Myth or Myopia

I’ve had it! I just read an article about nitrogen generators for laboratory applications that made some outlandish claims to justify their use.

Now don’t get me wrong. I have nothing against laboratory gas generators even though I was raised in an industrial gas neighborhood and recognize that I am somewhat biased. In certain cases, generators are fine — and sometimes even better and, perhaps, more economical than gas cylinders.

But what ticks me off is the way some gas generator companies try to position their products. Throughout the years, we’ve all heard the horror stories that make cylinders seem the most dangerous item in the lab. Rather than pointing out the advantages in the performance and/or purity arena — or their economics, based on cylinder costs - some generator advocates attack cylinders as a safety risk and claim that they are potentially dangerous.

That attitude is very hard for me to digest, and very annoying. Some even conjure up images of a cylinder flying through a wall when a valve is sheared off. Give me a break! When was the last time anyone heard about that happening, or of an accident caused by a cylinder exploding (other than in a catastrophic fire)?

Cylinders Have an Impeccable Safety Record

The gas industry — and laboratory personnel — have been handling cylinders for nearly a hundred years. And most companies follow the safety regulations concerning cylinders advocated by OSHA and the CGA, which minimize the possibility of any type of accident.

Misinformation Hits Below The Belt

The article I read, which set off this rebuttal, takes misinformation to a new low level altogether. It avoids the whole story, and fails to provide a reasonable apples-to-apples cost analysis. The article in question (published in a highly respected industry trade book) attempts to prove that cylinder nitrogen is unfriendly to the “green” concept.

The article compares the cost of generator - produced gaseous nitrogen (including the energy consumed) with the total cost of producing cylinder nitrogen via an air separation plant. A completely ludicrous comparison—as if the air separation plant was used only to produce liquid nitrogen for eventual use as cylinder nitrogen. If that were true, the author would be correct. But the cylinder part of the total nitrogen produced in an air separation plant is only a small fraction of its total production.

The author of that article did not bother to take into account that the bulk of the nitrogen from an air separation plant is used for applications that require nitrogen’s cryogenic qualities, such as freezing food.

Let’s see you make an economical lab generator to do that!

Nor did that author mention that the air separation plant also produces huge amounts of oxygen, as well as argon, neon, krypton, and xenon. In other words, he avoids the issue of multiple products AND economies of scale.

Come on guys, get off it! Tell the whole story and stop trying to sell generators by making people feel guilty about energy conservation or preserving the environment.

Generators Have a Viable Place in the Market

As I stated earlier, there are many instances where a generator is preferable over cylinders to deliver nitrogen used in a laboratory. And, yes, there are times when it is more economical and more efficient to use generators rather than cylinders—including handling and storage. Aside from these parameters, however, there are technical considerations that often may be more important.

Question: How do you know the nitrogen generator is working correctly? Most likely you don’t. And when the manufacturers of generators state that a generator produces 99.999 percent nitrogen, how do they verify this? It’s a loaded question— and I won’t attempt to answer it here.

Where Does the Argon Go?

During my participation in the many trade shows we attend, I asked three different generator companies how they verify the purity of the product that comes out of their generators. To date, not one has answered. They show this nice permeation device, illustrating that they put air in one end, and the oxygen and moisture slip through the membrane so that only nitrogen comes out the other end.

First, no one will tell me what kind of analyzer they use to check the purity of the N2 coming out. I suspect that they just stick an oxygen analyzer at the end, and ASSUME, therefore, that everything that’s not oxygen is nitrogen. Pray tell, where does the argon go?

As I stated twice earlier, generators certainly have a place in the laboratory. But so do cylinders. Each has its own set of properties that make it the better choice under certain conditions.

I believe that pointing up these positive characteristics is the way manufacturers should be marketing their products, and they should stay away from the practice of knocking the other guy’s product needlessly. Don’t we get enough of this every day during political campaigns? And who among us wants to be painted with that brush?