Japan aims to bury greenhouse gas emissions

Swathes of dirty clouds brood over a coal plant in rural Japan, but scientists are now hoping to send the pollutants the other way, deep into the bowels of mother earth.

The cutting-edge but controversial technology of carbon capture and storage is being tested at the Mikawa power station, located near the coast of Japan's southern Fukuoka prefecture.

Toshiba Corp. has chosen it as a pilot site for a technology it sees as a necessary complement to renewable energies such as wind and solar in the battle to cut industrial emissions blamed for global warming.

"There is no silver bullet" to reducing greenhouse gas emissions, said Toshiba engineer Kensuke Suzuki during a tour of the plant, about 900 kilometres southwest of Tokyo.

"Solar energy will not solve all the problems, and you can't just switch from coal to nuclear. You need to find a way to balance the reduction of emissions."

With worldwide coal use projected to rise in coming decades, especially in China and India, proponents of the technique say it can help fight climate change that is melting ice caps and threatening eco-systems.

"CCS will be the only technology to reduce emissions on a grand scale," said Shigeo Murai, who heads a study group on storing carbon dioxide, or CO2, at Japan's Research Institute of Innovative Technology for the earth.

"At the same time it won't be able to reduce overall emissions on its own. It will need help from solar and wind power."

Last month the six-storey Toshiba trial plant began trapping 10 tonnes of CO2 from flue gas, which is created when coal is burnt to make electricity.

In what is called the post-combustion method, the gas is pumped into a boiler which mixes it with amines and other liquid solvents. Subjected to high and low temperatures, the CO2 is then separated and compressed into a liquid.