title: Membrane electrochemical reactors (MER) for NADH regeneration in HLADH-catalysed synthesis: comparison of effectiveness.
abstract: Two membrane electrochemical reactors (MER) were designed and applied to HLADH-catalysed reduction of cyclohexanone to cyclohexanol. The regeneration of the cofactor NADH was ensured electrochemically, using either methyl viologen or a rhodium complex as electrochemical mediator. A semi-permeable membrane (dialysis or ultra-filtration) was integrated in the filter-press electrochemical reactor to confine the enzyme(s) as close as possible to the electrode surface. When methyl viologen was used, the transformation ratio of cyclohexanone varied from 0 to 65% depending on the internal arrangement of the reactor. Matching the reactor configuration to the reaction system was essential in this case. With the rhodium complex, the ultra-filtration MER was tested in continuous and recycling configurations. The best conditions led to 100% transformation of 0.1 L volume of 0.1 M cyclohexanone after 70 h with the recycling mode. Finally, the performances of the reactors are discussed with respect to different evaluations of the production yields.
authors.affiliation: Laboratoire de Génie Chimique-CNRS UMR 5503, Basso Cambo, 5 rue Paulin Talabot, BP1301, 31106 Toulouse, France.
authors.forename: K
authors.initials: K
authors.lastname: Délécouls-Servat
authors.forename: A
authors.initials: A
authors.lastname: Bergel
authors.forename: R
authors.initials: R
authors.lastname: Basséguy
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry*; D019149:Bioreactors; D002384:Catalysis; D003067:Coenzymes / Q000737:chemistry; D003511:Cyclohexanols / Q000138:chemical synthesis*; D003512:Cyclohexanones / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004789:Enzyme Activation; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008567:Membranes, Artificial; D009243:NAD / Q000737:chemistry*; D010084:Oxidation-Reduction; D014462:Ultrafiltration / Q000379:methods
chemical_list: D003067:Coenzymes; D003511:Cyclohexanols; D003512:Cyclohexanones; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D009243:NAD; C036468:cyclohexanone; D000426:Alcohol Dehydrogenase