Micro-engineered reactors

Abstract

The invention relates to a micro-engineered reactor device comprising a closely coupled reactor and electrochemical cell, and a method of using such a reactor for the synthesis of organic compounds by a process involving an electrochemical reaction. The synthetic processes are of a type in which a source material is electrochemically converted to a reactive primary product which is exposed at a reaction region within a channel, or chamber, to a precursor material so that the primary product and precursor material react to generate a secondary product.

1 . A micro-engineered reactor for performing chemical synthesis, said reactor comprising: 
 (a) a reaction chamber and an electrochemical cell in close communication with the interior of the reaction chamber;    (b) said reaction chamber being of micro-engineered dimensions and having micro-engineered inlet and outlet conduits for conveying fluids to, and from, the reaction chamber;    (c) said cell comprising at least two electrodes positioned and arranged relative to each other to define a space between them, which, in at least one mode of use of the cell, receives an ionically conductive fluid that is, or contains, a redox-active source material, and forms an electrically conductive path between the electrodes through which an electrical current passes when an electrical potential is applied to the electrodes so as to electrolyse the source material and form a primary product at, or adjacent to, a surface of an electrode within the interior of the reaction chamber;    (d) means for introducing into the reaction chamber a precursor material that will react with the primary product to produce a secondary product, and    (e) means for conveying the secondary product away from the reaction chamber through said outlet conduit.    
     
     
         2 . A reactor according to  claim 1  wherein at least one of the electrodes has a surface at which, in use, the primary product is formed, and the surface is located within, or forms a part of a boundary wall of, the reaction chamber.  
     
     
         3 . A reactor according to  claim 1  wherein at least one of the electrodes has a surface at which, in use, the primary product is formed, made of, or coated with, a sacrificial material that will react with the source material to form the primary product,  
     
     
         4 . A reactor according to  claim 3  wherein the cell further includes an electro-depositing means for selectively applying an electrical charge to each of the electrodes in the presence of an ionically conductive fluid that contains ions of the sacrificial material, thereby to cause the sacrificial material to be deposited on the electrode or electrodes and replenish the sacrificial material that is consumed by the electrolysis.  
     
     
         5 . A reactor according to  claim 4  wherein the electro-depositing means is operable to deposit the sacrificial material on the surface of the respective electrode or electrodes prior to, or during reaction of the sacrificial material with the source material to form the primary product.  
     
     
         6 . A reactor according to  claim 4  wherein the electro-depositing means is operable to deposit the sacrificial material on the surface of the respective electrode or electrodes prior to, or during reaction of the sacrificial material with the source material to form the primary product.  
     
     
         7 . A reactor according to  claim 4  wherein the electro-depositing means comprises means for applying a negative charge to one of the electrodes and a positive charge to the other electrode, and a fluid supply means is provided for introducing a source of an organic fluid containing a salt in which a cation is the sacrificial material to be deposited on the negatively charged electrode, and a means is provided for generating an electrical field between the two electrodes so as to cause electro-deposition of the material on to the surface of the negatively charged electrode.  
     
     
         8 . A reactor according to  claim 4  wherein the electro-depositing means comprises means for applying a negative charge to one of the electrodes and a positive charge to the other electrode, and a fluid supply means is provided for introducing a source of an organic fluid containing a salt in which an anion is the sacrificial material to be deposited on the positively charged electrode, and a means is provided for generating an electrical field between the two electrodes so as to cause electro-deposition of the material on to the surface of the positively charged electrode.  
     
     
         9 . A reactor according to  claim 7  wherein the organic fluid that contains the ions of the sacrificial material is also the organic reagent that will react with the deposited material to produce the primary product.  
     
     
         10 . A reactor according to  claim 7  wherein the organic fluid that contains the ions of the sacrificial material is also the precursor that will react with the deposited material to produce the secondary product.  
     
     
         11 . A reactor according to  claim 1  wherein at least one of the electrodes is made of a fluid permeable material and defines a part of the boundary wall of the reaction chamber through which a fluid source material permeates to react at a surface of the fluid permeable electrode that is in communication with the interior of the reaction chamber to form the primary product.  
     
     
         12 . A reactor according to  claim 11  wherein a second chamber is formed on a side of the fluid permeable electrode that is remote from the interior of the reaction chamber, and an electrode of the cell is located in the second chamber, said fluid permeable electrode being made of a material that allows a primary product created by electrolysis of a source material within the second chamber to permeate through the permeable electrode into the interior of the reaction chamber and to react with the precursor material to form the secondary product.  
     
     
         13 . A reactor according to  claim 11  wherein the second chamber has an inlet conduit for the supply of fluid containing fresh source material to the second chamber and an outlet for removal from the second chamber of fluids depleted of said source material.  
     
     
         14 . A reactor according to  claim 11  wherein a fluid permeable ionic or electronic conductor is provided between the electrodes so as to define a first region on one side of the conductor where an ion conductive solution is retained in contact with the one of the electrodes, and a second region on the other side of the said conductor, where the conductor is in contact with the source material.  
     
     
         15 . A reactor according to  claim 14  wherein the conductor is mercury or an amalgam.  
     
     
         16 . A reactor according to  claim 1  wherein the cell is a rechargeable cartridge.  
     
     
         17 . A reactor according to  claim 1  wherein there is provided a fluid pumping means connected to the reactor for pumping the fluids though the reactor.  
     
     
         18 . A reactor according to  claim 1  wherein the source material and the precursor are present in a common fluid.  
     
     
         19 . A reactor according to  claim 1  wherein the source material is present in a first fluid and the precursor is present in a second fluid.  
     
     
         20 . A reactor according to  claim 1  wherein the outlet conduit of the reaction chamber is divided into two or more discrete outlet paths.  
     
     
         21 . A reactor according to  claim 20  wherein at least one or more discrete outlet paths are connected to an inlet conduit of another reactor constructed in accordance with  claim 1 .  
     
     
         22 . A reactor according to  claim 20  wherein one of the electrodes of the cell is located in, or forms part of, the wall of the reaction chamber and one of the electrodes of the cell is located in or forms part of the wall of a conduit defining one of the discrete outlet paths.  
     
     
         23 . A reactor according to  claim 1  wherein the reaction chamber is constructed, dimensioned and arranged to define a plurality of adjacent flow paths through the reaction chamber via respective pairs of an inlet conduit and an outlet-conduit.  
     
     
         24 . A reactor according to  claim 1  wherein there is provided an ion permeable barrier located between an anode and a cathode of the cell so as to define an anodic compartment adjacent the anode on one side of the ion permeable barrier and a cathodic compartment adjacent the cathode on the other side of the ion permeable barrier.  
     
     
         25 . A reactor according to  claim 24  wherein the barrier is selected from the following materials, namely a porous or permeable sheet, a dialysis membrane, an ion exchange membrane, a region of gelled electrolyte or a region of immobilised electrolyte.  
     
     
         26 . A reactor according to  claim 1  wherein at least one of the electrodes is a porous block through which fluids may flow.  
     
     
         27 . A reactor according to  claim 1  wherein there is provided a first discrete inlet conduit for supplying the source material, a second discrete inlet conduit for supplying the precursor, and a third discrete conduit for supplying a flushing fluid for removing the secondary product from the reaction chamber.  
     
     
         28 . A reactor according to  claim 27  wherein valve means are provided for selectively opening and closing each of the first, second or third inlet conduits.  
     
     
         29 . A reactor according to  claim 1  wherein one or more reference electrodes means is provided in the reaction chamber or cell for monitoring and controlling the electrical potential applied to the electrodes of the cell.  
     
     
         30 . A reactor according to  claim 29  wherein one or more monitoring electrode means is provided for monitoring the composition of the products produced in the reactor.  
     
     
         31 . A reactor according to  claim 1  wherein there is provided within, or adjacent to, the reaction chamber, a heat exchanger for controlling the temperature of at least a region of the interior of the reaction chamber.  
     
     
         32 . A reactor according to  claim 1  wherein the output conduit is connected in flow series to an inlet conduit of another reactor constructed in accordance with  claim 1 .  
     
     
         33 . A reactor according to  claim 32  wherein a plurality of series connected reactors are provided on a common structure.  
     
     
         34 . A reactor according to  claim 32  wherein one or more arrays of series connected reactors are arranged relative to another one or more arrays of series connected reactors on a common structure.  
     
     
         35 . A method of performing chemical synthesis comprising the steps of: 
 (a) providing a reactor constructed in accordance with  claim 1     (b) presenting a source material to the space between at least two electrodes;    (c) electrolysing the source material to form a primary product at, or adjacent to, a surface of the electrode that communicates with the interior of the reaction chamber; and,    (d) contacting the primary product in the reaction chamber with a precursor that will react and/or mix with the primary product to produce a secondary product.    
     
     
         36 . A method according to  claim 35  including the step of removing the secondary product from the reaction chamber.  
     
     
         37 . A method according to  claim 36  including the step of reacting the secondary product with a material that is a precursor for use in a further reaction, or a series of further reactions, to produce a final product.  
     
     
         38 . A method for preparing a synthetic organic compound comprising the steps of: 
 (a) providing a micro-engineered reactor constructed in accordance with  claim 1  wherein at least one of the electrodes is made of, or coated with, a sacrificial material that will react with the precursor to form the secondary product;    (b) presenting a source material to at least the electrode that consists of, or has deposited thereon, the sacrificial material;    (c) electrolysing the source material and allowing the electrolysed source material to react with the sacrificial material to form the primary product at, or adjacent to a surface of the electrode; and,    (d) contacting the primary product in the reaction chamber with a precursor that will react with the primary product to form the said organic compound.    
     
     
         39 . A method for preparing a synthetic organic compound comprising the steps of: 
 (a) providing a micro-engineered reactor constructed in accordance with  claim 1  wherein at least one of the electrodes is made of, or coated with, a sacrificial material that will react with the precursor to form the secondary product;    (b) presenting an organic source material to at least the electrode that consists of, or has deposited thereon, the sacrificial product;    (c) electrolysing the source material and allowing the source material to react with the sacrificial material to form the secondary product at, or adjacent to a surface of the electrode; and,    (d) contacting the primary product in the reaction chamber with a precursor that will react with the primary product to form the said organic compound.    
     
     
         40 . A method according to  claim 38  further including the step of replenishing the consumed sacrificial material by electro depositing material on at least one of the electrodes.  
     
     
         41 . A method according to  claim 40  wherein the sacrificial material is deposited on the respective electrode or electrodes by connecting the electrodes to an electrical supply whereby one of the electrodes forms a cathode and the other forms an anode, and the method includes the steps of presenting to the cathode, a fluid containing a salt in which a cation is the sacrificial material, and applying an electrical field between the cathode and an anode thereby to deposit the sacrificial material on the cathode.  
     
     
         42 . A method according to  claim 40  wherein the sacrificial material is deposited on a surface of the respective electrode by connecting the substrate to an electrical supply whereby one of the electrodes forms a cathode and the other forms an anode, and the method includes the steps of presenting to the anode, an ionically conductive fluid containing a salt in which an anion is the sacrificial material, and applying an electrical field between the cathode and an anode thereby to deposit the sacrificial material on the anode.  
     
     
         43 . A method according to  claim 41  wherein a fluid containing the salt is presented to the electrodes whilst simultaneously applying an electrical charge to the electrodes thereby to deposit the sacrificial material onto at least one electrode, and the source material is subsequently presented to the electrodes and allowed to react electrolytically with the sacrificial material to form the primary product  
     
     
         44 . A method according to  claim 41  wherein a fluid containing the salt is presented to the electrodes whilst simultaneously applying an electrical charge to the cathode thereby to deposit the sacrificial material onto at least one electrode, and the source material is presented to the electrodes simultaneously with the salt, and allowed to react with the deposited sacrificial material to form the primary product.  
     
     
         45 . A method of performing chemical synthesis, comprising the steps of: 
 (a) providing a reactor constructed in accordance with  claim 1     (b) introducing into the second chamber a fluid containing said source material;    (c) electrolysing said source material in said second chamber so as to produce said primary product at a surface of the fluid permeable electrode that is in communication with the interior of the reaction chamber; and    (d) contacting the primary product in the reaction chamber with a precursor that will react and/or mix with the primary product to produce a secondary product.    
     
     
         46 . A method according to  claim 35  for the synthesis of lithium, or sodium, or potassium alkyls wherein the source material is derived from solutions of lithium, or sodium, or potassium salts, or solid or polymeric ion conductors thereof, and the precursor is an alkyl halide that reacts with the source material to form lithium, or sodium, or potassium alkyls as the secondary product.  
     
     
         47 . A method according to  claim 35  for the synthesis of Sodium Napthalenide wherein the source material is sodium, the precursor is napthalene and the secondary product is sodium Napthalenide.  
     
     
         48 . A method according to  claim 35  for the synthesis of potassium Napthalenide wherein the source material is potassium, the precursor is napthalene and the secondary product is potassium Napthalenide.  
     
     
         49 . A method according to  claim 35  for the synthesis of Sodium anthacenide wherein the source material is sodium, the precursor is anthracene and the secondary product is sodium anthacenide.  
     
     
         50 . A method according to  claim 35  for the synthesis of potassium anthacenide wherein the source material is potassium, the precursor is anthracene and the secondary product is potassium anthacenide  
     
     
         51 . A method according to  claim 35  for the synthesis of Sodium phenanthrenide wherein the source material is sodium, the precursor is phenanthrene and the secondary product is sodium phenanthrenide  
     
     
         52 . A method according to  claim 35  for the synthesis of Potassium phenanthrenide wherein the source material is potassium, the precursor is phenanthrene and the secondary product is potassium phenanthrenide  
     
     
         53 . A method according to  35  for the conversion of organotin compounds wherein the source material is sodium, the precursor is an organotin compound.  
     
     
         54 . A method according to  claim 53  for carrying out the conversion of organotin compounds by a reaction of the type  
         Na + +e − (from electrode)→Na o    (CH 3 ) 3 Sn—Sn(CH 3 ) 3 +2Na o →2(CH 3 ) 3 Sn − Na +   
     
     
         55 . A method according to  claim 54  wherein the sodium compound is further reacted with an organo halide in accordance with the following formula:  
         (CH 3 ) 3 Sn − Na + +CH 2= CH—CH—Cl→(CH 3 ) 3 Sn—CH 2- CH═CH+Na + Cl −   
     
     
         56 . A method according to  claim 35  for the generation of sodium, lithium or potassium alkoxide or phenoxide in accordance with formula  
         Na/K/Li + +e − (from electrode)→Na/K/Li o    Na/K/Li o +R  − OH→Na/K/Li + − OR+H 2    
       where R=CH 3 , C 2 H 5 , C 3 H 7 , C 4 H 9 , Ph, substituted Ph, heteroaryl, or substituted heteroaryl  
     
     
         57 . A method according to  claim 35  for the removal of halides from aromatics by sodium metal in accordance with the reaction  
         Na + +e − (from electrode)→Na o      6-n Na o +C 6 H n Cl 6-n +solvent→C 6 H 6 +NaHal+solvent  
       where Hal=Cl, Br, or I  
     
     
         58 . A method according to  claim 35  for carrying out a Birch Reduction of compounds in accordance with the reaction:  
       
         
           
           
               
               
           
         
       
       C 6 H 6  (benzone)+2Na+C 2 H 5  OH (in liquid ammonia)→C 6 H 8  (1,4 cyclohexadiene).  
     
     
         59 . A method according to  claim 35  for the generation of Grignard reagents in accordance with the reaction:  
         RX+Mg (in ether)→R—Mg—X  
       where R=C 6 H 5 , and X=Cl, Br, or I  
     
     
         60 . A method according to  claim 59  wherein the reaction is:  
         C 6 H 5 Br+Mg→C 6 H 5 MgBr.  
     
     
         61 . A method according to  claim 35  for the generation of halogenated products wherein the source material is a soluble halide, the primary product is a halogen produced by the electrochemical oxidation of the soluble halide, and the halogen is reacted with an organic precursor to produce a secondary halogenated product by addition to unsaturated bonds or by substitution.  
     
     
         62 . A method according to  claim 35  for the generation of halogenated products wherein the source material is a soluble halide, the primary product is a halogen produced by the electrochemical oxidation of the soluble halide, and the halogen is reacted with an inorganic precursor to produce an inorganic reactive intermediate.  
     
     
         63 . A method according to  claim 61  wherein the halogen is chlorine, the inorganic precursor is phosphorus, and the secondary product is PCl 3  or PCl 5 .  
     
     
         64 . A method according to  claim 61  wherein the secondary product is reacted in the reaction chamber with a carboxylic acid to generate acyl chloride products.  
     
     
         65 . A method according to  claim 35  for the generation of ylids from phosphonium salt cations by the Wittig reaction and the reaction of ylids and aldehyde to generate alkenes in accordance with the formulae  
         (C 6 H 5 ) 3 P + CH 2 C 6 H 4 NO 2 +e − →(C 6 H 5 ) 3 P + C − HC 6 H 4 NO 2    (C 6 H 5 ) 3 P + C − HC 6 H 4 NO 2 +HCOC 6 H 4 NO 2 →NO 2 C 6 H 4 CHCHC 6 H 4 NO 2    
     
     
         66 . A reactor according to  claim 8  wherein the organic fluid that contains the ions of the sacrificial material is also the organic reagent that will react with the deposited material to produce the primary product.  
     
     
         67 . A reactor according to  claim 8  wherein the organic fluid that contains the ions of the sacrificial material is also the precursor that will react with the deposited material to produce the secondary product.  
     
     
         68 . A reactor according to  claim 21  wherein one of the electrodes of the cell is located in, or forms part of, the wall of the reaction chamber and one of the electrodes of the cell is located in or forms part of the wall of a conduit defining one of the discrete outlet paths.  
     
     
         69 . A method according to  claim 39  further including the step of replenishing the consumed sacrificial material by electro depositing material on at least one of the electrodes.  
     
     
         70 . A method according to  claim 42  wherein a fluid containing the salt is presented to the electrodes whilst simultaneously applying an electrical charge to the electrodes thereby to deposit the sacrificial material onto at least one electrode, and the source material is subsequently presented to the electrodes and allowed to react electrolytically with the sacrificial material to form the primary product.  
     
     
         71 . A method according to  claim 42  wherein a fluid containing the salt is presented to the electrodes whilst simultaneously applying an electrical charge to the cathode thereby to deposit the sacrificial material onto at least one electrode, and the source material is presented to the electrodes simultaneously with the salt, and allowed to react with the deposited sacrificial material to form the primary product.  
     
     
         72 . A method according to  claim 62  wherein the halogen is chlorine, the inorganic precursor is phosphorus, and the secondary product is PCl 3  or PCl 5 .  
     
     
         73 . A method according to  claim 62  wherein the secondary product is reacted in the reaction chamber with a carboxylic acid to generate acyl chloride products.