Adiabatic plug flow reactors and processes incorporating the same

Abstract

The present invention provides adiabatic plug flow reactors suitable for the production of chlorinated and/or fluorinated propene and higher alkenes from the reaction of chlorinated and/or fluorinated alkanes and chlorinated and/or fluorinated alkenes. The reactors comprise one or more designs that minimize the production of by-products at a desired conversion.

1 . An adiabatic plug flow reactor suitable for use in a continuous, gas phase, free-radical process for the production of chlorinated and/or fluorinated propenes and higher alkenes from the reaction of chlorinated and/or fluorinated alkanes and chlorinated and/or fluorinated alkenes, wherein the reactor comprises a design that facilitates reduced backmixing and/or recirculation prior to entry into, or upon exit from, the reactor. 
     
     
         2 . The reactor of  claim 1 , wherein the design that facilitates reduced backmixing comprises a collector configured to accept a reactor effluent from the reactor and further configured to minimize backmixing and/or recirculation. 
     
     
         3 . The reactor of  claim 1 , wherein the design that facilitates reduced backmixing and/or recirculation comprises a mixer configured to accept one or more reactants, initiators, and/or diluents and further configured to minimize backmixing and/or recirculation of the same. 
     
     
         4 . The reactor of  claim 1 , wherein the design that facilitates reduced formation of by-products during any backmixing and/or recirculation that may occur prior to entry into the reactor comprises an inlet temperature of at least 370° C. or to provide a reactor productivity of at least 40 gr/hr/l. 
     
     
         5 . The reactor of  claim 1 , wherein the process involves at least one limiting reactant having a desired mass or molar conversion that is less than 80% of exhaustion. 
     
     
         6 . The reactor of  claim 1 , wherein the process comprises at least one thermally sensitive component selected from the group consisting of a reactant, product, byproduct, catalyst or combinations of these. 
     
     
         7 . The reactor of  claim 1 , wherein the reactor comprises a design that minimizes the production of by-products at a desired conversion, wherein the reactor design comprises one or more of: i) a design that minimizes heat transfer to and/or from the reactor; ii) a design that optimizes the flow of the reaction mixture at a boundary between the reaction mixture and at least a portion of at least one reactor tube wall; iii) a design that facilitates a reduction of the temperature of a reactor effluent to a temperature below which substantial formation of by-products does not occur, and/or iv) a design that allows the production rate of a process conducted in the reactor to be adjusted by controlling the temperature of the reactor effluent. 
     
     
         8 . The reactor of  claim 7 , comprising i) a design that minimizes heat transfer to and/or from the reactor; ii) a design that optimizes the flow of the reaction mixture at a boundary between the reaction mixture and at least a portion of at least one reactor tube wall; iii) a design that facilitates a reduction of the temperature of a reactor effluent to a temperature below which substantial formation of by-products does not occur, and iv) a design that allows the production rate of a process conducted in the reactor to be adjusted by controlling the temperature of the reactor effluent. 
     
     
         9 . The reactor of  claim 7 , wherein the design facilitating minimized heat transfer comprises insulating the reactor wherein the insulation is provided in layers with effective overall thermal conductivity of 0.5 W/M/° C. and thickness of at least 8 cm. 
     
     
         10 . The reactor of  claim 7 , wherein the design facilitating minimized heat transfer comprises providing the reactor with a diameter of at least about 0.5 feet. 
     
     
         11 . The reactor of  claim 7 , wherein the design that optimizes the flow of the reaction mixture at a boundary between the reaction mixture and at least a portion of at least one reactor tube wall comprises providing a turbulence flow region within the reactor having a Reynolds number of at least 2100. 
     
     
         12 . The reactor of  claim 7 , wherein the design that facilitates a reduction of the temperature of a reactor effluent comprises a liquid quench function. 
     
     
         13 . The reactor of  claim 7 , wherein the design that allows the production rate to be adjusted by controlling the temperature of the reactor effluent comprises individually adjusting the flow rate and/or temperature of one or more reactants, initiator(s), and/or diluent(s). 
     
     
         14 . The reactor of  claim 13 , wherein the design comprises a design that allows the flow rate and/or temperature of an initiator to be adjusted independently. 
     
     
         15 . A process for producing a chlorinated and/or fluorinated propene and higher alkene having the formula CH 2-c-g Cl c F g ═CH 1-d-h Cl d F h —CH 3-e-f Cl e F f  wherein c is 0-2, d is 0-1, e is 0-3, f is 0-3, and g is 0-2 while c+g≦2, d+h≦1, and e+f≦3, using the reactor of  claim 1 . 
     
     
         16 . The process of  claim 15 , wherein the chlorinated and/or fluorinated alkanes and chlorinated and/or fluorinated alkenes comprise methanes, chloromethanes, fluoromethanes, or chlorofluoromethanes, having the formula CH 4-a-b Cl a F b , wherein each a and b are independently 0-3 and 4-a-b is greater than 0. 
     
     
         17 . The process of  claim 15 , wherein the chlorinated and/or fluorinated propene/alkene comprises 1,1,2,3-tetrachloropropene or 1,1,2-chloro-3-fluoropropene. 
     
     
         18 . A process for preparing a downstream product utilizing a chlorinated and/or fluorinated propene/higher alkene prepared using the process of  claim 15 . 
     
     
         19 . A process for preparing 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234yf) or 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze) comprising converting 1,1,2,3-tetrachloropropene prepared by the process of  claim 15  into 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234yf) or 1,3,3,3-tetrafluoroprop-1-ene (HFO-1234ze).