摘要

Pressure-swing distillation (PSD) is widely used to separate pressure-sensitive azeotropes. In the PSD process, the bottom stream is heated by hot utility in reboiler and the vapor stream is condensed by cold utility in condenser. Consequently, most of the heat supplied to reboiler is wasted in condenser. Self-heat recuperation technology is applied to achieve a novel energy-saving SHR-PSD process. In the SHR-PSD process, two compressors are used to improve the energy levels of two overhead streams so that the heat of the streams discharged from the compressors can be used to heat reboilers for both columns, and the sensible heat can be used to heat feed streams. Additionally, the heat exchanger network is used to optimize the heat integration of the SHR-PSD process. The proposed SHR-PSD process is compared with PSD process and full heat-integrated PSD (FHIPSD) process in terms of the energetic, economic and environmental performance. The results revealed that SHR-PSD process reduces energy consumption by 72.39% and 53.06% compared with the PSD and FHIPSD respectively, and the total annual cost is reduced by 36.65% and 5.18% compared to that of the PSD and FHIPSD, respectively. Moreover, this SHR-PSD process leads to lower CO2 emissions and improve thermodynamic efficiency.