The rare gases krypton (Kr) and xenon (Xe) are both volatile global products. This volatility stems from their end use applications in fluctuating markets like construction, lighting, and electronics, and from the global control of sources of their production. Furthermore, the supply of krypton and xenon, which are byproducts of large scale oxygen production via air separation units (ASUs), is driven by the demand in the oxygen markets, not rare gas markets.
Given the high degree of market volatility for krypton and xenon, and some degree of concern for safety due to the concentration of hydrocarbons in the oxygen stream that contains the crude Kr/Xe, producers have been reluctant to make the necessary investment to add crude Kr/Xe capacity. There is a threeyear lead time required to design and build a large ASU with crude Kr/Xe capacity, and this process is very capital intensive. Today’s economic conditions make it difficult to find and sign long-term large-scale oxygen contracts, so going forward, I expect added or lost rare gases capacity to come in lumps relative to current global capacity for crude Kr/Xe. This will have an impact on the global supply/ demand balances of these gases, which in turn is likely to impact global pricing.
Current Production
The current world production of crude gas mixture (approximately 90 percent Kr, eight percent Xe, and two percent impurities) is around 111,000,000 liters. Of this, krypton is approximately 100,000,000 liters and xenon is about 11,000,000 liters. Note that xenon is about 10 percent of the total, not the eight percent you would expect given the ratio of xenon in the crude mixture. This is because a Kr/Xe crude production column is retrofitted to the hydrocarbon waste streams of some oxygen plants, instead of having these oxygen plants initially equipped with internal trays. Also, some newer plants are built and run to minimize power costs, which changes the economic benefit of Kr and Xe recovery. In both cases some of the krypton is not retained but most of the xenon is, causing a higher percentage of xenon to be produced than you would expect.
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