Exploring the feasibility of enzymatic biodiesel production from Tilapia (Oreochromis Niloticus) waste oil

Abstract

Fish waste and byproducts, found in nature or generated by the processing industry, represent a significant source for producing high-value products. Fertilizers, biomaterials, cosmetics, lubricants, and biodiesel can be derived from these residues. A bibliometric analysis was conducted to explore the potential for biodiesel production using residual fish oil. A notable gap was identified concerning the enzymatic synthesis of biodiesel using residual tilapia oil (Oreochromis niloticus) as the substrate and Lipase Eversa® Transform 2.0 as the catalyst. Following this, a theoretical and experimental study was performed on the biocatalytic production of biodiesel through the enzymatic hydroesterification of residual tilapia oil. The Taguchi methodology was employed during the esterification phase, evaluating the following parameters: temperature (25, 40, and 55 °C), molar ratio (1:1, 1:5, and 1:9), biocatalyst concentration (1%, 5%, and 9%), and reaction time (1, 3, and 5 hours). The experimental design yielded conversion results ranging from 19.3 ± 0.38% (1:9 molar ratio, 3 hours, 55 °C, 1% biocatalyst) to 83.8 ± 0.29% (1:5 molar ratio, 3 hours, 25 °C, 9% biocatalyst). The most significant factors influencing conversion were biocatalyst concentration, followed by temperature. The optimal reaction conditions, determined through statistical analysis, were 5 hours at 25 °C with a molar ratio of 1:1 (FFA/ethanol) and 9% biocatalyst. Under these conditions, the theoretical conversion was estimated at 96.73%. When the reaction was conducted with the specified parameters, an experimental conversion of 89.94 ± 0.09% was achieved, indicating a lower experimental value compared to the theoretical prediction. The bioproduct was characterized for its viscosity and density, yielding values of 2.47 cSt and 883.6 kg/m³, respectively. Additionally, a docking and molecular dynamics study was conducted to assess the stability of Lipase Eversa® Transform 2.0 with the FFAs, confirming the coupling of the enzyme's catalytic site with the substrate. In conclusion, residual tilapia oil proved to be a viable raw material for the synthesis of bioproducts. This study contributes to the advancement of sustainable biochemical processes.