Industrial cryogenic air separation technology used to produce oxygen, nitrogen, argon, and rare gases has an extremely good safety record. However, as with many present-day production processes, it has inherent potential hazards that shall be recognized and addressed by design and operating practice.
This publication addresses the operation of the reboilers of air separation plants. It contains a summary of current knowledge and industrial practices used in their safe application. It specifically applies to the main reboiler and oxygen product reboilers in which the oxygen concentration is greater than 75% in the liquid phase. Its guiding principles may be used for other reboilers within air separation plants, including auxiliary vaporizers, guard adsorber vaporizers, argon condensers, and the main reboilers in nitrogen generators.
Reboilers that are used in conjunction with krypton/xenon production are typically operated with higher hydrocarbon limits than typical air separation unit (ASU) reboilers. The allowable levels of hydrocarbons as well as additional safeguards for the bath-type reboilers used in these systems are listed in Appendix A.