System and process for production of nitrobenzene

Abstract

A system for production of nitrobenzene that may include a high shear device configured to produce a nanoemulsion having benzene particles dispersed in a mixture of nitric acid and sulfuric acid, wherein the particles have a mean diameter of less than about 1.5 microns; a pump configured to deliver a pressurized liquid stream to the high shear device; and a vessel operated under a pressure of greater than 304 kPa and less than 6080 kPa, the vessel configured to receive the nanoemulsion from the high shear device.

1 . A system for production of nitrobenzene, the system comprising:
 a high shear device configured to produce a nanoemulsion comprising benzene-containing particles dispersed in a mixture of nitric acid and sulfuric acid, wherein the particles have a mean diameter of less than about 1.5 microns;   a pump configured to deliver a pressurized liquid stream to the high shear device; and   a vessel operated under a pressure of greater than 304 kPa and less than 6080 kPa, the vessel configured to receive the nanoemulsion from the high shear device.   
     
     
         2 . The system of  claim 1 , wherein the mean diameter is less than about 400 nm. 
     
     
         3 . The system of  claim 1 , wherein the high shear device comprises at least one rotor and at least one complementarily-shaped stator, and wherein the device is configured to operate at a tip speed of at least 22.9 m/sec. 
     
     
         4 . The system of  claim 3 , wherein the high shear device is configured for operating at a flow rate of at least 300 L/h. 
     
     
         5 . The system of  claim 4 , wherein the high shear device is configured to subject the mixture to a shear rate of at least 20,000 s −1 . 
     
     
         6 . The system of  claim 2 , wherein the vessel is operated at a temperature in the range of about 20° C. to about 230° C., whereby at least a portion of benzene is nitrated to form nitrobenzene in the vessel. 
     
     
         7 . The system of  claim 6 , wherein the vessel further comprises a vessel outlet for a liquid reaction product comprising nitrobenzene, and wherein the system further comprises a separator tank fluidly connected with the vessel outlet, the separator tank being operable to separate a supernatant comprising nitrobenzene from benzene in the liquid reaction product. 
     
     
         8 . The system of  claim 7 , the system further comprising a recycle line fluidly connecting the separating tank with the high shear device. 
     
     
         9 . The system of  claim 7 , the system further comprising an aniline production apparatus fluidly connected with the separating tank, the aniline production apparatus operable to produce aniline from the supernatant. 
     
     
         10 . The system of  claim 6 , wherein the vessel further comprises a gas line configured for removal of a gas stream comprising at least one of benzene vapor, nitrobenzene, sulfuric acid, volatile products, or combinations thereof, from the vessel. 
     
     
         11 . The system of  claim 6 , the system further comprising a recycle line fluidly connecting the vessel with the high shear device, whereby nitric acid, sulfuric acid, or both, may be recycled to the high shear device. 
     
     
         12 . The system of  claim 1 , wherein the pressurized liquid stream comprises the mixture, and wherein the mixture has a molar ratio of 1:2 nitric acid to sulfuric acid. 
     
     
         13 . The system of  claim 12 , wherein the nanoemulsion comprises a molar ratio of benzene to nitric acid of 1:1. 
     
     
         14 . A system for production of nitrobenzene, the system comprising:
 a high shear device configured to produce a nanoemulsion comprising benzene-containing particles dispersed in a mixture of nitric acid and sulfuric acid, wherein the presence of nitric acid within the nanoemulsion is greater than 3.0 wt %;   a pump configured to deliver a pressurized liquid mixture comprising nitric acid, sulfuric acid, and benzene to the high shear device;   a vessel configured to receive the nanoemulsion from the high shear device, wherein the vessel comprises a vessel outlet for transferring a reaction product comprising nitrobenzene therefrom; and   a separator tank fluidly connected to the vessel outlet for receiving the reaction product therefrom, the separator tank configured to separate a supernatant comprising nitrobenzene from the reaction product.   
     
     
         15 . The system of  claim 14 , wherein the vessel is operable to subject the nanoemulsion to reaction conditions comprising a pressure in the range of about 203 kPa to about 6080 kPa, and a temperature in the range of about 20° C. to about 230° C., and wherein at least a portion of benzene is nitrated to form nitrobenzene in the vessel. 
     
     
         16 . The system of  claim 15 , wherein the mixture is delivered to the high shear device at a molar ratio of 1:2 nitric acid to sulfuric acid. 
     
     
         17 . The system of  claim 16 , wherein the nanoemulsion comprises a molar ratio of benzene to nitric acid of 1:1. 
     
     
         18 . The system of  claim 14 , wherein the high shear device comprises a rotor and a complementarily-shaped stator, wherein the device is configured to operate at a tip speed of at least 22.9 m/sec, and wherein the high shear device is configured to subject the mixture to a shear rate of at least 20,000 s −1 . 
     
     
         19 . The system of  claim 18 , wherein each of the rotor and the stator comprise a toothed surface.