Studies on the dynamics of equation-based chemical process flowsheeting systems

The mathematical modeling of the transient behavior of a complex chemical process naturally leads to the formulation of large sets of Differential and Algebraic equations (DAEs). The very flexible and effective equation-based (EB) approach in dynamic process flowsheeting calls for the simultaneous solution of the DAE set. However the numerical solution of DAEs is not trivial. The convergence properties of the numerical methods used for solving DAE systems depend upon a very important and peculiar property of a DAE, its index. Problems of index higher than two cannot be adequately handled by existing DAE codes and are practically unsolvable. It was shown that the index is affected by, among other factors, the choice of design variables and equations. Since these choices are often made rather arbitrarily, an important conclusion is that the index should be a criterion in making this choice. An algorithm was presented for selecting design equations and variables to ensure the formation of an index-one DAE. Furthermore alternative index-reducing formulations for incorporating design variables in the DAE model were shown to be possible.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Lefkopoulos, Alexandros

Contributors dc:contributor

• Stadtherr, Mark A.

• Applied Mechanics
• Engineering, Chemical

Statement dc:rights

• Copyright 1990 Lefkopoulos, Alexandros

Language dc:language

eng

Identifier

AAI9114311
(UMI)AAI9114311

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21290