A Simple Criterion for Feasibility of Heat Integration between Distillation Streams Based on Relative Volatilities

Journal Article · Tue Jul 06 00:00:00 EDT 2021 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/acs.iecr.1c01036· OSTI ID:1976099

Mathew, Tony Joseph ^[1]; Gooty, Radhakrishna Tumbalam ^[2]; Tawarmalani, Mohit ^[2]; Agrawal, Rakesh ^[2]

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1. Purdue University, West Lafayette, IN (United States); Purdue University, West Lafayette, IN, U.S.A.
2. Purdue University, West Lafayette, IN (United States)

In a multicomponent distillation configuration, there are numerous sources and sinks of heat, and a potential way to reduce the heat duty requirement is to perform heat integration. Unfortunately, an algorithmic search of the optimal heat integration opportunities is intractable when the required temperatures of intermediate streams are computed via complex models. Instead, in this work, we introduce pressure-scaled pseudo relative volatility, a new metric to compare stream temperatures. Here, we justify the use of pseudo relative volatility by proving that this variable is a monotonically increasing function of the liquid fraction in a saturated mixture stream. Using this metric, we derive a shortcut criterion to check the feasibility of various heat integration opportunities, such as thermal coupling via heat transfer (TCH). The advantage of this approach is that it circumvents the need for explicit temperatures and instead relies on composition, component relative volatilities, and pressure—quantities that are readily available in shortcut models for optimization of distillation configurations. Leveraging this fact, we propose a new optimization framework that identifies feasible TCHs that we consider within the formulation while minimizing the total heat duty of a distillation configuration. We demonstrate, on a few examples, that our formulation can identify heat duty efficient configurations, some of which are multieffect configurations. Using this methodology, we discover configurations that are not only simpler than the fully thermally coupled (FTC) configuration but also have a much lower heat duty.

• Research Organization: Purdue University, West Lafayette, IN (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: EE0005768
• OSTI ID: 1976099
• Alternate ID(s): OSTI ID: 1848413
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 28 Vol. 60; ISSN 0888-5885
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
42 ENGINEERING
97 MATHEMATICS AND COMPUTING
Distillation
Heat integration
Liquids
Mixtures
Multicomponent distillation
Optimization
Thermodynamic properties
Thermodynamics modeling