Method for operating an air separation plant

A method for the production of air gases with variable liquid production by the cryogenic separation of air, the method comprising the steps of:

• a) compressing air to a pressure suitable for the cryogenic rectification of air to produce a compressed humid air stream, the compressed humid air stream having a first pressure Po;
• b) purifying the compressed humid air stream of water and carbon dioxide within a front end purification system to produce a dry air stream having reduced amounts of water and carbon dioxide as compared to the compressed humid air stream;
• c) compressing a first portion of the dry air stream in a booster compressor to form a boosted air stream, the boosted air stream having a first boosted pressure PB1;
• d) introducing a second portion of the dry air stream and the boosted air stream to a cold box under conditions effective to separate air to form an air gas product, wherein the air gas product is selected from the group consisting of oxygen, nitrogen, and combinations thereof;
• e) withdrawing the air gas product from the cold box, the air gas product having a first product pressure PP1;
• f) introducing the air gas product to a pipeline, wherein the pipeline is configured to transport the air gas product to a location located downstream of the pipeline, wherein the pipeline operates at a pipeline pressure PPL, wherein the air gas product is introduced to the pipeline at a first delivery pressure PD1;
• g) monitoring the pipeline pressure PPL within the pipeline;
• h) adjusting one or more pressure set points within the cold box based on the pipeline pressure PPL;
• and
• i) adjusting liquid production from the cold box based on the one or more pressure set points adjusted in step h).