Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-V-10TRIGLYCERIDES ALCOHOLYSIS CATALYZED BYHETEROGENEOUS CATALYSTS FOR BIODIESEL PRODUCTIONA. Macario 1 , G. Giordano 1 , B. Onida 2 , L. Forni 31 Dept. of Chemical Engineering & Materials, University of Calabria, Rende (CS), Italye-mail: macario@unical.it, Tel. +39.0984.49.66.67, Fax +39.0984.49.66.552 Dept. Materials Science & Chemical Engineering, Politecnico di Torino, Torino, Italy3 Dept. Industrial Chemistry & Materials, Univ. of Bologna, Bologna, ItalyIntroductionBiodiesel is an attractive renewable fuel due to the similar main characteristics sharedwith conventional diesel and to its environmentally friendly use. Currently, the fatty acidmethyl ester mixture (biodiesel fuel) is produced by alkali-catalyzed transesterification ofvegetable oils with methanol. The main used catalysts are the homogeneous basic ones, suchas sodium hydroxide, potassium hydroxide and sodium or potassium methoxide [1]. Thehomogeneous basic catalysis show a very fast kinetic of reaction but also a collateralsaponification reaction that reduces the biodiesel production efficiency. By contrary, the acidtransesterification allows to obtain a biodiesel production without formation of by-products.The drawbacks of an acid transesterification are the corrosive homogeneous used catalyst(H 2 SO 4 , HPO 4 , HCl) and the slow reaction rate that can be increased by high temperature andpressure [2].In this contest, our work focus on the possibility to use silicates (with acid and baseproperties) and acid zeolites (Beta, MFI, FAU-X) as catalysts for the transesterification offatty acids with methanol to biodiesel. These type of catalysts allow combining theadvantages of the alkaline and acid transesterification with those of heterogeneous catalyticprocess. Besides the usual zeolites characterization techniques (XRD, TG-DTA, SEM, EDX),FT-IR and NH 3 -TPD analyses have been carried out on the catalysts in order to identify thenature and the strength of the catalytic active sites.Experimental partThe acid zeolites H-BEA, K-Silicalite-1, H-Silicalite-1, Na-Silicalite-1 and Fau-X havebeen prepared by conventional procedures. The silicates used have been the potassium andsodium ones, in powder form. The transesterification reaction catalyzed by silicates and acidzeolites have been carried out at reaction temperatures ranging between 40÷150 °C and usinga molar ratio of triglycerides to methanol ranging between 1:6 ÷1:50. The biodiesel475