China has successfully produced natural gas from methane hydrate, also known as “flammable ice”, in an experimental project in the South China Sea. The government has promised to “actively develop” natural gas hydrate over the 2016-2020 five-year plan period.
Flammable ice consists of methane trapped within water crystals, and has been identified as a potential new gas source for China, with the South China Sea thought to contain some of the world’s most promising deposits.
Officially known as methane clathrates or hydrates, they are formed at very low temperatures and under high pressure. They can be found in sediments under the ocean floor as well as underneath permafrost on land. Despite the low temperature, these hydrates are flammable.
By lowering the pressure or raising the temperature, the hydrates break down into water and methane – a lot of methane. One cubic metre of the compound releases about 160 cubic metres of gas, making it a highly energy-intensive fuel.
Many countries including the US and Japan are working on how to tap those reserves, but mining and extracting are extremely difficult.
Methane hydrates are thought to have the potential to be a revolutionary energy source that could be key to future energy needs – likely the world’s last great source of carbon-based fuel. Vast deposits exist basically underneath all oceans around the globe, especially on the edge of continental shelves. Countries are scrambling for a way to make the extraction safe and profitable.
Accessing the power of this flammable ice has been difficult, for two reasons.
First, these reserves are often distributed over a large area rather than concentrated in one spot as oil or natural gas reserves often are.
The bigger problem, however, is that, true to their moniker as flammable ice, methane hydrates are unstable and potentially explosive. Drilling into the sea floor could destabilize the methane ice crystals and cause explosions, spewing vast troves of methane into the atmosphere, where it is a more potent greenhouse gas than carbon dioxide (CO2).
Any exploitation of the reserves must be done with the utmost care because of environmental concerns. The potential threat is that methane can escape, which would have serious consequences for global warming. It is a gas that has a much higher potential to impact climate change than carbon dioxide.