title: Improvement of membrane performances to enhance the yield of vanillin in a pervaporation reactor.
abstract: In membrane reactors, the interaction of reaction and membrane separation can be exploited to achieve a "process intensification", a key objective of sustainable development. In the present work, the properties that the membrane must have to obtain this result in a pervaporation reactor are analyzed and discussed. Then, the methods to enhance these properties are investigated for the photocatalytic synthesis of vanillin, which represents a case where the recovery from the reactor of vanillin by means of pervaporation while it is produced allows a substantial improvement of the yield, since its further oxidation is thus prevented. To this end, the phenomena that control the permeation of both vanillin and the reactant (ferulic acid) are analyzed, since they ultimately affect the performances of the membrane reactor. The results show that diffusion of the aromatic compounds takes place in the presence of low concentration gradients, so that the process is controlled by other phenomena, in particular by the equilibrium with the vapor at the membrane-permeate interface. On this basis, it is demonstrated that the performances are enhanced by increasing the membrane thickness and/or the temperature, whereas the pH begins to limit the process only at values higher than 6.5.
authors: Dipartimento di Ingegneria civile, chimica, ambientale e dei materiali (DICAM), University of Bologna, via Terracini 28, Bologna 40131, Italy. giovanni.cameraroda@unibo.it.
authors: Giovanni
authors: G
authors: Camera-Roda
authors: Dipartimento di Ingegneria civile, chimica, ambientale e dei materiali (DICAM), University of Bologna, via Terracini 28, Bologna 40131, Italy. antonio.cardillo2@unibo.it.
authors: Antonio
authors: A
authors: Cardillo
authors: "Schiavello-Grillone" Photocatalysis group, Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici (DEIM), University of Palermo, viale delle Scienze, Palermo 90128, Italy. vittorio.loddo@unipa.it.
authors: Vittorio
authors: V
authors: Loddo
authors: "Schiavello-Grillone" Photocatalysis group, Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici (DEIM), University of Palermo, viale delle Scienze, Palermo 90128, Italy. leonardo.palmisano@unipa.it.
authors: Leonardo
authors: L
authors: Palmisano
authors: "Schiavello-Grillone" Photocatalysis group, Dipartimento di Energia, Ingegneria dell'Informazione e Modelli Matematici (DEIM), University of Palermo, viale delle Scienze, Palermo 90128, Italy. francesco.parrino@unipa.it.
authors: Francesco
authors: F
authors: Parrino