Industrial & Engineering Chemistry Research, Vol.52, No.16, 5781-5790, 2013
Comparison between Different Configurations of Internally and Externally Heat-Integrated Distillation by Numerical Simulation
The internally heat-integrated distillation column (HIDiC) is often compared with heat-pump-assisted distillation columns and claimed to be more energy efficient. Recently, the idea of simplifying the HIDiC by several external heat exchangers has come into favor and been thought to be a more practical configuration with greatly reduced capital costs. To investigate the energy and economic performances of heat-pump-assisted distillation along with the HIDiC and simplified HIDiC, comparisons based on numerical simulation were made in the present work. A propylene-propane splitter was chosen for the comparison. Compression ratios and total numbers of stages were optimized to achieve an optimal configuration in terms of total annualized costs for each scheme before comparison with others. For the HIDiC and its simplifications, the impacts of different heat distribution patterns were also considered. It was found that the results depend strongly on the basis selected for comparison, and some discussions and remarks are also presented.