Continuous Synthesis of Ethyl Esters from Triglycerides using Simulated Moving Bed Chromatographic Reactor Packed with Solid Acid Catalysts

A continuous simulated moving bed reactor packed with solid catalyst was proposed for simultaneous high-efficiency biodiesel production and the separation of biodiesel and by-product glycerol through the transesterification of triglyceride with alcohol. Kinetic analysis for the batch transesterification between model reactants of triacetin and ethanol at 323 K using Dowex 50WX2 in the H form as catalyst was conducted to estimate the parameters of equilibrium adsorption constants and reaction rate constants intrinsic to the model reaction system used. Numerical simulations based on the mass transfer model of simulated moving bed reactor were then performed for two switching interval conditions. For the shorter switching interval both calculated and experimental results showed that the model target product ethyl acetate was eluted from the extract port together with glycerol. On the other hand, with an adequate switching interval, both calculated and experimental results showed that triacetin completely disappeared, and ethyl acetate was continuously eluted from the raffinate port while glycerol was eluted from the extract port. The results thus showed theoretically and experimentally the effectiveness of the simulated moving bed reactor for biodiesel fuel production.