Scientists believe nanotubes may absorb carbon dioxide

Prof Eleanor Campbell, project leader and head of chemistry at Edinburgh University, told The Engineer: ‘The main emphasis of the project is on developing a highly porous nanotube-based material, which will have a high capacity for absorbing carbon dioxide.’

Campbell explained that when there are relatively low concentrations of CO₂ in the atmosphere, a material must be used that selectively absorbs CO₂ over other gases present in air.

‘The basic framework revolves around the carbon nanotubes but we’re chemically functionalising them to interact in a specific way with the CO₂,’ she said.

Each individual tube will be around one micrometre long and one nanometre in diameter. The researchers claim these carbon nanotubes could be used in systems of varying sizes.

‘You could have relatively small units that would be the equivalent of 10 trees in terms of CO₂ consumption. But, what might actually go down better is to implement this idea on a larger scale so that it is incorporated into general infrastructure, such as along motorways,’ said Campbell.

The idea of developing domestic units for people’s homes has also been discussed by the researchers.

‘You could potentially have a unit sitting on your balcony or on your roof sucking up the CO₂. The CO₂ would be stored in canisters that would need to be changed every so often when the old one is full,’ stated Campbell.

Campbell’s personal view is that trees should be planted where possible. However, where it’s not possible — such as in big cities — this is one way of doing something locally about the CO₂ in the atmosphere.

Campbell was also keen to express that this project in itself is not enough to combat rising CO₂ levels. ‘It will have some impact but it’s not going to be the complete answer, despite offering a valid contribution,’ she said.

The project at Edinburgh is a multi-disciplinary collaboration between various departments.

‘It would be very interesting if my chemistry colleagues were able to find a way of catalytically converting the captured CO₂ into something, such as fuel,’ said Campbell. ‘As a result a nice green cycle would be generated.’

The project, led by the Engineering and Physical Sciences Research Council with funding from the Research Councils UK Energy Programme, is due to run until April 2012.