Krypton, an element made famous by comic-book protagonists, is far more inert than mythology might suggest.
Indeed, although used to a lesser extent than its sister noble gases, krypton has many domestic uses which make it an invaluable product in modern day-to-day life.
As a member of the rare gases family, krypton occurs in small amounts within the air. In fact the atmosphere contains only 1.14 parts per 106 by volume. Similarly, it shares archetypal noble gas properties; it is monatomic, colourless, odourless, tasteless and non-toxic.
Furthermore the gas, which is three times heavier than air, was first discovered in the same era as many other rare gases when in 1989 Sir William Ramsay and Morris Travers came across the element while separating air.
Vice President of Specialty Gases at Messer, Dr Hermann Grabhorn, spoke to gasworld exclusively about the breadth of applications, “Our estimation is that about 40-50% of all krypton is used in lighting, 30-40% in window manufacturing and the rest for laser and other applications.”
Grabhorn elaborated, “Most of the krypton is used for lighting, window and laser applications. It is used as filling gas in halogen and energy saving fluorescent lamps.” He added, “Pure krypton or krypton-argon mixtures are filled into double glazed windows to improve the thermal insulation properties.”
In these instances, the gas is inserted into the gap between sealed glass insulated windows. Ordinarily, every square foot of window surface with glass panes 20mm apart contains about 1.8 litres of krypton. Its prevalence in lasers is also one based on combination; usually courtesy of a halogen such as fluorine. Similarly, it finds a use in the automobile industry, as it is often found in halogen sealed beam headlights.
Market and future
Despite the gamut of applications, Grabhorn observed a tempestuous era for the gas. He said, “In the last years we have had a very volatile krypton market. Due to high demand in all sectors, especially the fast-growing European market for krypton in insulated windows, and temporarily slow production, krypton has been short in 2008.”
Grabhorn remarked that the 2009 financial crisis also served a blow to both the production and demand of krypton. Nevertheless, the Messer member optimistically described a current equilibrium, “Since this year the market has stabilised again – supply and demand seems to be balanced now.”
Looking ahead, krypton’s range of applications may take to further dimensions. Indeed, space industries are investing in krypton technology; in particular, the sector is drawn to its use as a propulsion fuel. Although it currently competes with the better performing space fuel, xenon, krypton is around ten times cheaper to produce and consequently a very attractive alternative.
However, Grabhorn anticipates equal potential in current applications, he noted, “Growing demand of krypton is expected in the window market especially in the US, driven by increasing energy costs there is a higher demand for well insulated windows there. In particular for the refurbishment of old – often still single glazed windows in the US krypton – filled insulated windows are the best solution. The demand in lighting industry is growing in fast developing regions such as China.”
Despite these positive indications, the future of krypton will rest upon the supply and demand balance, and as Messer described, investment in production technology will be needed in order to handle the growth in demand, “The development of the krypton market depends on the balance between production and demand. Krypton (together with xenon) is produced at very large air separation units. To support the growing demand of krypton industrial gas companies have to equip their ASUs with the needed hardware.”