Biodiesel obtido a partir do óleo de soja e de algodão utilizando argilas naturais, pilarizadas e impregnadas com óxido de molibdênio.

Abstract

Biodiesel has emerged as an alternative to petroleum diesel having favorable characteristics to consumption for be derived from clean and renewable sources, not possessing responsible compounds for the greenhouse effect. Biodiesel consists on mixtures of esters obtained by esterification or transesterification reaction from feedstock with monoalcohol in the presence of a catalyst obtaining similar characteristics to petroleum diesel. Much has been researched on heterogeneous catalysts for biodiesel application by that possess the possibility of reuse and allowing the use of different fat sources. However, this study aimed to use chemically treated clay materials as catalysts on biodiesel obtaining using soybean oil and cotton by the transesterification reaction in ethyl route under two reaction systems. The clay material was pillared and chemically treated with molybdenum oxide by physical dispersion and were characterized by X-Ray Diffraction, X-ray Dispersive Energy, Electronic Microscopy Scanning, Spectroscopy Dispersive Energy and Spectroscopy in Infrared region by Fourier Transform. Through the characterizations results of the clay material, it was found successful in pillaring because of the clay basal spacing increase in its natural form and succeeded in metal impregnation on clay structure. The efficiency of catalysts was evaluated for biodiesel obtaining by converting oil into ester in two reaction systems (S<\ - Autogenous pressure Batch Reactor and S2 - High Pressure Batch Reactor). The biodieseis were submitted to viscosity and gas chromatography analysis. Comparing the biodieseis results there was a reduction of 30 to 50% in viscosity using chemically modified clay with molybdenum oxide as a catalyst and conversion of oil into ester in about 50% according to gas chromatographic analysis. The catalyst that presented the best result of conversion of oil into ester was the pillared clay impregnated using the S2 system and soybean oil as feedstock, obtaining a conversion of 54.80% into ethyl ester. This improved performance can be attributed to the fact that pillared clay has lower particle size and with molybdenum oxide, present acid sites to favoring the transesterification reaction.