Air separation process

摘要

Air separation process in which a portion (103) of the air is fed into a high pressure/low pressure column (130,230) and another portion (403) is passed into a second high/low pressure column (430,530). The two sections (130,230) of the first column are related through a heat exchange (119) whilst in the second column (430,530) the sections are related through heat exchange (419). Column (430,530) operates under a lower pressure than column (130,230). Oxygen is withdrawn as product at (201,202) in the first and at (501,502) in the second column from the low-pressure sections. A coarse oxygen fraction (112) is withdrawn from the first column at (130) and passed partially to an intermediate pressure column (330). Sump product from (330) is passed to the low-pressure sections (230,530) of the two columns. Also claimed is the plant for this process.