title: Kinetic modeling of solvent-free lipase-catalyzed partial hydrolysis of palm oil.
abstract: This work reports the experimental data and kinetic modeling of diacylglycerol (DAG) production from palm oil using a commercial immobilized lipase (Lipozyme RM IM) in a solvent-free medium. The experiments were performed in batch mode, at 55 °C and 400 rpm, and the effects of enzyme concentration (0.68-2.04 wt% related to the mass of substrates), initial water concentration (5-15 wt% related to the mass of oil), and reaction time were evaluated. A novel kinetic model is presented based on the ordered-sequential bi-bi mechanism considering hydrolysis and esterification steps, in which a correlation between water-in-oil solubility and surfactant molecules concentration in the oil allowed the model to describe the induction period in the beginning of the hydrolysis reaction. Moreover, mass transfer limitations related to the enzyme concentration in the system were also taken into account. The proposed model presented a very satisfactory agreement with the experimental data, thus allowing a better understanding of the reaction kinetics. The best conditions obtained for the product (partially hydrolyzed palm oil) in terms of DAG yield (35.91 wt%) were 2.87 wt% enzyme/substrate, 2.10 wt% water/oil, and 72 h of reaction.
authors.affiliation: Department of Chemical Engineering, Federal University of Paraná, Polytechnic Center, Jardim das Américas, Curitiba, PR, Brazil. fernando_voll@ufpr.br
authors.forename: Fernando Augusto Pedersen
authors.initials: FA
authors.lastname: Voll
authors.forename: Andreia Fatima
authors.initials: AF
authors.lastname: Zanette
authors.forename: Vladimir Ferreira
authors.initials: VF
authors.lastname: Cabral
authors.forename: Claudio
authors.initials: C
authors.lastname: Dariva
authors.forename: Rodrigo Octavio Mendonça Alves de
authors.initials: RO
authors.lastname: Souza
authors.forename: Lucio
authors.initials: L
authors.lastname: Cardozo Filho
authors.forename: Marcos Lúcio
authors.initials: ML
authors.lastname: Corazza
mesh_terms: D002384:Catalysis; D004075:Diglycerides / Q000737:chemistry; D004800:Enzymes, Immobilized / Q000737:chemistry*; D004951:Esterification; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase; D000073878:Palm Oil; D010938:Plant Oils / Q000737:chemistry / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D004075:Diglycerides; D004800:Enzymes, Immobilized; D010938:Plant Oils; D012997:Solvents; D014867:Water; D000073878:Palm Oil; D008049:Lipase