Heterogeneous enzymatic catalysts: Comparing their efficiency in the production of biodiesel from alternative oils

Abstract

In this study, four heterogeneous enzymatic catalysts were synthesized: three from the immobilization of Pseudomonasfluorescens lipase (LPf) on SBA-15, Ca/SBA-15, and Na/SBA-15,and one by the one-step coprecipitation technique, named LOBE (Low Ordered Biosilicificated Enzyme). The physicochemical properties of these materials were determined by smallangleX-ray scattering (SAXS), Fourier-Transform infrared spectroscopy(FT-IR), inductively coupled plasma atomic emission spectroscopy (ICP), and N2 adsorption/desorption measurements. The biocatalysts activity was evaluated in the production of biodiesel with different oily raw materials. From these results, it was possible to infer that confinement effects influence catalytic efficiency. While the SBA-15 material presents one-dimensional channels, the LOBE biocatalyst has interconnected three-dimensional cavities type MCM-48 that favor the mixing of reactant phases (oil-alcohol), the interaction with active sites in the structure, and mass transfer. Thus, this 3D architecture would increase the specific activity of the LOBEbiocatalyst approximately five times concerning the otherstudied biocatalysts.