Two-stage reforming process configured for increased feed rate to manufacture reformate

Abstract

Described herein is a two-stage reforming process using a unique configuration which allows the reforming unit to operate at a higher naphtha feed rate as compared to conventional reforming configurations. In the unique reforming process described herein, a naphtha feedstock undergoes a distillation step prior to the first reforming stage. The distillation step separates the naphtha feedstock into a top light a C 7 stream, which typically accounts for between 5 and 20 percent of the overall feedstock, and a C 8 + stream. The C 8 + stream undergoes reforming in a first stage consisting of at least one reactor containing conventional metallic reforming catalyst, under conditions sufficient to convert the C 8 + stream into a first intermediate reformate. The C 7 stream, bypasses the first stage and is combined with the intermediate reformate, and reformed in the second stage, at lower pressure than in the first stage, over a reforming catalyst containing a medium pore zeolite.

What is claimed is: 
     
         1 . A process for reforming a naphtha feedstock into a final reformate having a higher Research Octane Number than the naphtha feedstock Research Octane Number, the process comprising:
 separating the naphtha feedstock into a C 7  fraction and a C 8 + fraction;   contacting the C 8 + fraction with a first-stage metallic reforming catalyst at a first stage reforming pressure to produce an intermediate reformate having a Research Octane Number greater than the naphtha feedstock Research Octane Number; and   contacting the C 7  fraction and intermediate reformate with a second-stage medium pore zeolite-based reforming catalyst at a second stage reforming pressure to produce a final reformate having a Research Octane Number greater than the intermediate reformate Research Octane Number;   wherein the second stage reforming pressure is lower than the first stage reforming pressure.   
     
     
         2 . The process of  claim 1 , wherein the first stage reforming pressure is between 150 and 400 psig. 
     
     
         3 . The process of  claim 2 , wherein the second stage reforming pressure is between 40 and 140 psig. 
     
     
         4 . The process of  claim 3 , wherein the intermediate reformate as a Research Octane Number of between 88 and 95. 
     
     
         5 . The process of  claim 4 , wherein the final reformate has a Research Octane Number of between 92 and 102. 
     
     
         6 . The process of  claim 1 , wherein the second stage reforming pressure is between 40 and 140 psig. 
     
     
         7 . The process of  claim 1 , wherein the intermediate reformate as a Research Octane Number of between 88 and 95. 
     
     
         8 . The process of  claim 7 , wherein the final reformate has a Research Octane Number of between 92 and 102. 
     
     
         9 . The process of  claim 1 , wherein the medium pore zeolite-based reforming catalyst comprises ZSM-5. 
     
     
         10 . The process of  claim 9 , wherein the ZSM-5 is a high silica ZSM-5 zeolite with a molar ratio of SiO 2 :M 2 O 3  of at least 40:1, where M is selected from the group consisting of Al, B, or Ga. 
     
     
         11 . The process of  claim 10 , wherein the SiO 2 :M 2 O 3  mole ratio is at least 200:1. 
     
     
         12 . The process of  claim 10 , wherein the SiO 2 :M 2 O 3  mole ratio is at least 500:1. 
     
     
         13 . The process of  claim 12 , wherein the first stage reforming pressure is between 150 and 400 psig. 
     
     
         14 . The process of  claim 13 , wherein the second stage reforming pressure is between 40 and 140 psig. 
     
     
         15 . The process of  claim 14 , wherein the intermediate reformate as a Research Octane Number of between 88 and 95. 
     
     
         16 . The process of  claim 15 , wherein the final reformate has a Research Octane Number of between 92 and 102. 
     
     
         17 . The process of  claim 10 , wherein the first stage reforming pressure is between 150 and 400 psig. 
     
     
         18 . The process of  claim 17 , wherein the second stage reforming pressure is between 40 and 140 psig. 
     
     
         19 . The process of  claim 18 , wherein the intermediate reformate as a Research Octane Number of between 88 and 95. 
     
     
         20 . The process of  claim 19 , wherein the final reformate has a Research Octane Number of between 92 and 102.