Start-up Storage Means for Off-Spec Argon in an Air Separation Unit
Publication Date: 2003-Sep-12
The IP.com Prior Art Database
In an air separation unit (ASU), it is known that pure argon can be separated in an argon column by distillation alone. Many distillation stages are required to purify argon, so typically the distillation of an argon rich feed stream is configured as two (series) columns. During start-up of the argon distillation section, it can take many hours to reach product purity. If little or no argon were withdrawn from the column during this period, then excessive argon would accumulate in the low pressure column of the ASU. This could cause an adverse composition profile in the LP column which would result in loss of argon from the system and also result in more difficulty achieving oxygen and nitrogen purity. If instead, off-spec argon were withdrawn from the top of the argon column during start-up, then this would significantly prolong the time to achieve product purity.