Coker operation without recycle

Abstract

A process for coking a heavy oil feedstock with elimination of recycle is disclosed. In a preferred embodiment, heavy hydrocarbon feed is directly passed to the coking vessels, coker overhead vapors are combined and passed directly to a fractionator and fractionator bottoms are recovered as product for further processing in other refining systems. Distillate coker product is not used to reduce the heavy hydrocarbon feed viscosity or to manage coke fouling in the coker furnace.

What is claimed:  
     
         1 . A method for coking a heavy hydrocarbon feed comprising: 
 (a) directly feeding the heavy hydrocarbon feed through at least one pre-heater to a coking furnace;    (b) heating the feed in the coking furnace to coking temperatures;    (c) alternately feeding the heated feed directly to a first coke vessel and a second coke vessel to form a first hydrocarbon vapor product and a first coke accumulation in the first vessel and a second coke accumulation in the second vessel.    
     
     
         2 . The method of  claim 1  further comprising, alternately steam stripping the first and the second coke accumulations to form a second hydrocarbon vapor product and feeding the second hydrocarbon vapor product to a blowdown system to form a first condensate.  
     
     
         3 . The method of  claim 2  further comprising, alternately emptying the first coke accumulation from the first coke vessel and the second coke accumulation from the second vessel and alternately feeding the second hydrocarbon vapor through the empty vessel to a condensate drum to form a second condensate.  
     
     
         4 . The method of  claim 3  further comprising, combining the first condensate, the second condensate and the first hydrocarbon vapor product to form a quenched combination and feeding the quenched combination to the fractionator to form one or more hydrocarbon products.  
     
     
         5 . The method of  claim 1  wherein the heavy hydrocarbon feed is heated to temperatures in the range of about 850° F. to about 1100° F.  
     
     
         6 . The method of  claim 5  wherein the heavy hydrocarbon feed is heated to temperatures in the range of about 900° F. to about 975° F.  
     
     
         7 . The method of  claim 4  wherein the hydrocarbon products are selected from the group consisting of coker fractionator bottoms, heavy coker gas oil, light coker gas oil, a jet fuel cut, light naphtha, heavy naphtha and process gas.  
     
     
         8 . The method of  claim 7  wherein the heavy coker gas oil product has a boiling range between about 650° F. and 1150° F.;  
     
     
         9 . The method of  claim 7  wherein the light coker gas oil product has a boiling range between about 350° F. and 750° F.;  
     
     
         10 . The method of  claim 7  wherein the jet fuel product has a boiling range between about 250° F. and 570° F.;  
     
     
         11 . The method of  claim 7  wherein the heavy naphtha product has a boiling range between about 180° F. and 400° F.;  
     
     
         12 . The method of  claim 7  wherein the light naphtha product has a boiling range between about 50° F. and 250° F.;  
     
     
         13 . The method of  claim 7  wherein the process gas product has a boiling range less than about 100° F.;  
     
     
         14 . The method of  claim 7  wherein the coker fractionator bottoms product has a boiling range above about 650° F.  
     
     
         15 . The method of  claim 1  wherein step (a) further comprises feeding the heavy hydrocarbon feed through a surge drum before feeding to the coker furnace.  
     
     
         16 . The method of  claim 7  further comprising feeding the coker fractionator bottoms product to other refining processes.  
     
     
         17 . The method of  claim 7  further comprising feeding at least a portion of the heavy coker gas oil to the fractionator.  
     
     
         18 . The method of  claim 18  further comprising feeding the entire stream of heavy coker gas oil to the fractionator.