Energy & Fuels, Vol.29, No.8, 4981-4989, 2015
Enzymatic Production of Biodiesel from Nannochloropsis gaditana Microalgae Using Immobilized Lipases in Mesoporous Materials
A study of the production of fatty acid methyl and ethyl esters (FAMEs and FAEEs) to be used as biodiesel was carried out with Nannochloropsis gaditana oil using three fungal lipases (from Thermomyces lanuginosus, Candida antarctica B, and Mucor miehei) both free and immobilized in hexagonal (SBA-15 and MCM-41) and cubic (FDU-12 and SBA-16) mesoporous supports. The operating variables were optimized using free lipase (ethanol, 40 degrees C, 24 h, 500:1 oil/lipase mass ratio, and 8:1 ethanol/oil mass ratio). Higher FAEE yields were obtained with supported lipase than with free lipase because of the protection and stability given by the supports. The FAEE yields achieved were higher for lipase immobilized in hexagonal mesostructured materials because lipase molecules are more accessible than lipase immobilized in the three-dimensional cubic supports. C. antarctica lipase B immobilized in functionalized SBA-15 showed the better performance and reusability among the biocatalysts used.