Process and plant for the production of argon by cryogenic distillation of air

A process for the production of argon by cryogenic distillation, the process comprising the steps of:

• sending a gas enriched in argon that was produced by air separation in a system of columns to an argon separation column;
• withdrawing a flow rich in argon at a top of the argon separation column;
• and
• withdrawing a liquid enriched in oxygen at a bottom of the argon separation column;
• returning the liquid enriched in oxygen to the system of columns;
• determining, using a controller, whether a load of the argon separation column is below a first threshold;
• determining, using the controller, whether the load of the argon separation column is above a second threshold, wherein the second threshold is greater than the first threshold;
• whereupon a determination that the load of the argon separation column is below a first threshold, the process further comprises a first mode of operation,
• whereupon a determination that the load of the argon separation column is above a second threshold, the process further comprises a second mode of operation,
• whereupon a determination that the load of the argon separation column is between the first threshold and the second threshold, the process further comprises a third operation,
• i) wherein during the first mode of operation the process comprises the steps of:
• withdrawing a first liquid from a first intermediate location of the argon separation column and storing the first liquid in a first storage tank;
• preventing, using a first valve, the first liquid stored within the first storage tank from flowing to a second intermediate location of the argon separation column;
• withdrawing a third liquid from the argon separation column at a third intermediate location of the argon separation column and storing the third liquid in a second storage tank;
• preventing, using a second valve, the third liquid stored within the second storage tank from flowing to a fourth intermediate location of the argon separation column,
• ii) wherein during the second mode of operation, the process comprises the steps of:
• preventing, using a third valve, the first liquid from the first intermediate location of the argon separation column from flowing to the first storage tank;
• sending liquid argon from the first storage tank to the second intermediate location of the argon separation column, wherein the second intermediate location is separated from the first intermediate location by at least one layer of structured packing that is configured for the exchange of mass and of heat, the second intermediate location being located below the first intermediate location;
• preventing, using a fourth valve, the third liquid from the third intermediate location of the argon separation column from flowing to the second storage tank;
• and
• sending the third liquid from the second storage tank to the argon separation column at a fourth intermediate location of the argon separation column, wherein the fourth intermediate location is separated from the third intermediate location by at least one layer of structured packing that is configured for the exchange of mass and of heat, the fourth intermediate location being located below the third intermediate location and the third intermediate location not being located above the second intermediate location.