Krypton Production
Krypton Production
Krypton is a by-product of air disintegration. Gaseous oxygen, which contains Krypton and Xenon, is supplied from the oxygen generator output for rectification purposes to the so-called krypton column. Krypton and Xenon are separated in the column via washing by the reflux collected in the top of the column. The column liquor, enriched by Krypton and Xenon, is evapourated. The concentrate with 0.2% Krypton and Xenon is supplied to the gas receiver. By optimal reflux ratio value 0.13 the Krypton and Xenon output is 0.90. The separated concentrate is put under 0.5-0.6 MPa and is supplied through the heat exchanger into the contact apparatus at 1000 °K with CuO which burns the hydrocarbons out. After water-cooling, the gas mixture is refined from CO2 by KOH first in scrubbers, then in receivers. This cycle recurs several times. The refined concentrate is supplied into the rectification column under 0.2-0.25 MPa. Krypton and Xenon are collected in column liquor until their concentration reaches 95-98%. This raw Krypton and Xenon mixture is passed though gasifier, the hydrocarbons burner, into the gas receivers, from which the mixture goes to gasifier to be condensed at 77 °K. Some part of the mixture is exposed to fractional evaporation. On the last stage of refining with CuO pure Krypton is yielded. The rest of the gas mixture is absorbed by activated coal at 200-210 °K evolving pure Krypton; other part of Krypton along with Xenon is absorbed by coal and later separated by fractionate desorption. From 20000 m3/hour of air 105 m3 Krypton are annually produced. It is obtained also from purge gas methane fraction in NH3 production.