Energy conservation by multi-effect batch distillation system

A multi-effect batch distillation system, MEBAD, which separates multiple c omponents simultaneously, has higher energy efficiency compared with an ord inary batch distillation column. In this paper, in order to make the charac teristics of the MEBAD clearer, the energy consumption of the MEBAD is comp ared with that of a conventional continuous distillation system for various feed conditions. Results of the exhaustive simulations show that the MEBAD has the potential for having a higher energy efficiency than a continuous system when the number of components is increased or relative volatilities among the components are decreased. Furthermore, it is shown that there is little relationship between the number of column stages and the energy cons umption at the reboiler of the MEBAD while the number of stages strongly af fects the energy consumption of the continuous system. The reason why the n umber of stages does not affect the energy consumption of the MEBAD is expl ained from the relationship between the operating line and the VLE curve.