Advanced Distillation Techniques: Minimizing Exergy Costs in Thermodynamic Systems
This document focuses on the advanced application of thermodynamic principles to optimize distillation processes, as presented at the Udine Advanced School in October 2005 by Peter Salamon. It covers key concepts such as the sequence of K-stages, the necessity of heat input for each stage, and the implications of minimum exergy costs in designing efficient distillation columns. The discussion emphasizes the economic and political realities influencing operational decisions, including investment versus operating costs, the use of advanced heat pumps, and strategies for effective heat management in distillation systems.
Advanced Distillation Techniques: Minimizing Exergy Costs in Thermodynamic Systems
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Presentation Transcript
Thermodynamic Geometry 2 Peter Salamon Udine Advanced School October 2005
Distillation • Sequence of K-stages • Min Exergy cost implies constant distance stages • Stages need heat input • diabatic column
D, XD D, XD QD QD V1 V1 V2 V2 L1 L1 Additional Heat Sinks And Heat Sources V3 V3 L2 L2 V4 V4 F, Xf F, Xf L3 L3 V5 V5 L4 L4 V6 V6 L5 L5 V7 V7 L6 L6 L7 L7 QB QB B, XB B, XB AdiabaticDiabatic
A False Stumbling Block • Only a semi-metric • Scaling directions have zero length • Change of phase has zero length
Constant distance means that we should choose each Ti such that
Vi+1 coexistence Li Can construct these heat capacities Heat capacity of
Heat capacity that turns distillation problem into a coffee cup problem
Economic Realities Investment $ vs. Operating $ More trays. Smaller reboiler More heat exchangers. Smaller condenser Same total area More(?) heat pumps There exist clever heat pumps Saves 75% of the exergy cost ca. 200% of the capital cost Political realities: Installation is gathering dust, within $200K of finished after $3M invested. Ricardo Rivero had a physical breakdown over it.
