Multi-stage reforming process to produce high octane gasoline

Abstract

The present invention relates to a multistage reforming process to produce a high octane product. A naphtha boiling range feedstock is processed in a multi-stage reforming process, in which said process involves at least 1) a penultimate stage for reforming the naphtha feedstock to produce a penultimate effluent 2) a separation step for separating the penultimate effluent into at least an intermediate stream and a heavy stream based on boiling point and 3) a final stage for further reforming the intermediate stream.

1 . A reforming process comprising:
 a. contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce a penultimate effluent;   b. separating at least a portion of the penultimate effluent into at least an intermediate reformate comprising at least 70 vol % C 5 -C 8  hydrocarbons and a heavy reformate comprising at least 70 vol % C 9+  hydrocarbons; and   c. contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate.   
   
   
       2 . The process of  claim 1 , wherein the pressure in the final stage is lower than the pressure in the penultimate stage. 
   
   
       3 . The process of  claim 1 , wherein the naphtha boiling range feedstock boils in the range from about 50° F. to about 550° F. 
   
   
       4 . The process of  claim 1 , wherein the intermediate reformate comprises at least 70 vol % C 6 -C 9  hydrocarbons. 
   
   
       5 . The process of  claim 1 , wherein the RON of the intermediate reformate is higher than the RON of the naphtha boiling range feedstock. 
   
   
       6 . The process of  claim 1 , wherein the intermediate reformate has an RON of between about 65 to about 95. 
   
   
       7 . The process of  claim 1 , wherein the heavy reformate has an RON of at least 95. 
   
   
       8 . The process of  claim 1 , wherein the final reformate has an RON of at least 90. 
   
   
       9 . The process of  claim 1 , wherein the final reformate has an RON of at least 95. 
   
   
       10 . The process of  claim 1 , wherein the reforming pressure of the final reforming stage is within the range of about 40 psig to about 400 psig. 
   
   
       11 . The process of  claim 1 , wherein the reforming pressure of the final reforming stage is within the range of about 50 psig to about 250 psig. 
   
   
       12 . The process of  claim 1 , wherein the reforming pressure of the final reforming stage is within the range of about 50 psig to about 150 psig. 
   
   
       13 . The process of  claim 1 , wherein the reforming pressure of the penultimate reforming stage is within the range of about 70 psig to about 400 psig. 
   
   
       14 . The process of  claim 1 , wherein the first reforming catalyst comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support. 
   
   
       15 . The process of  claim 14 , wherein the Group VIII metal is platinum. 
   
   
       16 . The process of  claim 14 , wherein the catalyst comprises platinum and rhenium on an alumina support. 
   
   
       17 . The process of  claim 1 , wherein the second reforming-catalyst comprises a Group VIII metal and a promoter supported on a porous refractory inorganic oxide support. 
   
   
       18 . The process of  claim 17 , wherein the Group VIII metal is platinum. 
   
   
       19 . The process of  claim 17 , wherein the porous refractory inorganic oxide support is alumina, silica, or mixtures thereof. 
   
   
       20 . The process of  claim 17  wherein the second reforming catalyst comprises platinum and rhenium on an alumina support. 
   
   
       21 . The process of  claim 1 , wherein the second reforming catalyst comprises zeolite Beta. 
   
   
       22 . The process of  claim 1 , further comprising blending the heavy reformate with the final reformate to produce a fuel or a fuel blend stock. 
   
   
       23 . A reforming process comprising:
 a. contacting a naphtha boiling range feedstock in a penultimate stage of a multi-stage reforming process at a first reforming pressure with a first reforming catalyst to produce an penultimate effluent;   b. separating at least a portion of the penultimate effluent into at least a light reformate, an intermediate reformate, and a heavy reformate, wherein the light reformate has a mid-boiling point that is lower than that of the intermediate reformate and wherein the light reformate comprises at least 70 vol % C 5  hydrocarbons, and wherein the intermediate reformate has a mid-boiling point that is lower than that of the heavy reformate and wherein the intermediate reformate comprises at least 70 vol % C 6 -C 8  hydrocarbons; and   c. contacting the intermediate reformate in a final stage of the multi-stage reforming process at a second reforming pressure with a second reforming catalyst to produce a final effluent comprising a final reformate, wherein the final reformate has a higher RON than the intermediate reformate.   
   
   
       24 . The process of  claim 23 , wherein at the pressure of the final stage is lower than the pressure of the penultimate stage. 
   
   
       25 . The process of  claim 23 , wherein the light reformate comprises at least 70 vol % C 5  hydrocarbons. 
   
   
       26 . The process of  claim 23 , wherein the intermediate reformate comprises at least 70 vol % C 6 -C 8  hydrocarbons. 
   
   
       27 . The process of  claim 23 , wherein the intermediate reformate comprises at least 70 vol % C 6 -C 7  hydrocarbons. 
   
   
       28 . The process of  claim 23 , wherein the intermediate reformate has an RON of between about 65 and about 95. 
   
   
       29 . The process of  claim 23 , wherein the heavy reformate has an RON of at least 90. 
   
   
       30 . The process of  claim 23 , wherein the final reformate has an RON of at least 95. 
   
   
       31 . The process of  claim 23 , wherein the final reformate has an RON which is greater than the RON of the intermediate reformate. 
   
   
       32 . The process of  claim 23 , further comprising:
 a. separating the final effluent into at least a final C 5  stream and a final reformate stream;   b. combining the final C 5  stream with the light reformate stream; and   c. combining the final reformate with the heavy reformate.