Nanozeolites as solid supports for enzyme immobilization: Synthesis, characterization of complex nanozeolite/enzymes and their application as heterogeneous catalysts for biodiesel production via ethylic route

Abstract

Zeolites are crystalline aluminosilicates that can be natural or synthetic. Zeolites have well-defined channels and cavities of molecular dimensions that find extensive industrial use in modern chemical industry in several areas, especially in the heterogeneous catalysis. The synthetic zeolites have properties (ion exchange, adsorption and catalytic selectivity) very interesting of easy modulation. Due to these properties, there are several studies reporting of the use of zeolites as a solid support for enzyme immobilization these studies has allowed the formation of a variety of new alternative heterogeneous catalysts (zeolites/enzymes) that combine the advantages of catalytic enzymes with those of the zeolitic materials. Although there are studies reporting the immobilization of enzymes on zeolites for biodiesel production until now to the best of our knowledge there is no report clearly showing the use of nanozeolites as solid support for the immobilization of lipase. Therefore, the research proposal of this PhD project is the synthesis of nanozeolites, its use as support for the immobilization of lipases, and the use of these complexes (nanozeolite/enzyme) as catalysts for the transesterification of two different sources of raw materials: palm and microalgae oils to biodiesel via ethylic route. In order to achieve this purpose the transesterification reactions to the biodiesel production from palm and microalgae oils are studied both in pure nanozeolites, as with enzymes (lipases of Rhizomucor meihei, Thermomyces lanuginosus, Candida antarctica, Pseudomonas cepacia) free or immobilized on nanozeolites, and the following parameters are studied: the catalytic efficiency of pure nanozeolite and of the complex formed by the enzyme-nanozeolite, the interaction between the surface of nanozeolite and the enzyme, and structural changes on the surface of nanozeolites by enzyme immobilization.