Process for producing btx and lpg

Abstract

The invention is directed to a process for producing BTX and LPG, comprising: a) contacting a feed stream comprising C5-C12 hydrocarbons in the presence of hydrogen with a hydrocracking catalyst in a hydrocracking reactor to produce a hydrocracking product stream comprising hydrogen, methane, LPG and BTX, b) separating the hydrocracking product stream into a first gas stream and a first liquid stream, c) separating the first gas stream to obtain a second gas stream comprising hydrogen and methane and a second liquid stream comprising LPG and BTX, wherein the separation is performed such that the second liquid stream is substantially free of hydrogen and methane, d) separating the second liquid stream into a third gas stream comprising LPG and a third liquid stream comprising BTX, wherein step (c) involves adding a part of the third liquid stream to the first gas stream to absorb the LPG in the first gas stream to obtain the second liquid stream or adding a part of the third liquid stream to a gas stream sep crated from the first gas stream to absorb the LPG in said gas stream separated from the first gas stream to obtain the second liquid stream.

1 . A process for producing BTX and LPG, comprising:
 (a) contacting a feed stream comprising C5-C12 hydrocarbons in the presence of hydrogen with a hydrocracking catalyst in a hydrocracking reactor to produce a hydrocracking product stream comprising hydrogen, methane, LPG and BTX,   (b) separating the hydrocracking product stream into a first gas stream and a first liquid stream,   (c) separating the first gas stream to obtain a second gas stream comprising hydrogen and methane and a second liquid stream comprising LPG and BTX, wherein the separation is performed such that the second liquid stream is substantially free of hydrogen and methane,   (d) separating the second liquid stream into a third gas stream comprising LPG and a third liquid stream comprising BTX,   wherein step (c) involves adding a part of the third liquid stream to the first gas stream to absorb the LPG in the first gas stream to obtain the second liquid stream or adding a part of the third liquid stream to a gas stream separated from the first gas stream to absorb the LPG in said gas stream separated from the first gas stream to obtain the second liquid stream.   
     
     
         2 . The process according to  claim 1 , wherein step (c) involves
 (c1) separating the first gas stream into a gas stream and a liquid stream and   (c2) adding the part of the third liquid stream to the gas stream obtained by step (c1).   
     
     
         3 . The process according to  claim 2 , wherein step (c2) involves compressing the gas stream obtained by step (c1) and adding the part of the third liquid stream to the compressed gas stream. 
     
     
         4 . The process according to  claim 1 , wherein step (c) involves adding a part of the third liquid stream to the first gas stream. 
     
     
         5 . The process according to  claim 1 , wherein the second liquid stream substantially consists of LPG and BTX. 
     
     
         6 . The process according to  claim 1 , wherein at least part of the second gas stream is fed back to be mixed with the feed stream. 
     
     
         7 . The process according to  claim 1 , wherein the process further comprises step (e) of separating benzene from the third liquid stream. 
     
     
         8 . The process according to  claim 6 , wherein the third liquid stream is separated into benzene and a liquid stream comprising toluene and xylene and the liquid stream comprising toluene and xylene is used for absorbing the LPG in step (c). 
     
     
         9 . The process according to  claim 1 , wherein the part of the third liquid stream to be added to the first gas stream is cooled to a temperature below 0° C. before being added to the first gas stream. 
     
     
         10 . The process according to  claim 1 , wherein the part of the third liquid stream to be added to the first gas stream is cooled to −40° C. to −30° C. before being added to the first gas stream. 
     
     
         11 . The process according to  claim 1 , wherein the part of the third liquid stream to be added to the first gas stream is cooled to a temperature 0.5-5° C. higher than the temperature at which the third liquid stream freezes, before being added to the first gas stream. 
     
     
         12 . The process according to  claim 1 , wherein the hydrocracking catalyst of step (a) comprises 0.01-1 wt-% hydrogenation metal in relation to the total catalyst weight and a zeolite having a pore size of 5-8 Å and a silica (SiO 2 ) to alumina (Al 2 O 3 ) molar ratio of 5-200 and step (a) is performed under process conditions including a temperature of 425-580° C., a pressure of 300-5000 kPa gauge and a Weight Hourly Space Velocity of 0.1-15 h −1 . 
     
     
         13 . The process according to  claim 12 , wherein the hydrogenation metal of the hydrocracking catalyst is at least one element selected from Group 10 of the periodic table of Elements. 
     
     
         14 . The process according to  claim 12 , wherein the zeolite is selected from the group consisting of ZSM-5, MCM-22, ZSM-11, beta zeolite, EU-1 zeolite, zeolite Y, faujastite, ferrierite and mordenite. 
     
     
         15 . The process according to  claim 1 , wherein the feed stream comprises pyrolysis gasoline, straight run naphtha, light coker naphtha and coke oven light oil, FCC gasoline, reformate or mixtures thereof. 
     
     
         16 . The process according to  claim 13 , wherein the hydrogenation metal is Pt. 
     
     
         17 . The process according to  claim 14 , wherein the zeolite is ZSM-5. 
     
     
         18 . The process according to  claim 15 , wherein the feed stream is depentanized.