Vassilios S. Vassiliadis

Optimal control of multistage systems described by high-index differential-algebraic equations

An algorithm is described for computing time-varying controls and time-invariant parameters to optimize the performance of a dynamic system whose behaviour is described by differential-algebraic equations (DAEs) of arbitrary index.

Optimization of discrete charge batch reactors

Abstract A special class of multistage optimal control problems arises in the case of batch reactors fed by discrete instantaneous additions of raw material. The underlying differential-algebraic equations (DAEs) remain unchanged throughout the time horizon of interest, but the instantaneous additions of material are impulsive inputs that result in discontinuities in the state variables. Optimization parameters can include, among others, the amount of each charge and the reaction stage duration following each addition. In this paper, the problem of optimizing the operation of discrete charge batch reactors is addressed within a general framework that is independent of kinetic mechanisms and nonidealities. No approximation need be involved as the solution procedure is based on a general purpose robust algorithm for dynamic optimization problems.

Heat Exchanger Network Cleaning Scheduling: From Optimal Control to Mixed-Integer Decision Making

Support of this research by the Ministry of Higher Education in the Sultanate of Oman and Petroleum Development Oman (PDO) is gratefully acknowledged.