Abstract

MARULANDA-BUITRAGO, Paola-Andrea  and  MARULANDA-CARDONA, Víctor-Fernando. SUPERCRITICAL TRANSESTERIFICATION OF BEEF TALLOW FOR BIODIESEL PRODUCTION IN A BATCH REACTOR. C.T.F Cienc. Tecnol. Futuro [online]. 2015, vol.6, n.2, pp.57-68. ISSN 0122-5383.

Supercritical transesterification experiments of beef tallow with ethanol were carried out in a batch reactor in order to assess the effect of temperature (350 - 400°C), reactant molar ratio (9:1 - 15:1) and reaction time (8 - 40 min). Composition of the produced biofuel was assessed in terms of the percentage of peak area of the long chain Fatty Acid Ethyl Esters (FAEEs) identified, including also the decomposition products generated as a result of thermal cracking or cis-trans isomerization reactions. Thermal decomposition of FAEEs produced from beef tallow included short chain ethyl esters (C8 - C13), ethyl pentadecanoate (C15:0), heptadecanoate (C17:0), not initially present or prevalent in triglycerides sources, as well as ethyl stearate (C18:0) and n-alkanes. Glycerol decomposition reactions were also verified by the presence of glycerol ethers and water content in the produced biodiesel. The highest conversion of triglycerides was verified at 400°C, 15:1 triglycerides to ethanol molar ratio and 40-minute reaction time. At these conditions, ethyl oleate (C18:1) decomposed completely to form cis-trans isomers as well as ethyl octadecanoate (C18:0), which was attributed to double bond hydrogenation reactions. Short chain ethyl esters and glycerol decomposition products have the potential to benefit certain properties of the fuel such as viscosity and cold flow.

Keywords : Biodiesel; Transesterification; Vegetable oils; Fatty acids; Hydrotreating; Glycerol.

        · abstract in Spanish | Portuguese     · text in English     · English ( pdf )