Esterification of oleic acid using mesoporous aluminosilicate modified with zirconium oxide
ABSTRACT Challenges stemming from population growth, extensive use and degradation of natural resources and dependence on fossil resources have aroused interest in the development of technologies for the production of renewable fuels. Within this context technologies for the production of biodiesel have been well studied in order to combine economicity and reduction of environmental impacts. Esterification using heterogeneous acid catalyst enables the use of raw materials of low added value and reduction of unit operations for separation and purification of products. The objective of the present work was to synthesize and characterize the AlSBA-15 material in the Si / Al = 10 ratio modified with ZrO2 and to evaluate it as a heterogeneous catalyst in the esterification of oleic acid with methanol for the production of monoalkyl esters. The characterization of the catalyst was done by X -ray diffraction, infrared spectrometry, nitrogen adsorptiondesorption at -196 °C and Brönsted -Lowry acid quantification. The catalytic performance was evaluated in a 300 mL Parr reactor, with methanol/oleic acid ratio equal to 6/1, with 3% m/m of catalyst in relation to oleic acid and 3 h of reaction at 120 ° C. Conversion rates of oleic acid (%) were, respectively, 55.5 ± 2.9, 68.2 ± 3.4 and 79.8 ± 3.6 for SBA-15, AlSBA-15 and AlSBA -15-ZrO2, which proves the efficiency of the synthesis method in increasing the acidic strength of the heterogeneous catalyst for the esterification reaction. The leaching and reuse tests showed that AlSBA-15-ZrO2 is active and stable under the reaction conditions employed.