Methane Hydrate as a Potential Fuel
At the bottom of the world’s oceans lies a potential source of energy that could provide society with fuel well into the next century. These deposits are the product of ancient seafloor bacteria, and they store twice as much carbon as all the world’s other fossil fuel reserves combined. This potential fossil fuel is not oil or coal, or even natural gas as we know it, but methane gas locked in crystals of ice. Resembling sparkling snow, this peculiar ice, known as methane hydrate, burns if ignited, leaving behind a pool of water. Methane ice forms under pressure and expands to more than 160 times its original volume when it is brought to the surface.
First discovered in 1970， methane hydrate has been found within just a few hundred kilometers of almost every coastline, as well as in permafrost regions on land, such as those of the United States state of Alaska. And it has been found in enormous quantities. Off the east coast of the United States near the Carolinas, for example, the United States Geological Survey, a scientific agency that studies natural resources, has discovered two deposits of methane hydrate, each covering about 3,139 square kilometers. Together they are estimated to contain over 37 trillion cubic meters of methane gas, or more than 50 times the amount of natural gas consumed in the United States in 2012. Is methane hydrate the fuel of the future? The sheer volume and richness of methane hydrate deposits make them a strong candidate for development as an energy resource. However, the challenges are enormous.
Although methane hydrate forms in layers that could potentially be mined, gaining access to the deposits beneath the seabed poses huge technical problems. In addition to the problems of mining it, the hydrate is stable only at the icy temperatures and crushing pressures of the deep ocean and starts to break down long before it reaches the surface; thus, preventing the gas from escaping as the hydrate is recovered adds to the challenge of recovery.
Like conventional natural gas, the layers of methane hydrate could also be tapped by drilling. Several oil companies and government agencies are actively researching the possibility of such an endeavor. Because the deposits are fa deeper than most underwater oil and gas fields, special deepwater drilling vessels would have to be constructed. Nevertheless, drilling is at least a possible option, although the methane ice is under so much pressure, the challenge is akin to bursting a balloon and trying to capture all the escaping gas. One potential solution would be to expel the methane by pumping hot water or steam into the deposit through one drill hole and extracting the expelled methane through another. But once recovered, the methane would still have to be brought ashore, and this would pose an additional challenge.
Methane hydrate would provide a “cleaner”source of energy than oil and coal because methane releases less than half the amount of carbon dioxide (a greenhouse gas that traps heat in the atmosphere)into the atmosphere when it is burned and so contributes less significantly to climate change. However, its exploitation is not without potentially serious environmental consequences. It is estimated that the methane trapped in methane hydrate amounts to more than 3,000 times the volume of methane in the atmosphere, where it forms a potent greenhouse gas that is ten times more effective at trapping heat than carbon dioxide. The global warming effect of methane accidentally released into the atmosphere is consequently ten times more serious than that of carbon dioxide. Breakdown of methane hydrate at the base of hydrate layers is also known to have triggered massive landslides on the ocean floor, adding a further hazard to the production of this resource.
Although the technological challenges facing the successful exploitation of methane hydrate are great, they are not insurmountable. Indeed, both Japan and China have projects aimed at commercial-scale extraction, and the oil industry is field-testing the possibility of extracting methane. We may therefore live to witness the exploitation of this resource as other reserves of fossil fuel dwindle and methane hydrate becomes an economically attractive alternative.
1
At the bottom of the world’s oceans lies a potential source of energy that could provide society with fuel well into the next century. These deposits are the product of ancient seafloor bacteria, and they store twice as much carbon as all the world’s other fossil fuel reserves combined. This potential fossil fuel is not oil or coal, or even natural gas as we know it, but methane gas locked in crystals of ice. Resembling sparkling snow, this peculiar ice, known as methane hydrate, burns if ignited, leaving behind a pool of water. Methane ice forms under pressure and expands to more than 160 times its original volume when it is brought to the surface.
The word “peculiar”in the passage is closest in meaning to
Aunusual
Bshiny
Cvaluable
Dabundant
2
First discovered in 1970， methane hydrate has been found within just a few hundred kilometers of almost every coastline, as well as in permafrost regions on land, such as those of the United States state of Alaska. And it has been found in enormous quantities. Off the east coast of the United States near the Carolinas, for example, the United States Geological Survey, a scientific agency that studies natural resources, has discovered two deposits of methane hydrate, each covering about 3,139 square kilometers. Together they are estimated to contain over 37 trillion cubic meters of methane gas, or more than 50 times the amount of natural gas consumed in the United States in 2012. Is methane hydrate the fuel of the future? The sheer volume and richness of methane hydrate deposits make them a strong candidate for development as an energy resource. However, the challenges are enormous.
How do the Alaskan methane hydrate deposits described in paragraph 2 differ from those found near the Carolinas?
AThey were found as early as 1970 whereas the deposits near the Carolinas where discovered much later.
BThey are more than 50 times larger than the deposits near the Carolinas.
CUnlike the deposits near the Carolinas, they are located on land rather than under the ocean.
DUnlike the deposits near the Carolinas, they are already being developed as an energy resource.
3
First discovered in 1970， methane hydrate has been found within just a few hundred kilometers of almost every coastline, as well as in permafrost regions on land, such as those of the United States state of Alaska. And it has been found in enormous quantities. Off the east coast of the United States near the Carolinas, for example, the United States Geological Survey, a scientific agency that studies natural resources, has discovered two deposits of methane hydrate, each covering about 3,139 square kilometers. Together they are estimated to contain over 37 trillion cubic meters of methane gas, or more than 50 times the amount of natural gas consumed in the United States in 2012. Is methane hydrate the fuel of the future? The sheer volume and richness of methane hydrate deposits make them a strong candidate for development as an energy resource. However, the challenges are enormous.
In paragraph 2， why does the author compare the volume of methane gas in methane hydrate deposits in the Carolinas to the amount of natural gas consumed in the United States in 2012 ？
ATo emphasize the large size of methane hydrate deposits that have been discovered
BTo illustrate the importance of natural gas as a fuel
CTo confirm that methane hydrate is the fuel of the future
DTo highlight the enormous challenge of developing methane hydrate as an energy resource
4
Although methane hydrate forms in layers that could potentially be mined, gaining access to the deposits beneath the seabed poses huge technical problems. In addition to the problems of mining it, the hydrate is stable only at the icy temperatures and crushing pressures of the deep ocean and starts to break down long before it reaches the surface; thus, preventing the gas from escaping as the hydrate is recovered adds to the challenge of recovery.
Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
AAnother problem of mining the hydrate is that when the hydrate breaks down due to the temperatures and pressures of the deep ocean, the gas escapes before recovery.
BBecause the hydrate is stable only under the conditions of the deep ocean, bringing it to the surface without the gas escaping is challenging.
CThe stability of the hydrate in the deep ocean makes it difficult to recover the gas from the hydrate, which adds to the problems of mining the hydrate.
DRecovering the hydrate is challenging because of both the conditions in the deep ocean and the gas escaping from the hydrate during recovery.
5
Like conventional natural gas, the layers of methane hydrate could also be tapped by drilling. Several oil companies and government agencies are actively researching the possibility of such an endeavor. Because the deposits are fa deeper than most underwater oil and gas fields, special deepwater drilling vessels would have to be constructed. Nevertheless, drilling is at least a possible option, although the methane ice is under so much pressure, the challenge is akin to bursting a balloon and trying to capture all the escaping gas. One potential solution would be to expel the methane by pumping hot water or steam into the deposit through one drill hole and extracting the expelled methane through another. But once recovered, the methane would still have to be brought ashore, and this would pose an additional challenge.
According to paragraph 4， all of the following make drilling of methane hydrate challenging EXCEPT
Athe depth at which methane hydrate deposits are located
Bthe pressure that methane ice is under
Cexpelling methane through drill holes
Dbringing recovered methane to land
6
Like conventional natural gas, the layers of methane hydrate could also be tapped by drilling. Several oil companies and government agencies are actively researching the possibility of such an endeavor. Because the deposits are fa deeper than most underwater oil and gas fields, special deepwater drilling vessels would have to be constructed. Nevertheless, drilling is at least a possible option, although the methane ice is under so much pressure, the challenge is akin to bursting a balloon and trying to capture all the escaping gas. One potential solution would be to expel the methane by pumping hot water or steam into the deposit through one drill hole and extracting the expelled methane through another. But once recovered, the methane would still have to be brought ashore, and this would pose an additional challenge.
Paragraph 4 suggests which of the following about the possibility of tapping methane hydrate deposits through drilling
AUnderwater oil and gas fields might get in the way of driling.
BDrilling vessels currently in existence cannot reach methane hydrate deposits.
CHot water or steam that is pumped into deposits will reduce the amount of methane that can be extracted.
DSuch drilling would have to be supported by government agencies because oil companies believe it to be too costly.
7
Methane hydrate would provide a “cleaner”source of energy than oil and coal because methane releases less than half the amount of carbon dioxide (a greenhouse gas that traps heat in the atmosphere)into the atmosphere when it is burned and so contributes less significantly to climate change. However, its exploitation is not without potentially serious environmental consequences. It is estimated that the methane trapped in methane hydrate amounts to more than 3,000 times the volume of methane in the atmosphere, where it forms a potent greenhouse gas that is ten times more effective at trapping heat than carbon dioxide. The global warming effect of methane accidentally released into the atmosphere is consequently ten times more serious than that of carbon dioxide. Breakdown of methane hydrate at the base of hydrate layers is also known to have triggered massive landslides on the ocean floor, adding a further hazard to the production of this resource.
The word “hazard”in the passage is closest in meaning to
Adanger
Bcomplexity
Ccost
Ddisadvantage
8
Methane hydrate would provide a “cleaner”source of energy than oil and coal because methane releases less than half the amount of carbon dioxide (a greenhouse gas that traps heat in the atmosphere)into the atmosphere when it is burned and so contributes less significantly to climate change. However, its exploitation is not without potentially serious environmental consequences. It is estimated that the methane trapped in methane hydrate amounts to more than 3,000 times the volume of methane in the atmosphere, where it forms a potent greenhouse gas that is ten times more effective at trapping heat than carbon dioxide. The global warming effect of methane accidentally released into the atmosphere is consequently ten times more serious than that of carbon dioxide. Breakdown of methane hydrate at the base of hydrate layers is also known to have triggered massive landslides on the ocean floor, adding a further hazard to the production of this resource.
According to paragraph 5， which TWO of the following are true of methane gas? To receive credit, you must select TWO answers.
AWhen burned, it releases much less carbon dioxide than oil and coal do.
BIt has a greater global warming effect when released into the atmosphere than does carbon dioxide.
CThere is a great deal more methane currently in the atmosphere than there is trapped in methane hydrate.
DIts release can be triggered by landslides on the ocean floor.
9
First discovered in 1970， methane hydrate has been found within just a few hundred kilometers of almost every coastline, as well as in permafrost regions on land, such as those of the United States state of Alaska. And it has been found in enormous quantities. Off the east coast of the United States near the Carolinas, for example, the United States Geological Survey, a scientific agency that studies natural resources, has discovered two deposits of methane hydrate, each covering about 3,139 square kilometers. Together they are estimated to contain over 37 trillion cubic meters of methane gas, or more than 50 times the amount of natural gas consumed in the United States in 2012. [■] Is methane hydrate the fuel of the future? [■] The sheer volume and richness of methane hydrate deposits make them a strong candidate for development as an energy resource. However, the challenges are enormous. [■]
Although methane hydrate forms in layers that could potentially be mined, gaining access to the deposits beneath the seabed poses huge technical problems. [■] In addition to the problems of mining it, the hydrate is stable only at the icy temperatures and crushing pressures of the deep ocean and starts to break down long before it reaches the surface; thus, preventing the gas from escaping as the hydrate is recovered adds to the challenge of recovery.
Look at the four squaresthat indicate where the following sentence could be added to the passage
Moreover, many methane hydrate deposits are located close to high-population areas, where energy demand is greatest.
Where would the sentence best fit？Click on a square sentence to the passage.
10
Methane hydrate is made up of methane gas locked in crystals of ice and burns if ignited.
AMethane hydrate deposits have been found in various locations and in large quantities, but exploiting them as a source of alternative fuel poses many challenges.
BMethane hydrate deposits could either be mined or drilled, but reaching them and bringing the methane ashore could be very difficult.
CBurning methane from methane hydrate causes less global warming than burning fuels like coal and oil, but its extraction could cause serious harm to the environment.
DSeveral oil companies have discovered ways to tap methane hydrate layers using deepwater drilling vessels and bringing the methane safely to the surface.
EBecause the large reserves of other fossil fuels such as oil, coal, and natural gas are easier to exploit, methane hydrate is highly unlikely to become the fuel of the future.
FWhile the technological problems of extracting methane appear to have been solved, it will take several years before it can be done commercially.
