Upgrading Hydrocarbon Pyrolysis Products by Hydroprocessing

Abstract

The invention relates to processes for upgrading products obtained from hydrocarbon pyrolysis, equipment useful for such processes, and the use of upgraded pyrolysis products.

1 . A hydrocarbon conversion process, comprising:
 (a) providing a first mixture comprising ≧10.0 wt. % hydrocarbon based on the weight of the first mixture;   (b) pyrolyzing the first mixture to produce a second mixture comprising ≧1.0 wt. % of C 2  unsaturates and ≧1.0 wt. % tar, the weight percents being based on the weight of the second mixture;   (c) separating a tar stream from the second mixture wherein the tar stream contains ≧90.0 wt. % of the second mixture's molecules having an atmospheric boiling point of ≧290° C.;   (d) providing a utility fluid, the utility fluid comprising ≧40.0 wt. % aromatic carbon based on the weight of the utility fluid;   (e) exposing at least a portion of the tar stream to at least one hydroprocessing catalyst under catalytic hydroprocessing conditions in the presence of molecular hydrogen and the utility fluid at a utility fluid:tar weight ratio in the range of 0.05 to 3.5 to produce a hydroprocessor effluent; and   (f) separating a liquid phase from the hydroprocessor effluent, the liquid phase comprising ≧90.0 wt. % of the hydroprocessor effluent's molecules having at least four carbon atoms based on the weight of the hydroprocessor effluent, wherein the utility fluid comprises the separated liquid phase in an amount ≧90.0 wt. % based on the weight of the utility fluid.   
     
     
         2 . The process of  claim 1 , wherein the utility fluid comprises ≧60.0 wt. % aromatic carbon measured by NMR based on the weight of the utility fluid. 
     
     
         3 . The process of  claim 1 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧65.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         4 . The process of  claim 1 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧100.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         5 . The process of  claim 1 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧150.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         6 . The process of  claim 1 , wherein the density of the utility fluid at 15° C. is less than the density of the tar stream at 15° C. 
     
     
         7 . The process of  claim 1 , wherein the first mixture's hydrocarbon comprises one or more of naphtha, gas oil, vacuum gas oil, waxy residues, atmospheric residues, residue admixtures, or crude oil. 
     
     
         8 . The process of  claim 1 , wherein first mixture comprises ≧50.0 wt. % based on the weight of the first mixture of one or more of naphtha, gas oil, vacuum gas oil, waxy residues, atmospheric residues, residue admixtures, or crude oil. 
     
     
         9 . The process of  claim 1 , wherein the pyrolyzing step (b) is steam cracking. 
     
     
         10 . The process of  claim 1 , wherein the tar stream comprises (i) ≧10.0 wt. % of molecules having an atmospheric boiling point ≧565° C. that are not asphaltenes and (ii) ≦1000.0 ppmw metals, the weight percents being based on the weight of the tar stream. 
     
     
         11 . The process of  claim 1 , wherein the hydroprocessing conditions include one or more of a temperature in the range of 350° C. to 450° C., a pressure in the range of 20 bar to 100 bar, a space velocity (LHSV) in the range of 0.2 to 4.0, and a hydrogen consumption rate of 50 S m 3 /m 3  to 450 S m 3 /m 3 . 
     
     
         12 . The process of  claim 1 , wherein the utility fluid comprises the separated liquid phase of step (f) in an amount ≧99.0 wt. % based on the weight of the utility fluid. 
     
     
         13 . The process of  claim 1 , wherein the utility fluid:tar stream weight ratio of step (e) is in the range of 0.10 to 3.0. 
     
     
         14 . The process of  claim 1 , wherein the utility fluid:tar stream weight ratio of step (e) is in the range of 0.2 to 3.0. 
     
     
         15 . The process of  claim 1 , further comprising conducting a second portion of the liquid phase away from the process, the second portion being utilized for producing a fuel. 
     
     
         16 . The process of  claim 1 , further comprising providing a supplemental utility fluid to step (d) to replace at least a part of the utility fluid from a portion of the liquid phase in step (g), the supplemental utility fluid comprising aromatics and having an ASTM D86 10% distillation point ≧60.0° C. and a 90% distillation point ≦350.0° C. 
     
     
         17 . A hydrocarbon conversion process, comprising:
 (a) providing a first mixture comprising ≧10.0 wt. % hydrocarbon based on the weight of the first mixture;   (b) pyrolyzing the first mixture to produce a second mixture comprising ≧1.0 wt. % of C 2  unsaturates and ≧1.0 wt. % tar, the weight percents being based on the weight of the second mixture;   (c) separating a tar stream from the second mixture, wherein the tar stream contains 90 wt. % of the second mixture's molecules having an atmospheric boiling point of ≧290° C.;   (d) providing a utility fluid, the utility fluid comprising ≧40.0 wt. % aromatic carbon measured by NMR based on the weight of the utility fluid;   (e) exposing at least a portion of the tar stream to at least one hydroprocessing catalyst under catalytic hydroprocessing conditions in the presence of molecular hydrogen and the utility fluid at a utility fluid:tar stream weight ratio in the range of 0.05 to 3.5 to produce a hydroprocessor effluent;   (f) separating a liquid phase from the hydroprocessor effluent, the liquid phase comprising ≧90.0 wt. % of the hydroprocessor effluent's molecules having at least four carbon atoms based on the weight of the hydroprocessor effluent; and   (g) separating from the liquid phase a light liquid and a heavy liquid, wherein the heavy liquid comprises 90 wt. % of the liquid phase's molecules having an atmospheric boiling point of ≧300° C.;   wherein the utility fluid comprises the separated light liquid in an amount ≧90.0 wt. % based on the weight of the utility fluid.   
     
     
         18 . The process of  claim 17 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧65.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         19 . The process of  claim 17 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧100.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         20 . The process of  claim 17 , wherein the liquid phase comprises ≧90.0 wt. % of the hydroprocessor effluent's molecules having an atmospheric boiling point ≧150.0° C. based on the weight of the hydroprocessor effluent. 
     
     
         21 . The process of  claim 17 , wherein the heavy liquid comprises ≧90.0 wt. % of the liquid phase's molecules having an atmospheric boiling point of ≧250° C. 
     
     
         22 . The process of  claim 17 , wherein the heavy liquid comprises ≧90.0 wt. % of the liquid phase's molecules having an atmospheric boiling point of ≧350° C. 
     
     
         23 . The process of  claim 17 , further comprising conducting a second portion of the light liquid away from the process. 
     
     
         24 . A continuous hydrocarbon conversion process, comprising:
 (a) providing a first mixture comprising ≧10.0 wt. % hydrocarbon based on the weight of the first mixture;   (b) pyrolysing the first mixture to produce a second mixture comprising ≧1.0 wt. % of C 2  unsaturates and ≧1.0 wt. % tar, the weight percents being based on the weight of the second mixture;   (c) providing a utility fluid, the utility fluid comprising ≧40.0 wt. % aromatic carbon measured by NMR based on the weight of the utility fluid;   (d) exposing ≧50.0 wt. % of the second mixture's tar based on the weight of the second mixture's tar to at least one hydroprocessing catalyst under catalytic hydroprocessing conditions operating continuously for a time ≧24 hours, in the presence of the utility fluid and 50.0 S m 3 /m 3  to 890.0 S m 3 /m 3  molecular hydrogen at (i) an LHSV in the range of from about 1.0×10 −1  to about 10.0, (ii) a temperature in the range of 300.0° C. to 500.0° C., (iii) a pressure in the range of from 25 bar (absolute) to 100 bar (absolute), and (iv) a utility fluid:tar stream weight ratio in the range of 0.1 to 3.5, to produce a hydroprocessor effluent; and   (e) separating a liquid phase from the hydroprocessor effluent, the liquid phase comprising ≧95.0 wt. % of the hydroprocessor effluent's molecules having at least four carbon atoms based on the weight of the hydroprocessor effluent; wherein the utility fluid comprises the separated liquid phase in an amount ≧99.0 wt. % based on the weight of the utility fluid.   
     
     
         25 . The continuous hydrocarbon conversion process of  claim 24 , wherein the pressure drop across the exposing step (d) does not exceed the initial pressure drop by more than 300% after the 100 hours of continuous operation.