Stacked complex sequences for ternary zeotropic distillation
Journal
Computers and Chemical Engineering
Journal Volume
161
Date Issued
2022
Author(s)
Tang W.-T
Abstract
In this work, stacked complex sequences are studied as an alternative to thermal coupling for reducing cost and energy consumption in ternary zeotropic separations. Column stacking (CS) here refers to the strategy of adjusting the operating pressure of two columns so that the condenser of one column can power the reboiler of the other column. Stacking is not feasible in thermally coupled configurations because vapor communicates between all sections in a thermally coupled sequence. Results for seven liquid mixtures at ten feed compositions for each mixture (70 cases) show that if CS is not considered, a thermally coupled configuration is preferred in 39 out of 70 cases, saving on average 19.1% compared to the preferable conventional (direct or indirect) sequence. However, if CS is permitted, a stacked sequence is preferred in 58 out of 70 cases saving on average 21.0% compared to the preferable conventional sequence. A thermally coupled sequence is preferred in only 11 cases. This suggests that stacked and complex stacked sequences should be given serious consideration as an alternative to thermal coupling for reducing energy consumption in ternary distillation processes. © 2022 Elsevier Ltd
Subjects
column stacking; Distillation; dividing wall columns; side-stream columns
Other Subjects
Distillation columns; Energy utilization; Mixtures; Column stacking; Complex sequences; Dividing wall columns; Energy-consumption; Reducing costs; Side streams; Side-stream column; Stackings; Thermal coupling; Zeotropic; Distillation
Type
journal article