside of a div block.

Ensuring a net negative carbon impact

In our current fossil-based economy, producing hardware still comes with a carbon cost — meaning, certain carbon emissions are ‘embodied’ in the technology due to materials used, and the manufacturing and installation process. Operational maintenance and end-of-life processing also need to be navigated with care.

Conducting comprehensive life cycle analyses (LCA) takes into account the total environmental impact of a DAC project, ensuring that the right decisions are made to put the planet first. We work with third party providers to guarantee that we’re actively improving our LCA, alongside building a bank of real-world data from our three, on-the-ground projects.

This is some text inside of a div block.

Policies and partnerships for progress

Achieving gigatonne-scale carbon removal requires robust environmental policies. Access to renewable electricity, on-site or proximate geological storage (paired with affordable CO2 transport infrastructure), onsite shared utilities, and the efficient permitting of appropriate land are all essential components of the infrastructure required to keep the scaling of DAC on track.

This is some text inside of a div block.
Dive deeper

Brilliant DAC resources

The International Energy Agency’s DAC overview

Direct Air Capture Coalition’s FAQs

Breakthrough Energy’s brief introduction to DAC

CDR.FYI’s global map of known carbon removal projects (DAC and others)

DAC Coalition’s global map of known DAC projects

VC firm Extantia’s brief history of DAC

Wait, I still have questions...

Why don’t we just plant more trees?

What are DAC hubs?

Where is direct air capture happening around the world?

What’s the carbon footprint of a direct air capture plant?

Who is financing direct air capture?

Who is buying direct air capture?

Who are the main direct air capture companies?

Reinvent carbon with us

We partner with pioneering CO₂ users, project developers, engineers, and scientists around the world to turn historic carbon waste into new climate value.

Get in touch

The carbon narrative rewritten

Legal

Get in touch

Thank you

Thanks for reaching out. We will get back to you soon.
Oops! Something went wrong while submitting the form.
Send an email:
info@missionzero.tech
Studio 510, The Pill Box, 115 Witan Street, London E2 6GG, UK
x