Flash processing of asphaltic residual oil

Abstract

A method to upgrade virgin and partially hydrogenated asphaltic residual oils by utilizing hot, high velocity combustion gas jets to rapidly atomize and heat the residual oil, maintaining the reactant temperature required to achieve the desired residual oil conversion with the minimum practical residence time, rapidly separating vapor and liquid reactants, and rapidly cooling the vapor and liquid products. The minimum required temperature and practical residence time are used for the production of deasphalted oil and asphaltene products with minimum degradation due to thermal cracking. The maximum conversion of residual oil may be substantially increased by combining a portion of the heavy oil product with the residual oil feed and partially hydrogenating this mixture.

1 . A method for upgrading asphaltic residual oil comprising:
 a) producing a combustion gas jet by expansion of a combustion gas through a convergent-divergent nozzle   b) contacting said asphaltic residual oil with said combustion gas jet;   c) separating a vapor phase and a liquid phase formed by said contacting; and   d) cooling said vapor phase and said liquid phase products to form light and heavy oil products.   
   
   
       2 . The method as claimed in  claim 1  wherein said cooling is to a temperature less than 400° C. 
   
   
       3 . The method as claimed in  claim 1  wherein said asphaltic residual oil feed has an apparent viscosity less than 1000 cP. 
   
   
       4 . The method as claimed in  claim 1  wherein said asphaltic residual oil is at a temperature of about 100 to about 425° C. prior to contacting said combustion gas jet. 
   
   
       5 . The method as claimed in  claim 1  further comprising hydrotreating said asphaltic residual oil by contacting with a homogeneous catalyst prior to contact with said combustion gas. 
   
   
       6 . The method as claimed in  claim 1  wherein said homogeneous catalyst is a molybdenum sulfide catalyst. 
   
   
       7 . The method as claimed in  claim 1  wherein said hydrotreating is performed in an ebullated or fixed bed hydrotreating reactor. 
   
   
       8 . The method as claimed in  claim 1  wherein hydrogen is added to said asphaltic residual oil. 
   
   
       9 . The method as claimed in  claim 1  wherein said hydrogen is added to said asphaltic residual oil at about 100 to about 1500 standard cubic feed per barrel of asphaltic residual oil. 
   
   
       10 . The method as claimed in  claim 1  wherein said hydrogen is added to said asphaltic residual oil at about 150 to about 1000 standard cubic feed per barrel of asphaltic residual oil. 
   
   
       11 . The method as claimed in  claim 1  wherein said combustion gas jet is formed by reacting an oxidant with a fuel. 
   
   
       12 . The method as claimed in  claim 1  wherein said oxidant is selected from the group consisting of air, oxygen-enriched air and substantially pure oxygen. 
   
   
       13 . The method as claimed in  claim 1  wherein said fuel is selected from the group consisting of carbon monoxide, hydrogen, gaseous hydrocarbons and mixtures thereof. 
   
   
       14 . The method as claimed in  claim 1  further comprising adding steam to said fuel. 
   
   
       15 . The method as claimed in  claim 1  wherein the pressure ratio of said combustion gas to said reactant gas stream is between 2 and 20. 
   
   
       16 . The method as claimed in  claim 1  wherein the temperature of said combustion gas jet is a bout 1250 to about 2000° C. 
   
   
       17 . The method as claimed in  claim 1  wherein said convergent-divergent nozzle is axisymmetric. 
   
   
       18 . The method as claimed in  claim 1  further comprising an array of convergent-divergent nozzles. 
   
   
       19 . The method as claimed in  claim 1  wherein said asphaltic residual oil contacts said combustion gas jet from the periphery of said combustion gas jet. 
   
   
       20 . The method as claimed in  claim 1  wherein said convergent-divergent nozzle is conical. 
   
   
       21 . The method as claimed in  claim 1  wherein said asphaltic residual oil contacts said combustion gas jet along the axis of said conical convergent-divergent nozzle. 
   
   
       22 . The method as claimed in  claim 1  wherein said separation is performed in a cyclone. 
   
   
       23 . The method as claimed in  claim 1  wherein said reactant residence time above 425° C. is less than 400 milliseconds. 
   
   
       24 . The method as claimed in  claim 1  wherein a liquid distillate quench is used to rapidly cool said vapor phase and said gas phase. 
   
   
       25 . The method as claimed in  claim 1  wherein said quench is atomized. 
   
   
       26 . The method as claimed in  claim 1  wherein a purge gas is used to minimize loss of said liquid distillate in said heavy oil product. 
   
   
       27 . The method as claimed in  claim 1  wherein ratio of said combustion gas jet and said asphaltic residual feed flow rate is adjusted to obtain an adiabatic temperature for said reactant stream between 500 and 850° C.