Jiří Jaromír Klemeš, Petar Sabev Varbanov and Peng Yen Liew (Editors)
Proceedings of the 24
th
European Symposium on Computer Aided Process Engineering – ESCAPE 24
June 15-18, 2014, Budapest, Hungary.© 2014 Elsevier B.V. All rights reserved.
A Novel Real-Time Methodology for the
Simultaneous Dynamic Optimization and Optimal
Control of Batch Processes
Francesco Rossi,
a
Flavio Manenti,
a,
* Iqbal M. Mujtaba,
b
Giulia Bozzano
a
a
Politecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica
“Giulio Natta”, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
b
School of Engineering & Informatics, University of Bradford, Bradford BD7 1DP, UK
flavio.manenti@polimi.it
Abstract
A novel threefold optimization algorithm is proposed to simultaneously solve the
nonlinear model predictive control and dynamic real-time optimization for batch
processes while optimizing the batch operation time. Object-oriented programming and
parallel computing are exploited to make the algorithm effective to handle industrial
cases. A well-known literature case is selected to validate the algorithm.
Keywords: dynamic optimization; batch process control; nonlinear model predictive
control; optimal batch time operation.
1. Introduction
Discontinuous and multi-stage processes are often (and still) managed by means of
traditional and heuristic recipes, conventional controls and/or manual operations. This is
mainly due to their batch nature that requires frequent manual interventions, e.g., to
switch from on (operating) to off conditions, to enable/disable cooling and heating
operations or loading and unloading procedures. Moreover, the control methodology
adopted is often only partially effective to handle the setpoint changes dictated by the
recipes of batch productions and the uncertainties typical of semi-batch operations. For
these reasons, many authors focused on batch processes to find efficient solutions to
make them more automatic and better controlled with the aim of improving safety and
optimizing discontinuous operations: Balasubramhanya and Doyle (1997) developed a
MPC algorithm for the optimal control of distillation columns where the column model
was based on the wave theory, Mahadevan et al. (2001) studied a MPC procedure using
the differential flatness, Abel and Marquardt (2003) worked on a scenario integrated
MPC for batch reactors with the aim of avoiding the loss of control even in failure
circumstances, Vallerio et al. (2014) defined the tuning rules, Logist et al. (2012)
proposed some dedicated tools, and, finally, Joly and Pinto (2004) made a comparison
between the efficiency of sequential and simultaneous methodologies for the dynamic
optimization of discontinuous processes. Several other authors have shown the potential
for applying the dynamic optimization to batch systems using either neural networks
(Greaves et al., 2003) or standard simultaneous procedures (Zavala et al., 2005) or novel
adaptive shooting techniques (Vite-Martínez et al., 2014). Also the importance of
selecting the most appropriate control methodology to be used in dynamic optimization
of discontinuous processes has been recently broached (Pahija et al., 2013b) to make it
more appealing. The real problem is that the implementation of dynamic optimization
has several similarities to the traditional recipe. Actually, although optimized, the