Do you know the story of a gas you may use every day in your lab?
Helium has for decades been the reference carrier gas for laboratories and industrialists using gas chromatography (GC and microGC). This article will examine the obvious reasons for this choice. But let's go back a little bit to the origin of this gas so daily in the laboratory in order to understand also the challenges faced by repeated shortages and the explosion of its costs. Little by little, its use is now in question. A review of the fascinating history of this gas, its complex global market and the reasons why laboratories are now turning to hydrogen.
A gas spotted in space
Exceptional fact in the history of science: the helium was discovered in space long before being identified on Earth. On August 18, 1868, during a total solar eclipse in India, astronomers Jules Janssen (French) and Norman Lockyer (British) independently observed an unknown yellow ray in the spectrum of the Sun's chromosphere. Lockyer calls this new element "helium", from the Greek helios (Sun). Only more than 20 years later, in 1895, the helium was officially isolated on Earth.
Helium emission spectrum - Wave length nm
Earthly Origins and Limited Resources: A Slow-Motion Formation
Unlike hydrogen or oxygen, helium is not a human-scale renewable gas. On Earth, helium (isotope ^4He) is formed by slow radioactive decay of heavy elements, mainly uranium and thorium, present in the earth's crust.
This training takes millions of years. The helium then migrates to the surface and finds itself trapped in impermeable rocks, forming pockets often mixed with natural gas. Once released in the open air, its lightness makes it escape Earth's gravity and becomes permanently lost in space. So today, in a few decades, we are consuming a gas that has taken millions of years to form. You'll think about it by adjusting your split rate!
Helium ...and fossil fuels
Pure helium does not exist in the form of an exploitable deposit as is. It is extracted as a by-product of the natural gas industry. When a natural gas deposit contains a helium concentration considered cost-effective (usually between 0.3% and a few percent), it is separated during the natural gas liquefaction (NLG) process.
Therefore, helium supply is intrinsically linked to fossil energy extraction. Its carbon footprint is therefore very heavy, as it depends on petro-gas infrastructures, cryogenic purification (extremely energizing, helium liquefying at -269°C) and a very complex global transport.
Global Consumption: Key Market Figures
The global helium market is under constant stress. In 2023, world consumption rose to about Approximately 170 million cubic meters annually..
- Top Producers: The United States has historically dominated the market, followed closely by Qatar, Algeria and Russia.
- The French Context: France does not produce commercial helium. In 2023, French imports amounted to just over 6 million m3, mostly from Algeria (87%).
- Top Consumers: While analytical techniques and research use a significant proportion, the largest volumes are absorbed by medical imaging (cooling of MRI magnets, ~17% of the market), the semiconductor industry, and welding.
The Helium in GC and MicroGC: Performance and Safety
In gas chromatography, helium is the vector gas par excellence. Why such evidence in users of scanners such as those proposed by Chemlys ?
- Uncompromising Safety: Helium is an inert, non-flammable, non-toxic gas. There is no risk of explosion in the laboratory.
- Exceptional Performance: It has very high thermal conductivity (only hydrogen does better). This is a key feature for the use of TCD (Thermal Conductivity Detector) sensors, which equip the vast majority of microGCs. Small, it allows you to wait for good speeds in the column and obtain an excellent separation of components (beautiful chromatography) with very high sensitivity.
This is very well illustrated with van Deemter curves comparing the efficiency of the main vector gases in gas chromatography (GPC). Below: Evolution of height equivalent to a theoretical plateau (H) as a function of linear velocity (u) for three vector gases: nitrogen (N2, (blue)Helium (He, (red)) and hydrogen ((H2), (green)). Column efficiency is maximum when the H value is lowest.
- Nitrogen (N2) : Offers excellent efficiency at very low speed, but the loss of efficiency is abrupt as the speed increases, making it unsuitable for rapid analysis.
- Helium (He) : Serves as the optimal standard compromise, achieving peak efficiency at intermediate speeds.
- Hydrogen (H2) : Presents the flattest curve and a minimum offset to the right, allowing the use of very high gas flows (for much faster analysis) while maintaining an excellent separation.
Price evolution since 1950: From abundance to market shortage
After the Second World War, the United States massively stored helium (considered strategic for the Cold War and the conquest of space) in the Cliffside Reserve in Texas.
After the Second World War, the United States massively stored helium (considered strategic for the Cold War and the conquest of space) in the Cliffside Reserve in Texas.
The major turning point took place in 1996 with the Helium Privatization Act. To repay the debts related to this storage, the US government decided to liquefy this federal reserve at artificially low prices. This abundance made helium extremely cheap in the 2000s. But as the reserve drained (it is now almost exhausted), global supply fell. Since the 2010s, the market has undergone what are called "Helium Shortages" (strains 1.0, 2.0, 3.0...). As a result, its price exploded, sometimes multiplying by 3 or 4 over short periods.
Cliffside Reserve in Texas (Photo by U.S. Bureau of Land Management)
Replacement with hydrogen
In the face of rising costs and supply chain disruptions (geopolitical instability, dependence on scarce producing countries, embargoes, etc.), laboratories are making a strategic transition to hydrogen.
An Ecological and Logistical Upgrade
- Logistical Autonomy: Hydrogen can be produced directly on site, on demand, through a hydrogen generator (water electrolysis). No more high pressure bottle management, lease contracts and dependence on international deliveries.
- Decarbonization: On-site hydrogen generated from renewable electricity has an almost zero carbon footprint, decorated with fossil fuels.
... A Strategic Analytical Advantage
- Superior Chromatographic Performance Superior: In GC, hydrogen allows slightly faster analytical times than helium while maintaining excellent resolution.
- Controlled Safety: If hydrogen is flammable, today's modern generators and GC/microGCs integrate advanced safety (e.g. leak detectors, very small volume of gas stored internally) that make its use perfectly safe in the laboratory.
