| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a process for producing oxygen products, particularly oxygen products having intermediate purity of 80-99% and preferably of 85-95% by subjecting air feed to a crogenic distillation. SOLUTION: A process for producing oxygen products uses an auxiliary low presstre colunm D2 in addition to the conventional high pressure column DI and low pressure column D3. The auxiliary low pressure column D2 is provided for pretreating the crude liquid oxygen from the bottom of the high pressure column D1 and is operated preferably at the sanae pressure as the main low pressure column D3 and is heat integrated with the top of the high pressure column by means of its bottom reboiler/condenser R/C. The obtained column top vapor stream 40 and the column bottom stream 50 are, thereafter, fed to the main low pressure column D3. Preferably, at least a portion of the column bottom stream 50 is fed to the main low pressure column D3 in the vapor state.</p> |
