Process Simulation And Optimization Of Ester Distillation Unit Of Aliphatic Alcohol Plant

This subject is mainly studying simulating the overall flowsheet of Ester Distillation process in the production of Aliphatic Alcohol and its application. The Ester Distillation process mainly consists of two distillation columns and some other simple units. Since the distillation process is focused on this study, the stable state model is established, which is also used to the real time simulation and practical process.The characteristics of the technologic process are the complicated structure, numerous components and the highly non-ideal system. The two distillation towers are the typical separating equipments in this process. This paper deeply analyzed and demonstrated them, established a rigorous mathematical model and solves it with proper mathematical method. As to the non-linear process of the system, we calculate the constant of the vapor-liquid equilibrium by making use of the Modified UNIFAC Method(Dortmund) to solve the problem of the lack of experimental data.The basis of stable model is MESH equation, or mass, vapor-liquid, component addition, and enthalpy equilibrium equations. Its computation method is similar to the traditional method of solving tridia-matrix. The internal iterative calculation is to correlate the equations of mass and phase equilibrium into a tridia-matrix from which the liquid compositions can be found out. And then temperatures and equilibrium coefficients in the trays along the column are solved through bubble point calculation. The external iteration regards flow rate of vapor as discontinuous variable and can be calculated by heat equation. This method increases greatly the computation efficiency and stability.After establishment of the above-mentioned model, we have discussed the results of stable simulation. The result is so similar to industrial production that the accuracy of this model is verified. The technologic process was analyzed by the comparison between the simulation results and the practical industrial data under the basis of the analysis of mechanism of the main equipments. After the comprehension of the inner law of the process, the system was optimized on the basis of forecasting. Thus the method to optimize the operation was proposed and the application future of solutions and their economic benefits were forecasted. The effects of these were assessed scientific religiously.As a whole process of technology simulation, The whole simulation process is good to reflect the running conditions of equipment due to its great mechanism. The simulation results not only provide foundation for operators to analyse production process, but also provide technic workers with referential materials to develop potential and to make further improvement. This research has successfully applied in the systemic analysis on the production of Aliphatic Alcohol whose capacity is 5 million tons per year went into operation in Dalian Huaneng Chemical Factory. The result shows that this model has guide significantly to optimization and control of production units.