Published on 
November 16, 2023

DAC (Direct air capture) is a new and promising carbon capture technology that is increasingly recognized as having an important role in global governments’ net zero goals and in combating climate change. The Intergovernmental Panel on Climate Change has outlined carbon removal technologies such as DAC will be essential to avoid the worst effects of global warming.  

Plans for DAC research, development and expansion are well underway. Globally,  twenty-seven DAC plants have already been commissioned to date, according to the International Energy Agency, and there are plans for at least a further 130 DAC facilities now in different stages of development.

But unlike other - more mature clean technologies - DAC is not so widely understood. At Skytree we set out to demystify DAC with this DAC-tionary, to outline and explain common terminology within the sector. 

For the clean energy curious and climate tech followers, this serves as an elementary guide to the basics of DAC technology, which will be useful in furthering understanding of the tech as it becomes more widely referenced in the media, government policy, and commercial operations. 

Common terms


Direct air capture (DAC) technologies extract CO2 directly from the atmosphere - or ambient air. DAC is still in its early development stages, with the first operational DAC machine installed in 2017. But the potential of DAC is huge. Benefits include cost savings and a secure, local supply of CO2 that negates the need for oil and gas as producers of carbon dioxide. 

If all the current planned DAC projects were to be successfully completed, by 2030 DAC deployment would reach the level required under the Net Zero Emissions by 2050 (NZE) Scenario -capturing around 75MtCO2 a year.

At Skytree, we are unlocking the value of DAC technology to provide a regular supply of usable carbon dioxide, while driving forwards a more sustainable future through a circular CO2 supply that allows you to transition away from fossil fuels.


Decentralized Direct Air Capture (DDAC) is very similar to DAC, and is also relatively newly developed while showing great promise.

It gives companies, industrial operations, and agricultural growers the ability to capture, store and reuse the carbon dioxide surrounding their site in their own production and operations by installing a modular DDAC unit. 

These modular units - unlike large scale plants - suck carbon out of the atmosphere and store it for later use on demand. The stored CO2 can be used as fertilizer for plants in greenhouses, as a cooling agent in industrial processes, in cement production, metal fabrication, or it can be used to carbonate fizzy drinks. 

DDAC technology allows companies to generate the exact amount of CO2 they need. This innovation not only provides you with unprecedented flexibility, reliability, and ease, but also significantly reduces transportation costs and emissions.

Carbon removal (CDR)

Carbon removal is the process of extracting CO2 from the atmosphere and storing it long term in soil or plants, oceans, rocks, or other sources such as long-lived products like cement, which can store the carbon dioxide for decades or even centuries. 


Carbon capture and use (CCU) is the process of capturing carbon dioxide and using it in the production of valuable services. CCU refers to both the use of carbon captured from the atmosphere, like DAC, and for the use of carbon captured from flue gas. CCU is only considered as carbon removal when the carbon dioxide is captured from the atmosphere and stored for a significant period of time. 


Carbon capture and sequestration (CCS) often refers to capturing CO2 emissions at a point-source, like, for example flue gas. While CCS reduces emissions that newly enter the atmosphere, it does now remove existing atmospheric carbon dioxide. This means it is not considered carbon removal. 


Combining the above two concepts, carbon capture and use or sequestration (CCUS) is a commonly used term that refers to both carbon capture and use (CCU) and carbon capture and sequestration (CCS). Usually, it refers to CCU or CCS used within fossil fuels or cement, rather than to carbon removal. CCUS does not deliver any of the distinct advantages or benefits of

Unlike DDAC, carbon capture utilization and storage from point source or flue gases fails to deliver these distinct advantages, underlining the unique benefits of Skytree’s DDAC technology.

Carbon Neutral 

Carbon neutral is a term that describes an entity whose carbon dioxide emissions are equal to those it captures.

Bioenergy with Carbon Capture and Storage (BECCS)

Bioenergy with carbon capture and storage, is another negative emissions technology. BECCS refers to the extraction of bioenergy from organic matter (biomass), then capturing and storing the carbon, and removing it from the atmosphere. 


Biochar is a charcoal residue made of carbon and ash from decomposition of incinerated biomass. It is a form of charcoal that is stored in the soil to remove carbon dioxide from the atmosphere.

Carbon Sinks

A carbon sink is any process that absorbs more carbon dioxide from the atmosphere than it emits. Carbon sinks are commonly natural ecosystems or organisms such as plants, oceans, soil, forests, peatlands, marshes, seagrass beds, mangroves and - more recently - algae ponds.  


Mineralization, in the world of carbon capture, is when carbon dioxide is turned into a  solid mineral such as a carbonate, through a chemical reaction. Mineralization occurs when certain minerals inside rocks are exposed to atmospheric CO2. This carbon dioxide is then removed  from the atmosphere and sequestered in solid carbonate form.  

Sustainable aviation fuel (eSAF)

eSAF is a synthetic aviation fuel,  which can be produced by combining hydrogen from renewable energy sources, and carbon dioxide to produce a hydrocarbon that can be made into a fuel that is  more sustainable than fossil fuels for aviation.  eSAF is a newly developed product that requires carbon dioxide for its processing. It has gained prominence as a key driver of decarbonization in the airline industry, and it is likely to see a sharp increase in demand in the coming years. 

Learn more about DAC

Now equipped with the basic acronyms and concepts behind DAC, if you want to learn more about this powerful, potentially revolutionary new technology and its benefits, head to our technology page.

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