Exergy-based optimization for the synthesis of heat pump assisted distillation columns

First published in
Computer aided chemical engineering  
Number in series
53
Start Page
1351
End Page
1356
Citation
34th European Symposium on Computer Aided Process Engineering, ESCAPE 2024
Contribution to Conference
34th European Symposium on Computer Aided Process Engineering, ESCAPE 2024  
Publisher DOI
10.1016/B978-0-443-28824-1.50226-X
Scopus ID
2-s2.0-85196850191
Publisher
Elsevier
ISBN
978-0-443-28824-1
While distillation columns are the main unit operation in fluid separation processes, considered versatile, robust, and well-understood, they are also oftentimes framed as energy intensive and potentially inefficient. Heat pumps bear the potential to improve the energy efficiency of distillation processes and simultaneously allow for the electrification of the thermal-driven separation processes. However, the economic viability and potential for energy savings depend strongly on the temperature lift and the compression ratio of the heat pump. Both can be reduced by considering intermediate heat exchangers rather than a full temperature lift from below the top vapor to above the bottoms temperature. Such intermediate heat exchangers may furthermore improve the internal efficiency of the distillation column and thereby improve the overall energy efficiency. The current contribution presents an exergy-based optimization that allows for an improved heat load distribution that can provide significant improvements of the internal efficiency and further enables a conceptual design of heat pump assisted distillation, using vapor recompression to provide the heat loads at the intermediate heat exchangers. The benefits of the approach are illustrated for the separation of a nonideal acetone-water mixture, highlighting the capability to identify unintuitive designs with significant saving potential.
Subjects
conceptual design
distillation
exergy
heat pumps
optimization
DDC Class
004: Computer Sciences