Supercritical CO2 Solvated Process to Convert Coal to Carbon Fibers

Abstract

A method of forming high molecular weight (“HMW”) coal tar can include combining supercritical carbon dioxide (sCO 2 ) and an amount of coal tar, and fractionating the amount of coal tar to form the HMW coal tar. The method can further include forming the amount of coal tar from coal. Forming the amount of coal tar from coal can include extracting the coal tar from an amount of coal using sCO 2 .

What is claimed is: 
     
         1 . A system for processing coal tar, comprising:
 a high molecular weight (“HMW”) coal tar formation apparatus comprising a coal tar input and configured to form HMW coal tar from coal tar using supercritical carbon dioxide (“sCO 2 ”) and a co-solvent;   a mesophase pitch formation apparatus in communication with the HMW coal tar formation apparatus and configured to form mesophase pitch from HMW coal tar using sCO 2 ;   a sCO 2  source in communication with the HMW coal tar formation apparatus and the mesophase pitch formation apparatus to provide sCO 2  thereto; and   a co-solvent source in communication with the HMW coal tar formation apparatus to provide a co-solvent to the HMW coal tar formation apparatus.   
     
     
         2 . The system of  claim 1 , further comprising a carbon fiber formation apparatus in communication with the mesophase pitch formation apparatus configured to convert mesophase pitch from the mesophase pitch formation apparatus into carbon fiber. 
     
     
         3 . The system of  claim 1 , further comprising a carbon fiber formation apparatus in communication with the mesophase pitch formation apparatus configured to convert mesophase pitch from the mesophase pitch formation apparatus into carbon fiber;
 wherein at least one of the coal tar source, the HMW coal tar formation apparatus, the mesophase pitch formation apparatus, the sCO 2  source, or the co-solvent source is a bolt-on retrofit to the carbon fiber formation apparatus.   
     
     
         4 . The system of  claim 2 , wherein the carbon fiber formation apparatus comprises a high pressure pyrolysis type microcompounding reactor including a twin screw recirculator. 
     
     
         5 . A method of processing coal tar, comprising:
 providing an amount of coal tar; and   converting at least some of the amount of coal tar into mesophase pitch using supercritical carbon dioxide (“sCO 2 ”).   
     
     
         6 . The method of  claim 5 , wherein providing the amount of coal tar comprises providing high molecular weight coal tar. 
     
     
         7 . The method of  claim 5 , wherein converting at least some of the amount of coal tar into mesophase pitch comprises heat treating the amount of coal tar. 
     
     
         8 . The method of  claim 7 , wherein heat treating the amount of coal tar comprises heating the amount of coal tar to a temperature of between about 300° C. and about 500° C. 
     
     
         9 . The method of  claim 5 , further comprising extruding the mesophase pitch into one or more fibers. 
     
     
         10 . The method of  claim 9 , wherein extruding the mesophase pitch into one or more fibers comprises extruding the mesophase pitch through a high pressure pyrolysis type microcompounding reactor including a twin screw recirculator. 
     
     
         11 . A method of forming carbon fibers from coal tar, comprising:
 providing an amount of coal tar;   converting at least some of the amount of coal tar into mesophase pitch using supercritical carbon dioxide (“sCO 2 ”); and   extruding the mesophase pitch into one or more fibers.   
     
     
         12 . The method of  claim 11 , wherein providing the amount of coal tar comprises providing high molecular weight coal tar. 
     
     
         13 . The method of  claim 11 , wherein converting at least some of the amount of coal tar into mesophase pitch comprises heat treating the amount of coal tar to a temperature of between about 300° C. and about 500° C. 
     
     
         14 . The method of  claim 11 , wherein extruding the mesophase pitch into one or more fibers comprises extruding the mesophase pitch through a high pressure pyrolysis type microcompounding reactor including a twin screw recirculator.