Needle coke production from hpna recovered from hydrocracking unit

Abstract

A process for the treatment of a hydrocracking unit bottoms stream containing heavy poly-nuclear aromatic (HPNA) compounds and/or a fresh hydrocracking feedstock stream containing HPNA precursors to produce coke. The HPNA and/or HPNA precursors are removed from the hydrocracking unit bottoms stream and/or a fresh hydrocracking feedstock stream by solvent washing, and the HPNA and/or HPNA precursors are subjected to delayed coking for the production of coke.

1 - 18 . (canceled) 
     
     
         19 . A system for the treatment of a hydrocracking unit bottoms stream containing heavy poly-nuclear aromatic (HPNA) compounds and/or a fresh hydrocracking feedstock stream containing HPNA precursors and production of coke, the system comprising:
 an adsorption unit containing an effective amount of adsorbent material to adsorb the HPNA compounds and HPNA precursors and produce an adsorbent treated hydrocarbon stream;   a solvent feedstream configured for washing the adsorbent material, producing a solvent effluent stream HPNA compounds and HPNA precursors;   a separation unit for separating the solvent from the HPNA compounds and HPNA precursors; and   a delayed coking unit configured for converting the HPNA compounds and HPNA precursors to needle, anode, or fuel grade coke;   wherein the adsorption unit further comprises a first adsorber and a second adsorber configured to operate in swing mode where the first adsorber is in adsorption mode where the hydrocracking unit bottoms stream and/or a fresh hydrocracking feedstock stream is fed to the first adsorber to produce the adsorbent treated hydrocarbon stream, and the second adsorber is configured to operate in desorption mode where the solvent is washing the adsorbent laden with HPNA compounds and HPNA precursors to produce the solvent effluent stream; wherein after a period of time, the first adsorber is configured to switch to desorption mode and the second adsorber is configured to switch to adsorption mode, thereby continuously producing the adsorbent treated hydrocarbon stream and the solvent effluent stream.   
     
     
         20 . The system of  claim 19 , wherein the system for treatment of the hydrocracking unit bottoms stream produces needle coke. 
     
     
         21 . The system of  claim 19 , wherein the system for treatment of the fresh hydrocracking feedstock stream produces fuel coke. 
     
     
         22 . The system of  claim 19 , wherein the system for treatment of the hydrocracking unit bottoms stream and/or fresh hydrocracking feedstock stream produces anode grade coke. 
     
     
         23 . (canceled) 
     
     
         24 . The system of  claim 19 , wherein the delayed coking unit further comprises:
 a mixing unit configured for receiving the HPNA compounds and HPNA precursors from the separation unit and one or more of an intermediate product recycle stream and a coker product stream, forming a coking fractionator feedstream;   a coking fractionator configured for separating the coking fractionator feedstream into a coker feedstream and an intermediate product stream;   a coker unit furnace configured for heating the coker feedstream; and   a coking zone configured for coking the heated coker feedstream and producing an overhead coker product stream and a coke product stream.   
     
     
         25 . The system of  claim 24 , wherein the coking zone comprises a first coker unit and a second coker configured to operate in parallel in a swing mode. 
     
     
         26 . The system of  claim 24 , wherein the mixing unit is configured for receiving one or more of an intermediate product recycle stream and the overhead coker product stream.