Gases & Instrumentation - March/April 2008

Helium Sources Float Away:

But Some Balloons Go Down

PAUL NESDORE, ASSOCIATE PUBLISHER/EDITORIAL DIRECTOR

H elium, although the second most abundant element in the universe, exists only in one part per

million in the earth’s atmosphere. This is unfor-

tunate because the characteristics of helium make

it an extremely useful gas. Because of the low con-

centration, it is not economical to extract it from air.

The only cost-efficient method is to obtain it from

natural gas, which unfortunately, is not a renewable

resource. Natural gas has been known to contain high

percentages of helium since Hamilton Cady and David

McFarland discovered this fact in 1905. Such sources

can contain from 4–7% helium.

The uses for helium are many: leak detection; MRI machines; deep sea diving; cooling superconductors; balloons and airships; welding; and optical fiber manufacturing to name a few.

So why the shortage (which is causing prices to skyrocket) and what can we do about it? As quoted by William J. Kroll in an exclusive interview with Gases & Instrumentation [see the January/February 2008 issue, “Executive Views: A Perspective on the World Gases Markets and Technology”], “Until companies find a natural gas field that’s rich enough in helium and make very significant upstream investments in field development, in natural gas processing or LNG production, there is little possibility of an economically viable helium recovery.”

So we know there’s a shortage. What do we do about it? Since we have to wait for new natural gas fields that are rich in helium to start producing more, there are measures that can and are being taken to be smarter about the helium we use.

Recently, Air Liquide conducted a Webinar on helium conservation. The suggestions for conservation ran the entire gamut. Comments by Air Liquid’s Bruce Beaton, Director of Cylinder Operations, focused on the supply chain. Some simple rules, while seemingly obvious, needed to be emphasized. For example, don’t order your helium days before you need it. Helium has a small molecule (one of its leak testing advantages) and valves leak. He recommends that transporting from fill plant to end-user should be accomplished in a single day. The second commandment is thou shalt

March/April 2008

not transfill from one dewar to another—this can result in a 40% loss Beaton says. Periodic checking of your entire system (piping, valves, regulators) is essential. As far as piping goes, Beaton suggests welded joints, not fittings. He also suggests fitting helium cylinders with RPV (pressure retaining) valves

Regarding welding, the suggestion is to look carefully at your application. See whether or not you can use a lower percentage of helium. Bryan George, the Packaged Gas & Technical Division Manager suggests for short arc stainless welding, using an alternative mix of gases that can reduce the mixture from 75–85% helium to 15–20% helium.

In the specialty gas arena, Rich McCandless, Air Liquid’s Business Development Manager for Specialty Gases, also points out some basics, like using up as much of the gas in the cylinder as possible (don’t change out at 500 psi). Another suggestion: for leak testing us a 50/50 helium nitrogen mix. For gas chromatographs, some models have a “gas saver mode.” Use it. And shut down any GC’s if they are not being used on a regular basis.

There are other approaches that are not conservation measures. Intertech Development ( www.inter-techdevelopment.com) is selling the idea of replacing conventional leak testing using customized mass flow leak test methods with sensors and eliminating helium altogether. The service is designed to address leak test requirements in the 0.01 sccm range.

And we still haven’t mentioned the ubiquitous party balloon; McCandless addresses this also. He cites, for example, two companies, Western Enterprises and Conwin Carbonic supplying balloon gas using a 60/40 helium/air mixture.

It was at this point, I wondered, with the Republican and Democratic conventions coming up, where are they going to get the helium for the balloons—until I realized—they want the balloons to drop, not rise. All they need is air. [Note that G&I will have an upcoming feature on an alternative to helium for leak detection.]