Compact frameless bipolar stack for a multicell electrochemical reactor with planar bipolar electrical interconnects and internal ducting of circulation of electrolyte solutions through all respective cell compartments

A frameless multi-cell bipolar electrochemical reactor composed of stackable elements between two headers, hydraulically sealed by compressing the stacked elements, including planar bipolar electrical conductive elements alternated to a permionic membrane assembly fixture adapted to separate anodic and cathodic solution flow compartments defined between said permionic membrane separator and one and the other of said bipolar electrical elements and through which the two distinct electrolyte solutions are respectively flown, comprising

• two identical parallelepiped elastomer gaskets defining a central aperture and having at least two through holes along two opposite perimeter sides thereof, a flat perimeter seal surface on a backside and on the opposite or front side thereof:
• a bas-relief patterned perimeter seal area contouring one every two through holes along said two opposite perimeter sides and two similar pluralities of patterned seal areas defining there between flow channels extending from a rim region of non-contoured through holes to the edge of the nearest juxtaposed side of said central aperture of the gasket;
• the permionic membrane having perimeter edge portions sealingly held between said flat perimeter seal surfaces of the two identical gaskets, disposed back-to-back;
• the bas-relief patterned seal areas over the front side of the two identical gaskets, compressed between the surfaces of respective planar electrically conductive bipolar elements in alignment with the through holes of the gaskets for hydraulically sealing the perimeter of the two flow compartments in hydraulically communication with through holes non-contoured by said perimeter seal area of the patterned front side of the respective gasket.