Thermal integration temperature balancing of air separation unit and power generation system

Abstract

A method of temperature balancing for thermal integration of an air separation unit with an oxycombustion power generation system, including compressing air, routing a first stage compressed air stream through a first heat exchanger in heat exchange communication with a subsequent stage compressed air stream, taking the heated first stage compressed air stream and routing the heated first stage compressed air stream through a second heat exchanger in heat exchange communication with a first fluid going to the power generation system, routing the further cooled, first stage compressed air stream to a subsequent compression stage, routing the subsequent compressed air stream exiting from the heat exchanger to a third heat exchanger in heat exchange communication with the first and/or a second fluid going to the power generation system to cool the subsequent air stream exiting from the heat exchanger.

What is claimed is: 
     
         1 . A method of temperature balancing for thermal integration of an air separation unit with an oxycombustion power generation system, the method comprising the steps of:
 a) compressing air through a plurality of compression stages,   b) routing a first stage compressed air stream through a first heat exchanger in heat exchange communication with a subsequent stage compressed air stream thereby increasing the first stage compressed air stream temperature and decreasing the temperature of a subsequent stage compressed air stream,   c) taking the heated first stage compressed air stream from step b) and routing the heated first stage compressed air stream through a second heat exchanger in heat exchange communication with a first fluid going to the power generation system to further cool the cooled, first stage compressed air stream and increase the temperature of the first fluid going to the power generation system,   d) routing the further cooled, first stage compressed air stream to a subsequent compression stage to produce the subsequent air stream that is further compressed and heated from the compression,   e) routing the subsequent compressed air stream exiting from the heat exchanger in step b) to a third heat exchanger in heat exchange communication with the first and/or a second fluid going to the power generation system to cool the subsequent air stream
 exiting from the heat exchanger. 
   
     
     
         2 . The method of  claim 1 , further comprising routing the cooled subsequent air stream of step e) to precooling and drying steps and then to a main heat exchanger of the air separation unit. 
     
     
         3 . The method of  claim 1 , wherein the first stage compression is a MAC producing the first stage compressed air stream at less than about 10 bar. 
     
     
         4 . The method of  claim 1 , wherein the temperatures of the heated first stage compressed air stream exiting from the heat exchanger in step b) and the subsequent compressed air stream exiting from the heat exchanger in step b), are within twenty degrees Celsius of each other.