Catalytic Cracking And Hydroprocessing Process For High Diesel Yield With Low Aromatic Content And/Or High Propylene Yield

Abstract

Processes for maximizing low aromatics LCO yield and/or propylene yield in fluid catalytic cracking are disclosed. The processes employ catalytic compositions that comprise a predominantly basic material and little to no large pore zeolite.

1 . A fluid catalytic cracking process comprising:
 (a) contacting a FCC feed with a catalyst composition in a catalytic cracking stage under catalytic cracking conditions to produce cracked products;   (b) separating at least a bottoms fraction from the cracked products;   (c) hydrogenating at least a portion of the bottoms fraction in the presence of a hydrogenating catalyst under hydrogenation conditions to form a hydrogenated bottoms product; and,   (d) optionally, recycling at least a portion of the hydrogenated bottoms fraction to the catalytic cracking stage,   
     wherein the catalyst composition comprises a predominantly basic material and less than about 15 wt % large pore zeolite. 
   
   
       2 . The process of  claim 1  wherein the catalyst composition comprises less than about 10 wt % large pore zeolite. 
   
   
       3 . The process of  claim 2  wherein the catalyst composition comprises less than about 5 wt % large pore zeolite. 
   
   
       4 . The process of  claim 3  wherein the catalyst composition comprises less than about 3 wt % large pore zeolite. 
   
   
       5 . The process of  claim 4  wherein the catalyst composition comprises substantially no large pore zeolite. 
   
   
       6 . The process of  claim 1  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 900° C. 
   
   
       7 . The process of  claim 6  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 600° C. 
   
   
       8 . The process of  claim 7  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 500° C. 
   
   
       9 . The process of  claim 1  wherein the predominantly basic material is substantially free of components having a dehydrogenating activity or hydrogen transfer activity. 
   
   
       10 . The process of  claim 1  wherein the catalytic composition has sufficient catalytic activity to provide a conversion of FCC feedstock of at least about 30% at a cat to oil ratio of 10 and a reaction temperature below 600° C. 
   
   
       11 . The process of  claim 1  wherein the predominantly basic material is selected from the group consisting of compounds of alkali metals, compounds of alkaline earth metals, compounds of trivalent metals, compounds of transition metals, and mixtures thereof. 
   
   
       12 . The process of  claim 1  wherein the predominantly basic material is supported on a carrier material. 
   
   
       13 . The process of  claim 10 , wherein the predominantly basic material is the oxide, the hydroxide or the phosphate of a transition metal, an alkali metal, an earth alkaline metal, or a transition metal, or a mixture thereof. 
   
   
       14 . The process of  claim 1  wherein the basic material is a mixed metal oxide. 
   
   
       15 . The process of  claim 14  wherein the basic material is a hydrotalcite. 
   
   
       16 . The process  claim 1  wherein the basic material is an aluminum phosphate. 
   
   
       17 . The process of  claim 1  wherein the basic material is doped with a metal cation. 
   
   
       18 . The process of  claim 17  wherein the dopant metal cation is selected from metals of Group IIb, Group IIIb, Group IVb, the rare earth metals, and mixtures thereof. 
   
   
       19 . The process of  claim 18  wherein the dopant metal is selected from the group consisting of La, Zn, Zr, and mixtures thereof. 
   
   
       20 . The process of  claim 12  wherein the carrier is a refractory oxide. 
   
   
       21 . The process of  claim 20  wherein the carrier is selected from alumina, silica, silica-alumina, titania, and mixtures thereof. 
   
   
       22 . The process of  claim 1  further comprising a material having acidic sites. 
   
   
       23 . The process of  claim 22  wherein the material having acidic sites is selected from the group consisting of silica sol, metal doped silica sol, and nano-scale composites of silica with other refractory oxides. 
   
   
       24 . The process of  claim 1  wherein the catalyst composition further comprises at least one intermediate or small pore zeolite. 
   
   
       25 . The catalytic composition of  claim 24  wherein the at least one intermediate or small pore zeolite is selected from the ZSM family of zeolites. 
   
   
       26 . The catalytic composition of  claim 25  wherein the ZSM family zeolite is ZSM-5. 
   
   
       27 . A fluid catalytic cracking process comprising:
 (a) contacting a FCC feed with a first catalyst composition in a first catalytic cracking stage under catalytic cracking conditions to produce cracked products;   (b) separating at least a bottoms fraction from the cracked products;   (c) hydrogenating at least a portion of the bottoms fraction in the presence of a hydrogenating catalyst under hydrogenation conditions to form a hydrogenated bottoms product; and,   (d) optionally contacting at least a portion of the hydrogenated bottoms product with a second catalytic cracking catalyst under catalytic cracking conditions in a second fluid catalytic cracking stage, the second fluid catalytic cracking stage being separate from the first fluid catalytic cracking stage;   wherein the first catalyst composition comprises a predominantly basic material and less than about 15 wt % large pore zeolite.   
   
   
       28 . The process of  claim 27  wherein the catalyst composition comprises less than about 10 wt % large pore zeolite. 
   
   
       29 . The process of  claim 28  wherein the catalyst composition comprises less than about 5 wt % large pore zeolite. 
   
   
       30 . The process of  claim 29  wherein the catalyst composition comprises less than about 3 wt % large pore zeolite. 
   
   
       31 . The process of  claim 30  wherein the catalyst composition comprises substantially no large pore zeolite. 
   
   
       32 . The process of  claim 27  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 900° C. 
   
   
       33 . The process of  claim 32  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 600° C. 
   
   
       34 . The process of  claim 33  wherein the catalytic cracking conditions include a reaction temperature of between about 480 to about 500° C. 
   
   
       35 . The process of  claim 27  wherein the predominantly basic material is substantially free of components having a dehydrogenating activity or hydrogen transfer activity. 
   
   
       36 . The process of  claim 27  wherein the catalytic composition has sufficient catalytic activity to provide a conversion of FCC feedstock of at least about 30% at a cat to oil ratio of 10 and a reaction temperature below 600° C. 
   
   
       37 . The process of  claim 27  wherein the predominantly basic material is selected from the group consisting of compounds of alkali metals, compounds of alkaline earth metals, compounds of trivalent metals, compounds of transition metals, and mixtures thereof. 
   
   
       38 . The process of  claim 27  wherein the predominantly basic material is supported on a carrier material. 
   
   
       39 . The process of  claim 37 , wherein the predominantly basic material is the oxide, the hydroxide or the phosphate of a transition metal, an alkali metal, an earth alkaline metal, or a transition metal, or a mixture thereof. 
   
   
       40 . The process of  claim 27  wherein the basic material is a mixed metal oxide. 
   
   
       41 . The process of  claim 40  wherein the basic material is a hydrotalcite. 
   
   
       42 . The process  claim 27  wherein the basic material is an aluminum phosphate. 
   
   
       43 . The process of  claim 27  wherein the basic material is doped with a metal cation. 
   
   
       44 . The process of  claim 43  wherein the dopant metal cation is selected from metals of Group IIb, Group IIIb, Group IVb, the rare earth metals, and mixtures thereof. 
   
   
       45 . The process of  claim 44  wherein the dopant metal is selected from the group consisting of La, Zn, Zr, and mixtures thereof. 
   
   
       46 . The process of  claim 38  wherein the carrier is a refractory oxide. 
   
   
       47 . The process of  claim 46  wherein the carrier is selected from alumina, silica, silica-alumina, titania, and mixtures thereof. 
   
   
       48 . The process of  claim 27  further comprising a material having acidic sites. 
   
   
       49 . The process of  claim 48  wherein the material having acidic sites is selected from the group consisting of silica sol, metal doped silica sol, and nano-scale composites of silica with other refractory oxides. 
   
   
       50 . The process of  claim 27  wherein the catalyst composition further comprises at least one intermediate or small pore zeolite. 
   
   
       51 . The catalytic composition of  claim 50  wherein the at least one intermediate or small pore zeolite is selected from the ZSM family of zeolites. 
   
   
       52 . The catalytic composition of  claim 51  wherein the ZSM family zeolite is ZSM-5.