Discovery could cut power station emissions to zero

GREENHOUSE gas emissions from power stations could be cut to almost zero by cleaning up the combustion process, British engineers said today.

Using ceramic tubes made from an advanced material called LSCF (Lanthanum Strontium Cobalt Ferric Oxide) inside the combustion chamber could revolutionise the way gas is burnt to produce energy.

LSCF has the remarkable property of being able to filter oxygen out of the air, and by burning fuel in pure oxygen it is possible to produce a stream of almost pure carbon dioxide, which has potential for reprocessing into useful chemicals.

British government figures show Britain’s power stations create more than 200 million tonnes of CO2 a year, more than a third of the country’s total output.

The ceramic material was developed for fuel cell technology but engineers at Newcastle University and Imperial College London recognised its potential in power stations.

Gas-fired power stations burn methane in a stream of air, producing a mixture of nitrogen and greenhouse gases including carbon dioxide and nitrogen oxides.

LSCF tubes would allow only the oxygen component of air to reach the methane gas, resulting in the production of almost pure carbon dioxide and steam, which can be separated by condensing out the steam as water.

The resulting stream of carbon dioxide could be piped to a processing plant for conversion into useful chemicals such as methanol.

The research was published yesterday in Materials World and The Chemical Engineer.

When air is blown around the outside of the tubes, oxygen is able to pass through the wall of the tube to the inside, where it combusts with methane gas that is being pumped through the centre of the tubes.

The oxygen-depleted air, which consists mainly of nitrogen, can be returned to the atmosphere with no harmful effects on the environment, while the carbon dioxide can be collected separately after combustion.

In theory the technology could also be applied to coal and oil-fired power stations.

Professor Ian Metcalfe of Newcastle University said: “Whether it is economical to introduce it will depend largely upon the carbon credit system that governments operate in the future.”