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30 May 2017

Extracting Gas from Flammable Ice

Yes, you did read that headline correctly. Flammable ice may sound like an implausible contradiction, but once you understand the underlying science it all starts to make sense.

Img: John Ripmeester, National Research Council of Canada
You see, the flammable ice to which I refer is not really ice at all, at least in the traditional sense of the word. Rather, it is a substance known as Methane Hydrate, which consists of concentrations of methane enclosed within a cage of water molecules. Burning rather than melting upon contact with fire, methane hydrate is being touted as a possible successor to previous hydrocarbon resources such as oil, coal, and natural gas. In fact, the Earth’s vast concentrations of the substance are believed to outweigh the total hydrocarbon resource provided by all three aforementioned fuels alone.

The deposits are formed in the ocean’s depths due to a perfect combination of low temperatures and moderate pressure. However, they do tend to be highly unstable, with changes to either parameter resulting in the release of any and all trapped methane as the substance is disrupted. Due to this fact, successfully extracting the gas reserves locked within such concentrations is a challenging task for researchers and engineers.

Rising admirably to said challenge, a team of researchers and engineers based out of China recently announced success in their latest attempt at extracting the natural gas from these vast reserves of ’fire ice’, as the substance is now commonly known, bringing the world’s methane hydrate deposits one step closer to being considered a viable fuel source.

Making use of a floating gas extraction platform in the South China Sea, the engineering team drilled directly down into the deposits and depressurised them on the spot before piping the gas to the surface. According to reports published by the Chinese media, they managed to extract up to 35,000 cubic metres per day, showing signs of a potential for commercialisation in the future.

"Compared with the results we have seen from Japanese research, the Chinese scientists have managed to extract much more gas in their efforts," chemical engineer Praveen Linga from the National University of Singapore told the BBC.

The mention of Japan is in reference to their 2013 breakthrough, which saw them achieving some level of success in pioneering the extraction of such gas deposits. However, they almost immediately experienced problems and were unable to push further forward until earlier this very month.

China and Japan are not alone in their efforts to access the ocean’s gas reserves, with countries including the USA, India, and South Korea all investing heavily in in the exploration of methane hydrates as a viable fuel source.

Despite the engineers’ success, there remain countless concerns regarding the extraction of methane deposits from the oceans. The environmental impact of such projects is yet to be properly investigated or understood, and methane’s status as a greenhouse gas 36 times more potent than CO2 means that should the methane held in these reserves be inadvertently released, the implications could be highly damaging and long-lasting.

Remaining undeterred by the aforementioned concerns is Ingo Pecher, an accomplished geoscientist based out of the University of Auckland. Speaking recently to ScienceAlert, Pecher said of the research and its potential future applications, "In order to reduce CO2 emissions starting now, not in 20 to 30 years, we need to promote switching from coal to natural gas.

"Natural gas from hydrates may play a key role for such a switch in many parts of the world."

Burning gas does in fact contribute less to levels of damaging emissions than the burning of traditional fuels such as coal, so Pecher may be correct in asserting that we need to make the switch. There is still much work to be done before any plans for commercialisation can be drawn up however, so for now we’re forced to play the waiting game and see if any further news or developments emerge.

Sam Bonson

Sam is an aspiring novelist with a passion for fantasy and crime thrillers. He is currently working as a content writer, journalist & editor in an attempt to expand his horizons.