Synthesis and characterization of new biocatalysts formed by nanozeolite and laccase enzymes complexes: their applications in oxidation reactions of glycerol to tartronic acid and mesoxalic acid compounds

Abstract

The increase in the glycerol production by transesterification of fats or vegetable oils enables the studies of new technological applications for its use as raw material. For every 10 kg of biodiesel synthesized, 1 kg of glycerol is produced. The transformation of glycerol in other products with greater added economic values has gained high industrial interest, once it also favors the biodiesel production economy, and concomitantly, provides the chemical industry with more versatile raw materials or building blocks that can be used to make more complex molecules. Etherification, oxidation, catalytic reforming and esterification, are examples of reaction that glycerol may be applied. The goal of this project is to explore the selective glycerol oxidation to tartronic acid and mesoxalic acid, using new biocatalysts. Both tartronic and mesoxalic acids are compounds with several applications in the pharmaceuticals, cosmetics and fine chemicals industries, what makes the development of new catalytic routes that allows to convert low price biomass to these products a relevant technical-scientific challenge. In this work, the biocatalyst for the selective glycerol oxidation will be different laccase enzymes (oxidoreductase family) immobilized onto zeolitic nanomaterials. Although there are studies of immobilization of enzymes in zeolitic supports in micrometric scale for various purposes, to the best of our knowledge, to the present, there is no report about the use of nano sized zeolites as solid support to the laccase enzymes immobilization and its use for the glycerol oxidation to mesoxalic and tartronic acids. The new biocatalysts will associate the advantages of the heterogeneous catalysts with those of the enzymatic catalysts. (AU)