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Helium is drifting away.
Helium is applied broadly in
science and technology, from nuclear magnetic resonance to
computer microchip production and devices like this mass
spectroscopy apparatus.
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Generally the larger users of helium (He),
such as the national laboratories, have the infrastructure to
efficiently use and recycle helium, Sobotka said. The same cannot be
said of many smaller scale users.
Helium plays a role in nuclear magnetic resonance, mass spectroscopy,
welding, fiber optics and computer microchip production, among other
technological applications. NASA uses large amounts annually to
pressurize space shuttle fuel tanks.
"Helium is non-renewable and irreplaceable. Its properties are unique
and unlike hydrocarbon fuels (natural gas or oil), there are no
biosynthetic ways to make an alternative to helium. All should make
better efforts to recycle it."
Drift away
The helium we have on Earth has been built up over billions of years
from the decay of natural uranium and thorium. The decay of these
elements proceeds at a super-snail's pace. For example, one of the
most important isotopes for helium production is uranium-238. In the
entire life span of the earth only half of the uranium-238 atoms have
decayed (yielding eight helium atoms per uranium atom decay in the
process) and an inconsequential fraction decay in about 1,000 years.
As the uranium and thorium decay, some of the helium is trapped along
with natural gas deposits in certain geological formations. Some of
the produced helium seeps out of the Earth's mantle and drifts into
the atmosphere, where there is approximately five parts per million of
helium. However this helium, as well as any helium ultimately released
into the atmosphere by users, drifts up and is eventually lost to the
Earth.
"When we use what has been made over the approximate 4.5 billion of
years the Earth has been around, we will run out," Sobotka said . "We
cannot get too significant quantities of helium from the sun
- which can be viewed as a helium factory 93
million miles away - nor will we ever produce
helium in anywhere near the quantities we need from Earth-bound
factories. Helium could eventually be produced directly in nuclear
fusion reactors and is produced indirectly in nuclear fission reactors,
but the quantities produced by such sources are dwarfed by our needs."
Unlike any other element, helium 4 (two protons, two neutrons) becomes
a liquid below 4.2 Kelvin, just four degrees short of absolute zero.
When one puts an object next to liquid helium, energy is extracted
from the object, making it colder. The energy extracted from the
object vaporizes the helium. It is this helium vapor which, Sobotka
claims, should always be recaptured, to be recycled for future use.
Much of the world's supply of helium lies in a reserve in the Texas
Panhandle, better known for the locales of Larry McMurtry's novels,
such as "The Last Picture Show," and "Texasville," than as an
elemental factory farm.
Scientists haven't even approached mining helium out of the air
because costs are too prohibitive.
A rebel, a loner
Both hydrogen and helium, the first two elements on the Periodic Table
are very abundant in the universe (about 92 percent and about 8
percent of the atoms, respectively). Helium is rare on Earth while
hydrogen is abundant. The reason is that helium is a rebel, a loner,
and it does not combine with other atoms while hydrogen does. Hydrogen
is one of the two elements that make water. Under standard conditions,
there are no combined or molecular forms of helium.
"It's the most Noble of gases, meaning it's very stable and
non-reactive for the most part," Sobotka said. "Helium has a closed
electronic configuration, a very tightly bound atom. If you try to
extract an electron from helium, you pay a lot of energy to pull it
off. It's very high in ionization energy. It is this coveting of its
own electrons that prevents combination with other elements."
In addition to the Texas panhandle, helium can be found in small
regions of Colorado, Kansas and Oklahoma. It is marketed in Australia
and Algeria. And Russia has the world's largest reserves of natural
gas, where helium certainly exists. But there is no push to market it,
as, for the short term, supplies are adequate, though increasingly
costly.
Sobotka believes that Russia will be the world's major source of
helium in 30 years.
The price of liquid helium is about $5 per liter, having gone up more
than 50 percent over the past year because of what Sobotka calls "conventional"
economics. He cited the withdrawal of some companies from the
marketplace, and the emergence of others that are not yet in
production, as the driving force behind higher prices, and not (as yet)
a scarcity of the element.
Helium capture in the United States began after World War I, when the
primary use of the gas was for dirigibles. Because helium is
non-flammable, its use in balloons prevented another Hindenburg
tragedy. The U.S. government ran the helium industry for 70 years, but
since the mid-90s it has been in the domain of the oil and natural gas
industries.
Tell it like it is
"The government had the good vision to store helium, and the question
now is: Will industry have the vision to capture it when extracting
natural gas, and consumers the wisdom to capture and recycle?" Sobotka
said. "This takes long-term vision because present market forces are
not sufficient to compel prudent practice."
Helium plays second fiddle to marketing oil and natural gas, and much
of it is lost in a process that removes noncombustible nitrogen and
helium from the product of prime interest.
"When they stick that straw into the ground to suck out oil and gas,
the helium comes out, and if it doesn't get captured it drifts into
the atmosphere and is lost," Sobotka said. "Helium production is a
side industry to oil and natural gas, an endeavor that nobody wants to
lose money on."
Meanwhile, laboratories worldwide could make better attempts at
conserving helium. They can either use costly machines called
liquefiers that can capture, store and reliquefy helium on site, or
researchers can take captured helium in gas form, return it to the
company that originally sold it to them and receive a monetary return,
just as in a deposit on a bottle.
"We have to be thinking of these things," he said. "Up to now, the
issue often hasn't risen to the level that it's important. It's a
problem for the next generation of scientists. But it's incumbent upon
us to have a vision, and tell it like it is - a
resource that is more strictly non-renewable than either oil or gas."
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