TITLE:

Optimal control of chemical systems

DATE:

Friday, August 24th, 2018

TIME:

3:30 PM

LOCATION:

GMCS-314

SPEAKER:

Christian Schoen, MPI for Solid State Research, Stuttgart, Germany.

ABSTRACT:

While the first step of chemical investigations is often the synthesis of a new product, a
careful analysis quickly forces us to deal with issues concerning the purity of the product,
the amount of product, or, especially in chemical engineering contexts, the cost of the product
obtained. Addressing these issues, directly leads us to the formulation of one or more
objective functions that need to be optimized during the synthesis process. A common
approach to solve such problems consists in performing many experiments with carefully
chosen sets of synthesis parameters and then using statistical analyses to find optimal
sets of these parameters. However, in many cases, it is possible to write down (phenomenological)
rate equations that describe the processes involved in the development of the chemical system.
This allows us to formulate analytical objective functions as function of state and control
variables, casting the optimization of the chemical synthesis into the language of optimal control.[1-4]

In this talk, I am going to present a number of examples of the application of optimal control
methods to the optimization of chemical processes, such as the optimization of a liquid-gas
phase transition,[3] the optimal control of homogeneous nucleation and growth of crystals,[4]
and the optimal control of the transfer of a chemical system between different crystalline modifications.[5]

[1] J. C. Schoen: On the way to a theory of solid state synthesis: Issues and open questions, Advances
in Chemical Physics, (2015), 175, 125-133
[2] J. C. Schoen, B. Andresen: Finite-Time Optimization of Chemical Reactions: n_A (right arrow – left arrow) n_B, Journal of
Physical Chemistry, (1996), 100, 8843-8853
[3] M. Santoro, J. C. Schoen, M. Jansen: Finite-time thermodynamics and the Gas-Liquid phase transition,
Physical Review E, (2007), 76, 061120-1-14
[4] J. C. Schoen: Finite-Time Thermodynamics and the Optimal Control of Chemical Syntheses, Zeitschrift
fur Anorganische und Allgemeine Chemie, (2009), 635, 1794-1806
[5] K. H. Hoffmann, J. C. Schoen: Controlled dynamics on energy landscapes, European Physics Journal,
(2013), 86, 220_1-10; Combining pressure and temperature control in dynamics on energy landscapes,
European Physics Journal B, (2017), 90, 84_1-12