Low temperature air separation process for producing pressurized gaseous product

1. A method of low temperature air separation which may be used for producing pressurized gaseous product comprising:

a) cooling a compressed air stream in an exchanger to form a compressed cooled air stream;

b) forming a first pressurized gas stream by cryogenically compressing at least a portion of said compressed cooled air stream in a first compressor, wherein said first compressor comprises a first inlet temperature;

c) cooling at least a portion of said first pressurized gas stream in said exchanger to form a first cooled pressurized gas stream;

d) forming a second pressurized gas stream by cryogenically compressing at least a portion of said first cooled pressurized gas stream in a second compressor, said second compressor comprising a second inlet temperature;

e) cooling and at least partially liquefying said second pressurized gas stream;

f) feeding said cooled, partially liquefied second pressurized gas stream to a system of at least one distillation column;

g) feeding said distillation column system with a liquid feed stream;

h) extracting a liquid product from said distillation column system;

i) pressurizing at least part of said liquid product;

j) vaporizing at least part of said liquid product; and

k) warming at least part of said liquid product in said exchanger to yield a pressurized gaseous product.

2. The method of claim 1 , wherein said liquid feed stream comprises liquid air.

3. The method of claim 1 , wherein said liquid feed stream further comprises at least one component of air.

4. The method of claim 2 , wherein said liquid product comprises at least one member selected from the group consisting of:

a) nitrogen;

b) oxygen; and

b) argon.

5. The method of claim 1 , wherein said liquid product comprises at least one member selected from the group consisting of:

a) oxygen; and

b) nitrogen.

6. The method of claim 1 , wherein said first inlet temperature is about the boiling temperature of said liquid product.

7. The method of claim 1 wherein said second inlet temperature is about the boiling temperature of said vaporized liquid product.

8. The method of claim 1 wherein all said cooling is performed in the absence of turboexpansion.

9. The method of claim 1 wherein at least part of said liquid feed stream originates from a storage means.

10. A method of low temperature air separation which may be used for producing pressurized gaseous product comprising:

a) performing the following actions during a first period when the cost of electricity is above a predetermined threshold, said first period actions comprising:

1) cooling a compressed air stream in an exchanger to form a compressed cooled air stream;

2) forming a first pressurized gas stream by cryogenically compressing at least a portion of said compressed cooled air stream in a first compressor, wherein said first compressor comprises a first inlet temperature;

3) cooling at least a portion of said first pressurized gas stream in said exchanger to form a first cooled pressurized gas stream;

4) forming a second pressurized gas stream by cryogenically compressing at least a portion of said first cooled pressurized gas stream in a second compressor, said second compressor comprising a second inlet temperature;

5) cooling and at least partially liquefying said second pressurized gas stream;

6) feeding said cooled, partially liquefied second pressurized gas stream to a system of at least one distillation column;

7) feeding said distillation column system with a liquid feed stream;

8) extracting a liquid product from said distillation column system;

9) pressurizing at least part of said liquid product;

10) vaporizing at least part of said liquid product; and

11) warming at least part of said liquid product in said exchanger to yield a pressurized gaseous product; and

b) producing at least part of said liquid feed stream during a second period when the cost of electricity is below said predetermined level.

11. An apparatus which may be used for producing pressurized gaseous product comprising:

a) a system of at least one distillation column;

b) a conduit for feeding a liquid stream to said distillation column system, wherein said liquid stream is derived from air;

c) a heat exchanger comprising a warm end and a cold end;

d) a first compressor comprising a first inlet temperature;

e) a second compressor comprising a second inlet temperature;

f) a conduit for feeding a compressed air stream to said exchanger;

g) a conduit for removing a compressed cooled air from at least one member selected from the group consisting of:

i) an intermediate part of said exchanger; and

ii) the cold end of said exchanger;

h) a conduit for sending said compressed cooled air to said first compressor to create a first pressurized gas stream;

i) a conduit for sending at least a portion of said first pressurized gas stream to said exchanger to form a first cooled pressurized gas stream;

j) a conduit for sending at least a portion of said first cooled pressurized gas from said exchanger to said second compressor to form a second pressurized gas stream;

k) a conduit for sending at least part of said second pressurized gas stream to said exchanger;

l) a conduit for removing at least part of said second pressurized gas stream and feeding said second pressurized gas stream to said distillation column system;

m) a conduit for sending a liquid feed stream to said distillation column system;

n) a conduit for removing a liquid stream from said distillation column system;

o) a means for pressurizing at least part of said removed liquid stream to form a pressurized liquid stream; and

p) a conduit for sending at least part of said pressurized liquid stream to said exchanger.

12. The apparatus of claim 11 , further comprising a means for sending gaseous cooled compressed air from said exchanger to said distillation column system.

13. The apparatus of claim 11 , further comprising:

a) at least one turboexpander; and

b) a conduit for feeding a fluid from said distillation column system to said turboexpander.

14. The apparatus of claim 11 , further comprising:

a) a storage tank for said liquid feed stream produced by said distillation column system; and

b) a conduit to connect said storage tank to at least one member selected from the group consisting of:

1) said exchanger; and

2) said distillation column system.

15. The apparatus of claim 11 , further comprising:

a) a storage tank for storing said liquid feed stream;

b) a conduit said storage tank to an external source of liquid; and

c) a conduit connecting said storage tank to said distillation column system.