Investigation on energy-efficient heterogeneous pressure-swing azeotropic distillation for recovery of cyclohexane and tert-butanol from industrial effluent

This paper highlights the separation of cyclohexane/tert-butanol from industrial effluent by heterogeneous pressure-swing azeotropic distillation based on the properties of pressure-sensitive distillation boundaries and natural liquid-liquid separation. There is no excess component in the separating process. The optimal parameters of the conventional process are obtained by using the simulated annealing algorithm. Additional heat pump and heat integration strategies are introduced into the process with the optimal operation parameter to save more energy. Evaluation indicators, such as total annual cost (TAC), total energy consumption (TEC), gas emission, and exergy destruction, are used to assess the potential of economic and environment friendly processes. The heat pump assisted HADPSD process employing auxiliary reboilers and heat integration is the optimal energy -saving process, exhibiting decreases of 41.98%, 55.32%, 52.30%, and 55.26% for TAC, TEC, gas emission, and exergy destruction compared to conventional HADPSD.

Automated summary

This paper proposes a heterogeneous pressure-swing azeotropic distillation (HADPSD) process for the separation of cyclohexane/tert-butanol from industrial effluent. The optimal operating parameters are obtained through the simulated annealing algorithm. Heat pump and heat integration strategies are introduced to save energy. The evaluation indicators show that the heat pump assisted HADPSD process with auxiliary reboilers and heat integration is the optimal energy-saving process.