(142g) Evaluation and Comparison of Internal /External Heat Integration Configurations for the Separation of Propane and Propylene

The separation of propane and propylene by distillation consumes vast amount of energy owing to the close-boiling feature of the binary mixture. Various energy saving schemes have been proposed, including the state-of-the-art heat pump configuration and the promising internally heat integrated distillation column (HIDiC). More recently, the idea of simplifying HIDiC by several external heat exchangers has come into notice and was claimed to be a more practical configuration with greatly reduced capital cost. To investigate the energy and economical performances of heat pump assisted distillation along with HIDiC and its various simplifications, comparisons based on simulation was made in the present work. Compressing ratios and total numbers of stages were optimized to achieve an optimal configuration in terms of total annualized costs for each scheme before compared with others. For HIDiC and its simplifications, the impacts of different heat distribution patterns were also considered. It was found that the result greatly depended on the criterion selected for comparison, and some discussions and remarks were also presented.