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The future of energy

Source: BBC.UK

Article by Martha Henriques

23 November 2018

Why 'flammable ice' could be the future of energy

Last year, Japan succeeded in extracting an

untapped fuel from its ocean floor - methane

hydrate, or flammable ice. Proponents argue that

it will offset energy crises, but what are the

environmental risks?By Martha Henriques23

November 2018 Future Now  The Economics

of ChangeBuried below the seabed around Japan,

there are beds of methane, trapped in molecular

cages of ice. In some places, the sediment covering

these deposits of frozen water and methane has

been eroded away, leaving whitish mounts of what

looks like dirty ice rearing up out of the seafloor.

Put a match to this sea ice and it doesn't just melt,

it ignitesTake a chunk of this stuff up to the surface

and it looks and feels much like ice, except for a

give-away fizzing sensation in the palm of your hand,

but put a match to it and it doesn't just melt, it ignites.

Large international research programmes and

companies in Japan, among other countries, are

racing to retrieve this strange, counter-intuitive

substance - known as fiery ice - from beneath the

seafloor to use its methane for fuel.

If all goes to plan, they may even start extraction

by the end of the next decade. But the journey

so far has been far from smooth.(Credit: US

Department of Energy)Could this humble

material solve future energy crises? (Credit: US

Department of Energy) There's no doubt tha

t methane hydrates could offer a major

source of fuel, with recent estimates suggesting

they constitute about a third of the total carbon

held in other fossil fuels such as oil, gas and coal.

Several nations, notably Japan, want to extract it.

It is not hard to find, often leaving a characteristic

seismic signature that can be detected by research

vessels. The problem is retrieving that gas and

bringing it to the surface."One thing that's clear is

that we're never going to go down and mine these

ice-like deposits," says Carolyn Ruppel, who leads

the US Geological Survey's Gas Hydrates Project.

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drink from the enormous lakes in the airIt all

comes down to physics. Methane hydrates are

simply too sensitive to pressure and temperature

to simply dig up and haul to land. They form at

typically several hundred metres beneath the

seafloor at water depths of about 500 metres,

where pressures are much higher than at the

surface, and temperatures are close to 0C. Take

them out of these conditions, and they begin

to break down before the methane can be

harnessed. But there are other ways to do it.

"Instead, you have to force those deposits to

release the methane from the formation in the

seafloor. Then you can extract the gas that comes

off," says Ruppel.(Credit: Nigel Hawtin)(Credit:

Nigel Hawtin, data from Renewable and

Sustainable Energy Reviews, 41, 884-900

)A Japanese government funded research

programme is trying to do just that. Its initial

mission, after several years of preliminary

research scoping out likely spots for methane

hydrates, was in 2013. "It was a world-first,"

says Koji Yamamoto, director general of the methane

hydrate research and development group at the Japan

Oil, Gas and Metals National Corporation, and one of

the leading researchers in Japan's national gas

hydrates research programme.The team managed

to produce gas from the methane hydrate reserves

by drilling a borehole down into the seabed of the

Nankai Trough, off the eastern coast of Japan's main island.

By lowering the pressure on the reserves, they were able

to release and collect the gas. The test ran for six days,

before sand entered the well and blocked the supply.

A second test in 2017 ran in the Nankai Trough.

This time the researchers used two test wells.

The first encountered the same problem as before

and became blocked with sand after several days.

But the second of the well ran for 24 days without

technical problems, Yamamoto says.

In 2013, the deep-sea drilling vessel Chikyu succeeded

in extracting methane hydrate from the waters around

central Japan (Credit: Getty Images) In general, people

just feel really scared to do anything to the ocean floor.

The place is known to be unstable and earthquakes

happen - Ai OyamaEven though the tests ran for a

short time, they showed that there was a glimmer

of potential that Japan might have usable carbon-

based natural resources. The public reaction,

however, was mixed, says Ai Oyama, a technical

translator and former research analyst working on

methane hydrates at the Hawai'i Natural Energy

Institute. Some welcomed the idea that Japan may

have energy independence. Others were very wary

about any technique that disturbed the seafloor

near tectonic plate boundaries."In general, people

just feel really scared to do anything to the ocean

floor. The place is known to be unstable and

earthquakes happen," Oyama says.The fear is

that depressurising one part of the methane

hydrate deposit might make the whole reserve

become unstable."People worry that we'll start

extracting methane from the gas hydrates and

get into a runaway breakdown where we can't

stop it," says Ruppel.The problem with this

would be two-fold. First, a lot of methane gas

would suddenly be released into the ocean -

which could potentially add vast amounts of the

greenhouse gas to the atmosphere.Second, methane

hydrate releases a lot of water as well as a lot of

methane when it destabilises, which would introduce

a lot more liquid into the sediment below the ocean floor.

In a steeply sloping environment, a lot of excess water

could lead to landslips. Some environmentalists even

fear that it could lead to a tsunami.(Credit: Nigel Hawtin)

(Credit: Nigel Hawtin, based on data from Reviews of

Geophysics, 55(1), 126-168) However, the physical

properties of methane hydrate put a natural brake on

this chain of events, says Ruppel. To release methane

from a deposit, you have to put energy into the system.

Without working hard to release the gas - through

lowering the pressure or raising the temperature of the

deposit - it simply stays put in its stable form of methane

hydrate."So the problem is actually the opposite.

You may start the process of getting the gas to come off,

but to keep that process going, you have to introduce

more energy to make it happen,"

says Ruppel.While a runaway reaction isn't likely, the

Japanese programme is still carrying out extensive

environmental studies to test the safety of the methane

hydrate production. The data gathered at the first test in

2013, and at a second longer test in 2017, so far hasn't

suggested that the technique will destabilise the ocean

floor, Yamamoto says. But given Japan's history of

natural disasters - around 24,000 people are still under

evacuation order since the 2011 Tōhoku earthquake

and tsunami - the public is highly risk-averse.(Credit: Alamy)

Flammable ice can be fragile, and if it crumbles during drilling,

it could release a 'methane burp' into the ocean. Some fear

that this may unleash a tsunami (Credit: Alarmy)"We feel that

gas hydrate production is environmentally safe," says Yamamoto.

"But still, [the public] have a concern about negative effects of

gas hydrate production."As well as the reserves buried beneath

the sea floor, there is another type of methane hydrate deposit

that has been gaining attention from Japanese researchers.

Efforts to research shallower deposits, very close to the

seafloor surface, is also being explored off in the Sea of

Japan to the west of the country. Accessing these shallow

reserves poses a very different potential risk.Japan's untold

storiesWelcome to BBC Future Now's Japan season, in which

we explore the country's most exciting medical, technological,

environmental and social trends.
Coming up:
The Olympic medals made from recycled phonesHow Japan

made fatherhood sexyThe secrets of Okinawa's superagers
... and many more."These are very active biological

environments," says Tim Collett, a senior scientist at the

US Geological Survey's Gas Hydrate Project. "There are

whole communities that live off the methane."These

environments are rich in unique organisms, from bacteria

to very large tubeworms and crabs, all specialised to live

off the methane as their source of energy. In other parts

of the world where these methane-based communities

live, they are often protected as rare natural environments.

Beneath the permafrostJapan's main efforts in extracting

methane hydrate, however are not in the seafloor at all,

but in the only other place that flammable ice can found -

deep in the permafrost, the permanently-frozen layer of

rock or soil that covers the ground at polar regions and

high-rise mountains. Researchers from Japan, which

doesn't have its own permafrost, are assisting in the

most ambitious on-land production test for methane

hydrate so far, in Alaska's North Slope.In December,

researchers from Japan's national research programme

are set to start work with the US Geological Survey and

the US's Department of Energy, to begin what they

hope will be a long-term production test site. While this

source of methane hydrate is very different, the methods

used to get to it are actually very close. (Credit: Getty Images

Flammable ice appears to smoke as it melts

(Credit: Getty Images) "The conditions at those

reservoirs under the permafrost are pretty similar pressure

and temperature conditions as they are in the Nankai Trough

," says Collett. "It turns out, to the best of our knowledge,

even though the Arctic and the marine environment are

very different, the physical properties of the deposits and

how they occur in the sediments appears to be very similar

."The production techniques used in Alaska could end up

being transferrable to the marine environment. But there

are still big challenges. A long-term production of methane

hydrates hasn't been carried out anywhere yet, on land or

under the sea."We're still very much in research mode,"

says Collett.Given the difficulty of retrieving gas from methane

hydrate reserves, and the concerns around extraction, the

stakes have to be high for a nation to invest heavily in this

technology. Having very few other options in terms of

domestic energy makes this hard-to-access source of

methane an appealing prospect. Japan is not a country

that has other carbon-based sources of energy to fall back on.

"Japan imports a lot of natural gas, but it is very costly.

If we have our own domestic resource, [it could] contribute

to the energy security of Japan," says Yamamoto.

As an economic resource, it's easy to see the appeal

of methane hydrate. But, fundamentally, it is just

another source of natural gas and burning it would

contribute to climate change.All the social and

environmental issues associated with fossil fuels apply to gas

hydrates"The most important thing is the recognition

and appreciation that gas hydrates are just another fossil

fuel," says Collett. "All the social and environmental issues

associated with fossil fuels apply to gas hydrates.

"In this context, methane hydrates - if they are to play a

role in Japan's energy future - are likely to be used as a

bridging fuel, in the transition towards renewables.

Natural gas is the least carbon-intensive form of fossil fuel,

releasing less carbon dioxide per unit of energy released

than coal or oil. But, as a carbon-based fuel, burning it

still contributes to climate change.(Credit: Getty Images)

Japan has been researching the potential of flammable

ice for decades, but it is only within the last few years

that extraction has come within reach (Credit: Getty Images)

"We need to shift to renewable energy," says Koji Yamamoto.

"But complete switch to renewable energy [takes] a

very long time."Even as a transition fuel, gas hydrates

could be hugely important, Ruppel says. "Were a country

able to efficiently produce methane from these deposits,

it could open a new realm in bridge fuels to another energy

future," she says.How useful a role it can play in the future

depends on how quickly methane hydrate can be accessed

and produced on a commercial scale. The Japanese government

hopes to begin commercial projects exploring methane hydrate

between 2023 and 2027, according to its latest Strategic

Energy Plan.This target could be a bit ambitious. Jun Matsushima

, a researcher at the Frontier Research Center for Energy

and Resources at the University of Tokyo, puts the estimate

at around 2030 to 2050. "There is a long way to commercialise

methane hydrate," says Matsushima.The make-or-break

moment will be when a long-term production test can be

sustained without technical problems or budget constraints

shutting it down, says Ruppel."I would guess there will be

a long-term production test - from months to more than

a year - by 2025. But I don't have a crystal ball," Ruppel says.

But at the same time, Japan is committing to moving towards

renewable energies and decarbonisation. As technologies for

harnessing renewable energy become better and cheaper,

the role for fossil fuels - especially experimental and expensive

ones like methane hydrate - decreases. The longer it takes to

get methane from gas hydrate reserves on a commercial scale,

the shorter the useful window for using it may be.

The other possibility is that adding in a new accessible

source of fossil fuel could delay the transition to renewables,

says Collett.This source of carbon, the most abundant in the

world, may be one of the last new forms of fossil fuel to be

extracted on a commercial scale. It is also the only one to

be developed with the end of fossil fuels in sight.

The race for methane hydrates is a unique one, where

researchers are working towards a goal that might be made

irrelevant by renewables by the time they reach it.