Nassim Tahouni - Dep. of Chemical Engineering, University of Tehran, P.O Box: ۱۱۳۶۵/۴۵۶۳, Tehran, Iran
Hassan Panjeshahi - Dep. of Chemical Engineering, University of Tehran, P.O Box: ۱۱۳۶۵/۴۵۶۳, Tehran, Iran
Robin Smith - Centre for Process Integration, School of Chemical Engineering and Analytical Science, University of Manchester, Manchester, U.K., M۶۰ ۱QD

In low-temperature processes, heat rejected from separation columns is removed by refrigeration systems to heat sinks, to process streams, to other refrigeration streams, or to external utilities. The need for efficient utilization and recovery of energy in sub-ambient gas separation processes is still challenging. Performance and reliability of Simulated Annealing for simultaneous design and optimization of such systems has been investigated previously [7]. In this work, the effect of different refrigerants satisfying a set of process cooling duties at different temperatures is addressed. Cost reduction can be realized by encompassing both effective screening of heat-integrated separation columns and selecting the best refrigerants. Afterwards, a comprehensive thermodynamic analysis has been carried out on achieved solutions to verify the accuracy of existing shortcut models and robustness of optimized structure. Moreover, we have indicated that both utility costs and exergy losses can be considered as an objective function when optimizing the designs.

Low-temperature Process, Different Refrigerants, Optimization, Exergy Analysis, Simulated Annealing