The coming scarcity of the noble gas Helium has been the topic of a few media articles recently, for example the one by John Timmer from Ars Technica (who also was of great help during my preparation of the interview below). The basic idea comes from Robert Richardson who got the 1996 Physics Nobel for discovering suprafluidity in, yes, Helium. His lecture at the Lindau Nobel Laureate Meeting attracted a great deal of attention, precisely because no one really had ever heard of that problem.
Helium is, essentially a non-renewable resource that is, while being the second-most abundant element in the universe, comparatively scarce on earth. The main source is alpha decay of certain unstable isotopes in minerals, and as you might imagine, that’s a rather slow process. There are several cryogenic applications like high-end NMR spectrometers that won’t run without Helium, so there is no easy replacement. On the other hand, there are huge amounts of helium wasted every day because the gas is kept artificially cheap.
I met Professor Richardson at the Lindau conference and he was kind enough to answer a few questions about the looming resource crisis, it’s causes and possible solutions.
Professor Richardson, when did you first recognize Helium as a resource issue?
Richardson: About 15 or 20 years ago, because there is only so much Helium in the world. There are two sources of helium in the world. One is the sun. Helium was first discovered in the sun. The flux of alpha particles from the sun results in an equilibrium saturation of five parts per million in the atmosphere, and the recovery of helium from the atmosphere will be very difficult and expensive because of the low concentration. Another source, and indeed the primary source of helium is rocks, granite. It contains uranium and Radium that produce helium by alpha decay. In the 19th century the alpha decay was the principal evidence for the age of the earth, and the exact age of the earth is 4.7 billion years. And the helium in natural gas formations accumulated through alpha decay over those 4.7 billion years. And the problem is, we will soon dissipate our helium.
By using it up?
Well, there are two issues: The rich wells are in the USA, they contain up to 2 % helium within the natural gas. But the United States decided to sell their strategic helium reserve five years ago, driving prices down. And second, the rest of the helium in the U.S. will last only 25 years at current usage.
Is there any replacement?
For cryogenic instruments that need liquid helium that boils at four degrees Kelvin there is no replacement. Superconducting magnets, MRI machines, high-field magnets in nuclear magnetic resonance in about every chemistry department depend on a reliable source of liquid helium. And there is no replacement. There are other uses of helium for which there are replacements. In the U.S. helium is used for welding metals, whereas in Europe argon is used. Argon is roughly one percent of the atmosphere rather than 5 ppm. But the government policy in the US has fixed helium at a price that is ridiculously cheap. Frequently it’s less expensive to use helium than argon, and that is insane.
What you are saying is that helium should be far more expensive.
Yes. It should be treated as a precious commodity rather like just another gas that will last forever. There is no chemical process available to produce Helium.
And nuclear fusion?
Well, maybe in a thousand years or something. It is at least 50 years away. I don’t hold my breath.
Are there resource management strategies in place?
Helium is just too cheap. For instance, NASA uses about 30 percent of the helium for purging rocket engines. They use liquid helium to wash out the fuel, hydrogen and oxygen, out of the rocket engines, and they don’t bother to recover it, because it is too cheap. If helium became a hundred times more expensive, they would use shrouds to recover it.
Wouldn’t far higher helium prices hurt scientists that use cryogenic equipment?
Yes, it would. But they will be able to do their science only for the next 25 years otherwise. The clock is already ticking. The strategy I propose is treat it as a rare gas, a precious gas and have it forever.