Divided Wall Column Modeling and Simulation in an Open-Source Environment

João Paulo Henrique,Ruy De Sousa Jr,Caliane Bastos Borba Costa,Argimiro Resende Secchi,Mauro Antonio Da Silva Sá Ravagnani,Abdessamad Barbara

doi:10.15255/cabeq.2020.1824

Abstract

The divided wall column (DWC) can achieve sharp separations of three or more components in a single shell, substituting conventional sequences of two or more binary<br /> distillation columns, with lower expenses. Despite these advantages, DWC models are not available in commercial chemical process simulators. To simulate DWC, users must employ instances of conventional column model and couple them in different configurations. In this paper, a DWC model was developed in EMSO (Environment for Modeling, Simulation and Optimization). DWC model was then used for simulating the separation of an equimolar mixture of three hydrocarbons. Results show that, depending on the number of trays, DWC presented energy savings compared to two ordinary distillation columns. Better separation was obtained when the number of divided trays was close to half the number of total trays. However, the liquid and vapor flow rates split into the divided section play a key role in the separation.

Highlights

Proposed in the 1940s by Wright[1], the divided wall column (DWC) is an alternative to multicomponent distillation systems
Since the usual representation of DWC in analysis and simulation reports in the literature is made with the coupling of conventional distillation column models, due to the lack of a model of DWC in process simulators, this paper aimed to develop a DWC model in EMSO
The same case study was simulated in both simulators for comparison and validation of the EMSO distillation column model

Summary

Introduction

Proposed in the 1940s by Wright[1], the divided wall column (DWC) is an alternative to multicomponent distillation systems. This separation scheme integrates two conventional columns into one single device, and allows the sharp separation of multicomponent mixtures with a smaller amount of equipment. Tillation sequences using process simulators, and showed that two side stream connections involved in the thermal coupling can be substituted with a combination of a material and an energy stream connecting the pre-fractionator to a main column. In addition to the reduction in equipment construction material, DWC can generate a saving of more than 40 % in the space allotted to the distillation system in industrial sites (plot area)[7]

Objectives

Methods

Results

Conclusion