Comparing Xenon Gas to Argon and Krypton
IntroductionDespite its invisibility to the naked eye and scarcity in the air, xenon gas plays a visible role in several cutting-edge technologies. But how is this rare gas obtained? This blog explores the xenon extraction and purification process.
The Source: Earth's AtmosphereXenon gas is not found in compounds naturally—it exists as a trace component in air, making up roughly 0.087 parts per million. Unlike helium, which can be extracted from natural gas, xenon is sourced only through air separation.
Air Separation Process
Liquefaction: Atmospheric air is compressed and cooled to cryogenic temperatures.
Fractional Distillation: The air is then distilled in steps to separate oxygen, nitrogen, and noble gases. Xenon comes out last, along with krypton.
Krypton-Xenon Mixture: The small fraction containing krypton and xenon is further processed.
Cryogenic Distillation: This mixture is subjected to fine separation techniques, isolating xenon from krypton.
Purification: Finally, xenon is purified to industrial or medical grade.
By-product UseXenon production is often a by-product of oxygen manufacturing, meaning that a rise in oxygen demand (such as during the COVID-19 pandemic) can indirectly increase xenon availability.
Challenges and Innovations
Low yield: Over 20 million cubic meters of air may be needed to get just 1 liter of xenon.
High cost: The infrastructure required is expensive and energy-intensive.
Emerging technologies: Laser isotope separation and advanced membrane filtration are being explored to improve yield.