Process and apparatus for producing ultrapure oxygen

Abstract

For the production of ultrapure oxygen, conduct the followig steps: introduce a feed air stream ( 10, 11, 42, 43 ) into a single distillation column ( 12 ) for producing nitrogen; withdraw an oxygen-containing stream ( 36, 39 ) from an intermediate stage of the single distillation column ( 12 ), introduce the oxygen-containing stream ( 36, 39 ) into an upper section of a high-purity oxygen column ( 38 ), and withdraw an ultrapure oxygen product stream ( 44 ) from the high-purity oxygen column ( 38 ), with the caveat that rising vapour for the high-purity oxygen column ( 38 ) is produced by indirect heat exchange in a reboiler ( 37 ) between a liquid fraction from a lower section of the high-purity oxygen column and a gaseous heating stream ( 42 ), so that the heating stream ( 42 ) is at least partially condensed during such indirect heat exchange.

1 . A process for producing ultrapure oxygen, the process comprising the following steps: 
 introducing a feed air stream ( 10 ,  11 ,  42 ,  43 ) into a single distillation column ( 12 ) for producing nitrogen,    withdrawing an oxygen-containing stream ( 36 ,  39 ) from an intermediate stage of the single distillation column ( 12 ),    introducing the oxygen-containing stream ( 36 ,  39 ) into an upper section of a high-purity oxygen column ( 38 ), and    withdrawing an ultrapure oxygen product stream ( 44 ) from the high-purity oxygen column ( 38 ), wherein    rising vapour for the high-purity oxygen column ( 38 ) is produced by indirect heat exchange in a reboiler ( 37 ) between a liquid fraction from a lower section of the high-purity oxygen column and a gaseous heating stream ( 42 ),    whereby the gaseous heating stream ( 42 ) is at least partially condensed during such indirect heat exchange.    
   
   
       2 . A according to  claim 1 , whereby the gaseous heating stream ( 42 ) comprises at least a portion of the feed air stream ( 10 ).  
   
   
       3 . A process according to  claim 1 , wherein or the gaseous heating stream ( 42 ) downstream of the indirect heat exchange ( 37 ) is introduced into the single distillation column ( 12 ).  
   
   
       4 . A process according to  claim 1 , wherein the oxygen-containing stream ( 36 ,  39 ) is introduced into the top of the high-purity oxygen column ( 38 ).  
   
   
       5 . A process according to  claim 1 , wherein at least a portion of the oxygen-containing stream ( 36 ) is subcooled in the reboiler ( 37 ) before being introduced ( 39 ) into the high-purity oxygen column ( 38 ).  
   
   
       6 . A process according  claim 1 , wherein the ultrapure oxygen product stream ( 44 ) is withdrawn from an intermediate section of the high-purity oxygen column ( 38 ).  
   
   
       7 . A process according to  claim 1 , wherein the ultrapure oxygen product stream ( 44 ) is withdrawn from the high-purity oxygen column ( 38 ) in a liquid state.  
   
   
       8 . A process according to  claim 7 , wherein the ultrapure oxygen product stream is withdrawn as a final liquid product.  
   
   
       9 . Apparatus for producing ultrapure oxygen the process comprising 
 means for introducing a feed air stream ( 10 ,  11 ,  42 ,  43 ) into a single distillation column ( 12 ) for producing nitrogen,    means for withdrawing an oxygen-containing stream ( 36 ,  39 ) from an intermediate stage of the single distillation column ( 12 ),    means for introducing the oxygen-containing stream ( 36 ,  39 ) into an upper section of a high-purity oxygen column ( 38 ), and    means for withdrawing an ultrapure oxygen product stream ( 44 ) from the high-purity oxygen column ( 38 ),    the apparatus further comprising    a reboiler ( 37 ) for producing rising vapour for the high-purity oxygen column ( 38 ) by indirect heat exchange in a reboiler ( 37 ) between a liquid fraction from a lower section of the high-purity oxygen column and a gaseous heating stream ( 42 ).    
   
   
       10 . A process according to  claim 2 , wherein the heating stream ( 42 ) downstream of the indirect heat exchange ( 37 ) is introduced into the single distillation column ( 12 ).  
   
   
       11 . A process according to  claim 10 , wherein the oxygen-containing stream ( 36 ,  39 ) is introduced into the top of the high-purity oxygen column ( 38 ).  
   
   
       12 . A process according to  claim 2 , wherein at least a portion of the oxygen-containing stream ( 36 ) is subcooled in the reboiler ( 37 ) before being introduced ( 39 ) into the high-purity oxygen column ( 38 ).  
   
   
       13 . A process according to  claim 3 , wherein at least a portion of the oxygen-containing stream ( 36 ) is subcooled in the reboiler ( 37 ) before being introduced ( 39 ) into the high-purity oxygen column ( 38 ).  
   
   
       14 . A process according to  claim 10 , wherein at least a portion of the oxygen-containing stream ( 36 ) is subcooled in the reboiler ( 37 ) before being introduced ( 39 ) into the high-purity oxygen column ( 38 ).  
   
   
       15 . A process according to  claim 12 , wherein at least a portion of the oxygen-containing stream ( 36 ) is subcooled in the reboiler ( 37 ) before being introduced ( 39 ) into the high-purity oxygen column ( 38 ).  
   
   
       16 . A process according to  claim 15 , wherein the ultrapure oxygen product stream ( 44 ) is withdrawn from the high-purity oxygen column ( 38 ) in a liquid state.  
   
   
       17 . A process according to  claim 16 , wherein the ultrapure product stream is withdrawn as a final liquid product.