Direct Air Capture Insights from Dr John Breen – Interview with Niall Kitson on the Tech Radio Podcast
NEG8 Carbon’s Chief Technology Officer, John Breen, was interviewed by Niall Kitson on the Tech Radio podcast where they discussed using Direct Air Capture, a carbon removal technology, as a strategy for tackling the climate crisis.
Listen to the full episode (Dr Breen’s interview is from 32 minutes).
The Problems with Relying on Trees to Remove Carbon
When we think of removing carbon from the air, our minds go straight to trees and how nature has provided a way to capture CO2. However, it’s just not viable to plant the number of trees needed to deal with the excess amount of CO2 in the atmosphere.
Dr Breen elaborates:
“Trees do capture CO2, but the problem with trees is that the rate of carbon capture is very low. A metre squared of trees would capture 0.3 tonnes of CO2 in a year. So, if you want to take a billion tonnes of CO2 out of the atmosphere, you’d need to plant an area the size of Germany. Trees are great, but we don’t have enough land. If we planted all those trees, we’d have to do away with land used to produce food.”
There are other problems with trees that cannot be overlooked, such as the forest fires that devastate enormous areas, as we’ve seen recently in California and Greece. Disease is another problem, as those living in Ireland can testify where Ash dieback disease is predicted to wipe put 90% of the country’s ash trees.
Direct Air Capture Technology
While trees can capture 0.3 tonnes of CO2 per metre squared per year, carbon capture units, like those that NEG8 Carbon have developed, can capture up to 12 tonnes of CO2per metre squared per year.
So, to put it in real terms, to capture 1 billion tonnes of CO2, we would need an area less than the size of Dublin city compared to an area the size of Germany if we used trees.
We can also verifiably quantify the amount of CO2 that we’ve captured from the atmosphere.
How the DAC work?
Dr Breen explains:
“Essentially, we use large fans to drive large volumetric flows of air through what we call an absorber. The adsorber contains material that takes the CO2 out of the atmosphere and allows the rest of the air to pass through.
Although CO2 is the primary cause of global warming and accounts for 65% of it, it actually makes up only 0.04% of the atmosphere. So, we need to pass a large amount of air through this solid adsorbent that takes out the CO2 and allows everything else to pass through.
When the adsorbent becomes full of CO2, much like a sponge, we need to regenerate it so it can be reused. We apply heat and vacuum to drive off the CO2, collect it, and then give it to our partners who will inject it underground using geological storage to lock it away permanently.”
For more, read about NEG8 Carbon’s Direct Air Capture Technology
Global Support for Direct Air Capture
The Intergovernmental Panel on Climate Change has called out that we need Direct Air Capture. The organisations says that Direct Air Capture should be capable of capturing 310 billion tonnes of CO2 from the atmosphere by the end of this century. This might seem like a tall order, but it is achievable.
NEG8 Carbon Developments
NEG8 Carbon has built a demo carbon capture unit in Waterford that has been operating for the last year, capturing one tonne of CO2 per annum. The company is well into the design phase of their full-scale unit, the first of which will be deployed in Canada next year, and which will capture 300 tonnes of CO2 per year.
Dr Breen adds:
“We’re at the forefront of the technology. The pilot we’re doing in Canada is being put together by a company called Deep Sky. They’ve gone around the world and looked at who they think has the best technology from all the companies doing this, and they’ve chosen us as one of a handful of companies to deploy and demonstrate our technology in Canada.”
Partnering with the Walton Institute to use AI to Optimise Processes
DAC carbon capture rates depend on several factors, one of them being climate conditions. Depending on where you are in the world, the temperature and humidity vary quite considerably, especially in places like Canada where temperatures can range between -30 and +30 degrees Celsius over the course of a year. Another factor that affects the economics is the cost of electricity used.
DAC is already effective but AI optimisation of carbon capture technology can improve efficiency by 20-40% and help make the technology more sustainable, as Dr, Breen explains:
“The idea is to work with the Walton Institute to look at ways to optimise the running of our units based on inputs such as temperature, humidity of the ambient air, the cost of electricity, and the state of our absorbent. We also look forward to using weather forecasts and electricity cost forecasts, moving forward hours and days ahead, to predict how to optimise the performance of our units.”
For more:
What is Direct Air Capture?
How Does Direct Air Capture Work?