Hydrotreating process and multifunction hydrotreater

Abstract

A multifunction hydrotreater includes a particulate removal zone having a particulate trap to remove particulate contaminants from a coal tar stream and a demetallizing zone including a demetallizing catalyst to remove organically bound metals from the departiculated stream. The demetallizing zone is positioned after the particulate removal zone. The hydrotreater also includes a hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone positioned after the demetallization zone, which includes at least one hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation catalyst to provide a hydrotreated coal tar stream.

What is claimed is: 
     
         1 . A multifunction hydrotreater comprising:
 a particulate removal zone comprising a particulate trap to remove particulate contaminants from a coal tar stream;   a demetallizing zone comprising a demetallizing catalyst to remove organically bound metals from the de-particulated stream, the demetallizing zone positioned after the particulate removal zone; and   a hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone comprising at least one hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation catalyst to provide a hydrotreated coal tar stream, the hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone positioned after the demetallizing zone.   
     
     
         2 . The multifunction hydrotreater of  claim 1 , wherein said hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone comprises:
 a first zone comprising a first hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation catalyst; and   a second zone comprising a second hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation catalyst.   
     
     
         3 . The multifunction hydrotreater of  claim 2 , wherein each of said first and second catalysts includes one or more of a nickel-molybdenum catalyst, a cobalt-molybdenum catalyst, a nickel-tungsten catalyst, and a nickel-cobalt-molybdenum catalyst. 
     
     
         4 . The multifunction hydrotreater of  claim 3 , wherein said first catalyst and said second catalyst are distinct. 
     
     
         5 . The multifunction hydrotreater of  claim 2 , wherein said first catalyst is a large pore catalyst and said second catalyst is a small pore catalyst. 
     
     
         6 . The multifunction hydrotreater of  claim 1 , wherein said hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone includes a plurality of beds arranged sequentially. 
     
     
         7 . The multifunction hydrotreater of  claim 6 , further comprising:
 a quench medium injection port between each of said plurality of beds.   
     
     
         8 . The multifunction hydrotreater of  claim 1 , wherein said demetallizing catalyst is a low-acidity large pore catalyst including at least one of a nickel-molybdenum catalyst and a cobalt-molybdenum catalyst. 
     
     
         9 . The multifunction hydrotreater of  claim 1 , further comprising:
 a quench medium injection port in said demetallizing zone.   
     
     
         10 . The multifunction hydrotreater of  claim 1 , further comprising: a condenser in fluid communication with an upstream coal pyrolysis zone, said condenser positioned after the hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation zone, a condensed water portion of the hydrotreated coal tar stream being provided to said upstream coal pyrolysis zone as a hydrogen donor stream. 
     
     
         11 . A hydrotreating process comprising:
 pyrolyzing a coal feed in a pyrolysis zone to produce a coke stream and a coal tar stream;   separating a pitch fraction from the coal tar stream to form a reduced pitch coal tar stream;   contacting the reduced pitch coal tar stream with a particulate trap to remove particulate contaminants from the coal feed to form a de-particulated coal tar stream;   contacting the de-particulated coal tar stream with a demetallizing catalyst to remove organically-bound metals to form a demetallized coal tar stream;   contacting the demetallized coal tar stream with one or more catalysts for hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation to produce a hydrotreated coal tar stream.   
     
     
         12 . The hydrotreating process of  claim 11  further comprising:
 introducing the hydrotreated coal tar stream into a separation column to separate the coal tar stream into at least a naphtha stream, a kerosene stream, a diesel stream, and a vacuum gas oil stream. 
 
     
     
         13 . The hydrotreating process of  claim 12 , wherein said separation further produces an ammonia stream. 
     
     
         14 . The hydrotreating process of  claim 13 , further comprising:
 introducing the ammonia stream to said pyrolysis zone as a hydrogen donor stream.   
     
     
         15 . The hydrotreating process of  claim 11 , further comprising:
 injecting a quench medium into the de-particulated coal tar stream.   
     
     
         16 . The hydrotreating process of  claim 11 , wherein contacting the demetallized coal tar stream with one or more catalysts for hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation comprises contacting the de-metallized coal tar stream with said one or more catalysts for hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation in a series of sequential beds, and further comprising:
 injecting a relatively cool quench medium into the de-metallized coal tar stream between said sequential beds.   
     
     
         17 . The hydrotreating process of  claim 11 , wherein said one or more catalysts for hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation comprise one or more of a nickel-molybdenum catalyst, a cobalt-molybdenum catalyst, a nickel-tungsten catalyst, and a nickel-cobalt-molybdenum catalyst. 
     
     
         18 . The hydrotreating process of  claim 11 , wherein said one or more catalysts for hydrodesulfurization, hydrodenitrogenation and hydrodeoxygenation comprise a plurality of catalysts comprising at least one large pore catalyst and at least one small pore catalyst. 
     
     
         19 . The hydrotreating process of  claim 11 , wherein said one or more catalysts for hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation comprises a plurality of stacked catalysts. 
     
     
         20 . The hydrotreating process of  claim 11 , wherein said demetallizing catalyst is a low-acidity large pore catalyst including at least one of a nickel-molybdenum catalyst and a cobalt-molybdenum catalyst.