Two basic approaches to reduce computational requirements for solving
distillation problems have been studied: simplifications of the model based on
physical approximations and order reduction techniques based on numerical
approximations.
Several problems have been studied using full and reduced-order
techniques along with the following distillation models: Constant Molar
Overflow, Constant Molar Holdup and Time-Dependent Molar Holdup.
Steady-state results show excellent agreement in the profiles obtained using
orthogonal collocation and demonstrate that with an order reduction of up to
54%, reduced-order models yield better results than physically simpler models.
Step responses demonstrate that with a reduction in computing time of the
order of 60% the method still provides better dynamic simulations than those
obtained using physical simplifications. Frequency response data obtained
from pulse tests has been used to verify that reduced-order solutions preserve
the dynamic characteristics of the original full-order system while physical
simplifications do not.
The orthogonal collocation technique is also applied to a coupled columns
scheme with good results. / Graduation date: 1992
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/36669 |
| Date | 12 December 1991 |
| Creators | Matandos, Marcio |
| Contributors | Levien, Keith L. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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