Thermal integration of vapor recompression in a heat-integrated distillation: Impact of multiple intermediate reboilers

Abstract

Combining the vapor recompression (VRC) with an intermediate reboiler (VRCIR) and an internally heat integrated distillation column (HIDiC) has emerged as a promising technology. The present work aims at advancing this hybrid HIDiC-VRCIR configuration by introducing multiple intermediate reboilers (IRs). Increasing the number of IR leads to provide a better distribution of internal heat along the column, thereby increasing the energy efficiency. In designing a sample double IR (DIR) based HIDiC-VRC, the location of IRs and their coupling with stripper trays play a crucial role. The optimal position of DIR system is proposed to identify based on two criteria: lowest total annualized cost (TAC) and highest energy savings. Further, aiming to enhance the energetic and economic potential of the HIDiC-VRCDIR structure, it is proposed to choose either the series or parallel mode of compressor applying the same two criteria stated above. By simulating a ternary wide-boiling hydrocarbon system, the promising performance of the sample HIDiC-VRCDIR configuration is evaluated with a couple of unique features. Extending this proposed thermal integration mechanism, one can configure the hybrid HIDiC-VRCIR column with any suitable number of IRs.