Fluorinated oxiranes as organic rankine cycle working fluids and methods of using same

Abstract

A process and an apparatus for converting thermal energy into mechanical energy in a Rankine cycle is provided. The process and apparatus include a working fluid that comprises a fluorinated oxirane. The fluorinated oxirane can contain substantially no hydrogen atoms bonded to carbon atoms and can have from about 4 to about 9 carbon atoms. The process can drive a turbine and, in some embodiments, generate electricity.

What is claimed is: 
     
         1 . A process for converting thermal energy into mechanical energy in a Rankine cycle comprising:
 vaporizing a working fluid with a heat source to form a vaporized working fluid;   expanding the vaporized working fluid through a turbine;   cooling the vaporized working fluid using a cooling source to form a condensed working fluid; and   pumping the condensed working fluid;   
       wherein the working fluid comprises a fluorinated oxirane. 
     
     
         2 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the fluorinated oxirane compound includes up to a maximum of three hydrogen atoms. 
     
     
         3 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the fluorinated oxirane compound contains substantially no hydrogen atoms bonded to carbon atoms. 
     
     
         4 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the fluorinated oxirane has a total of from about 4 to about 9 carbon atoms. 
     
     
         5 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 4 , wherein the fluorinated oxirane contains 6 carbon atoms. 
     
     
         6 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the fluorinated oxirane has a critical temperature greater than about 150° C. 
     
     
         7 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the turbine generates electrical energy. 
     
     
         8 . A process for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 1 , wherein the vaporized working fluid is at a pressure greater than ambient pressure. 
     
     
         9 . A process for recovering waste heat comprising:
 passing a liquid working fluid through a heat exchanger in communication with a process that produces waste heat to produce a vaporized working fluid;   removing the vaporized working fluid from the heat exchanger;   passing the vaporized working fluid through an expander, wherein the waste heat is converted into mechanical energy; and   cooling the vaporized working fluid after it has been passed through the expander, wherein the fluorinated oxirane compound contains substantially no hydrogen atoms bonded to carbon atoms.   
     
     
         10 . A process for recovering waste heat comprising according to  claim 9 , wherein the fluorinated oxirane has a total of from about 4 to about 9 carbon atoms. 
     
     
         11 . A process for recovering waste heat comprising according to  claim 10 , wherein the fluorinated oxirane contains 6 carbon atoms. 
     
     
         12 . A process for recovering waste heat comprising according to  claim 10 , wherein the fluorinated oxirane has a critical temperature of greater than about 150° C. 
     
     
         13 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle comprising:
 a working fluid;   a heat source to vaporize the working fluid and form a vaporized working fluid;   a turbine through which the vaporized working fluid is passed thereby converting thermal energy into mechanical energy;   a condenser to cool the vaporized working fluid after it is passed through the turbine; and   a pump to recirculate the working fluid,   
       wherein the working fluid comprises a fluorinated oxirane. 
     
     
         14 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 13 , wherein the working fluid is in a closed loop. 
     
     
         15 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 13 , wherein the fluorinated oxirane contains substantially no hydrogen atoms bonded to carbon atoms. 
     
     
         16 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 15 , wherein the fluorinated oxirane has a total of from about 4 to about 9 carbon atoms. 
     
     
         17 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 16 , wherein the fluorinated oxirane contains 6 carbon atoms. 
     
     
         18 . An apparatus for converting thermal energy into mechanical energy in a Rankine cycle according to  claim 13 , wherein the fluorinated oxirane has a critical temperature greater than about 150° C.