Dense phase fluidized bed reactor to maximize btx production yield

Abstract

Systems and methods for producing aromatics are disclosed. A mixture of hydrocarbons having an initial boiling point of less than 250° C. with catalyst in a fluidized bed under reaction conditions effective to produce one or more aromatics. The reaction conditions include an average solids volume fraction of the fluidized bed in a range of 0.35 to 0.45.

1 . A method of producing aromatics, the method comprising:
 contacting a mixture of hydrocarbons having an initial boiling point of less than 250° C. with catalyst in a fluidized bed under reaction conditions effective to produce one or more aromatics, wherein the reaction conditions comprise the fluidized bed having an average solids volume fraction in a range of 0.35 to 0.45.   
     
     
         2 . The method of  claim 1 , wherein the fluidized bed is a dense phase fluidized bed with a bulk density of 80 to 240 kg/m 3 . 
     
     
         3 . The method of  claim 1 , wherein the reaction conditions further comprise a superficial gas velocity of 0.25 to 0.5 m/s. 
     
     
         4 . The method of  claim 1 , wherein the mixture of hydrocarbons include full range naphtha, light naphtha, or heavy naphtha. 
     
     
         5 . The method of any of  claims 1  and  2 , wherein the mixture of hydrocarbons is flowed in a direction counter current to flow of the catalyst in the fluidized bed. 
     
     
         6 . The method of  claim 1 , wherein the mixture of hydrocarbons is flowed through a sparger feed distributor into a reactor containing the fluidized bed. 
     
     
         7 . The method of  claim 6 , wherein the reactor comprises internals including sieve plates, multi-orifice distributors, perforated plates, or combinations thereof. 
     
     
         8 . The method of  claim 1 , wherein the catalyst comprises H-ZSM-5, silica-alumina, or combinations thereof. 
     
     
         9 . The method of  claim 1 , wherein the reaction conditions further include a reaction temperature of 630 to 700° C. and a reaction pressure of 1 to 2 bar. 
     
     
         10 . The method of  claim 1 , wherein the reaction conditions further include a weight hourly space velocity in a range of 1.7 to 2.1 hr −1 . 
     
     
         11 . The method of  claim 1 , wherein the reaction conditions further include residence time distribution of 70 to 90% within 60 minutes. 
     
     
         12 . The method of  claim 1 , wherein the method further produces one or more olefins including ethylene, propylene, 1-butene, 2-butene, isobutene, or combinations thereof. 
     
     
         13 . The method of  claim 1 , wherein the aromatics comprise benzene, toluene, xylene, or combinations thereof. 
     
     
         14 . The method of  claim 13 , wherein the benzene, toluene, and/or xylene are produced at a combined yield of 25 to 36%. 
     
     
         15 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.   
     
     
         16 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.   
     
     
         17 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.   
     
     
         18 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.   
     
     
         19 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.   
     
     
         20 . The method of  claim 1 , further comprising:
 after the contacting step, regenerating the catalyst in a catalyst regenerator to produce a regenerated catalyst; and   flowing the regenerated catalyst into the fluidized bed.