Semicontinuous Distillation of Quintenary and N‑ary Mixtures

This work examines the feasibility of the separation of a five-component mixture using a semicontinuous distillation process. The results are used to generalize semicontinuous separation to N-component mixtures. The proposed five-component separation system, called quintenary semicontinuous separation, requires just a single distillation column with three middle vessels. In contrast, a conventional continuous distillation process would require four columns to achieve the same separation objectives. This process is an extension of three- and four-component semicontinuous separation. These processes are more economical at intermediate throughputs when compared to traditional continuous separations processes as has been demonstrated in previous literature. The feasibility of the process and profitability compared to a conventional continuous process was demonstrated using a mixture of n-alkanes from C6–C10. Dynamic simulation results show that this system is able to remain within safe operating limits. An economic comparison between the continuous and semicontinuous processes shows that the semicontinuous separation process is economically favorable at intermediate flow rates.