Work

Eversa transform 2.0 immobilized on a hydrophobic support enables the solvent-free almost quantitative esterification of the free fatty acids from soybean oil with neopentylglycol

Year: 2024

Type: article

Abstract: The performance of Eversa Transform 2.0 (ETL) and lipase from Thermomyces lanuginosus (TLL) was compared in the solvent-free esterification of the free fatty acids (FFAs) from soybean oil with neopentylglycol (NPG) to produce NPG-diesters, which may be used as biolubricants. Enzymes were immobilized by interfacial activation on an octadecyl-coated methacrylate macroporous resin (C18) and compared to commercially immobilized TLL (Lipozyme® TL IM), free ETL and TLL. ETL@C18 surpassed the performance of all tested biocatalysts, reaching up to 98 % of FFAs conversion after 6 h of reaction at 50 °C and using a biocatalyst content of 9 wt% (related to the mass of FFAs). After optimization, the reactor temperature had a higher influence on the production of the NPG-diesters than the biocatalyst content, so that 45 °C and 3 wt% were determined to be the optimal values. Under such conditions, ETL@C18 retained approximately 88 % of its initial conversion into the NPG-diesters even after 10 consecutive reaction cycles. The biolubricant is composed mainly of NPG-diesters (∼91 %) and unreacted NPG (∼9 %), as confirmed by NMR analysis. The NPG-diesters exhibited a higher viscosity index (from 190.84 to 215.86) and oxidative stability (from 0.10 h to 1.34 h) than the starting material. The NPG-diesters biolubricant also exhibited a lower friction coefficient (0.049 against 0.064) and wear scar diameter (139.03 μm against 151.43 μm) than the 20W-50 mineral lubricant.

Source: Renewable Energy

DOI: 10.1016/j.renene.2024.121598