Solvent Control for Centrifugation of Steam Cracked Tar

Abstract

Processes for preparing a low particulate liquid hydrocarbon product are provided and includes blending a tar stream containing particles with a fluid to produce a fluid-feed mixture containing tar, the particles, and the fluid, where the fluid-feed mixture contains about 30 wt % or greater of the fluid based on a combined weight of the tar stream and the fluid. The method also includes separating, e.g., by centrifuging, from the fluid-feed mixture a higher density portion and a lower density portion, where the lower density portion contains no more than 25 wt % of the particles in the fluid-feed mixture, based on the weight of the particles in the fluid-feed mixture.

1 . A process for preparing a low particulate liquid hydrocarbon product comprising:
 blending a tar stream comprising particles with a fluid to produce a fluid-feed mixture comprising tar, the particles, and the fluid; and   separating from the fluid-feed mixture a higher density portion and a lower density portion, wherein at least 75% by weight of the particles are transferred from the fluid-feed mixture to the higher density portion, based on the weight of the particles in the fluid-feed mixture.   
     
     
         2 . The process of  claim 1 , wherein the fluid-feed mixture comprises wherein the fluid-feed mixture comprises about 30 wt % or greater of the fluid based on a combined weight of the tar stream and the fluid, and the separation includes applying a centrifugal force to the fluid-feed mixture. 
     
     
         3 . The process of  claim 1 , wherein the fluid-feed mixture comprises about 40 wt % to about 70 wt % of the fluid based on the combined weight of the tar stream and the fluid, and the separation includes applying a centrifugal force to the fluid-feed mixture in at least one centrifuge. 
     
     
         4 . The process of  claim 1 , wherein the fluid comprises a utility fluid that includes one or more of benzene, ethylbenzene, trimethylbenzene, xylenes, toluene, naphthalenes, alkylnaphthalenes, tetralins, and alkyltetralins. 
     
     
         5 . The process of  claim 1 , wherein the lower density portion comprises no more than 10 wt % of the particles in the fluid-feed mixture, based on the weight of the fluid-feed mixture. 
     
     
         6 . The process of  claim 1 , wherein the lower density portion comprises ≤5 wt % the particles, based on the weight of the particles in the fluid-feed mixture. 
     
     
         7 . The process of  claim 1 , wherein the lower density portion is substantially free of the particles of size greater than 25 μm, and further comprising hydroprocessing at least a portion of the lower density portion. 
     
     
         8 . The process of  claim 1 , wherein the utility fluid has a solubility blending number≥90. 
     
     
         9 . The process of  claim 8 , wherein the utility fluid has a solubility blending number in the range of about 100 to about 160. 
     
     
         10 . The process of  claim 1 , wherein the particles comprise one or more of coke, oligomeric and/or polymeric material, inorganic solids, asphaltenes, inorganics, agglomerates, and aggregates. 
     
     
         11 . The process of  claim 10 , wherein the particles comprise one or more of pyrolytic coke, polymeric coke having a specific gravity of about 1.04 to about 1.1, fines, metal, metal-containing compounds, and ash. 
     
     
         12 . The process of  claim 1 , wherein the fluid further comprises at least one separation fluid. 
     
     
         13 . A process for preparing a low particulate liquid hydrocarbon product comprising:
 blending a tar stream comprising particles with a fluid to produce a fluid-feed mixture comprising tar, the particles, and the fluid, wherein the fluid-feed mixture comprises about 30 wt % or greater of the fluid based on a combined weight of the tar stream and the fluid, and   wherein the fluid-feed mixture comprises >500 ppmw of the particles having a size of greater than 25 μm, based on the weight of the fluid-feed mixture; and   centrifuging the fluid-feed mixture to produce a higher density portion and a lower density portion,
 wherein:
 the lower density portion comprises ≤25% of the particles in the fluid-feed mixture, based on the weight of particles in the feed-fluid mixture, or 
 the lower density portion comprises ≤500 ppmw of particles having a size of greater than 25 μm, based on the weight of the lower density portion. 
 
   
     
     
         14 . The process of  claim 13 , wherein the lower density portion comprises about 250 ppmw or less of particles having a size>25 μm, based on the weight of the lower density portion. 
     
     
         15 . The process of  claim 13 , wherein the lower density portion comprises about 100 ppm or less of the particles having a size>25 μm, based on the weight of the particles in the feed-fluid mixture. 
     
     
         16 . The process of  claim 13 , wherein the fluid-feed mixture comprises about 40 wt % to about 70 wt % of the fluid based on the combined weight of the tar stream and the fluid. 
     
     
         17 . The process of  claim 13 , wherein the fluid comprises a solvent selected from the group consisting of benzene, ethylbenzene, trimethylbenzene, xylenes, toluene, naphthalenes, alkylnaphthalenes, tetralins, alkyltetralins, and any combination thereof. 
     
     
         18 . The process of  claim 13 , wherein the lower density portion comprises ≤5 wt % of the particles in the fluid-feed mixture, based on the weight of the particles in the feed-fluid mixture. 
     
     
         19 . The process of  claim 13 , wherein the lower density portion is substantially free of the particles of size>25 μm. 
     
     
         20 . The process of  claim 13 , wherein the utility fluid has a solubility blending number in the range of about 100 to about 160. 
     
     
         21 . A process for preparing a low particulate liquid hydrocarbon product comprising:
 blending a tar stream comprising particles with a fluid to produce a fluid-feed mixture comprising tar, the particles, and the fluid, wherein the fluid-feed mixture comprises about 30 wt % to about 70 wt % of the fluid based on a combined weight of the tar stream and the fluid, wherein the fluid-feed mixture comprises ≥500 ppmw of the particles having a size of greater than 25 μm, based on the weight of the fluid-feed mixture, and wherein the particles have a specific gravity from about 1.04 to about 1.5; and   centrifuging the fluid-feed mixture to produce a higher density portion and a lower density portion, wherein the lower density portion comprises ≤500 ppmw of particles having a size of greater than 25 μm, based on the weight of the lower density portion.   
     
     
         22 . The process of  claim 21 , wherein the lower density portion comprises ≤250 ppmw of particles having a size of greater than 25 μm, based on the weight of the lower density portion. 
     
     
         23 . The process of  claim 21 , wherein the lower density portion comprises about 100 ppmw or less of particles having a size>25 μm, based on the weight of the lower density portion. 
     
     
         24 . The process of  claim 21 , wherein the fluid-feed mixture comprises about 45 wt % to about 60 wt % of the fluid based on the combined weight of the tar stream and the fluid. 
     
     
         25 . The process of  claim 21 , wherein the fluid comprises a solvent selected from the group consisting of benzene, ethylbenzene, trimethylbenzene, xylenes, toluene, naphthalenes, alkylnaphthalenes, tetralins, alkyltetralins, and any combination thereof. 
     
     
         26 . The process of  claim 21 , wherein the lower density portion comprises no more than 5 wt % of the particles in the fluid-feed mixture, based on the weight of the particles in the fluid-feed mixture. 
     
     
         27 . The process of  claim 26 , wherein the lower density portion is substantially free of the particles of size>25 μm. 
     
     
         28 . A process for preparing a low particulate liquid hydrocarbon product comprising:
 heat soaking a steam cracker tar stream comprising particles having a size>25 μm; then   blending the steam cracker tar stream with a utility fluid to produce a fluid-feed mixture comprising the steam cracker tar and the fluid, wherein the fluid-feed mixture comprises about 30 wt % to about 70 wt % of the utility fluid based on a combined weight of the steam cracker tar stream and the utility fluid, wherein the fluid-feed mixture comprises ≥500 ppm by weight of the particles in the steam cracker tar having a size>25 μm, and wherein the particles have a specific gravity from about 1.04 to about 1.5; and   centrifuging the fluid-feed mixture to produce a higher density portion and a lower density portion, wherein the lower density portion comprises ≤100 ppmw of particles having a size>25 μm.