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

PP-V-14Alkali catalyst. For a basic catalyst,either sodium hydroxide (NaOH) orpotassium hydroxide (KOH) should beused with ethanol as well as any kind ofoil. The reason why there is a greatinterest in the alkali process is it is moreefficient and less corrosive than the acidprocess, making it a preferred catalyst tobe used in industries. The limits of this Fig. 1. Transesterification stage to biodiesel production.technology are due to the sensitivity thatthis process has to purity of reactants, to the fatty acid, as well as to the water concentration ofthe sample.Acid catalyst. This type of catalyst gives a very high yield in esters but the reaction isvery slow. The acid most commonly used is sulfuric acid with temperature range from 55 to80 °C. A kinetics modeling for soybean oil has been made by Freedman et al. 4 .Lipase as catalyst. Lipases are enzymes used to catalyze some reaction such as hydrolysisof glycerol, alcoholysis and acidolysis, but it has been discovered that they can be used ascatalyst for tranesterification and esterification reactions too.The simulated reactors in this work are shown in Fig. 1. The palm oil was chosen for thetransesterification process considering the average percentage of fatty acids in Colombiavariety. The following composition in fatty acids: 45% palmitic acid, 40% oleic acid and 15%linoleic acid was defined for the process simulation. The reaction was carried out with ethanolusing NaOH and KOH as catalysts to 60 °C, H 2 SO 4 to 70 °C and 150 kPa and the results wereanalyzed and compared with those of Nelson et al. 5 and Shimada et al. 6 using immobilized C.antarctica lipase. Several differences were founded in reaction conditions, yield of biodieselobtained and velocity of production depending upon the catalyst used. Nevertheless, allprocesses were designed properly and with high efficiency.References1. Corporación Colombia Internacional. Oferta agropecuaria ENA. Cifras 2006 www.cci.org.co.2. Periodico El Tiempo. Date: Abril 21/2007 «Sube producción de etanol, baja azúcar».3. FEDEPALMA. www.fedepalma.com.4. Freedman, B., Butterfield, R., Pryde, E., JAOCS, 63, 10. 1375-1380(1986).5. Nelson LA, Folgia TA, Marmer WN. JAOCS 1996;73(8):1191–5.6. Shimada Y, Watanabe Y, Sugihara A, Tominaga Y. J Mol Catal B: Enzymatic 2003;17:133–42.484