3fD - Helium is running out - who cares?19 January 2014
We recently had first hand experience of Helium use - Cryogenic Coolers.
Oxford Instruments have been working on a range of 'dry' Cryostats and they engaged us to work on the mechanical elements. Most Cryogenic coolers reach close to absolute zero by using Helium Liquid. Helium allows for the lowest attainable temperatures to be reached.
In fact, cryogenics is the largest single use of Helium, absorbing about a quarter of production, particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners.
Helium is stored in large aluminium or stainless steel tanks or dewars, ready to use on site in places nuclear research centres, different research laboratories, university centres, medical and biological applications.
But the Helium leaches out of these dewars and, if not used up, is lost. Once helium is released into the atmosphere, it is lost the Earth forever. So companies like Oxford offer a technology that doesn't utilise liquid Helium.
Oxford's Optistat Dry is cooled by a closed cycle refrigerator. The system is capable of cooling samples to Helium temperatures without the need for liquid cryogens. This provides significant benefits in terms of ease of use and running costs. And it doesn't use Helium.
So why do we care?
Helium is the second-lightest element in the Universe, and has the lowest boiling-point of any gas and is commonly used through the world to inflate party balloons. Its inert nature makes it safe to use.
But helium is also a non-renewable resource and the world's reserves of the precious gas are about to run out, a shortage that is likely to have far-reaching repercussions.
Scientists have warned that the world's most commonly used inert gas is being depleted at an astonishing rate. A law passed in the US in 1996 stipulates that the US National Helium Reserve, by far the biggest store of helium in the world, must all be sold off by 2015, irrespective of the market price.
The experts warn that the world could run out of helium within 25 to 30 years, potentially spelling disaster for hospitals, whose MRI scanners are cooled by the gas in liquid form, and anti-terrorist authorities who rely on helium for their radiation monitors, as well as the millions of children who love to watch their helium-filled balloons float into the sky.
Helium is made either by the nuclear fusion process of the Sun, or by the slow and steady radioactive decay of terrestrial rock, which accounts for all of the Earth's store of the gas. There is no way of manufacturing it artificially, and practically all of the world's reserves have been derived as a by-product from the extraction of natural gas, mostly in the giant oil- and gasfields of the American South-west, which historically have had the highest helium concentrations.
The Earth is 4.7 billion years old and it has taken that long to accumulate our helium reserves, which we will dissipate in about 100 years.
Liquid helium is critical for cooling infrared detectors, nuclear reactors and the machinery of wind tunnels. The space industry uses it in sensitive satellite equipment and spacecraft, and NASA uses helium in huge quantities to purge the potentially explosive fuel from its rockets.
The basic problem is that helium is too cheap. We used to value Helium as being strategically important because of its use in military airships. In 1925 the US established the National Helium Reserve in 1925 (known as The Helium Capital of the World). A billion cubic metres (roughly half of the world's reserves) are now stored in this cluster of mines, pipes and vats that extend underground for more than 200 miles.
But in 1996, the US passed the Helium Privatisation Act which directed that this reserve should be sold by 2015 at a price that would substantially pay off the federal government's original investment in building up the reserve. As a result of that Act, helium is far too cheap and is not treated as a precious resource. In short, it's being squandered.
It is so cheap that no one attempts to recycle it. Nasa, for instance, makes no attempt to recycle the helium used to clean is rocket fuel tanks, one of the single biggest uses of the gas.
What helium is used for
As helium is lighter than air it can be used to inflate airships, blimps and balloons, providing lift. Although hydrogen is cheaper and more buoyant, helium is preferred as it is non-flammable and therefore safer.
Helium's low boiling point makes it useful for cooling metals needed for superconductivity, from cooling the superconducting magnets in medical MRI scanners to maintaining the low temperature of the Large Hadron Collider at Cern.
Divers and others working under pressure use mixtures of helium, oxygen and nitrogen to breathe underwater, avoiding the problems caused by breathing ordinary air under high pressure, which include disorientation.
As well as being used to clean out rocket engines, helium is used to pressurise the interior of liquid fuel rockets, condense hydrogen and oxygen to make rocket fuel, and force fuel into the engines during rocket launches.
Helium can be used to estimate the age of rocks and minerals containing uranium and thorium by measuring their retention of helium.
The gas is used in solar telescopes to prevent the heating of the air, which reduces the distorting effects of temperature variations in the space between lenses.
And of course, cryogenics. The 'Helium Capital of the World' will run out in 2018, while the Earth is set to use up all its Helium resources within the next 20 years.
We need to value Helium, and recycle where possible. One way to ensure this would be to increase the cost, making recycling commercially viable. So next time you buy a Helium balloon for £5, have a thought what the real cost should be... experts say it should be closer to £100!
Source: New Scientist Magazine, Oxford Instruments