Explore Challenges
- Countryside in Crisis?
- The Energy Water Food Stress Nexus
- Unsustainable Fishing
- Keeping pace with a digital revolution
- Global health in the 21st Century
- Adapting to an urban future
- Educating for tomorrow
- Digital technology in Africa
- Persistent poverty in Britain
- Can the UK ever be sustainable?
- Plastic pollution in the oceans
- Natural disasters: how to improve?
- Not In My Back Yard
- Digital Divide in the UK?
- Importing goods, exporting drought?
- Britain’s ageing population
- Engineering our climate
- The future shape of Capitalism
- Migration: skills and the job market
- Razing the Rainforest
- London under water
- Concreting the countryside
- Future of low carbon energy
- Africa in the 21st Century
Artificial trees
What is the idea?
Professor Lackner, a Physicist at Columbia University in New York, has led a team in designing a machine that can capture carbon dioxide from the air.
First suggested over 10 years ago, the 'artificial trees', also known as 'carbon scrubbers', filter out carbon dioxide as air passes through them.
The team states that the so-called 'carbon scrubbers' can trap the CO2 from air on absorbent plastic sheets called ion exchange membranes, commonly used to purify water.
They have recntly discovered that humid air can then make the membranes "exhale" their trapped CO2.
The captured CO2 then needs to be buried in deep underground in porous rock or under the seabed.
Global Research Technologies (GRT), of which Professor Lackner is Vice President of Research is working to build a prototype at a laboratory in Arizona, USA.
When CO2 comes into contact with sodium hydroxide, it is absorbed, producing a liquid solution of sodium carbonate.
It is this liquid solution which is thought could be piped away, and the time at which the CO2 could be recovered as a concentrated gas in preparation for its final storage.
Professor Lackner's vision is to have thousands of artificial trees and estimates that every single one would remove 90,000 tonnes of carbon dioxide a year - the equivalent emissions of 20,000 cars.
Problems
It require would around 1 million of the devices to soak up the world's carbon emissions, and the CO2 trapped would still need to be disposed of after that.
It is uncertain whether the technology would be efficient enough at the huge scales required.
A detailed report on carbon capture from the Intergovernmental Panel on Climate Change (IPCC) in 2005 effectively dismissed the option of air capture as unworkable.
Comments
- John Nelson said
- 1st September, 2009 at 12:09pm
I’m confused. The first part talks about ion-exchangemembranes. The second part sodium hydroxide solution absorbing CO2 to form sodium carbonate (Na2CO3). The manufacture of sodium hydroxide (NaOH) requires electrolysis- usually of common salt (NaCl) solution. This process uses a lot of electricity (and also produces chlorine). This route doesn’t seem very environmentally friendly to me.