Nonlinear dynamic modeling of multicomponent batch distillation: a case study

Abstract

-The aim of this work is to compare several of the commercial dynamic models for batch distillation available worldwide. In this context, BATCHFRAC™, CHEMCAD™ BATCH, and HYSYS.Plant ® software performances are compared to experimental data. The software can be used as soft sensors, playing the roll of ad-hoc observers or estimators for control objectives. Rigorous models were used as an alternative to predict the concentration profile and to specify the optimal switching time from products to slop cuts. The performance of a nonlinear model obtained using a novel identification algorithm was also studied. In addition, the strategy for continuous separation was revised with residue curve map analysis using Aspen SPLIT™.

Batch distillation control improvement by novel model predictive control

“…The measurement equations hx kjkÀ1 À Á of relevant temperatures are derived from Antoine's equations. Furthermore, the instant vapor flow rate is estimated by the knowledge of vaporization heat and heating power [15,16]. On the other hand, the exact solution of the heat of vaporization is rather difficult to compute, hence, the assumption of the constant vapor load along the batch is made.…”

“…In addition, the differentiated states can be easily initialized with the values of zero. It is noted that this work develops the state-space models based on the first-principle equations; alternatively, one can obtain the system matrices through experimental information by a subspace state-space identification method [15][16][17].…”

Operational Design and Improvement of Conventional Batch Distillation and Middle-Vessel Batch Distillation

“…Batch distillation is widely used in the pharmaceutical industry to purify and recover highvalue liquid components. It has better operational flexibility and reduces equipment costs compared to continuous distillation (Jimenez et al, 2002;Narvaes-Garcia et al, 2015). Over many years of improvement, batch distillation processes have been developed that can be used in special distillation processes, such as pressure-swing distillation Repke et al, 2007), extractive distillation (Fang et al, 2010;Navarrete-Contreras et al, 2014;Pacheco-Basulto et al, 2012), and reactive distillation (Khazraee and Jahanmiri, 2010;, which are based on different column configurations, including conventional and unconventional column configurations.…”