Simulation And Optimization Of Biodiesel Process Catalyzed By Immobilized Lipase

Immobilized lipase has been widely used in the field of biodiesel production for the characteristics of mild reaction conditions, environmental friendliness, and easy separation of product et al. In our previous study, tert-butanol was proposed as the reaction medium for biodiesel production and the stability of the lipase could be enhanced significantly in this novel system. Based on this, a detailed simulation of this process was designed to estimate the operating costs and the optimization of equipment and operating conditions was carried out accordingly.Firstly, the suitable thermodynamic models were selected. Due to the presence of the highly polar components, the NRTL thermodynamic models were chosen for further study and the UNIFAC method was used to estimate the missing parameters such as some basic properties of methanol, tert-butanol and triglycerides.Secondly, whole process simulation was studied systematically, including equipment selection (used for transesterification, recovery of methanol and solvent, separation of glycerol and purification of FAME) and the optimization of operating conditions. Triple effect evaporator was selected to separate the methanol and solvent; and distillation column with partial condenser was recommended for the purification of FAME.Further comparison with acid/alkali process and supercritical process showed that enzyme catalyzed process had the advantages of fewer requirements of equipments and less energy consumption and it was very promising for biodiesel production in the future.