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August 03, 2010

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Shrinking helium reserves may threaten more than kids’ play

Jan. 5, 2008
Courtesy Washington University in St. Louis
and World Science staff

Helium, the el­e­ment that lifts things like bal­loons, spir­its and voice ranges, is be­ing de­plet­ed so quickly that the world’s larg­est re­serve of it is ex­pected to run out by 2015, sci­en­tists say.

Courtesy Washington University in St. Louis

The element that lifts things like balloons, spirits and voice ranges is being depleted so quickly that the world’s largest reserve—in Texas—is expected to run out of it by 2015, scientists say. This would deflate more than the Goodyear blimp and party favors. Its larger impact is on science and technology, according to Lee Sobotka of Washington University in St. Louis. “helium’s use in science is extremely broad, but its most important use is as a coolant,” said Sobotka, a specialist in nuclear chemistry and physics who collaborates with researchers at several national laboratories. Larger helium consumers, such as these, generally are equipped to recycle it, Sobotka said; not so for many smaller-scale users. Yet “helium is non-renewable and irreplaceable,” as it can’t be manufactured in significant amounts, Sobotka said. “All should make better efforts to recycle it.” helium’s applications, he added, include nuclear magnetic resonance, mass spectroscopy, welding, fiber optics and computer microchip production. NASA uses large amounts to pressurize space shuttle fuel tanks. Drift away The helium on Earth has built up over billions of years from the decay, or disintegration, of the natural elements uranium and thorium, Sobotka said. The process occurs in super-slow motion, he added. For example, the uranium variant, or isotope, uranium-238 is particularly important for helium production. In Earth’s entire life span, Sobotka said, only half of the uranium-238 atoms have decayed, each yielding eight helium atoms. As uranium and thorium decay, some of the helium is trapped along with natural gas deposits in certain geological formations, Sobotka said. Some of the produced helium seeps out of the Earth’s mantle and drifts into the atmosphere, where there is about five parts per million of helium. This helium, along with any let into the atmosphere by users, drifts up and is eventually lost to 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.” Nuclear reactors can make some helium, but not nearly enough, he added. Unlike any other element, ordinary helium, which contains two protons and two neutrons, becomes a liquid below the temperature 4.2 Kelvin. That’s just four celsius degrees above the lowest temperature possible, called 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 helium supply lies in a reserve outside Amarillo in the Texas Panhandle. It’s an area 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, Sobotka said. A rebel, a loner Both hydrogen and helium, the first two elements on the Periodic Table of Elements, are abundant in the universe (about 92 percent and about 8 percent of the atoms, respectively). But helium is rare on Earth. That’s because helium is a rebel, a loner that doesn’t normally combine with other atoms, as hydrogen does, Sobotka said. “It’s the most ‘noble’ of gases, meaning it’s very stable and non-reactive for the most part,” Sobotka said. Elements combine by sharing electrons, the subatomic particles that carry electric charge. But helium is “a very tightly bound atom” that clings closely to its electrons, preventing such partnerships, he explained. In addition to the Texas panhandle, helium can be found in small regions of Colorado, Kansas and Oklahoma, Sobotka said. It’s 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 in 30 years. Liquid helium costs about $5 per liter, having gone up more than 50 percent over the past year as demand gradually outstrips the supplies, he said. He cited the withdrawal of some companies from the marketplace, and the emergence of others not yet in production, as the driving force behind higher prices. 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 a repeat of the 1937 Hindenburg tragedy, in which a German airship burst into flames. 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, Sobotka continued: 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.” Laboratories worldwide could make better attempts at conserving helium, he said. 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.”