TH19288B - Bipolar multi-cell electrochemical reactor with membrane separation - Google Patents

Abstract

DC60 (05/09/47) The multi-cell assembly is constructed by stacking two types of pre-assembled components in an alternating manner: a bipolar electrode subassembly and a membrane subassembly. The alternating stacks of components are placed on top of the base end components, and the stacks end with the top electrode end component placed on top of the final membrane subassembly component. Each bipolar electrode subassembly component and ion exchange separator subassembly component are integrated into a highly rectangular frame made of a chemically resistant, non-conductive material—typically a molded plastic—with grooves on the top face (assembly) to accommodate O-ring compression pathways, and through channels and holes at various interlocking positions arranged on both opposite sides of the rectangular frame. When assembled, this creates separate tubes for the circulation of the anionic and cationic solutions through the total anionic solution flow cylinder and the total cationic solution flow cylinder, respectively. The bipolar reactor has no separate tubes. The inlets and outlets for two types of electrolytic solutions, conversely, flow different solutions through the cylinders, each flowing in a zigzag pattern, which is more important in series hydraulics or sequential modes than in parallel hydraulics. Therefore, bypass currents can be "driven" by a relatively low voltage difference of approximately one cell voltage. Ideally, two parallel flow channels are bounded within felt electrodes to minimize voltage drop. All parallel channels of each sequence extend perpendicularly from the base channels, assembled along each inlet and outlet side of the cylinder and ending before the base channels of the other sequence. Each sequence defines a comb-shaped flow distribution channel boundary, forming parallel needle-like channels separated by the needle-like channels of the other sequence. Multi-cell assemblies are constructed by stacking two types of pre-assembled parts in an alternating manner: a bipolar electrode holder sub-assembly and a membrane holder sub-assembly. Alternating stacks of parts are placed on top of the base end parts, and the stacks end with the top electrode end part placed on top of the last membrane holder part. The bipolar electrode holder and membrane holder parts... Each ion exchange separator's mounting component is comprised of a highly rectangular frame made of a chemically resistant, non-conductive material—typically a molded plastic—with grooves on the top face (assembly) to accommodate O-ring type compression strips. Through channels and holes are strategically placed on opposite sides of the rectangular frame, which, once assembled, create separate flow paths for the anionic and cationic solutions, passing through the total anionic solution cylinder and the total cationic solution cylinder, respectively. The bipolar reactor has no separate inlet and outlet tubes for the two electrolytic solutions; conversely, the electrolytic solutions flow through cylinders... Each cylinder flows in a zigzag pattern, which is more important in series or sequential hydraulics than in parallel hydraulics. Therefore, the bypass current can be "driven" by a relatively low pressure difference of approximately one cell pressure. Ideally, two parallel flow channels are bounded within felt electrodes to minimize pressure drop. All parallel channels of each sequence extend perpendicularly from their base channels, which are assembled along each inlet and outlet side of the cylinder and end before the base channel of the other sequence. Each sequence defines its own boundary channel, distributing the comb-shaped flow into parallel needle-like channels separated by the needle-like channels of the other sequence.

Claims (6)

1. A multi-phase, bipolar electrochemical reactor separated by a membrane for reduction and oxidation half-cell reactions in positive and negative electrolytic solutions, respectively, without gas production, consisting of several alternating bipolar plate electrodes and an ion-exchange membrane separator, which places the positive solution flow chamber on one side of each membrane and the negative solution flow chamber on the opposite side of the positive solution flow chamber, assembled in a filter-compression arrangement between the two electrodes, at the ends electrically coupled to an electrical circuit that functionally integrates a power source to force current through the electrochemical reactor or a current-absorbing conductor from the electrochemical reactor. The aforementioned bipolar plate electrodes and ion-exchange membrane separator include a chemically resistant, non-conductive frame material operating with gasket sealing pathways and with various channels and crevices at the various connection points created when assembled, and tubes for the segmented circulation of the negative and negative solutions. The positive electrolytic solution, arranged sequentially in the flow chambers of the aforementioned negative electrolytic solution and in the flow chambers of the aforementioned positive electrolytic solution, respectively, where the entire structure of the dual-polarized electrode element and the ion-exchange membrane separator element have inner flanges that are recessed from one plane face of the structure on the opposite face of the other face of the structure with various grooves to accommodate O-shaped gaskets around the electrolytic solution passages and around the outer sealing circumference, on which the outer part of the dual-polarized electrode element or ion-exchange membrane separator is located. A number of retaining pins protrude from the surface of the recessed inner flanges and pass through the various channels of the outer part of the dual-polarized electrode element or membrane separator on the flanges. Retaining beam flanges of chemically resistant and non-conductive material with channels coordinated with the positions of the retaining pins are functionally mounted above the outer part of the dual-polarized electrode element or membrane separator on the recessed inner flanges of the structure and are permanently secured on them by making the various heads. The protruding bracing pins from the interlocking slots of the beam wing were heat-flattened. The pre-assembled dual-polarity plate electrode elements and membrane separators were adjusted to form a pre-assembled, staggered horizontal stack with the other side of the frame showing the O-shaped gasket facing upwards. 2. The electrochemical reactor according to claim 1, where the aforementioned other faces and the aforementioned first plane of each structural element are provided with a number of locking and aligning pins and slots of varying shapes in sequence that prevent the stacking of the aforementioned bipolar plate electrode elements and the aforementioned ion-exchange membrane separator elements in an incorrect alternating sequence and/or incorrect orientation. 3. The electrochemical reactor according to claim 1, in which the so-called recessed inner fins, the so-called dual-polarized plate electrode element, and the so-called ion-exchange membrane separator element are rectangular and the so-called structure has a convex outer surface. 4. An electrochemical reactor according to claim 1, in which the flow directions of the negative electrolytic solution and the positive electrolytic solution in the respective flow chambers along opposite sides of each ion-exchange membrane separator are opposite to each other. 5. The electrochemical reactor according to claim 1, in which each such two-phase plate electrode consists of an impermeable, fluid-permeable three-dimensional electrode structure on its opposite face that has a porous, fluid-permeable three-dimensional electrode structure in the form of felt or carbon fiber cloth bonded in an electrical continuity with the said conductive plate, the electrolyte entering the electrode chamber along one side and exiting the chamber on the opposite side; and further characterized that such porous electrode structure has two distinctly different comb-shaped working channels, the pointers of one working channel arranged in parallel and separated by parallel pointers of the other working channel; the first comb-shaped working channel or source has a base or branching tube channel moving along the side of the chamber through which the electrolyte is fed into the chamber and the second working channel or outlet has its own base or branching tube channel moving along the opposite side from which the electrolyte is exited the chamber; all pointers of one working channel extend from the corresponding base or branching tube channel and terminate. Go down before reaching the branching pipe channel of another work area. 6. The electrochemical reactor according to claim 1, where the tubes for the separate circulation of each such anionic and anionic solution, bounded by such passages, cut through the thickness of each such bipolar plate electrode section and of the such ion-exchange membrane separator section, bounded by two or more openings spaced along one side of the rectangular section of the structure.