Automated Cryogenic Unit for Xenon Extraction from Concentrated Mixtures

Abstract

Recycling to recover Xe from its mixtures is proposed because of its shortage and high price. The simplest recycling scheme involves several consumers connected to a common centralized Xe enrichment and purification complex. However, such a scheme has limited applicability because it can cover only small regions. A versatile recycling scheme is based on deployment of a network of cryogenic separators operating in unison with rare-gas consumers. Such a solution can be implemented using fully automated units and remote control of their operation, possibly over the internet. Introduction into the rectification column of an intermediate gas, the boiling point of which is between those of the mixture components to be separated, is proposed to prevent Xe from freezing on contact with the low-temperature component. Control methods that ensure stable rectification of Ar–Xe mixtures in the presence of Kr as an intermediate are developed and tested.