Ultra high purity oxygen distillation unit integrated with ultra high purity nitrogen purifier

摘要

A method for producing ultra high purity liquid oxygen from standard grade liquid oxygen which integrates the oxygen purification process with a nitrogen purification process by utilizing the condensing duty of liquid nitrogen, thereby causing the nitrogen to vaporize which is desirable prior to delivery to a nitrogen purification unit. The method of the present invention includes pressurizing a source of liquid nitrogen and vaporizing at least a portion of the pressurized liquid nitrogen. The resulting high pressure gaseous nitrogen stream is introduced to at least one bottom reboiler/condenser of a high purity liquid oxygen unit, which also purifies standard grade liquid oxygen into ultra high purity liquid oxygen. The gaseous nitrogen provides the needed heat to the distillation columns of the high purity liquid oxygen unit. The condensed nitrogen is subsequently delivered to at least one top reboiler/condenser of the high purity liquid oxygen unit to provide refrigeration to the unit, and at the same time forming gaseous nitrogen which is then introduced to a nitrogen purification unit. The following streams are withdrawn from the unit: (a) ultra high purity liquid oxygen; (b) an argon-enriched waste stream; (c) a hydrocarbon-enriched waste stream. The oxygen purification portion of the method of the present invention can be accomplished on a portable skid, which includes primarily tanks, distillation columns, and heat exchangers, but no pumps or compressors.