xStartup of an ideal heat integrated distillation column (HIDiC) is considered in this paper. A procedure for the startup operation is suggested by taking the special characteristics of the ideal HIDiC into account. An overhead trim-condenser and a bottom trim-reboiler look necessary to be added to the process configuration during this period. However, it is found that the ideal HIDiC can also start smoothly without the presence of the bottom trim-reboiler, The transition from semi-continuous phase to normal operation mode is investigated and compared by employing two control systems. One is a gain-scheduled decentralized PI controller, the other is a nonlinear process model-based one (NPMC), It appears that the ideal HIDiC could start quite smoothly with no special difficulties compared with its conventional counterparts. The NPMC holds more advantages than the gain-scheduled PI controller, since the former provides safer and more economic startup operation of the ideal HIDiC than the latter.