Fears that the world is about to run out of helium are subsiding, but major technological advances are needed to ensure the long-term supply of this valuable, but elusive element, according to the Institution of Chemical Engineers (IChemE).
Most people know helium as an essential ingredient in party balloons, but since major underground reserves were discovered in the US in the early 1900s, helium has become vital to a wide range of industries and products including semi-conductors, space flight, medical devices such as MRI scanners, welding and even underwater diving apparatus.
But with 99.997 per cent of the Earth’s helium having escaped into space1 and underground supplies starting to diminish, chemical engineers are looking at new solutions to guarantee supplies of this valuable element for future generations.
One immediate challenge facing chemical engineers, and others, is to improve the recovery of helium from natural gas. Since the 1990s it has been known that helium can be produced when natural gas is liquefied, but around half is lost during gas production processes.
Richard Clarke, a Fellow of IChemE and a consultant and writer on helium supply said: “As the conventional US helium reserves diminish this decade, it is critical that the best helium recovery technologies are brought into production in the natural gas industry. Helium that is not separated and stored at source is lost and remains out of reach.”
In fact, most of the Earth’s remaining helium is stored in the atmosphere – estimated at 3.8 billion tonnes – although it is difficult to extract due to low concentration levels.
Clarke continued: “Helium concentration levels in the air are low at just 5.2 parts per million. Another challenge for chemical engineers is to create a sustainable and economic supply of helium from the air.
“We are just beginning, but progress is being made with emerging technologies that can extract helium from air successfully. However, to meet the world’s helium needs of 30,000 tonnes per year from the air – using current technology – would require a fleet of gas plants as big and as energetic as power stations.
“Other solutions include recycling helium, developing new and alternative materials, and using helium more efficiently. Technology advances in some or all of these areas are needed in the years ahead to ensure that this mostly unseen component of modern technology is available for future generations.”
This latest assessment of the future supply of helium was published in tce (the chemical engineer) by co-authors William Nuttall – professor of energy at the Open University; Bartek Glowacki – professor of energy and materials science at the Department of Materials Science and Metallurgy, University of Cambridge; and Richard Clarke2.
The majority of terrestrial helium derives from the nuclear decay of uranium and thorium in the earth's crust. Most of the helium has diffused to the surface and escaped into the atmosphere over the last four billion years, but a small fraction has been trapped by impermeable layers of rock. Natural gas, consisting mainly of methane, also collects in such geological constellations, so that helium for commercial use is normally produced from natural gas, where it is a minor component with a concentration up to, but very rarely exceeding, about one per cent. Most helium reserves are held in the US, Qatar, Algeria and Russia.
Main uses of helium are
* Magnetic resonance imaging (MRI) – 21 per cent.
* Welding – 17 per cent.
* Semiconductors, optic fibres (heat transfer) – 14 per cent.
* Party (8 per cent) and weather balloons (5 per cent) – 13 per cent.
* Pressurisation and purging including rockets – 11 per cent.
* Cryogenic applications including physics research – 8 per cent.
* Controlled atmospheres including diving – 6 per cent.
* Leak detection – 5 per cent.
* Analysis including chromatography – 5 per cent.
1 Nuclear fusion and the helium supply problem. A.M. Bradshaw, T. Hamacher: http://www.sciencedirect.com/science/article/pii/S0920379613000690
2 Endangered helium – busting the myth by Richard Clarke, consultant and writer on helium supply and cryogenic process engineering; William Nuttall, professor of energy at the Open University, and Bartek Glowacki, professor of energy and materials science at the Department of Materials Science and Metallurgy, University of Cambridge.
For more information, www.icheme.org