Controlling solids flow in a gas-solids reactor

Abstract

This invention is to a process and system for controlling solids distribution in a gas-solids reactor. Solids distribution is controlled by controlling electrical charges between solid particles flowing between conductive surfaces within a gas-solids reactor. The electrical charges are controlled by conventional means such as by grounding the opposing conductive surfaces, or by applying a voltage to one of the opposing conductive surfaces.

1 . A process for controlling flow of solid catalyst particles in a gas-solids reactor, the process comprising the steps of: 
 a) flowing solid catalyst particles between opposing conductive surfaces in a gas-solids reactor; and    b) controlling electrical charges between the flowing solid catalyst particles and the opposing conductive surfaces in the gas-solids reactor to move the solid catalyst particles away from at least one of the opposing conductive surfaces.    
     
     
         2 . The process of  claim 1 , wherein the electrical charges are controlled by grounding the opposing conductive surfaces.  
     
     
         3 . The process of  claim 1 , wherein the electrical charges are controlled by applying a voltage to one of the opposing conductive surfaces.  
     
     
         4 . The process of  claim 1 , wherein the voltage applied is at least 10 KV.  
     
     
         5 . The process of  claim 4 , wherein the voltage applied is at least 25 KV.  
     
     
         6 . The process of  claim 5 , wherein the voltage applied is at least 50 KV.  
     
     
         7 . The process of  claim 1 , wherein a gas is flowed with the solid catalyst particles.  
     
     
         8 . The process of  claim 7 , wherein the gas is a chemical reactant.  
     
     
         9 . The process of  claim 8 , wherein the chemical reactant is an oxygenate.  
     
     
         10 . The process of  claim 9 , wherein the oxygenate is methanol.  
     
     
         11 . The process of  claim 1 , wherein the solid catalyst particles are selected from the group consisting of molecular sieve catalyst particles, maleic anhydride forming catalyst particles, and acrylonitrile and methacrylonitrile forming catalyst particles.  
     
     
         12 . The process of  claim 11 , wherein the solid catalyst particles are molecular sieve catalyst particles.  
     
     
         13 . The process of  claim 12 , wherein the molecular sieve catalyst particles are silicoaluminophosphate molecular sieve catalyst particles.  
     
     
         14 . The process of  claim 7 , wherein the catalyst particles and gas are flowed at a weight hourly space velocity of 2 hr −1  to 5000 hr −1 .  
     
     
         15 . The process of  claim 7 , wherein the catalyst particles and gas are flowed at a gas superficial velocity of at least 2 meters per second.  
     
     
         16 . The process of  claim 7 , wherein the catalyst particles and gas are flowed at a catalyst to gas mass ratio of from 5:1 to 75:1.  
     
     
         17 . A gas-solids reactor system for controlling electrical charges between flowing solid particles and conductive surfaces in a gas-solids reactor, the system comprising: 
 a) a gas-solids reactor having a wall with an inner surface, at least a portion of the inner surface being made of conducting material;    b) a conductive surface internal to the inner surface of the gas-solids reactor wall; and    c) an electric potential inducer in connection with the conductive surface portion of the gas-solids reactor wall and the conductive surface internal to the inner surface of the gas-solids reactor wall, wherein the inducer controls electrical charges between solids flowing through the reactor, the conducting material of the inner surface of the gas-solids reactor wall, and the conductive surface internal to the inner surface of the gas-solids reactor wall.    
     
     
         18 . The gas-solids reactor system of  claim 17 , wherein the electric potential inducer is a ground connected to each of the conductive surfaces.  
     
     
         19 . The gas-solids reactor system of  claim 18 , wherein the ground is a common ground connected to each of the conductive surfaces.  
     
     
         20 . The gas-solids reactor system of  claim 17 , wherein the electric potential inducer supplies electric current to the conducting material of the inner surface of the gas-solids reactor wall or the conductive surface internal to the inner surface of the gas-solids reactor wall.  
     
     
         21 . The gas-solids reactor system of  claim 17 , wherein the gas-solids reactor further comprises a redirection conduit, and wherein said wall with an inner surface is a wall with an inner surface in the redirection conduit.  
     
     
         22 . A process for controlling flow of solid catalyst particles in a gas-solids reactor, the process comprising the steps of: 
 a) providing a gas-solids reactor having a wall with an inner surface, at least a portion of the inner surface being made of conducting material;    b) providing a conductive surface internal to the inner surface of the gas-solids reactor wall;    c) flowing solid catalyst particles between the conducting material of the inner surface of the of the gas-solids reactor wall and the conductive surface internal to the inner surface of the gas-solids reactor wall; and    d) controlling electrical charges between the flowing catalyst, the conducting material of the inner surface of the of the gas-solids reactor wall, and the conductive surface internal to the inner surface of the gas-solids reactor wall to move the solid catalyst particles away from the conducting material of the inner surface of the of the gas-solids reactor wall or the conductive surface internal to the inner surface of the gas-solids reactor wall.    
     
     
         23 . The process of  claim 22 , wherein the electrical charges between the flowing catalyst, the conducting material of the inner surface of the of the gas-solids reactor wall, and the conductive surface internal to the inner surface of the gas-solids reactor wall are controlled by grounding the conducting material of the inner surface of the gas-solids reactor wall and the conductive surface internal to the inner surface of the gas-solids reactor wall to one another.  
     
     
         24 . The process of  claim 22 , wherein the electrical charges between the flowing catalyst, the conducting material of the inner surface of the of the gas-solids reactor wall, and the conductive surface internal to the inner surface of the gas-solids reactor wall are controlled by by applying a voltage to the conducting material of the inner surface of the gas-solids reactor wall or the conductive surface internal to the inner surface of the gas-solids reactor wall.  
     
     
         25 . The process of  claim 22 , wherein the voltage applied is at least 10 KV.  
     
     
         26 . The process of  claim 25 , wherein the voltage applied is at least 25 KV.  
     
     
         27 . The process of  claim 26 , wherein the voltage applied is at least 50 KV.  
     
     
         28 . The process of  claim 22 , wherein a gas is flowed with the catalyst particles.  
     
     
         29 . The process of  claim 28 , wherein the gas is a chemical reactant.  
     
     
         30 . The process of  claim 29 , wherein the chemical reactant is an oxygenate.  
     
     
         31 . The process of  claim 29 , wherein the oxygenate is methanol.  
     
     
         32 . The process of  claim 22 , wherein the solid catalyst particles are selected from the group consisting of molecular sieve catalyst particles, maleic anhydride forming catalyst particles, and acrylonitrile and methacrylonitrile forming catalyst particles.  
     
     
         33 . The process of  claim 32 , wherein the catalyst particles are molecular sieve catalyst particles.  
     
     
         34 . The process of  claim 33 , wherein the molecular sieve catalyst particles are silicoaluminophosphate molecular sieve catalyst particles.  
     
     
         35 . The process of  claim 28 , wherein the catalyst particles and gas are flowed at a weight hourly space velocity of 2 hr −1  to 5000 hr −1 .  
     
     
         36 . The process of  claim 28 , wherein the catalyst particles and gas are flowed at a gas superficial velocity of at least 2 meters per second.  
     
     
         37 . The process of  claim 28 , wherein the catalyst particles and gas are flowed at a catalyst to gas mass ratio of from 5:1 to 75:1.  
     
     
         38 . The process of  claim 22 , wherein the gas-solids reactor further comprises a redirection conduit, and wherein said wall with an inner surface is a wall with an inner surface in the redirection conduit.