Atmospheric carbon dioxide (CO2) capture is one of the hot topics in climate initiatives. And for good reason – we’re looking at a number of serious climate impacts and there just isn’t any way to achieve our goals without drastic carbon sequestration. That means looking at more aggressive methods of removing large quantities of CO2 from the atmosphere, particularly from around power plants where the biggest amount of CO2 exhalation occurs. The most common method for capturing CO2 is called “post-combustion” which is done by trapping tons of CO2 that comes out of chimneys. This method though, can be very expensive so alternatives like direct air capture are being explored.
Direct air capture (DAC)
-is a technology that removes carbon dioxide directly from the atmosphere to then be used in a variety of applications. It is a relatively new method of carbon capture, as compared to other methods such as carbon sequestration and bioenergy with carbon capture and storage (BECCS), which have been used for decades. DAC has seen significant growth since 2008, when it was first discussed at the Global Commons Institute in London.
The basic idea behind direct air capture is that we can manage our climate by removing excess CO2 from the atmosphere. We do this by using machines to filter out CO2 from the air we breathe. Theoretically, these machines could be placed anywhere around the world, allowing us to control our own climate without having to rely on other countries or companies to do it for us.
How Does Direct Air Capture Work?
Direct air capture works by using chemical reactions between magnesium oxide or calcium oxide with water in order to remove CO2 from the atmosphere. This process happens inside large tanks known as absorbers that are filled with salts like potassium hydroxide and sodium hydroxide. These absorbers are then heated until they reach temperatures between 400°F and 550°F (200°C – 300°C).
Carbon dioxide (CO2) is the most significant greenhouse gas
-emitted by human activity, and is responsible for around two-thirds of current global warming.
Direct air capture (DAC) is a method of capturing CO2 from the air, which could help reduce the impact of climate change.
The process involves using chemical processes to pull CO2 out of the atmosphere, where it would otherwise remain indefinitely. This can then be stored underground or used to generate synthetic fuels or other products.
The technology has been developing rapidly in recent years, with a number of companies working on different approaches to DAC, including Climeworks and Carbon Engineering.
Our primary way to remove CO2 is planting trees and other plants
-but that approach has limitations given how much we emit.
Direct air capture is one way to supplement these efforts by removing CO2 directly from the atmosphere, which helps us achieve our climate goals faster, cheaper and more efficiently than ever before.
The most effective way is to stop emitting fossil fuels
The most effective way to prevent climate change would be to widely stop emitting fossil fuels, but that’s not realistic without new alternatives. According to estimates from the Intergovernmental Panel on Climate Change (IPCC), if all countries implemented their current plans for reducing greenhouse gas emissions by 2030, global temperatures would still rise 1.5 degrees Celsius above pre-industrial levels by 2100 — with disastrous results for human health and safety as well as for wildlife habitats around the world.
DAC could help us achieve “net zero” emissions
This means that an equal amount of greenhouse gases is emitted as captured and removed from the atmosphere.
As its name suggests, direct air capture works by removing carbon dioxide directly from the air. The process involves first cooling down ambient air to condense the CO2 into a liquid form before capturing it as a gas or solid and storing it somewhere safe. This can be done through a variety of methods — one design uses a filter-based system while another uses adsorption technology.
An important note: when we talk about “capturing” CO2 in this context, this doesn’t actually mean “reversing” climate change; rather, it refers to removing CO2 from the atmosphere so that it doesn’t continue to contribute to global warming over time.
DAC is also more resilient than other approaches
-because it can be deployed anywhere on earth, including locations where conventional carbon capture technologies aren’t possible (such as offshore).
The goal of DAC is to remove CO2 from the atmosphere and store it safely, which would help decarbonize our economy and reduce global warming.
It is a bold and exciting common goal to keep CO2 levels down on a global scale. The battle against climate change will be an ongoing struggle worldwide, but hopefully these efforts can spark further interest in the subject, both from public and private sectors. Perhaps one day we will no longer have a need for “Direct Air Capture” operations to suck up excess carbon dioxide from the atmosphere.
With global temperatures rising, many innovative methods have been developed to remove human pollution from Earth’s atmosphere.