(119a) Systematic Workflow to Design Electrified Distillation Systems for Binary and Ternary Separations

In contemporary chemical process development, there is a notable surge of interest in the electrification of unit operations. This transition is a direct response to the Paris Agreement and the rising proportion of renewable energy sources in the electricity mix (Energy Information Administration, 2021). Distillation, as a dominant technology in downstream processes, stands out as a prime candidate for electrification. Enhancing lower-grade heat, such as condenser heat operating at lower temperatures, through the application of electricity in reboiler heating represents a highly efficient approach to electrify a distillation system, and heat pump technology embodies this innovation (Null, 1976).

Vapor recompression, bottom flashing, and external loop heat pumps, which are the primary alternatives, have been thoroughly examined in the existing literature and have showcased remarkable success in various industrial applications. Conversely, tools such as feed preheating, intermediate reboilers/condensers, and multi-effect distillation have demonstrated significant efficiency improvements under specific feed conditions (Tumbalam Gooty et al., 2021). The integration of these tools with heat pumps has the potential to significantly reduce electricity consumption even further. Therefore, the primary goal of this current research is to develop a decision framework that can guide industrial practitioners when considering the electrification of distillation technology.

In this research, we embark on a two-fold approach. First, we illustrate various electrification alternatives using both single and dual compressors. Subsequently, we construct shortcut models for estimating multi-component phase change temperatures (Nogaja et al., 2022), compressor work consumption, to evaluate the performance of all the different alternatives. These shortcut models facilitate a rapid initial assessment to identify configurations suitable for more comprehensive simulation. Finally, we develop an easy to use distillation framework relying only on the feed properties, while producing high purity products, to guide the design of optimal heat pump assisted distillation (HPAD) system.

References:

Energy Information Administration, U. (2021). Annual Energy Outlook 2021 Narrative. www.eia.gov

Nogaja, A. S., Mathew, T. J., Tawarmalani, M., & Agrawal, R. (2022). Identifying Heat-Integrated Energy-Efficient Multicomponent Distillation Configurations. Ind. & Eng. Chem. Res., 61(37).

Null, H. R. (1976). Heat Pumps in Distillation. Chem. Eng. Prog., 58, 58–64.

Tumbalam Gooty, R., Chavez Velasco, J. A., & Agrawal, R. (2021). Methods to assess numerous distillation schemes for binary mixtures. Chemical Engineering Research and Design, 172, 1–20.