SINGAPORE — Ice that burns? It sounds like a magician’s trick. So do some of the exotic names given to gas hydrate — “flammable sorbet,” “crystal gas” and “burning ice.” But recent scientific surveys and test drilling in Asia and elsewhere have proven that this substance exists in massive, potentially recoverable quantities and that it could be an important commercial energy source for the future.
Indeed, some of the world’s biggest economies and energy users, including the United States, Japan, China, India, South Korea and Canada, are racing to develop production techniques and equipment to tap gas hydrate and bring it to market within the next decade. For all of them, except energy self-sufficient Canada, the ability to tap new domestic sources of natural gas offers the prospect of substantially reducing dependence on expensive gas imports.
Hydrate deposits up to several hundred meters thick are generally found in two places: on or beneath the deep ocean floor, or underground close to the Arctic permafrost layer, where high pressure and cold temperatures turn natural gas (methane, ethane and propane) into semi-solid form.
Gas hydrate looks like ordinary ice, although it is sometimes discolored. But when brought to the surface and allowed to warm, it can be lit with a match. It then burns with a soft orange flame. One cubic meter of gas hydrate releases as much as 164 cubic meters of natural gas, in which methane is usually the chief constituent.
While global estimates vary considerably, the U.S. government’s energy department says that the energy content of methane in hydrate form is “immense, possibly exceeding the combined energy content of all other known fossil fuels,” meaning coal, oil and conventional gas.
The presence of hydrates has been inferred from seismic surveys and subsea sampling along most of the world’s continental shelf margins. Some of the biggest deposits so far found are on the ocean floor off Japan, South Korea, India and China, and on and off U.S. and Canadian Arctic land territory.
Japan’s economy, trade and energy ministry announced last year that there were over 1.1 trillion cubic meters of methane hydrates in a Pacific Ocean trench, called the Nankai Trough, some 50 kilometers from the coast of Honshu, the main Japanese island. This reserve is equivalent to 14 years of gas use by Japan, which imports nearly all the oil, gas and coal needed to run its vast economy, the world’s second-largest after the United States.
Three years ago, the Japanese government said it believed commercial exploitation of methane hydrate was economically viable when oil traded above $54 a barrel, less than half its present price. In November 2007, the government in Seoul said it had found enough gas hydrates in the sea between South Korea and Japan to meet 30 years of demand. Six months earlier, China announced that it had for the first time managed to tap into seabed sediment containing gas hydrates in the northern part of the South China Sea. It said initial estimates indicated that the find contained the equivalent of more than 100 million metric tons of oil — about one-third of China’s annual oil consumption.
In doing so, China became the fourth country after the U.S., Japan and India to achieve this technological breakthrough in the deep sea search for energy. India announced in 2006 that it had made several huge discoveries of gas hydrates off its east and west coasts.
Since last April, the U.S. has signed separate agreements with India, South Korea and Japan to cooperate in hydrate research, exploration and production. Japan, the U.S. and Canada, working in close collaboration, have achieved several days of continuous extraction of methane from underground hydrate reserves in the Arctic permafrost. Large-scale production tests are planned in the Canadian Arctic this winter and in the U.S. Arctic next year.
Test production from offshore Arctic finds is expected to lag by three to five years, because marine deposits are less well documented than those on land. Sea sampling and drilling are also much more expensive. Japan said recently it plans to start test drilling in the Nankai Trough in 2012, possibly leading to commercial production by 2016. Korea has a similar production timetable.
However, apart from the high costs and technical challenge, all the hydrate explorers face another possible danger — environmental disaster. While governments are attracted to an abundant clean fuel, scientists are concerned that drilling when combined with global warming risks disturbing the seabed and triggering an uncontrolled release of methane, a potent greenhouse gas.
The British government’s former chief scientific adviser, Sir David King, warned recently that one big unknown about global warming is the stage at which dangerous tipping points may be reached that lead to runaway heating of the planet. He cited as an example the release of methane hydrate deposits in the Arctic.
Some evidence suggests that a catastrophic release of methane from the ocean 55 million years ago, possibly caused by undersea volcanic explosions and landslides, was responsible for making the earth much warmer.
The modern hydrate quest is built on a paradox. When released to the air, methane is a greenhouse gas that traps around 20 times more solar heat in the earth’s atmosphere than carbon dioxide, the main global warming gas. But when burned, methane releases up to 25 percent less carbon dioxide than combustion of the same amount of coal. It also emits no nitrogen and sulfur oxides, which poison the air and human health when coal is burned without effective filters.
The world’s abundant methane hydrate deposits have been safely stored for thousands of years in the ocean depths and Arctic permafrost. Those who now seek to exploit what is probably the world’s greatest reserve of new fossil fuel must therefore be sure that in doing so they improve, not harm, the global environment.
Michael Richardson, a former Asia editor of the International Herald Tribune, is an energy and security specialist at the Institute of South East Asian Studies in Singapore.