Study On The New Operation Method And Simulation Of Batch Distillation

Dynamic-accumulation cyclic operation (DACO) is one of the new operating modes of batch distillation. It involves three periods: total reflux, dumping and filling up. DACO has several advantages over conventional operation with high efficiency, energy saving and convenient controlling. It was proposed in the 1960's and developed rapidly in the 1990's. However, some theory problems, for example, the fluid dynamics and mass transfer during the filling up period which could not be dealt with in conventional distillation theories has been remained unstudied. And the simulation and mathematical models have to be made based on some assumptions, which are different from the actual situation obviously. Therefore the further development of DACO was restrained in the past years. The models for DACO were established in this paper. The fluid dynamic relations were involved in the models without general assumptions of constant molar liquid flow and constant molar holdup. It is the main difference between our models and literature's. Calculation results were compared with experimental results. It shows that our models are coincident with the experimental data. The alternation between two relatively small accumulation drums was proposed in the thesis, in which the alternation of accumulation drums was realized via temperature. The viability of controlling the transitional fraction sect of DACO by time impulse was demonstrated by experiments too. Thus, the operation become more successive and compact, and the automatic control of dynamic-accumulation batch distillation was made easy. Isopropyl alcohol and n-Propyl alcohol was used to conduct the experimental study of this operation. Experiments about filling up were carried out in the laboratory batch distillation column. Experimental results were in good agreement with simulation results.