Transesterification of Palm Oil Catalyzed by Pseudomonas fluorescens Lipase in a Packed-Bed Reactor

• Published in: Energy & fuels 2012-09, Vol.26 (9), p.5977-5982
• Main Authors: Dors, Gisanara, Freitas, Larissa, Mendes, Adriano A, Furigo, Agenor, de Castro, Heizir F
• Format: Article
• Language: English
• Subjects: Ethyl alcohol; Lipase; Miscibility; Palm oil; Pseudomonas fluorescens; Reactors; Strategy; Transesterification; Triton
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef300931y

Transesterification of palm oil with ethanol catalyzed by Pseudomonas fluorescens lipase immobilized on epoxy–polysiloxane–polyvinyl alcohol composite (epoxy–SiO2–PVA) was performed in a continuous packed-bed reactor (PBR). Two strategies were used for improving the miscibility of the substrates: the addition of the organic solvent tert-butanol and the surfactant Triton X-100. Results were compared to those obtained in a solventless reactor, which displayed a biphasic system that passed through the reactor. Using this system, the ethyl ester yield of 61.6 ± 1.2% was obtained at steady state. Both Triton X-100 and tert-butanol systems were found to be suitable to promote the miscibility of the starting materials; however, the use of Triton X-100 reduced the yield to levels lower than 20%, because of the enzyme desorption from the support surface, as confirmed by scanning electron microscopy analysis. The best performance was found for the reactor running in the presence of tert-butanol, which resulted in a stable operating system and an average yield of 87.6 ± 2.5%. This strategy also gave high biocatalyst operational stability, revealing a half-life of 48 days and an inactivation constant of 0.6 × 10–3 h–1.