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Engineering, Architecture and Technology

The AIChE Journal is the premier research monthly in chemical engineering and related fields. This peer-reviewed and broad-based journal reports on the most important and latest technological advances in core areas of chemical engineering as well as in other relevant engineering disciplines. The AIChE Journal’s Futures Issues are published annually to highlight the pioneering early career research in chemical engineering. Each year, nominations for inclusion in this special issue were developed from suggestions from AIChE Journal’s Associate Editors, Consulting Editors, academic department heads, and authors from earlier editions of the Futures Issue. This year, a total of 17 articles were nominated and selected to be included in the 2022 Futures Issue and were recently honored in the “New Direction in Chemical Engineering Research” session at the 2022 AIChE Annual Meeting in Phoenix, Arizona.

 

One of these articles is Dr. Zheyu Jiang’s paper entitled “Minimum Reflux Calculation for Multicomponent Distillation in Multi-Feed, Multi-Product Columns: Mathematical Model”. In this paper, Dr. Jiang and his collaborators, Dr. Rakesh Agrawal and Dr. Mohit Tawarmalani at Purdue University, solved a longstanding problem in chemical engineering of developing the first accurate, easy-to-implement shortcut mathematical model for multicomponent distillations in any general multi-feed, multi-product (MFMP) column.

 

Distillation is an important separation process that accounts for 90-95% of all liquid separations and consumes more than 40% of energy in chemical and refining industries. MFMP columns are ubiquitous in various applications of multicomponent distillation, such as crude fractionation, shale gas separation, and air separation. For the past 80 years, researchers and industrial practitioners have been searching for a general shortcut model that is as simple and powerful as the classic McCabe-Thiele or Underwood’s method to perform quick and accurate design calculations and optimization of MFMP columns.

 

In this paper, Dr. Jiang and his collaborators utilize and develop multiple rigorous mathematical tools to accurately model the complex relationships among the energy requirement, compositions of feed and product streams, and internal liquid and vapor flow rates of a general MFMP column. They also explore the physical and mathematical properties of the shortcut model, derive constraints for feasible separation and minimum reflux operation, and discuss their geometric interpretations. They show that the classic McCabe-Thiele or Underwood’s method turns out to be a special case of this generalized algorithmic approach. They also revisit some of the well-accepted design heuristics and modeling assumptions widely used in existing literature and design practices, some of which are shown to be inaccurate and can sometimes lead to minimum reflux ratio values that are off by more than a factor of 10 compared to the true results in several case studies. As a result, this paper can potentially change how researchers and industrial practitioners understand, model, and design energy-efficient multicomponent distillation systems.

 

Zheyu Jiang is an assistant professor in the School of Chemical Engineering at OSU. The published article is made open access at https://aiche.onlinelibrary.wiley.com/doi/full/10.1002/aic.17929.