Kinetic model of biodiesel production catalyzed by free liquid lipase from Thermomyces lanuginosus

Publication date: Available online 25 July 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Mohamad Firdaus Mohamad Yusoff, Jesper Brask, Per Munk Nielsen, Zheng Guo, Sergey Fedosov Conversion of plant oil to biodiesel was investigated using liquid lipase from Thermomyces lanuginosus. Presence of 2–3% water was necessary to preserve the enzymatic activity under methanolysis (3×0.5 equivalents of MeOH added in steps). Several individual reaction blocks were investigated and became the individual segments of the full kinetic scheme. Additional reaction schemes were introduced to imitate changing solubility/surface area of the reactants in aqueous and organic phases. The relevant rate constants were evaluated and included into a mathematical model. The experimental results and computer modeling showed that conversion of oil to 92–97% of biodiesel is feasible at 1% enzyme load (24hours, 35°C) using the feedstocks containing 2–20% of water, 0–10% of glycerol, 0–20% of free fatty acids (“F”). The enzyme can be collected in a narrow white layer settled between biodiesel and glycerol-water phases, containing also “F” and monoglycerides (“M”). The lipase can be then reused after compensation for 5–10% loss of the enzyme. The main contaminants in the produced biodiesel are “F” (2–6%) and “M” (1–3%). Monoglycerides decrease below 0.2% if methanolysis is continued after separation of glycerol, while the level of “F�...

Source: Journal of Molecular Catalysis B: Enzymatic - July 25, 2016 Category: Biochemistry Source Type: research