Friday, October 19, 2007

Lighter Than Air

If you ever want to stump someone at a party, particularly one decorated with balloons, ask them where we get helium. And if someone says, "The Sun," they'd only be half-right. Although it's not widely advertised, most of our current supply of the gas is derived as a byproduct of natural gas production, especially from the helium-rich gas fields of the US mid-continent. Last Friday's broadcast of Science Friday on NPR included a short segment on the growing global shortage of helium, and some of its consequences. This isn't only important to balloon sellers and blimp operators. And while the current shortfall is related to temporary production problems in the US, Middle East and North Africa , it remains to be seen whether new international supplies can offset the natural depletion of our current sources.

Although most of the helium on earth is found in the atmosphere, it is present there in such low concentrations (roughly 5 parts per million) that it is uneconomical to extract it from the inert gases produced at air separation plants. Natural gas from certain fields contains much higher concentrations, ranging up to 8%, or 15,000 times higher than the atmosphere. The Federal Helium Reserve near Amarillo, TX, which dates back to the 1920s, is the linchpin of global helium distribution. It gathers the helium-rich streams from gas fields and their associated processing facilities in the region and stores the crude helium for later refining and sale, at volumes averaging 2 billion cubic feet per year. At one time, this complex was the largest helium source in the world, though commercial facilities have since surpassed its output, though not its storage capacity.

So what does this have to do with energy, other than as a trivia question? Helium itself has relatively few energy applications, beyond its use in superconducting magnets and energy storage, and as a heat transfer medium in advanced nuclear reactors. There's even an exotic wind turbine design that relies on helium's buoyancy, though it may never get off the drawing board.

The bigger issue here is the linkage between the helium and natural gas businesses, which leaves global helium production at the mercy of natural gas market trends. Many of the helium-rich US gas fields are mature, and so US production will eventually decline. Even before then, however, the ongoing sale of the Federal Helium Reserve stockpile could make the global market for helium as volatile as the oil market. As the NPR segment discussed, LNG production outside the US will become an increasingly important source of helium, until the point at which global natural gas production reaches a peak, bringing about Peak Helium, as well. That doesn't sound as ominous as Peak Oil, unless you're in an industry that depends on helium in your manufacturing or operations.

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