Biodiesel Preparation From Microalgal Oil By Two-Step Enzymatic Catalysis

Biodiesel preparation by the traditional chemical method underrelatively stringent conditions. Deal with a lot of water will consume a lotof energy. Microalgae in the water-rich environment and its have richgrease, so separate of the hydrolysis in the aqueous and esterification inthe alcohol phase, it can be overcome many shortcomings.This thesis is a preliminary study microalgae oil use the Laboratoryhomemade lipase Candida.99-125as a catalyst for hydrolysis andesterification process two-step preparation of biodiesel. Investigated theamount of free lipase in the process of hydrolysis and esterification,respectively, the single factor of the oil-water ratio, the initial amount ofethanol, methanol to oil molar ratio, temperature, pH value, the life of thefree enzyme, different amount of additives and reaction time, etc.experiment on the reaction. Important factor in the reaction, the singlefactor experiment, will be the single factor response surface optimization.The experiment can be algae oil hydrolysis rate was89.6%, and fatty acidesterification rate of91.8%, the final crude biodiesel was80.1%. Verifythe moisture content of high energy microalgae into the hydrolysis andesterification step reaction of Candida sp.99-125lipase-catalyzedboundary catalysis and biodiesel. In order to further a bettercharacterization of the role of oil, water, enzymes, as well as alcohol, oil,enzyme relationship dynamics on the hydrolysis and esterification of thetwo-step reaction mechanism analysis with V=Kp[E][S]/(Km+[S])and V=Vm[S]/Km,the lipase catalyzed hydrolysis of the system ofmicroalgae oils,hydrolysis rate of the enzyme concentration(E),substrate concentration (S). There is a certain relationship: S and t. The same circumstances. The degree of hydrolysis as the initial enzymeconcentration E. The higher as the drop reaches the critical value; thecontrary, in E. The same circumstances, the degree of hydrolysis with theinitial substrate concentration S increases and then decreases.Preparation of biodiesel from microalgae oil two-step enzymaticreaction from the shake flask experiments,500ml round bottom flask ofthe amplification reaction, chemical one-step method and enzymatictwo-step method process were compared from the biodiesel yield,chemical one-step> lipase two-step method, by chemical system can notexist water, while high water content of microalgae from on the water aswell as the use of lipase effect analysis showed that the chemical methodthe cost of the reaction system is also more than the cost of the enzymaticreaction system. It can seen that the lipase two-step enzymatic processenergy microalgae biodiesel production system is superior to chemicalprocess technology.