Comparison of three methods for rendering plant fat transesterification

Abstract

Prošková A., Kuera J., Kopicová Z., Škarková L., 2013. Comparison of three methods for rendering plant fat transesterifi cation. Res. Agr. Eng., 59: 51-55.Th ree most frequently used methods for fat transesterifi cation were compared using rendering plant fat (RPF) as model. Acid-catalysed transesterifi cation was found to be the most eff ective (conversion 90%) at optimum conditions (fat: methanol ratio 1:10, sulphuric acid amount of 2% v/v, temperature 95°C). Base-catalysed transesterifi cation of RPF on the other hand, results in much lower conversion (45%) at optimum conditions (fat:methanol ratio 1:20, NaOH amount 8% w/v, optimum temperature 95°C). Th e diff erence is done (among others) by the fact that RPF has high concentration of free acid (high acidity number) compared with the fats usually used for transesterifi cation and that free acids are not esterifi ed in alkaline media. Enzyme-(lipase) catalysed reaction could lead to partial esterifi cation of free fatty acids, but with much lower reaction velocity. Th is fact leads to higher conversion in the case of enzyme-catalysed transesterifi cation of RPF compared with base-catalysed reaction; nevertheless, even in this case the conversion is much lower in comparison with acid-catalysed reaction. Th e optimum conversion in enzyme-catalysed reaction was 55%.

Degradation of animal malodour

“…were concluded by Malaťák et al (2013) utilising chemical, stoichiometric and thermal analysis. Alternative methods for rendering plant fat transesterification was analysed by Prošková et al (2013).…”