2003 Volume 36 Issue 12 Pages 1503-1509
The operation of a fully thermally coupled distillation column (FTCDC) is known to be difficult, which prevents wide application of the column. By separating the main column of the FTCDC into two sections the transfer of material between the two sections is disconnected, while heat transfer is sustained by installing a heat exchanger between the sections as a substitute of a reboiler of the upper section and a condenser of the lower section. It is expected that the modification of the FTCDC improves column operability with the maintained benefit of high thermodynamic efficiency of the original FTCDC.
The structural analysis and design detail of the modified column are addressed here, and the design outcome is compared with the original column. In addition, the operability of the new column is examined from the evaluation of various multivariable controllability indices. The comparison of the indices with those of the original column indicates the improved operability.