Methyl Ester Of Fatty Acid By Continuous Reaction Rectify

It's a hot topic of producing methyl ester of fatty acid (biodiesel)with waste oil nowadays. This paper focused on the synthesis of it. Methyl oleate was synthesized in a packed reactor with cationic exchange resin as catalyst. The influencing factors of reaction and the kinetics were investigated. Two - step catalyzed process was adopted to prepare biodiesel from Soybean oil with high acid value and the fatty acid in soapstock of cottonseed oil with high acid value. Free fatty acid of the oil with high acid value was esterified with methanol in the reactor in order to made the acid value degreed in the first step, and then triglyceride (TG) of the oil with high acid value was transesterified with methanol catalyzed by potassium hydroxide.Results showed that when catalyst loading is 20g in the reactor, the optimum technology factors of Methyl oleate were gained as follows: molar ratio of methanol to oleic acid is 2:1, reaction temperature is 60℃, speed of reactant is 20 mL/h, on these conditions, conversion of oleic acid is 99.43%. The esterification reaction kinetics of oleic acid with methanol was studied at temperatures of 30℃, 40℃, 50℃and 60℃. The positive and negative reaction rate constants were obtained by fitting the experimental data to a pseudo-homogeneous phase model. The relation between the reaction rate and the temperature was described by the Arrhenius equation with the activation energy of the positive reaction E = 60.687 kJ/mol. The optimal esterification conditions of Soybean oil with high acid value are: the ratio of methanol to fatty acid is 2:1, reaction temperature is 60℃, dosage of reactant is 3mL/min.Under this condition, the acid value of Soybean oil was under 1mgKOH/g. Transesterification was performed at 2 % of potassium hydroxide, 60℃of reaction temperature, 60min of reaction time, and 6:1 of mole ratio of methanol to TG . The yield of methyl ester of Soybean oil can reach 95%. The optimal reaction conditions of Methyl ester of cottonseed oil are: the ratio of methanol to fatty acid is 2:1, reaction temperature is 60℃, reaction time is 80 min. On that conditions, the esterification rate of soapstock were above 94%. Results got by orthogonal experiments indicated the order of effect factor is: reaction time > the ratio of methanol to fatty acid > reaction temperature. The yield of biodiesel can reach 93% and biodiesel has very similar properties to America standard of biodiesel。...