A system and method of optimizing the production of argon in a cryogenic air separation unit using a temperature profile of a distillation column or distillation column section obtained via fiber optic temperature measurements on the exterior surface of the distillation column or the distillation column section is provided. The temperature profiles are used to determine the vertical location and/or spatial movement of the maximum argon concentration in the distillation column or the distillation column section. Distillation column operation is then adjusted such that the vertical location or spatial movement of the maximum argon concentration is aligned proximate with the location of an argon-rich draw from the distillation column.

A system and method of ultra-high purity (UHP) oxygen production from an argon and oxygen producing cryogenic air separation unit incorporating a dedicated methane rejection column or column section having a liquid to vapor (L/V) ratio lower than the L/V ratio in the associated argon rectifier is provided.