Patent ID: 11879685
Assignee: L'AIR LIQUIDE, SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE
Field: Chemical engineering (Chemistry)
Classification: CPC F | IPC F

Claim 6:
7. A method for producing high-purity oxygen, the method comprising the steps of:
providing an air separation apparatus including a main heat exchanger, a medium-pressure column and a low-pressure column;
providing a high-purity oxygen production apparatus including a nitrogen compressor, a nitrogen heat exchanger and at least one high-purity oxygen rectification column;
supplying an oxygen-containing stream serving as a starting material for high-purity oxygen from the low-pressure column to the high-purity oxygen production apparatus; and
supplying liquid nitrogen obtained from the medium-pressure column to the high-purity oxygen production apparatus in order to replenish cold heat required for operation of the high-purity oxygen production apparatus,
wherein the high-purity oxygen production apparatus further comprises a nitrogen expansion line and a nitrogen expander, wherein the nitrogen expansion line is in fluid communication with an intermediate section of the nitrogen heat exchanger and is configured to receive nitrogen after being compressed in the nitrogen compressor by sending a partially cooled and pressurized nitrogen steam to the nitrogen expander to form an expanded nitrogen steam, wherein the nitrogen expansion line is further configured to send the expanded nitrogen steam to a cold end of the nitrogen heat exchanger and then recycled.