A Novel Hybrid Exergy/Pinch Process Integration Methodology
Résumé
The trend of global energy demand forecasts a continuous increase in the forthcoming years together with a
diversification and differentiation of energy sources. In order to ensure the energy systems transition towards
a sustainable functioning mode while avoiding early depletion of energy resources, industrial activities need
to foster process improvement. For decades, efforts allowed valuable energy efficiency improvements,
operating costs reductions and minimization of environmental impacts. Among energy efficient process
design methodologies, pinch analysis and exergy analysis are two powerful methods but each one shows
drawbacks. This paper introduces a new methodology based on the Jacobian Matrix of exergy destruction as
a mathematical indicator to couple the Pinch and the exergy analysis and overcome their individual
limitations. In the proposed approach, exergy analysis is used not only to assess the exergy losses but also
to guide the changes needed in industrial processes structures and operating conditions. And while the pinch
analysis considers only heat integration, the proposed methodology allows including other recoverable
exergy in a process. The guidelines of the methodology are detailed and applied on a natural gas
liquefaction process to prove its effectiveness. The main advantage of the methodology is time saving
compared to holistic operating conditions improvement as in the traditional process design methods and
automatic process structure modification leading to better heat integration.