NATURAL GAS ENERGY
GAS HYDRATES
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How much natural gas energy do we really have left? To answer that question we must include a largely overlooked form of natural gas that may be the most important energy resource in history.
Gas
Hydrates
, or more exactly, methane hydrates are almost certainly the newest energy form yet discovered. Gas hydrates have been known to industry for some time because they have a habit of forming ice-gas globs that can plug up the works in gas pipelines. But gas hydrates weren’t discovered in nature until the mid 1960’s.
Gas hydrates are a form of
Clathrate
. Simply stated, they are molecules of methane gas locked within a frozen water structure.
Gas hydrates resemble a snow cone in appearance and texture. But if you plop a spoonful of gas hydrate onto a plate and expose it to a lit match, it will burn; flammable ice.
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Methane locked in ice crystals burns. The inset shows a molecule of methane, shown in green, surrounded by water molecules, shown in red.
(Photo Courtesy of US Office of Naval Research)
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Geologists have discovered huge volumes of natural gas energy in the form of hydrates. The research is ongoing but scientists around the world agree that available energy from natural gas hydrates is far greater than all other forms of natural gas energy combined.
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Natural gas energy deposits in the form of gas hydrates are located all over the world just off the coast of every major continent as indicated in this map from Oak Ridge National Laboratory. Deposits are also found in polar regions.
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According to a
U.S. Department of Energy Gas Hydrate Analysis
, U.S. gas hydrate resources alone exceed 200,000 TCF (Trillion Cubic Feet). And global natural gas energy from gas hydrates may well exceed 500,000 TCF.
More recent data suggests, however, that actual global gas hydrate resources may be more in the range of about 25,000 TCF to 135,000 TCF as indicated in this
Gas Energy From Methane Clathrate
discussion from Wikipedia (Note: For consistency and simplicity sake I translated the Wikipedia numbers from metric scientific notation measurements into the TCF figures above).
That still far exceeds known, proved natural gas energy reserves of about 6,000 TCF. It also far exceeds the total known natural gas energy from all sources other than gas hydrates of about 13,000 TCF.
To say that gas hydrates are a vast natural gas energy resource is a vast understatement.
Though recovering and bringing this form of natural gas energy to market will prove challenging, it is a challenge that must be met. The incredible size of these deposits holds the promise of energy supplies that can last well beyond this century.
Beyond the promise of continued plentiful energy supplies, the incredible volume of natural gas energy in the form of gas hydrates has revealed a problem that could be globally devastating.
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Methane is a highly efficient
Greenhouse Gas
. In fact, it is over 20 times more efficient than carbon dioxide. Whether global warming is a good or bad thing continues to be debated. Most scientists do agree on the notion that, for the most part, the less we interfere with natural processes, the less harm we are apt to do to the environment.
It could be, however, that we may need to ‘interfere’ with certain natural processes involved with gas hydrates. A growing body of scientific evidence is bringing many researchers to the conclusion that natural gas energy in the form of oceanic gas hydrates may have a strong influence on global warming patterns.
Historical influences may have been so great that minor global warming trends of the past have, because of gas hydrate involvement, turned into runaway global warming periods that led to several periods of mass extinctions.
Scientists have considered a number of theories to explain why our planet has gone through mass extinction cycles. These cycles are much more than academic curiosities. Because they have happened on more than one occasion, there is a very real concern that they could happen again. And there is reason to believe that we may be at the beginning of similar cycle.
Super volcanic activity and meteor strikes have been given a lot of publicity as serious candidates as world killers. But the media has paid scant attention to the possible involvement of gas hydrates.
Since methane is such an efficient greenhouse gas, it follows that, if a large volume is released in a relatively short time, it could cause runaway global warming. Runaway warming would upset the balance of the ecosystem worldwide causing yet another mass extinction. And increased atmospheric methane levels have been found in ancient ice samples that have been dated to the same periods of mass extinctions. But where would all of this methane come from?
Most gas hydrate deposits form in deep, cold areas under the ocean floor. They tend to form as a thick layer of gas hydrate that contains a free gas zone beneath it. These areas form gas blisters of sorts. During natural, periodic warming trends the gas hydrates can warm and start thinning. They reach a point where the gas hydrate layer thins enough so that it can no longer contain the free gas pocket beneath it. It ruptures and releases millions of cubic feet of methane into the atmosphere.
As detailed in the
U.S. Department of Energy Gas Hydrate Analysis
, these areas can be over a thousand feet in diameter and leave depressions over a hundred feet deep. There are many thousands of these gas blisters on the ocean floor and many of them have started rupturing in just the last decade.
What can we do about it? It may be that we need to shift much of our global natural gas energy production to the ocean floor to harvest the pressure zones under the hydrate fields to prevent those sudden, massive releases of methane.
The chemical symbol for methane is CH4 (one carbon atom and four hydrogen atoms). When methane burns (or, more correctly, oxidizes) it combines with oxygen and produces heat. The exhaust from methane combustion is H2O (water), and CO2 (carbon dioxide).
Since carbon dioxide has less than 5% of the green house capability of methane, it follows that harvesting methane from the ocean floor, and using it to run the engines of civilization, could reduce future global warming trends significantly.
The best course of action isn’t known yet and much research needs to be done. Don’t worry too much, though, the world isn’t likely to end soon because of methane induced warming.
The most notable extinction, the
Permian-Triassic Extinction
took place over many thousands of years. Still, the evidence suggests that we can do something to prevent runaway global warming and at the same time recover a valuable natural gas energy resource.
One last point on gas hydrates. Methane hydrates appear to be generated by bacterial action. Recent research has shown that possibly 90% of the gas hydrate deposits in the world are the result of biological metabolism. That almost certainly means that gas hydrate deposits are renewable and oceanic methane farming could be the next great agricultural frontier.
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