Graphical Design and Analysis of Mass Exchange Networks Using Composition Driving Forces

Abstract

Pinch analysis is a methodology for minimizing energy and mass consumption in different industries. It has been widely applied for more efficient processes. This study presents a new graphical-approach to analyze and design Mass Integration (MI) and exchange networks that follows Pinch principles to guarantee maximum mass recovery with minimum losses. This technique uses the composition driving forces in network representation as it rules the mass transfer between streams. The proposed approach can be applied on both existing mass networks as well as new ones. This graphical representation a visual descriptive design tool to describe and explain the details of operations with minimum calculations. Besides, it is found to be valuable for conceptual applications on linear dilute systems. The performance of mass-exchange networks is evaluated and suggested improvements can be recommended in terms of composition driving forces inside mass exchangers. In this approach, the x-axis represents the equivalent lean stream compositions, whilst the y-axis represents the difference in compositions for each stream in the exchanger. Pinch Analysis principles are embedded within the graphical representation. A scrap-tires-to-fuel plant case study was considered for the application of the new approach. The plant was designed with Mass Integration targets in consideration. Optimum matches were selected based on maximum driving force, minimum flow and minimum cost. In general, this approach can help synthesize mass networks, whilst maintaining maximum driving force - and thus minimum equipment size and minimum flow.

Keywords

• Mass integration
• Composition driving force
• Mass exchange networks
• Equivalent composition
• Graphical approach
• Pinch analysis