PRELIMINARY ASSESSMENT OF THE PROCESSING OF HIGH-ACIDITY FATTY MATERIALS USING SOLID CATALYSTS FOR THE OBTAINMENT OF FATTY ACID METHYL ESTERS

This work presents the processing of a high-acidity oil through sequential reactions of esterification using montmorillonite K10 and transesterification using zinc monoglycerolate. Since these solids had not been employed along with this approach beforehand, the objective of this work is to provide a general insight of the proposed process and demonstrate its technical feasibility. In this sense, the processing of a synthetic mixture containing soybean oil and lauric acid provided a reduction of the free fatty acid content from (40.8 +/- 0.1) % to (3.1 +/- 0.4) % after the esterification reaction and a fatty acid methyl ester yield of (95.4 +/- 0.2) % was obtained after the transesterification reaction. As compared to traditional homogeneous catalysts, the solid catalysts employed in this work require higher reaction times to achieve satisfactory ester yields but, on the other hand, they are less sensitive to the presence of both water and free fatty acids in the raw materials and can be easily recovered and reused. Therefore, the results accomplished may help the development of a technology for processing high-acidity fatty materials in order to obtain biodiesel, although its economic feasibility still needs a further assessment.