PROCESS TO OBTAIN KRYPTON-XENON CONCENTRATE FROM LIQUID FEED

摘要

An air separation unit may produce gaseous or liquid oxygen and the Krypton-Xenon will concentrate in either oxygen product. When the Krypton and Xenon are recovered in gaseous oxygen and the Krypton-Xenon concentration process must be carried out at the same time as the air separation process, it is impractical to store gaseous oxygen in the quantities produced by an air separation plant. It may be desirable to recover the Krypton-Xenon in liquid oxygen, since this liquid can be stored and can be combined with other such liquids. However, recovering liquid oxygen from air separation plant is costly because of the associated refrigeration, which is removed from the air separation unit. This paper presents a method to obtain Krypton-Xenon concentrate, which requires no stream input other than the feed. This feed liquid provides the input for the Krypton-Xenon mass transfer in the heat pump circuit and also for the concentrating phase change in reboiling zone. Because the heat exchange in reboiling zone is between very similar fluids, the compression is very small. This is advantageous both from an energy use and safety standpoints.