Fully thermally coupled distillation column design for liquid petroleum gas recovery

A fully thermally coupled distillation column is conceived and applied to a system of pretreated natural gas stream containing C3 through nC7. The design procedure consists of computation of limiting requirements and rigorous simulation using material and energy balances. The results of the proposed design are compared with those of the conventional two-column system; the comparison shows that the fully thermally coupled distillation column requires 30.8% less energy than conventional system. From the required energy, the thermodynamic efficiency of fully thermally coupled distillation column is higher than that of conventional distillation system in the separation of the ternary mixture considered in this study.