ORIGINAL PAPER Kinetics of enzymatic trans-esterification of glycerides for biodiesel production Vincenza Calabro ` • Emanuele Ricca • Maria Gabriela De Paola • Stefano Curcio • Gabriele Iorio Received: 23 March 2009 / Accepted: 21 October 2009 / Published online: 10 November 2009 Ó Springer-Verlag 2009 Abstract In this paper, the reaction of enzymatic trans- esterification of glycerides with ethanol in a reaction medium containing hexane at a temperature of 37 °C has been studied. The enzyme was Lipase from Mucor miehei, immobilized on ionic exchange resin, aimed at achieving high catalytic specific surface and recovering, regenerating and reusing the biocatalyst. A kinetic analysis has been carried out to identify the reaction path; the rate equation and kinetic parameters have been also calculated. The kinetic model has been validated by comparison between predicted and experimental results. Mass transport resis- tances estimation was undertaken in order to verify that the kinetics found was intrinsic. Model potentialities in terms of reactors design and optimization are also shown. Keywords Biodiesel  Lipase  Kinetics  Oil trans-esterification  Enzyme List of symbols CSTBR Continuous stirred tank bio-reactor D Diolein (in reaction mechanism) d p Catalyst particle diameter [e] Enzyme concentration (g/l) E Enzyme (in reaction mechanism) E 0 Activate complex (in reaction mechanism) E–Et Enzyme–ethanol complex (in reaction mechanism) E–D Enzyme–diolein complex (in reaction mechanism) E–M Enzyme–monolein complex (in reaction mechanism) E–P Enzyme–product complex (in reaction mechanism) E–T Enzyme–triolein complex (in reaction mechanism) EO Ethyloleate (in reaction mechanism) [EO] Ethyloleate molar concentration (mol/l) D[EO] Ethyloleate production (mol/l) Et Ethanol (in reaction mechanism) [Et] Ethanol molar concentration (mol/l) G Glycerol (in reaction mechanism) [G] Glycerol molar concentration (mol/l) Ki Kinetic parameters (various dimension) k s Mass transport coefficient (m/s) M Monolein (in reaction mechanism) me Mass of enzyme (g) mso Mass of simulating oil (g) MW Molecular weight [Da] P Products in terms of total sum of glycerol, monolein and diolein (M ? D ? G) (in reaction mechanism) [P] Concentration of products in terms of total sum of glycerol, monolein and diolein (M ? D ? G) (mol/l) Sh Sherwood number T Triolein (in reaction mechanism) [t] Triolein mass concentration (g/l) [T] Triolein molar concentration (mol/l) t Time (h) t D Diffusion time (h) t v Reaction time (h) U Units of enzyme (Unit) [U] Concentration of enzyme in terms of Unit (Unit/l) V. Calabro `  E. Ricca (&)  M. G. De Paola  S. Curcio  G. Iorio Department of Engineering Modelling, University of Calabria, via P. Bucci Cubo 45/A, Arcavacata di Rende (CS), Italy e-mail: ericca@unical.it 123 Bioprocess Biosyst Eng (2010) 33:701–710 DOI 10.1007/s00449-009-0392-z