Optimization of the Production of Enzymatic Biodiesel from Residual Babassu Oil (Orbignya sp.) via RSM
Katerine S. Moreira, Lourembergue S. Moura Júnior, Rodolpho R. C. Monteiro, André Luiz Barros de Oliveira, Camila Peixoto do Valle, Tiago Melo Freire, Pierre Basílio Almeida Fechine, Maria Cristiane Martins de Souza, Gloria Fernández‐Lorente, José M. Guisán, José Cleiton Sousa dos Santos
Abstract
Residual oil from babassu (Orbignya sp.), a low-cost raw material, was used in the enzymatic esterification for biodiesel production, using lipase B from Candida antarctica (Novozym® 435) and ethanol. For the first time in the literature, residual babassu oil and Novozym® 435 are being investigated to obtain biodiesel. In this communication, response surface methodology (RSM) and a central composite design (CCD) were used to optimize the esterification and study the effects of four factors (molar ratio (1:1–1:16, free fatty acids (FFAs) /alcohol), temperature (30–50 °C), biocatalyst content (0.05–0.15 g) and reaction time (2–6 h)) in the conversion into fatty acid ethyl esters. Under optimized conditions (1:18 molar ratio (FFAs/alcohol), 0.14 g of Novozym® 435, 48 °C and 4 h), the conversion into ethyl esters was 96.8%. It was found that after 10 consecutive cycles of esterification under optimal conditions, Novozym® 435 showed a maximum loss of activity of 5.8%, suggesting a very small change in the support/enzyme ratio proved by Fourier Transform Infrared (FTIR) spectroscopy and insignificant changes in the surface of Novozym® 435 proved by scanning electron microscopy (SEM) after the 10 consecutive cycles of esterification.