Avaliação da incorporação de La2O3 na zeólita NH4-MCM-22 na produção de biodiesel.

Abstract

Biodiesel is an attractive alternative source to fossil fuels from the petroleum industry, which are currently used in diesel oil production and have harmful consequences for the environment and society. In this context, the present work aims the application of zeolites after ion exchange and lanthanun incorporation in soybean oil transesterification reaction by methyl route in biodiesel production. Factorial design (23 + 2PtCt) was used for this evaluation, with the study of variables impregnated lanthanum mass content, reaction time and reaction temperature. Zeolite Na-MCM-22 was synthesized by static hydrothermal method. Ion exchange to obtain the NH4-MCM-22 ammoniacal zeolite was performed by stirring the Na-MCM-22 zeolite in NH4Cl solution for 24 h. The La2O3 incorporation into the zeolitic structure was accomplished by pore saturation impregnation. From the thermogram of the zeolitic precursor MCM-22 (P) and the diffractometry of MCM-22 (P) and zeolite Na-MCM-22 was found that the calcination temperature of 550 ° C removed the structural agent and the crystalline phases of Na-MCM-22 were formed. Nitrogen physisorption showed characteristics of microporous materials with uniform pores. The micrographs indicated the formation of particles of uniform espherical morphology. The ion exchange treatment for Na-MCM-22 zeolite did not change its textural properties. However, it was possible to realize that the volume and area of the microporous structure were reduced, as well as the diameter and total pore volume increased. The optimal point of the experimental design was associated with higher temperature and reaction time levels and lower % lanthanum in the zeolitic structure, with 20.1% methyl ester content. The properties of density, viscosity and content of methyl esters did not specify the oil obtained as biodiesel. The statistical treatment of the data showed that the independent variables and their interactions presented statistical significance for the response variable ester content. A linear model was obtained as representative for the adopted factorial design.