Steady State and Dynamic Operability of Continues Processes

Prof. Dr. Christos Georgakis

   Zeit: Montag, 10. 09. 2001, 16:00
   Ort: Hörsaal V 9.22 Pfaffenwaldring 9, Universitätsbereich Stuttgart-Vaihingen

Abstract:

It is well known that the effectiveness of a chemical process is dependent both on its steady state and its dynamic characteristics. Traditional approaches address the issue in a sequential manner; by first designing the plant from the steady state point of view and addressing the dynamic characteristics and the controller design tasks after the plant is built. This often results in a substantially over-designed and sub-optimal plant whose dynamic and control characteristics were not difficult to handle with simple single-input-single-output controllers. Efforts to build more optimal and less polluting processes have resulted in the introduction of a substantial number of heat integration schemes and a large number of recycle streams, making the process several orders of magnitude more complex than before. Such processes are very difficult to operate or are totally inoperable, unless their dynamic and control characteristics are examined very early in the design phase. Such a need to examine the interaction between process design and control has recently started to be recognized in the literature.
The seminar presents a new and systematic approach that examines the operability of a plant design prior to its physical construction. This enables the examination of the operability characteristics of several alternative designs and suggests design changes that improve process operability. The proposed operability measure is a multivariable and nonlinear one based on such concepts as the Available Input or the Expected Disturbance Spaces and their transformations by either the steady state or dynamic model of the process. After the initial definition of the new concepts, the proposed approach is used for the examination of the operability characteristics of some traditional non-linear process units such as CSTR and Tubular reactors or plant-wide examples that involve more than one unit. The seminar also draws attention to the Plant-wide operability problem and its related computational challenges.

Education:

Ph.D University of Minnesota, 1975.
M.S. in Ch.E. University of Illinois, 1972.
Ch.E. Dipl. National Technical University, Athens, Greece, 1970.

Professional Experience:

Professor of Chemical Engineering, Lehigh University, and Founding Director, Chemical Process Modeling and Control Research Center, Lehigh University.

Honors:

Computing in Chemical Engineering Award of the Computing and Systems Tech. Division (CAST) of the AIChE, 2001. Iacocca Professor of Chemical Engineering, 2001. O. Hugo Schuck Best Paper Award of the American Automatic Control Council, 1998. Fellow, American Institute of Chemical Engineers, 1998. Dreyfus Foundation Teacher-Scholar, 1979-1983.

Biographical Sketch:

Dr. Christos Georgakis is a Professor of Chemical Engineering and Founding Director of the Chemical Process Modeling and Control Center, an Industry/University Cooperative Research Center. His research interests are focused on the following areas: Modeling, Optimization, and Control of Batch Processes by Use of Tendency Models; Nonlinear Model Predictive Control and Identification; Statistical Process Monitoring techniques for the detection of changes and abnormalities in the operation of the process as well as of the controller; and the impact of Process Design on Controllability characteristics. Dr. Georgakis is presently the Vice President and President-Elect of the American Automatic Control Council and the Chair of the Technical Committee in Chemical Process Control of the International Federation of Automatic Control (IFAC). Professor Georgakis was the Chairman of the 5th IFAC Symposium on Dynamics and Control of Process Systems (DYCOPS-5) in Corfu, Greece in June of 1998.