Sunday, May 10, 2009

Let's party 'til the helium's gone

Helium is fun. When you fill balloons with it, they defy gravity. If you fill your lungs with it and then talk, you'll probably sound like one of The Chipmunks, a fictional all-animal singing group whose voices were sped up to give them a high-pitched, squeaky quality. Children, of course, love to have helium-filled balloons floating around their birthday parties; and adults like them, too, for weddings, anniversary parties and even for adult birthday parties.

The fun qualities of helium, however, stand in stark contrast to its deadly serious applications which are increasingly endangered. For although helium is the second most abundant element in the universe--hydrogen is the first--it is exceedingly rare on Earth; and, our cavalier attitude toward its use threatens tasks that are critical to maintaining our complex society.

Unlike, say, rubber which is a compound that can be synthesized using other substances, helium is an element. Therefore, it cannot be synthesized from other more abundant elements or molecules. A small amount of helium is produced in nuclear reactions, but the cost of extracting it is exceedingly high, and no commercialization has been attempted. Essentially, we're stuck with what we have--that is, until it runs out.

Perhaps the most important uses of helium are in its liquid form. Helium is the gold standard for low-temperature processes and research. In its liquid state it can reach temperatures as low as -459 degrees F or almost absolute zero, the temperature at which all molecular motion would cease. (No one has ever succeeded at reaching absolute zero, and theoretically, it is thought to be impossible to achieve.)

Liquid helium simply has no equal. Currently, it is critical in magnetic resonance imaging, a non-invasive diagnostic procedure that allows physicians to obtain images of many tissues and organs, notably the brain, that are superior to those provided by X-rays. This is an application for which superconductivity is critical, and very low temperatures are essential for optimum results. In addition, superconductivity is an area of intense ongoing scientific research for ways to reduce electricity losses in the electrical grid and increase the efficiency of power storage and electric motors.

Perhaps the most visible use for helium beyond filling balloons is that in filling airships or blimps. More exotic uses include rocketry where helium is used to flush out fuel tanks and then prepare liquid oxygen and hydrogen for those tanks. Helium is preferred for this work and for blimps because it is nonflammable and inert, that is, under ordinary circumstances it doesn't chemically combine with other elements.

These two properties also make it ideal as a shielding gas for certain types of critical welding. Preventing normal atmospheric gases from reaching a weld can enhance its strength and quality. The same properties make helium critical for producing silicon wafers, the basis of today's electronic world.

In addition, helium is used for heat transfer in gas-cooled nuclear reactors, and it is used to check for leaks in critical equipment because it flows more readily through such leaks. There are many more uses, both industrial and scientific, but you get the idea.

The vast majority of helium reserves and production are located in the United States. The only economical way to obtain helium is to separate it from natural gas. Helium is produced in the Earth's crust as a product of radioactive decay, primarily of uranium and thorium. In most cases the helium migrates to the surface, rises into the atmosphere and escapes into outer space. But some of the helium is trapped in natural gas reservoirs which are the richest source available. (Helium occurs in the atmosphere, but at far too low a concentration to be economically extracted.)

Unfortunately, the fate of helium supplies is inextricably linked with natural gas supplies. No one extracts natural gas for the helium content since the helium concentration is no more than 7 percent, and that's in the very richest fields. And, very few fields in the world have enough helium in them to make it worth extracting. At the rest of the world's natural gas fields helium is simply removed along with other impurities and vented into the atmosphere.

Since natural gas is a fossil fuel, its days are numbered. No one knows for certain when production will peak and then begin to decline though some estimates put it around 2030. Regional peaks may occur sooner. Helium is expensive enough to be shipped worldwide, and so its extraction may peak with that of natural gas worldwide, though the peaks of the helium-rich fields that produce it will be the crucial factor.

What should we do? One obvious strategy is to recycle helium. This is difficult and expensive to do, and so only sufficiently funded research laboratories that use a lot of helium bother to do it. Most of the world's helium once it is used is simply vented to the atmosphere where it eventually floats up into space. Certain uses such as in party balloons could be banned or heavily taxed. But as demand drops from such a restriction so would the price causing other users in all likelihood to use more.

Recycling could become mandatory. But this would rule out many current applications or make them so prohibitively expensive that the result would be the same. A very high across-the-board tax could make recycling more attractive, but would certainly bring resistance from heavy industrial users. And, such a tax would have to be applied worldwide to be effective.

Another strategy is to find substitutes. There are already substitutes for some uses such as the use of argon in welding. We could go back to using hydrogen in airships and balloons, but that could easily result in another Hindenburg. For processes that require temperatures below -429 degrees F there is simply no substitute.

The problem with helium is not an isolated one. The way we've used it and become dependent on it mirrors the way we've become dependent on other rare and finite resources. Instead of building sustainability into our systems by making sure the component processes and materials are sustainable, we seek the immediate benefits provided by finite resources without a thought about ultimate consequences. The response to this concern is almost always that we will find substitutes when it becomes necessary in the quantities we need at the prices we can afford. With 6.7 billion people on the planet and growing, and a rapidly increasing proportion of that number gaining access to the modern industrial way of life, can we be certain this is how things will turn out?

I had an exchange not too long ago with a professional in the computer industry. Disbelieving my assertion that in the next decade we could run short of indium and gallium, two key metals in electronics, he insisted that these metals simply can't be scarce because they have already been and continue to be put into billions of electronic devices. So far, the world's policymakers have adopted the same line of argument with helium, leaving all of us essentially to blow up a few more balloons and party 'til the helium's gone.

3 comments:

Professor Chris Rhodes said...

Nice article, Kurt.

I have written in the science magazine Chemistry and Industry, on Scitizen (http://www.scitizen.com/stories/Future-Energies/2008/09/METALS-SHORTAGES-/) and also on my blog (ergobalance.blogspot.com/) about "Metals Shortages" and yes, the electronics industry is due for collapse in the wake of "peak" gallium and indium. There are potential organic conductors but only at the research stage and they are very unlikely to come-in within the 5 - 10 years forecast for peak Ga and In.

Helium too, is an essential cooling fluid (in liquid form) for superconducting magnets, e.g. in MRI applications...

and then you come in with the punch-line that it is peak-(methane) GAS that is the real threat, and in about 15 years!

Yes, we really are in for some changes and the happiest solution I can come up with, is a relocalisation of society, and fed by regenerative agriculture - i.e. that depends far less on oil and gas for fuel and chemical fertilizers.

But that too will take something like 50 - 100 years in totality.

Regards,

Chris (Rhodes).

Jan Steinman said...

Hi Kurt. I'm an amateur welder, meaning I do it for love ("amore") rather than money.

Helium is typically used in combination with argon for stainless steel and exotic metals. It is generally 25% or less of the total gas in these unusual applications. It is used for its high thermal conductivity, which enhances welds, though welds in any material can be done with pure argon if necessary.

But the vast majority of welding is done with CO2 and argon, including almost all non-stainless steel and aluminum welding.

I'm not at all trying to be argumentative here, just pointing out that the use of helium in welding is a small portion of a small portion, and that it is a convenient, not a necessary, gas for welding applications.

Kurt Cobb said...

Chris,

Thanks including the link to your metal shortages piece. People have asked about other critical resources including lithium which I know you did a nice piece on as well.

Jan,

Always appreciate your comments, in this case, fleshing out a little more helium's use in welding. It's good to hear from people who have hands on experience with things I write about. As for argon, perhaps you missed the one sentence I wrote about argon as a substitute for helium.