Enzymatic Synthesis of Oleyl Oleate, a Liquid Wax Ester, in a Stirred Tank Reactor

• Main Author: Mat Radzi, Salina
• Format: Thesis
• Language: English
• Published: 2006
• Subjects: Esterification; Oleic acid; antartic*
• Online Access: http://psasir.upm.edu.my/id/eprint/6261/; http://psasir.upm.edu.my/id/eprint/6261/1/FS_2005_36.pdf

High performance enzymatic synthesis of oleyl oleate, a liquid wax ester was successfully synthesized via enzymatic esterification reaction of oleic acid and oley alcohol. Immobilised Candida antartica lipase B (Novozym 435) was used as biocatalyst. The study was divided into four parts which are the optimisation of reaction synthesis at different scales, the reactor study in term of mixing efficiency, the stability of immobilised enzyme and the analysis and characterization of the product of the reaction. Preliminary synthesis of oleyl oleate was carried out in a small scale reaction with a total volume of 3.5 mL using screw-capped vials. Optimisation reaction study via conventional method of varying one parameter at-a-time approach was carried out. A high percentage conversion yield of >90% was achieved at optimum reaction time of 5 min, reaction temperature of 40-6O0C1 molar ratio of substrates (oleyl alcoholloleic acid) of 2:1, amount of enzyme of 0.4 g and organic solvents of Log P23.5 at fixed agitation speed of 150 rpm. Investigation in larger scale production of oleyl oleate was performed using 2 L stirred tank reactor (STR). The reaction was scaled-up to 300X with a total volume of 1.05 L. A high percentage conversion of oleyl oleate was achieved of >95% by conventional experiment method at reaction time of 30 min, agitation speed of 400 rpm, reaction temperature of 45-50°C, molar ratio of substrate (oleyl alcoholloleic acid) of 2:l and amount of enzyme of 90 g. The reaction synthesis was further optimised by response surface method (RSM) based on five-level, three-variable central composite rotatable design (CCRD) to evaluate the interactive effects of important parameters in larger scale processing. Generally, simultaneously increasing amount of enzyme, agitation speed and reaction temperature would improved the yields. A high percentage conversion of 97.4% was achieved under the optimum condition, which compared well with the maximum predicted value of 97.7%. In order to improve the production ...