Improvement of Cyclohexene/Cyclohexane separation process design via chemical looping technology using reactive distillation and thermally coupled configurations

Separation of close boiling point components such as cyclohexene/cyclohexane is an interesting topic due to the difficulty in its separation process. Recently, the separation of cyclohexene/cyclohexane using two reactive distillation columns has been studied by Yu et al. However, a high energy consumption was presented due to a large amount of water was observed at the bottom of RDC-2 in the conventional RDC (c-RDC). In this work, the chemical-looping technology was applied in which hydration (RDC-1) and dehydration (RDC-2) of cyclohexene was involved. The c-RDC with bottom recycle (br-RDC) was studied. A bottom stream was added to the RDC-2 so that some water could be recycled to the RDC-1. The result showed that the amount of water entered the top decanter could be reduced through the reactive section, thereby the energy consumption of the RDC-2 could be reduced. However, a remixing effect happens in the RDC-1 of both cases. Thus, the thermally coupled configuration based on c-RDC (c-TCRDC) and br-RDC (br-TCRDC) is investigated. The simulation results showed that the br-RDC, c-TCRDC, and br-TCRDC saved 9.87%, 10.64%, and 14.66% in TAC and saved 7.53%, 12.95%, and 28.21% in energy consumption, respectively, compared to the c-RDC.