Síntese dos compostos ZnAl2O4 e Cu/ZnAl2O4 e aplicação na produção de biodiesel

Abstract

The search for renewable sources of energy has become increasingly urgent due to population growth. In addition to being non-renewable, fossil fuels are highly polluting. In this way, the search for fuels produced from biomass has been growing over the years, being an example the biodiesel. There are several technologies for the production of biodiesel and several are the catalysts used for the transesterification of oils and fats. The present work had as objective to produce heterogeneous catalysts, that can be recovered and reused, with structures of spinel type of formula AB2O4 and to analyze its catalytic power against the methyl and ethyl transesterification of soybean oil. For this purpose, the catalyst ZnAl2O4 was synthesized and then doped with Cu to obtain the Cu/ZnAl2O4 catalyst, both catalysts were used in the ethylic and methyl reaction media with soybean oil. FTIR analyzes for ZnAl2O4 showed bands at 488 cm-1 and 677 cm-1 for the stretches of the Zn-O and Al-O bonds characteristic of the structure. The copper impregnated compound, had ZnAl2O4 characteristic bands, and at 550 cm-1 referring to Cu-O binding. The ester syntheses had yields of 0.6% and 0.8% for the closed system using the ZnAl2O4 catalyst. For the reflux system the yields were 0.8% with the use of the ZnAl2O4 catalyst and 4.6% and 5.2% with the Cu/ZnAl2O4 catalyst. The synthesis by combustion of the catalyst was efficient to obtain the ZnAl2O4 catalyst, the impregnation with copper was effective, with an increase of the catalytic power by 16% against the production of biodiesel esters.