New biofuel integrating glycerol into its composition through the use of covalent immobilized pig pancreatic lipase

• Published in: International journal of molecular sciences Vol. 13; no. 8; pp. 10091 - 10112
• Main Authors: Luna, Diego, Posadillo, Alejandro, Caballero, Verónica, Verdugo, Cristóbal, Bautista, Felipa M, Romero, Antonio A, Sancho, Enrique D, Luna, Carlos, Calero, Juan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-08-2012; Molecular Diversity Preservation International (MDPI)
• Subjects: Alcohols - chemistry; Alcohols - metabolism; amorphous AlPO 4; Animals; Biocatalysts; Biodiesel fuels; Biofuels; Chromatography, Gas; covalent immobilization; Diesel fuels; Efficiency; Enzymes; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Esterification; Fatty acids; Fatty Acids - chemistry; Fatty Acids - metabolism; Glycerol; Glycerol - chemistry; Glycerol - metabolism; Lipase - chemistry; Lipase - metabolism; monoglyceride; pig pancreatic lipase (PPL); Plant Oils - chemistry; Plant Oils - metabolism; Potassium; Sepiolite; Sunflower Oil; sunflower oil transesterification; Swine; Temperature; Triglycerides; Vegetable oils; Viscosity; Spain; covalent immobilization; biofuels; pig pancreatic lipase (PPL); Sepiolite; sunflower oil transesterification; amorphous AlPO4, monoglyceride
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms130810091

By using 1,3-specific Pig Pancreatic lipase (EC 3.1.1.3 or PPL), covalently immobilized on AlPO(4)/Sepiolite support as biocatalyst, a new second-generation biodiesel was obtained in the transesterification reaction of sunflower oil with ethanol and other alcohols of low molecular weight. The resulting biofuel is composed of fatty acid ethyl esters and monoglycerides (FAEE/MG) blended in a molar relation 2/1. This novel product, which integrates glycerol as monoacylglycerols (MG) into the biofuel composition, has similar physicochemical properties compared to those of conventional biodiesel and also avoids the removal step of this by-product. The biocatalyst was found to be strongly fixed to the inorganic support (75%). Nevertheless, the efficiency of the immobilized enzyme was reduced to half (49.1%) compared to that of the free PPL. The immobilized enzyme showed a remarkable stability as well as a great reusability (more than 40 successive reuses) without a significant loss of its initial catalytic activity. Immobilized and free enzymes exhibited different reaction mechanisms, according to the different results in the Arrhenius parameters (Ln A and Ea). However, the use of supported PPL was found to be very suitable for the repetitive production of biofuel due to its facile recyclability from the reaction mixture.