Process for hydrotreating a coal tar stream

Abstract

A process for hydrotreating a coal tar stream is described. A coal tar stream is provided, and the coal tar stream is expanded with an inert gas stream to provide an expanded liquid coal tar stream. The expanded liquid coal tar stream is hydrotreated. The coal tar stream can be reacted with a hydrocarbon solvent before it is expanded.

What is claimed is: 
     
         1 . A process comprising:
 providing a coal tar stream;   expanding the coal tar stream with an inert gas stream to provide an expanded liquid coal tar stream; and   hydrotreating the expanded liquid coal tar stream.   
     
     
         2 . The process of  claim 1  wherein hydrotreating the expanded liquid coal tar stream comprises subjecting the expanded liquid coal tar stream to hydrodesulfurization, or hydrodenitrogenation, or both. 
     
     
         3 . The process of  claim 1  further comprising:
 processing the hydrotreated stream by one or more of hydrocracking, fluid catalytic cracking, alkylation, transalkylation, oxidation, and hydrogenation to provide at least one product. 
 
     
     
         4 . The process of  claim 1  wherein the inert gas is selected from the group consisting of carbon dioxide, nitrogen, and light hydrocarbons. 
     
     
         5 . The process of  claim 1 , wherein the hydrotreating takes place at a temperature range of about 260° C. (about 500° F.) to about 370° C. (about 700° F.). 
     
     
         6 . The process of  claim 1 , wherein the hydrotreating takes place at a pressure range of about 4.8 MPa (about 700 psi) to about 8.3 MPa (about 1200 psi). 
     
     
         7 . The process of  claim 1 , wherein the hydrotreating takes place in the presence of a catalyst. 
     
     
         8 . The process of  claim 1  further comprising:
 feeding the coal tar stream and a hydrocarbon solvent into a reaction zone; 
 reacting the coal tar stream and the hydrocarbon solvent in the reaction zone to provide a liquid coal tar stream; and 
 wherein expanding the coal tar stream comprises expanding the liquid coal tar stream. 
 
     
     
         9 . The process of  claim 8  wherein the hydrocarbon solvent comprises an aromatic hydrocarbon. 
     
     
         10 . The process of  claim 8  wherein the coal tar stream and the hydrocarbon solvent are reacted at a pressure ranging from about 4.8 MPa (about 700 psig) to about 8.3 MPa (about 1200 psig). 
     
     
         11 . The process of  claim 1  wherein providing the coal tar stream comprises pyrolyzing a coal feed into at least the coal tar stream and a coke stream. 
     
     
         12 . A process comprising:
 providing a coal tar stream;   feeding the coal tar stream and a hydrocarbon solvent into a reaction zone;   reacting the coal tar stream and the hydrocarbon solvent in the reaction zone to provide a liquid coal tar stream; and   expanding the reacted coal tar stream with an inert gas stream to provide an expanded liquid coal tar stream; and   hydrotreating the expanded liquid coal tar stream.   
     
     
         13 . The process of  claim 12 , wherein the hydrotreating takes place at a temperature range of about 260° C. (about 500° F.) to about 370° C. (about 700° F.) and a pressure range of about 4.8 MPa (about 700 psi) to about 8.3 MPa (about 1200 psi). 
     
     
         14 . The process of  claim 12  wherein the inert gas is selected from the group consisting of carbon dioxide, nitrogen, and light hydrocarbons. 
     
     
         15 . The process of  claim 12  wherein hydrotreating the expanded liquid coal tar stream comprises subjecting the expanded liquid coal tar stream to hydrodesulfurization, or hydrodenitrogenation, or both. 
     
     
         16 . The process of  claim 12  further comprising:
 processing the hydrotreated stream by one or more of hydrocracking, fluid catalytic cracking, alkylation, transalkylation, oxidation, and hydrogenation to provide at least one product. 
 
     
     
         17 . The process of  claim 12 , wherein the hydrotreating takes place in the presence of a catalyst. 
     
     
         18 . The process of  claim 12  wherein the hydrocarbon solvent comprises an aromatic hydrocarbon. 
     
     
         19 . The process of  claim 12  wherein the coal tar stream and the hydrocarbon solvent are reacted at a pressure ranging from about 4.8 MPa (about 700 psig) to about 8.3 MPa (about 1200 psig). 
     
     
         20 . The process of  claim 12  wherein providing the coal tar stream comprises pyrolyzing a coal feed into at least the coal tar stream and a coke stream.