Method for fractionation of hydrocarbons

Abstract

A process for separation of a liquid phase from a gas phase and a process for production of a hydrocarbon product employing such a separation as well as a fractionation section and a hydrocracker section for carrying out such processes. The separation process includes: directing a feed for separation to a feed inlet of a means of separation; directing a stripping medium to a stripping medium inlet of the means of separation; withdrawing a liquid product stream from a means of separation; withdrawing a gaseous fraction comprising the stripping medium from the means of separation; directing the stripping medium fraction or the gaseous fraction as a recycled stripping medium; pressurizing at least an amount of the recycled stripping medium and directing it as the stripping medium, wherein the stripping medium comprises at least 80% vol/vol % of gases from the group comprising N 2 , H 2 , He, Ar, Ne and CO 2 .

1 . A process for separation of a hydrocarbonaceous liquid phase from a gas phase comprising the steps of
 a. directing a feed for separation to a feed inlet of a means of separation,   b. directing a stripping medium to a stripping medium inlet of said means of separation,   c. withdrawing a liquid product stream from said means of separation,   d. withdrawing a gaseous fraction comprising said stripping medium from said means of separation,   e. optionally cooling and separating said gaseous fraction in a light product fraction and a stripping medium fraction,   f. directing said stripping medium fraction or said gaseous fraction as a recycled stripping medium,   g. pressurizing at least an amount of said recycled stripping medium and directing it as said stripping medium of step b,   wherein said stripping medium comprises at least 80% vol/vol % of gases from the group comprising N 2 , Hz, He, Ar, Ne and CO 2 .   
     
     
         2 . The process of  claim 1  further comprising the steps of
 h. directing said liquid product stream to a secondary means of separation, 
 i. directing an amount of said stripping medium as a side stream stripping medium to said secondary means of separation, 
 j. withdrawing a gaseous side stream fraction comprising said side stream stripping medium from said secondary means of separation, 
 k. directing said gaseous side stream fraction to the means of separation and 
 l. withdrawing a liquid product fraction from said secondary means of separation. 
 
     
     
         3 . The process according to  claim 1  wherein the operating pressure of said means of separation is from atmospheric pressure to 3 barg and said pressurizing of said recycled stripping medium involves increasing the pressure by 0.1 bar to 2 bar. 
     
     
         4 . The process according to  claim 1  wherein the operating pressure of said means of separation is from 0 bar absolute to 500 mbar absolute and said pressurizing of said recycled stripping medium involves increasing the pressure by between 5 mbar and 200 mbar. 
     
     
         5 . The process according to  claim 1  wherein less than 5 wt/wt % of said feed is non-condensable at the boiling point of said stripping medium. 
     
     
         6 . The process according to  claim 1  wherein at least 95 wt/wt % of said feed is withdrawn from said means of separation in liquid form. 
     
     
         7 . The process according to  claim 1  wherein the feed has an initial boiling point of at least 100° C. 
     
     
         8 . The process according to  claim 1  wherein the 95 wt/wt % boiling point of said feed is at least 400° C. 
     
     
         9 . The process according to  claim 1  wherein the ratio between the amount of stripping medium and the amount of feed directed to the means of separation is from 10 NL/kg to 500 NL/kg. 
     
     
         10 . The process according to  claim 1  wherein from 1% to 10% of said recycled stripping medium is withdrawn as a purge. 
     
     
         11 . A process for production of a low boiling product, said process comprising the steps of
 x. directing a feed comprising at least 50 wt/wt % hydrocarbons boiling above an upper target boiling point, to contact a material catalytically active in hydrocracking under hydrocracking conditions selected for converting from 30 wt/wt % to 100 wt/wt % of the hydrocarbons boiling above the upper target boiling point to products boiling below the upper target boiling point, providing a hydrocracked product   y. directing said hydrocracked product as a feed for separation, optionally after gas/liquid separation in one or more steps, to a process of fractionation employing a recycled stripping medium,   z. withdrawing a fraction of hydrocracked product boiling in the low boiling product range.   
     
     
         12 . A fractionation section comprising a means of separation having a feed inlet, a means of separation stripping medium inlet, one or more product outlets and a vapor outlet, and a means of pressurization having an inlet and an outlet characterized in said vapor outlet being in fluid communication with the inlet of said means of pressurization, and said outlet of said means of pressurization being in fluid communication with said means of separation stripping medium inlet. 
     
     
         13 . The fractionation section according to  claim 12  further comprising a side column, having a side column feed inlet, a side column stripping medium inlet, a side column vapor outlet and a side column liquid outlet, wherein said side column stripping medium inlet is in fluid communication with the outlet of said means of pressurization. 
     
     
         14 . The fractionation section according to  claim 12 , further comprising a bottoms stripper having a bottoms stripper stripping medium inlet, a stripper vapor outlet, a bottoms stream inlet and a stripped bottoms outlet, and where said means of separation further has a bottoms outlet, and wherein said bottoms stream inlet is configured for being in fluid communication with said bottoms outlet, optionally via a means of heating, wherein said bottoms stripper stripping medium inlet is configured for being in fluid communication with said outlet of said means of pressurization optionally via a means of heating, and wherein said stripper vapor outlet is in fluid communication with said means of separation stripping medium inlet. 
     
     
         15 . A hydrocracker section comprising a hydrocracking reactor having an inlet and an outlet and a fractionation section comprising a means of separation having a feed inlet, a make up stripping medium inlet, one or more product outlets and a vapor outlet, and a means of pressurization having an inlet and an outlet characterized in said hydrocracker section being configured for directing an amount of product from the hydrocracking reactor outlet to the means of separation feed inlet, the vapor outlet being in fluid communication with the inlet of said means of pressurization, and said outlet of said means of pressurization being in fluid communication with said stripping medium inlet.