Patent ID: 7204101

Claim:
A system for optimizing the recovery of argon comprising: an air input subsystem configured to intake and process atmospheric air; at least one distillation column to receive a processed air stream from the air input and to output a raw argon stream, wherein the at least one distillation column is located downstream from the air input system; a crude argon column to receive and process the raw argon stream and to output a crude argon stream; and a controller to automatically control the composition of the raw argon stream so as to decrease a concentration of oxygen in the raw argon stream while preventing a concentration of nitrogen in the crude argon stream from exceeding a selected value, wherein the controller is a multivariable predictive controller that effects control of at least one constraint variable and to at least one manipulated variable, wherein the at least one constraint variable includes at least one of: liquid nitrogen reflux impurity and raw argon stream midpoint purity.