Separation of a Fluid Mixture Using Self-Cooling of the Mixture

Abstract

The use of an inexpensive heat exchanger for self-cooling of a fluid mixture is disclosed. The heat exchanger is made up of a plurality of plates and each plate has at least two channels defined in the plate. A fluid mixture is cooled and expanded, and separated, generating at least two process streams. One or more of the process streams are passed back to the heat exchanger to cool the fluid mixture.

1 . A process for separating the components of a mixture, by creating a stream comprising a liquid and a vapor, the process comprising:
 passing the mixture through a self-cooling heat exchanger;   controlling the expansion of the mixture within the heat exchanger;   passing the liquid and vapor though a separation unit, thereby creating a first stream and a second stream; and   passing the first stream or the second stream through the self-cooling heat exchanger   
     
     
         2 . The process of  claim 1  further comprising passing the other of the first or second streams through the self-cooling heat exchanger. 
     
     
         3 . The process of  claim 1  wherein the first stream comprises a vapor stream. 
     
     
         4 . The process of  claim 2  wherein the second stream comprises a liquid stream. 
     
     
         5 . The process of  claim 1  wherein the separation unit comprises a fractionation column, thereby generating an overhead first stream, and a bottoms second stream. 
     
     
         6 . The process of  claim 1  wherein the separation unit comprises a vapor/liquid separator. 
     
     
         7 . The process of  claim 1  wherein the mixture comprises a hydrocarbon mixture. 
     
     
         8 . The process of  claim 7  wherein the mixture comprises natural gas containing natural gas liquids. 
     
     
         9 . The process of  claim 7  wherein the mixture comprises olefins and paraffins 
     
     
         10 . The process of  claim 1  wherein the control of the expansion is through a Joule-Thomson valve. 
     
     
         11 . The process of  claim 1  wherein the control of the expansion is through a mechanical device for extracting work. 
     
     
         12 . The process of  claim 11  wherein the mechanical device is a micro-turbine. 
     
     
         13 . The process of  claim 11  further comprising recovering power from the micro-turbine. 
     
     
         14 . The process of  claim 11  further comprising controlling the expansion with the micro-turbine to control the amount of cooling. 
     
     
         15 . The process of  claim 1  wherein the first or second stream flows in a substantially counter-current direction to the flow of the mixture in the heat exchanger. 
     
     
         16 . The process of  claim 2  wherein the second or first stream flows in a substantially counter-current direction to the flow of the mixture in the heat exchanger. 
     
     
         17 . A process for separating the components of a mixture, by self-cooling the mixture and creating a stream comprising a liquid and a vapor, the process comprising:
 partially cooling the mixture through a heat exchanger;   passing the partially cooled mixture to a separation unit, thereby creating a liquid stream and a vapor stream;   passing the liquid stream through the heat exchanger;   passing the vapor stream through the heat exchanger;   controlling the expansion of the vapor stream in the heat exchanger to generate the desired cooling, thereby creating a cooled stream; and   passing the cooled stream through the heat exchanger to cool the mixture, liquid, and vapor streams.   
     
     
         18 . The process of  claim 17  wherein the mixture comprises a natural gas stream and the liquid stream comprises natural gas liquids. 
     
     
         19 . A process for cooling and separating a mixture by creating a stream comprising a liquid and a vapor, the process comprising;
 partially cooling the mixture through a heat exchanger;   passing the partially cooled mixture to a separation unit thereby creating a liquid stream and a vapor stream;   passing the liquid stream through the heat exchanger;   passing the vapor stream through the heat exchanger;   passing a refrigerant through the heat exchanger;   controlling the expansion of the refrigerant to generate the desired cooling and to generate a cooled refrigerant; and   passing the cooled refrigerant through the heat exchanger to self-cool the refrigerant and to cool the mixture, liquid and vapor streams.