Comparing exergy and heat pump work in distillation systems

作者：Akash Sanjay Nogaja, Mohit Tawarmalani, Rakesh Agrawal · 发表于：AIChE Journal · 年份：2025 · DOI：10.1002/aic.18895 · 被引用次数：2 · 研究领域：Process Optimization and Integration、Advanced Control Systems Optimization、Advanced Thermodynamics and Statistical Mechanics

Abstract This study compares the exergy supplied to a distillation column with the actual energy consumption of a heat pump‐assisted distillation (HPAD) system. It evaluates the reliability of exergy as a proxy for heat pump work demand in such systems. While exergy can serve as a reasonable approximation when the thermal duties of the source and sink are nearly equal, it is not a consistent indicator of heat pump work in general. To address this limitation, we propose the Minimum Heat Pump Work Model, which establishes a theoretical lower bound on the work required to operate a heat pump between a given set of heat sources and sinks. Unlike exergy, this model is based on the direct thermal interaction between the source and sink, independent of the environment. It offers more accurate predictions of heat pump work and provides useful insights for designing energy‐efficient configurations in hybrid and multicomponent distillation systems.