It
was a spring evening in early May when hundreds of people descended on a landing
field in Lakehurst, New Jersey for their first glimpse of a trans-Atlantic
airship. There had been storms earlier in the day, but by 7 p.m., the storms
had passed and the weather was deemed suitable for the landing of the
Hindenburg, a German zeppelin – a sausage-shaped balloon filled with
lighter-than-air hydrogen gas. The airship approached and circled before
hovering about 400 feet over the landing site. Ropes were dropped to moor the
zeppelin and pull it closer for passengers to disembark. Shortly after the
ropes were dropped, a fire started near the rear of the airship. The outer skin
of the zeppelin was breached and the hydrogen began to escape and mix with
oxygen in the air, making an explosive mixture. The zeppelin quickly exploded
in flames. Thirty-six passengers and crew were killed, and newsreel footage of
this disaster has become iconic.
The Zeppelin LZ 129 Hindenburg explosion, May 6, 1937 in Lakehurst, NJ. Public domain image, courtesy Wikipedia.
Hydrogen
is highly explosive, so why did the German’s use it instead of non-explosive
helium in their zeppelins? Because at that time, the U.S. was the world’s main
source of helium and tensions with the Nazi government led to an embargo of
that critical resource. The U.S. is still the world’s leading source of helium,
but you may have seen news reports about a possible shortage in the near future
with rapidly increasing prices. Where do we get this gas and why is it so
important?
Modern blimps use helium instead of hydrogen for safety reasons. Courtesy, D. Jensen and Wikipedia.
Helium,
element #2 on the Periodic Table, is the second most abundant material in the
universe, just after hydrogen. But it is rare on the Earth because it is so
light, and once it escapes into the atmosphere, it quickly leaves the Earth
forever. It is therefore a non-renewable resource, like oil. Almost all of the
Earth’s helium supply was slowly produced by the radioactive decay of uranium
and thorium, both present in small amounts in crustal rocks. Because it is a
gas, it tends to be trapped where natural gas is also trapped, so most of our
helium is taken from natural gas wells in the Midwest (Oklahoma, Texas, Kansas)
where it makes up a few percent of all the gas coming from the wells. Back in
the 1920’s, the U.S. built plants, pipeline, and underground storage facilities
near Amarillo, Texas to extract and store the helium, thus establishing the National
Helium Reserve (NHR).
Helium
has many unique properties that make it valuable. It stays liquid even near
temperatures of absolute zero and, for this reason, is used for deep cooling of
superconducting magnets like those used in MRI machines, super-colliders, and
high-speed bullet trains. It is used in the manufacturing of computer chips and
optical fibers. One of its biggest uses is in arc welding and high-tech plasma
coating applications where its main job is to keep more chemically reactive air
away from the surfaces being welded or coated. In sum, helium is a critical
resource for many of our highest tech industries and scientific research.
MRI machines are the largest single user of helium in the world today. Courtesy, KasugaHuang and Wikipedia.
By
1995, the U.S. had huge reserves of helium stored in the NRH, but it was more
than a billion dollars in debt. So Congress passed a law in 1996 directing the
liquidation and sale of the reserve to private industry by 2014 to recoup the
costs. This law was controversial at the time, but has become more so because
it was discovered that the formula used to sell the helium was well below
market price and encouraged waste. By 2014, the NRH will be out of money, and
whatever helium remains in the storage reservoir will not be accessible. This
sudden disruption in the supply of a critical resource will likely lead to price
spikes; in anticipation, prices have already jumped significantly. The U.S. Senate
is now considering a bill (S.2374) to maintain the reserve for an additional 15
years to ease the transition to private suppliers. Other countries have started
to look for their own supplies.
Out
of curiosity, I checked to see if helium was present in the Marcellus shale gas
being produced locally. I could find nothing definitive, but if helium prices
do spike, you can expect to see it becoming a bigger issue.
Originally published in the Bloomsburg Press Enterprise on May 22, 2012.
No comments:
Post a Comment