Low-pressure nitrogen turbine with air booster parallel to the booster air compressor

Abstract

An air separation process having a first booster air compressor comprising a first outlet stream and a second booster air compressor comprising a second outlet stream. Wherein the first booster air compressor and the second booster air compressor are in parallel, and the second booster air compressor is driven by a nitrogen turboexpander. The first outlet stream and/or the second outlet stream may be at least partially condensed by heat exchange with a vaporizing low pressure oxygen stream, and the low-pressure gaseous oxygen pressure is in the range of 1.1 bara to 3 bara.

What is claimed is: 
     
         1 . An air separation process comprising:
 a first booster air compressor comprising a first outlet stream,   a second booster air compressor comprising a second outlet stream   wherein the first booster air compressor and the second booster air compressor are in parallel, and   wherein the second booster air compressor is driven by a nitrogen turboexpander.   
     
     
         2 . The air separation process of  claim 1 , wherein the first outlet stream and the second outlet stream are combined and introduced into a common after-cooler. 
     
     
         3 . The air separation process of  claim 1 , wherein the first booster air compressor has a first inlet pressure and the second booster air compressor has a second inlet pressure, and wherein the first inlet pressure and the second inlet pressure are within 1 bar. 
     
     
         4 . The air separation process of  claim 1 , wherein the first booster air compressor has a first outlet pressure and the second booster air compressor has a second outlet pressure, and wherein the first outlet pressure and the second outlet pressure are within 1 bar. 
     
     
         5 . The air separation process of  claim 1 , wherein the nitrogen turboexpander has an inlet pressure in the range of 4 to 10 bara and outlet pressure in the range of atmospheric pressure to 2 bara. 
     
     
         6 . An air separation process producing low pressure gaseous oxygen comprising:
 a first booster air compressor comprising a first outlet stream,   a second booster air compressor comprising a second outlet stream   wherein the first booster air compressor and the second booster air compressor are in parallel,   wherein the second booster air compressor is driven by a nitrogen turboexpander,   wherein, the first outlet stream and/or the second outlet stream is at least partially condensed by heat exchange with a vaporizing low pressure oxygen stream, and   wherein the low-pressure gaseous oxygen pressure is in the range of 1.1 bara to 3 bara.   
     
     
         7 . The air separation process of  claim 6 , wherein the first outlet stream and the second outlet stream are combined and introduced into a common after-cooler. 
     
     
         8 . The air separation process of  claim 6 , wherein the first booster air compressor has a first inlet pressure and the second booster air compressor has a second inlet pressure, and wherein the first inlet pressure and the second inlet pressure are within 1 bar. 
     
     
         9 . The air separation process of  claim 6 , wherein the first booster air compressor has a first outlet pressure and the second booster air compressor has a second outlet pressure, and wherein the first outlet pressure and the second outlet pressure are within 1 bar. 
     
     
         10 . The air separation process of  claim 6 , wherein the nitrogen turboexpander has an inlet pressure in the range of 4 to 10 bara and outlet pressure in the range of atmospheric pressure to 2 bara. 
     
     
         11 . air separation process of  claim 6 , wherein the low-pressure gaseous oxygen pressure is in the range of 1.2 bara and 2 bara. 
     
     
         12 . The air separation process of  claim 6 , wherein the first outlet stream and the second outlet stream are combined, and the combined stream is at least partially condensed by heat exchange with a vaporizing low pressure oxygen stream.