title: Immobilised lipase on structured supports containing covalently attached ionic liquids for the continuous synthesis of biodiesel in scCO2.
abstract: Different nanostructured supports, based on 1-decyl-2-methyimidazolium cations covalently attached to a polystyrene divinylbenzene porous matrix, were used as carriers to immobilise Candida antarctica lipase B. The suitability of these immobilised lipase derivatives for the synthesis of biodiesel (methyl oleate) by the methanolysis of triolein has been tested in both tert-butanol and supercritical (sc)CO(2) (18 MPa, 45 °C) as reaction media. The use of modified supports with low ionic-liquid loading covalently attached to the main polymeric backbone chains provide structured materials that led to the best biodiesel yields (up to 95 %) and operational stability (85 % biodiesel yield after 45 cycles of 8-4 h) in scCO(2) (45 °C, 18 MPa). The presence of tert-butanol as an inert cosolvent in the scCO(2) phase at the same concentration as triolein was key to avoid poisoning the biocatalyst through the blockage of its active sites by the polar byproduct (glycerol) produced in the biodiesel synthesis.
authors.affiliation: Departamento de Bioquímica y Biología Molecular B e Inmunología, Facultad de Química, Universidad de Murcia, Murcia, Spain. plozanor@um.es
authors.forename: Pedro
authors.initials: P
authors.lastname: Lozano
authors.forename: Eduardo
authors.initials: E
authors.lastname: García-Verdugo
authors.forename: Juana M
authors.initials: JM
authors.lastname: Bernal
authors.forename: Diana F
authors.initials: DF
authors.lastname: Izquierdo
authors.forename: M Isabel
authors.initials: MI
authors.lastname: Burguete
authors.forename: Gregorio
authors.initials: G
authors.lastname: Sánchez-Gómez
authors.forename: Santiago V
authors.initials: SV
authors.lastname: Luis
mesh_terms: D056804:Biofuels; D002245:Carbon Dioxide / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D056804:Biofuels; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D007093:Imidazoles; D052578:Ionic Liquids; D011137:Polystyrenes; D014753:Vinyl Compounds; D002245:Carbon Dioxide; D008049:Lipase; C431349:lipase B, Candida antarctica; C004985:divinyl benzene