Biodiesel production using immobilized lipase supported on a zirconium-pillared clay. Effect of the immobilization method

Edible oils, used in restaurants and households, have become a potential source of environmental pollution because their residuals are indiscriminately poured into rivers and lakes. One cost-effective and sustainable way to treat this waste is using this biomass in the production of biofuels, such as biodiesel. The main reactions for obtaining biodiesel are catalyzed in a homogeneous phase, using basic or acid solutions (NaOH or H2SO4, respectively) or in a heterogeneous phase, using a porous material with or without metals. One interesting reaction, owing to its low energy consumption, is carried out using biocatalysts of enzymes immobilized in porous materials. In this work, a porcine pancreatic lipase (PPL) was immobilized in a zirconium-pillared clay (Zr-PILC) by means of two syntheses: adsorption (PPL/Zr-PILC ADS) and cross-linking (PPL/Zr-PILC CL). The biocatalysts were used in the transesterification of canola oil. The amount of methyl esters was produced in the order Zr-PILC approximate to PPL << PPL/Zr-PILC CL << PPL/Zr-PILC ADS. According to these results, the activity and selectivity are a function of the method of synthesis and show the potential of these biocatalysts to transform waste oil in biodiesel at low cost by means of a sustainable process.