Method and apparatus for addition of aqueous solutions to high temperature processes

Abstract

Methods and systems for extending the life of a dehydrogenation catalyst are described herein. For example, one embodiment includes providing a reaction vessel loaded with a dehydrogenation catalyst with a feedstream via a conduit in operable communication with the reaction vessel. The feedstream may include an alkyl aromatic hydrocarbon and the dehydrogenation catalyst may be adapted to convert the alkyl aromatic hydrocarbon to a vinyl aromatic hydrocarbon. The feedstream may be contacted with an aqueous catalyst life extender, wherein the aqueous catalyst life extender enters the conduit at a linear velocity sufficient to prevent vaporization of the catalyst life extender in the conduit prior to contact with the feedstream.

1 . A catalytic dehydrogenation system comprising: 
 at least one reaction vessel loaded with a dehydrogenation catalyst adapted to convert an alkyl aromatic hydrocarbon to a vinyl aromatic hydrocarbon, the reaction vessel comprising a vessel inlet and a vessel outlet;    a first conduit operably connected to the vessel inlet and adapted to provide a feedstream thereto, the feedstream comprising the alkyl aromatic hydrocarbon; and    a supply system comprising a second conduit adapted to provide an aqueous catalyst life extender to the feedstream at a linear velocity sufficient to minimize fouling within the first conduit.    
   
   
       2 . The catalytic dehydrogenation system of  claim 1 , wherein the alkyl aromatic hydrocarbon comprises ethylbenzene and the vinyl aromatic hydrocarbon comprises styrene.  
   
   
       3 . The catalytic dehydrogenation system of  claim 1 , wherein the dehydrogenation catalyst comprises an iron compound and an alkali metal compound.  
   
   
       4 . The catalytic dehydrogenation system of  claim 3 , wherein the alkali metal compound comprises potassium.  
   
   
       5 . The catalytic dehydrogenation system of  claim 1 , wherein the catalytic dehydrogenation system is a multistage process.  
   
   
       6 . The catalytic dehydrogenation system of  claim 1 , wherein the aqueous catalyst life extender comprises non-halogen sources of alkali metals.  
   
   
       7 . The catalytic dehydrogenation system of  claim 6 , wherein the aqueous catalyst life extender comprises potassium hydroxide.  
   
   
       8 . The catalytic dehydrogenation system of  claim 6 , wherein the aqueous catalyst life extender comprises a potassium salt of a carboxylic acid.  
   
   
       9 . The catalytic dehydrogenation system of  claim 1 , wherein the feedstream is passing through the first conduit at a high velocity.  
   
   
       10 . The catalytic dehydrogenation system of  claim 1 , wherein the second conduit comprises a diameter of about 0.25 inches or less.  
   
   
       11 . The catalytic dehydrogenation system of  claim 1  further comprising a nozzle operably connected to the second conduit and adapted to provide the aqueous catalyst life extender to the first conduit.  
   
   
       12 . The catalytic dehydrogenation system of  claim 1  further comprising a third conduit adapted to provide a gas to an exterior portion of the second conduit.  
   
   
       13 . A method comprising: 
 providing a reaction vessel loaded with a dehydrogenation catalyst with a feedstream via a conduit in operable communication with the reaction vessel, the feedstream comprising an alkyl aromatic hydrocarbon and the dehydrogenation catalyst adapted to convert the alkyl aromatic hydrocarbon to a vinyl aromatic hydrocarbon; and    contacting the feedstream with an aqueous catalyst life extender, wherein the aqueous catalyst life extender enters the conduit at a linear velocity sufficient to prevent vaporization of the catalyst life extender in the conduit prior to contact with the feedstream.    
   
   
       14 . The method of  claim 13 , wherein the alkyl aromatic hydrocarbon comprises ethylbenzene and the vinyl aromatic hydrocarbon comprises styrene.  
   
   
       15 . The method of  claim 13 , wherein the dehydrogenation catalyst comprises an iron compound and an alkali metal compound.  
   
   
       16 . The method of  claim 15 , wherein the alkali metal compound comprises potassium.  
   
   
       17 . The method of  claim 13 , wherein the aqueous catalyst life extender comprises non-halogen sources of alkali metals.  
   
   
       18 . The method of  claim 17 , wherein the aqueous catalyst life extender comprises potassium hydroxide.  
   
   
       19 . The method of  claim 17 , wherein the aqueous catalyst life extender comprises a potassium salt of a carboxylic acid.  
   
   
       20 . The method of  claim 13 , wherein the feedstream is passing through the conduit at a high velocity.  
   
   
       21 . The method of  claim 13  further comprising supplying a gas to the aqueous catalyst life extender.  
   
   
       22 . The method of  claim 21 , wherein the gas comprises a non oxygen containing gas.  
   
   
       23 . The method of  claim 13 , wherein the feedstream comprises a high first temperature.  
   
   
       24 . The method of  claim 23  further comprising increasing a temperature of the feedstream to a second temperature that is greater than the first temperature.  
   
   
       25 . A catalytic dehydrogenation system comprising: 
 at least one reaction vessel loaded with a dehydrogenation catalyst, the reaction vessel comprising a vessel inlet and a vessel outlet adapted to pass a feedstream therethrough to contact the dehydrogenation catalyst and form a product;    a first conduit operably connected to the vessel inlet and adapted to provide the feedstream thereto; and    a supply system comprising a second conduit adapted to provide an aqueous catalyst life extender to the feedstream at a linear velocity sufficient to minimize fouling within the first conduit.    
   
   
       26 . The catalytic dehydrogenation system of  claim 25 , wherein, the feedstream comprises propane and the product comprises propylene.  
   
   
       27 . The catalytic dehydrogenation system of  claim 25 , wherein the feedstream comprises butylene and the product comprises butadiene.  
   
   
       28 . The catalytic dehydrogenation system of  claim 25 , wherein the feedstream comprises an alkyl aromatic hydrocarbon and the product comprises a vinyl aromatic hydrocarbon.  
   
   
       29 . The catalytic dehydrogenation system of  claim 28 , wherein the dehydrogenation catalyst comprises an iron compound and an alkali metal compound.  
   
   
       30 . The catalytic dehydrogenation system of  claim 25 , wherein the catalytic dehydrogenation system is a multistage process.  
   
   
       31 . The catalytic dehydrogenation system of  claim 25 , wherein the feedstream is passing through the first conduit at a high velocity.  
   
   
       32 . The catalytic dehydrogenation system of  claim 25 , wherein the second conduit comprises a diameter of about 0.25 inches or less.  
   
   
       33 . The catalytic dehydrogenation system of  claim 25  further comprising a third conduit adapted to provide a gas to an exterior portion of the second conduit.