High-density fluidized bed systems

Abstract

Systems and methods for producing an olefin and/or an aromatic via catalytic cracking are disclosed. Naphtha is sub-jected to catalytic cracking conditions in one or more fluidized bed reactors sufficient to produce one or more olefins and/or one or more aromatics. In the fluidized bed reactors, the solid volume fraction of the fluidized bed is in a range of 0.07 to 0.2 and the bulk density of the fluidized bed is greater than 100 kg/m 3 .

1 . A method of producing an olefin and/or an aromatic, the method comprising:
 contacting naphtha with catalyst of a fluidized bed, under reaction conditions sufficient to produce one or more olefins and/or one or more aromatics, where the fluidized bed has (1) catalyst volume fraction between 0.07 and 0.2 and (2) average catalyst bed density greater than 100 kg/m 3 .   
     
     
         2 . The method of  claim 1 , wherein the one or more olefins include ethylene, propylene, 1-butene, 2-butene, isobutene, or combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein the one or more aromatics include benzene, toluene, xylene, or combinations thereof. 
     
     
         4 . The method of any of  claim 1 , wherein the average catalyst bed density is in a range of 100 kg/m 3  to 240 kg/m 3 . 
     
     
         5 . The method of any of  claim 1 , wherein the catalyst particles have a density of at least 1400 kg/m 3 . 
     
     
         6 . The method of any  claim 1 , wherein the catalyst of the fluidized bed is disposed in one or more riser reactors. 
     
     
         7 . The method of  claim 6 , wherein the one or more riser reactors are operated using a lift gas comprising nitrogen, methane, an inert gas, or combinations thereof. 
     
     
         8 . The method of  claim 6 , wherein the fluidized bed has a superficial gas velocity in a range of 1 to 3 m/s. 
     
     
         9 . The method of any  claim 6 , wherein the one or more riser reactors are operated with reaction kinetics substantially follows plug flow reactors. 
     
     
         10 . The method of any of  claim 1 , wherein the reaction conditions include a reaction temperature of 650 to 700° C. 
     
     
         11 . The method of any of  claim 1 , wherein the reaction conditions include a weight hourly space velocity of 10 to 40 hr −1 . 
     
     
         12 . The method of any of  claim 1 , wherein the reaction conditions include an average contact time between naphtha and the catalyst in a range of 1 to 3 s. 
     
     
         13 . The method of any of  claim 1 , wherein the reaction conditions include an operation pressure in a range of 100 to 300 Pa. 
     
     
         14 . The method of any  claim 1 , wherein the method has a methane yield of less than 10%. 
     
     
         15 . The method of  claim 3 , wherein the method has a methane yield of less than 10%. 
     
     
         16 . The method of  claim 4 , wherein the method has a methane yield of less than 10%. 
     
     
         17 . The method of  claim 5 , wherein the method has a methane yield of less than 10%. 
     
     
         18 . The method of  claim 6 , wherein the method has a methane yield of less than 10%. 
     
     
         19 . The method of  claim 7 , wherein the method has a methane yield of less than 10%. 
     
     
         20 . The method of  claim 8 , wherein the method has a methane yield of less than 10%.