A deisobutanizer heat-pump retrofit for improved economic, water, and carbon sustainability

Abstract

This manuscript accompanies a Jupyter Notebook file and Python module used for a modeling study assessing the economic, water, and carbon sustainability improvements to a commercial-scale deisobutanizer. This study was developed as part of a senior-level Chemical Engineering capstone design class in Spring of 2026 at the University of Maryland to demonstrate how sustainability can be quantified. The retrofit considered in this study consists of replacing the cooling water and low-pressure steam utilities of the distillation unit total condenser and reboiler, respectively, with an electric-powered heat pump that transfers heat removed by the condenser and upgrades it to heat the reboiler. The retrofitted process uses less than 10% of the total power of the base-case design, has a discounted cash-flow rate of return of over 40%, and results in significantly reduced CO2 production and essentially no water consumption when renewable electricity is used for the heat pump system.