Desenvolvimento de um processo para a produção sustentável de um éster (levulinato de isoamila) catalisada por eversa transform 2.0 imobilizada via ativação interfacial

Abstract

Levulinic acid (LA) esters are of great importance due to their different applications as aromatics, aromatics and plasticizers. The present study consists of the enzymatic production of levulinic acid ester by enzymatic esterification using isoamyl alcohol (AI). The reactions were catalyzed by a low cost commercial lipase (Esferas® Transform 2.0) immobilized on mesoporous polystyrene-divinylbenzene (PSTY-DVB) spheres via interfacial selection (hydrophobic gaze adsorption). Uptake was performed in i (buffer 5 low satin strength, pH 5.0) employing an initial protein load of 40 mg.g -1 support. The immobilization process was accompanied by protein activation and hydrolytic activity disappeared in the supernatant. Initially, its catalysis was tested in the production in organic solvent media and it was developed with the reaction in solvents. In, a central rotational design (DCCR) composed with two independents (biocatalyst concentration and followed by decision) was proposed for the production of the ester in terms of temperature influenced by the conversion and the productivity which were dependent variables (responses). The influence of the ratio:AI and reaction time was also molar. Under optimal reaction conditions, reuse tests of the biocatalyst prepared after successive batches of reaction were performed. According to the results obtained, a maximum immobilized protein concentration of 31.2 ± 2.8 mg g-1 and an immobilization yield of ≈83% was obtained. This satisfactory result is due to the high surface area and pore diameter of the tested support. Isoamyl levulin was favored with the addition of organic reaction solvents in the reaction medium. Among the solvents tested, the maximum production of the ester was obtained using methyl isobutyl ketone (MIBC). Under optimal reaction conditions, a maximum conversion of the order of 65% was achieved after 12 h of reaction: reflecting at 40° of biotalyst concentration of 20% m.m-1 AL:AI molar ratio of 1 in MIBC medium. The strategy proposed in this study proved to be very promising, as it is a sustainable process and uses a low-cost immobilized lipase as a biocatalyst.