China will put environmental concerns as top priority in tackling ways to exploit combustible ice, a kind of natural gas hydrate, in the permanent tundra in its northwest plateau region, said a combustible ice project leader.

"We do not need to drill very deep to get the flammable frozen compound from tundra here in Muli Prefecture in Qinghai Province. However, as the sample is taken out, methane gas is easily released into the atmosphere," said Wen Huaijun, chief engineer of the combustible ice project in Qinghai.

He said the project team under the China National Administration of Coal Geology is carrying out research to guarantee that the exploitation of the frozen natural gas does not cause environmental problems.

Combustible ice is regarded as a potential source of alternative energy to coal and oil. One cubic meter of combustible ice can release 164 cubic meters of natural gas.

The Ministry of Land Resources said on Friday that the prospective volume of the natural gas hydrate in the country's frozen earth regions is estimated to reach 35 billion tonnes of oil equivalent.

China announced the first discovery of the resource under the bed of the South China Sea in May 2007.

Wen said the environmental threats from the use of the resource even in a land-based region is enormous, because it releases carbon dioxide or methane into the atmosphere.

"The plateau region is very sensitive to environmental changes. The biological conditions here are vulnerable," he said.

Combustible ice usually exists in seabed or tundra areas (two mediums having the strong pressure and low temperature necessary to its stability). It can be lit up like solid ethanol, which is why it has the name "combustible ice."

Wen said the combustible ice research project has been carried in Muli Prefecture, 4,100 meters above sea level, since 2004.

"It still takes time and a huge amount of research investment to realize the dream of exploiting the resource, while ensuring the environment," he said.

Wang Jianbin, deputy director of the Qinghai Bureau of Land Resources, said at the present stage, the project focus is still to ascertain locations of the deposit, and carry out a feasibility study on its exploitation.

(Xinhua News Agency October 3, 2009)