Design of a fully heat-integrated pressure-swing distillation for close-boiling separation

Enlightened by recent progress in pressure-swing distillation (PSD) and double-effect heat integration, this work combines these two concepts for close-boiling separation, by using two fully heat-integrated columns operating at different pressure plus a recycle stream. The developed fully heat-integrated pressure swing distillation (FHIPSD) is therefore proposed, followed by two close-boiling binary systems with different relative volatility and latent enthalpy as case studies. The main advantage of the FHIPSD is to lower the separation difficulty of each column, circumventing manufacturing a very high column. For certain feed conditions, the FHIPSD can save energy cost and provide higher-temperature residual heat for further heat integration, compared to a conventional distillation column (CDiC).