Helium shortage: When it’s gone, it’s really, truly gone

Article By : Bill Schweber

Helium is the ultimate non-renewable resource; what will we do when there is no more helium left for scientific and engineering designs?

We hear a lot about shortages these days, with good reason. The list includes ICs, baby formula, rare-earth mineral, lower-cost energy sources, food, housing, skilled employees…it’s a long list. While I suspect some of this noise about shortage is to get attention and thus more funding—it’s often interesting to see who is making that noise—many of these shortage concerns are genuine. In some cases, the needed items are simply not available, or supply and demand have made them available but only at many times their customary price.

But there’s one important shortage that is getting worse while only getting attention in niche communities: the present shortage and eventual total disappearance of elemental helium. And that worries me a great deal. While technical and geopolitical issues related to capturing and extracting helium have sharply reduced the supply (hopefully temporary), it’s that total loss of helium as a resource which scares me.

How is this possible? Unlike other elements and materials that can be recycled and recaptured after the original use (admittedly, often at a significant cost), helium is not recoverable, period, end of story. Once it escapes or is released into the atmosphere, whether from a scientific project or birthday balloon, it will continue rising until it escapes into space, making it the only truly unrecoverable element.

What’s the connection between the many facets of “analog” and helium? If you look at the list of areas which require helium, many of them are analog-centric applications, including sensors, scientific experiments, supercooling, MRIs, lasers, thermal imaging, and inert arc welding, to cite just a few. For some of these, there may be substitutes such as argon and neon, but for many, helium is the only element which will work. Some leading research projects that need large qualities of helium have already had to cut back due to inadequate or erratic supply even at much higher costs.

There are two ironic aspects to the helium story. The first and obvious question is: “where does helium come from?” Mostly, helium is a radioactive decay product of uranium and thorium, a fact that would probably scare many people, if they knew (Figure 1). The results of this reaction are alpha particles containing two neutrons and two protons. These small fragments then collect electrons from their surroundings and form helium, which later makes its way up through the crust of the earth and all the way up to space.

Figure 1 Helium is a byproduct of the natural radioactive decay of uranium located deep within the Earth. Source: American Chemical Society

Noble gases which exist in the atmosphere in very low concentrations, such as neon, can be extracted via complicated processes, while gases such as oxygen and hydrogen can be obtained from air or water. But very unlike those gases, helium capture is a byproduct of oil and gas drilling and is found under the Earth’s crust with other natural gases.

Fortunately for us, some of that helium-4 gets entrapped and mixes with the natural gas found under layers beneath the earth’s surface. The helium-4 is then extracted from the ground with wells drilled to release it. The amount of helium gas found in the natural gas varies from almost negligible to 4% by volume.

The natural gas containing helium-4 then undergoes a process of cryogenic distillation to obtain the helium particles. Commercial helium is sold in two grades: so-called “balloon-grade” and ultra-high purity grade for scientific, medical, and industrial uses. Much of the helium produced in the United States is stored in the United States. National Helium Reserve is located deep underground in Amarillo, Texas—close to dominant helium sources in the Texas panhandle and Kansas—but this reserve has had some serious technical and administrative issues in the past few years.

The radioactive decay deep below the surface as the source of helium is the first irony. The second one is that scientists and astrophysicists believe helium is the second most-abundant element in the universe, after hydrogen (even our Sun is 25% helium). Either way, helium’s presence deep under the Earth’s crust makes it difficult to “harvest,” while its existence in space makes it unreachable, at least for now.

Transporting helium is also a challenge, as its molecules are so small that they can escape through many seals and diffuse through some “solid” material; that’s why latex balloons lose their helium, but mylar doesn’t’. It can be transported as a highly pressurized gas at normal temperatures or as a cryogenic liquid in special trucks and pipes—obviously, not a trivial situation. In many liquid and gaseous applications, the helium is used in a closed loop and any boil-off can be captured, but this requires a costly and complicated arrangement.

There are even special railroad tank cars with many smaller cylindrical tanks—rather than the one larger vessel of conventional tank cars—for transporting pressurized, non-cryogenic helium (Figure 2). These cars, which have an empty (tare) weight about twice that of a conventional single-tank car, are used to bring helium to high-volume users such as NASA, Space X, and other launch sites. I doubt if people getting party balloons realize how rare and unique helium is, and how truly finite it is as a long-term resource.

Figure 2 The extra-heavy-capacity railroad cars, which mount an array of cylinders on a flat car, are used to transport gaseous helium under high pressure to high-volume users.

Have you ever used helium for an informal science project? Have you ever had to use it in a formal engineering design? Did you need to consult with specialists to guide you on how to do so? Are you worried about the eventual disappearance of helium? Do you think the use of helium for party balloons and similar use cases should be discouraged or even banned, given its undeniable uses and irreplaceability? Or is this helium “shortage” and eventual disappearance really nothing to worry about?

This article was originally published on Planet Analog.


Leave a comment