Patent Publication Number: US-7901569-B2

Title: Process for upgrading heavy oil using a reactor with a novel reactor separation system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/303,427 with a filing date of Dec. 16, 2005 now U.S. Pat. No. 7,431,822, the disclosure of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The instant invention relates to a process for upgrading heavy oils using a slurry catalyst composition. 
     BACKGROUND OF THE INVENTION 
     There is an increased interest at this time in the processing of heavy oils, due to larger worldwide demand for petroleum products. Canada and Venezuela are sources of heavy oils. Processes which result in complete conversion of heavy oil feeds to useful products are of particular interest. 
     U.S. Pat. No. 6,278,034 recites a hydrogenation process which employs a reactor having an internal means of separating gaseous product from a slurry of oil and catalyst. 
     The following patent applications, which are incorporated by reference, are directed to the preparation of highly active slurry catalyst compositions and their use in processes for upgrading heavy oil: 
     U.S. Ser. No. 10/938,202 is directed to the preparation of a catalyst composition suitable for the hydroconversion of heavy oils. The catalyst composition is prepared by a series of steps, involving mixing a Group VIB metal oxide and aqueous ammonia to form an aqueous mixture, and sulfiding the mixture to form a slurry. The slurry is then promoted with a Group VIII metal. Subsequent steps involve mixing the slurry with a hydrocarbon oil and combining the resulting mixture with hydrogen gas and a second hydrocarbon oil having a lower viscosity than the first oil. An active catalyst composition is thereby formed. 
     U.S. Ser. No. 10/938,003 is directed to the preparation of a slurry catalyst composition. The slurry catalyst composition is prepared in a series of steps, involving mixing a Group VIB metal oxide and aqueous ammonia to form an aqueous mixture and sulfiding the mixture to form a slurry. The slurry is then promoted with a Group VIII metal. Subsequent steps involve mixing the slurry with a hydrocarbon oil, and combining the resulting mixture with hydrogen gas (under conditions which maintain the water in a liquid phase) to produce the active slurry catalyst. 
     U.S. Ser. No. 10/938,438 is directed to a process employing slurry catalyst compositions in the upgrading of heavy oils. The slurry catalyst composition is not permitted to settle, which would result in possible deactivation. The slurry is recycled to an upgrading reactor for repeated use and products require no further separation procedures for catalyst removal. 
     U.S. Ser. No. 10/938,200 is directed to a process for upgrading heavy oils using a slurry composition. The slurry composition is prepared in a series of steps, involving mixing a Group VIB metal oxide with aqueous ammonia to form an aqueous mixture and sulfiding the mixture to form a slurry. The slurry is then promoted with a Group VIII metal compound. Subsequent steps involve mixing the slurry with a hydrocarbon oil, and combining the resulting mixture with hydrogen gas (under conditions which maintain the water in a liquid phase) to produce the active slurry catalyst. 
     U.S. Ser. No. 10/938,269 is directed to a process for upgrading heavy oils using a slurry composition. The slurry composition is prepared by a series of steps, involving mixing a Group VIB metal oxide and aqueous ammonia to form an aqueous mixture, and sulfiding the mixture to form a slurry. The slurry is then promoted with a Group VIII metal. Subsequent steps involve mixing the slurry with a hydrocarbon oil and combining the resulting mixture with hydrogen gas and a second hydrocarbon oil having a lower viscosity than the first oil. An active catalyst composition is thereby formed. 
     SUMMARY OF THE INVENTION 
     A process for the hydroconversion of heavy oils, said process employing an upflow reactor with a separator located internally to do phase separation. At least one reactor with an internal separator may be employed, although it is more common to use reactors in series. A hydroconversion process with reactors in series may employ the following steps: (a) combining a heated heavy oil feed, an active slurry catalyst composition and a hydrogen-containing gas to form a mixture; (b) passing the mixture of step (a) to the bottom of a reactor, which is maintained at hydroprocessing conditions, including elevated temperature and pressure; (c) separating internally in the reactor a stream comprising reaction products, hydrogen gas, unconverted oil, and slurry catalyst into two streams, a vapor stream comprising reaction products and hydrogen, and a liquid stream comprising unconverted material and slurry catalyst; (d) passing the vapor stream overhead to further processing, and passing at least a portion of the liquid stream, to the next reactor in series. 
     This invention is intended to perform phase separation within one or more reactors in the process scheme depicted, so that a single vapor phase product is the only product leaving the top of the reactor. A liquid phase product is the only stream leaving the lower portion of the reactor (through the bottom or side) for further processing. If internal separation occurs, there is no need for a hot high pressure separator or flash drum to separate the phase following their exit from the reactor. 
     The instant invention further employs a reactor differential pressure control system that regulates the vapor product leaving the top of the reactor, thus making a control valve on the feed stream to the next reactor unnecessary. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURE 
       The FIGURE shows the process scheme of this invention as applied to a multiple reactor system in series. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The instant invention is directed to a process for catalyst activated slurry hydrocracking. Interstage separation of gaseous reaction products and liquid streams comprising uncoverted oil and catalyst is effective in maintaining heat balance in the process. In the FIGURE, stream  1  comprises a heavy feed, such as vacuum residuum. Other feeds may include atmospheric residuum, vacuum residuum, tar from a solvent deasphalting unit, atmospheric gas oils, vacuum gas oils, deasphalted oils, olefins, oils derived from tar sands or bitumen, oils derived from coal, heavy crude oils, synthetic oils from Fischer-Tropsch processes, and oils derived from recycled oil wastes and polymers. 
     The feed enters furnace  80  where it is heated, exiting in stream  4 . Stream  4  combines with a hydrogen containing gas (stream  2 ), recycle slurry (stream  17 ), and a stream comprising an active slurry composition (stream  3 ), resulting in a mixture (stream  24 ). Stream  24  enters the bottom of the first reactor  10 . Vapor Stream  31  exits the top of the reactor comprising primarily reaction products and hydrogen, due to a separation apparatus inside the reactor (not shown). Liquid stream  26 , which contains slurry in combination with unconverted oil, exits the bottom, or side, of reactor  10 . 
     Stream  26  is combined with a gaseous stream comprising hydrogen (steam  15 ) to create stream  27 . Stream  27  enters the bottom of second reactor  20 . 
     Vapor stream  8 , comprising primarily reaction products and hydrogen, exits the top of the reactor  20  and joins the vapor product from reactor  20 . Liquid stream  27 , which contains slurry in combination with unconverted oil, exits the bottom, or side, of reactor  20 . 
     Stream  32  is combined with a gaseous stream comprising hydrogen (stream  16 ) to create stream  28 . Stream  28  enters the bottom of reactor  30 . Vapor stream  12 , comprising primarily reaction products and hydrogen, exits the top of the reactor and joins the vapor product from the first two reactors in stream  14 . Liquid stream  17 , which contains slurry in combination with unconverted oil, exits the bottom, or side, of reactor  30 . A portion of this stream may be drawn off as stream  18  or recycled back to the first reactor  10 , as stream  17 . 
     Overhead streams from reactors  10 ,  20  and  30  (streams  31 ,  8  and  12  respectively) create stream  14 , which passes to downstream equipment for further processing. 
     The preferred type of reactor in the instant invention is a liquid recirculating reactor, although other types of upflow reactors may be employed. Liquid recirculating reactors are discussed further in copending application Ser. No. 11/305,359 or US Patent Publication No. US2007140927 (T-6493), which is incorporated by reference. 
     A liquid recirculation reactor is an upflow reactor which feeds heavy hydrocarbon oil and a hydrogen rich gas at elevated pressure and temperature for hydroconversion. Process conditions for the liquid recirculating reactor include pressures in the range from 1500 through 3500 psia, preferably 2000 through 3000 psia. Temperatures are in the range from 700 through 900 F, preferably 775 through 850 F. 
     Hydroconversion includes processes such as hydrocracking and the removal of heteroatom contaminants (such sulfur and nitrogen). In slurry catalyst use, catalyst particles are extremely small (1-10 micron). Pumps may be used for recirculation of slurry, although they not required to be used. 
     The process for the preparation of the catalyst slurry composition used in this invention is set forth in U.S. Ser. No. 10/938,003 and U.S. Ser. No. 10/938,202 and is incorporated by reference. The catalyst composition is useful for but not limited to hydrogenation upgrading processes such as hydrocracking, hydrotreating, hydrodesulphurization, hydrodenitrification, and hydrodemetallization.