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,
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
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.
Ph.D University of Minnesota, 1975.
M.S. in Ch.E. University of Illinois, 1972.
Ch.E. Dipl. National Technical University, Athens, Greece, 1970.
Professor of Chemical Engineering, Lehigh University, and
Founding Director, Chemical Process Modeling and Control Research Center,
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,
Fellow, American Institute of Chemical Engineers, 1998.
Dreyfus Foundation Teacher-Scholar, 1979-1983.
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
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.