Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2005 / Fennentation is the process that results in the fonnation ofalcohol or organic acids on
the basis of growth of bacteria, moulds or fungi on different nutritional media (Ahmed
et al., 1982). Fennentation process have three modes of operation i.e. batch, fed-batch
and continuous ones. The process that interests a lot of control engineers is the
fed-batch fennentation process (Johnson, 1989). The Fed-batch process for the
production ofyeast is considered in the study.
The fennentation is based on the Saccharomyces cerevisiae yeast. It grows in both
aerobic and anaerobic environmental conditions with maximum product in the aerobic
conditions, also at high concentration of glucose (Njodzi, 200I). Complexity of
fed-batch fennentation process, non-linearity, time varying characteristics, application
of conventional analogue controllers provides poor control due to problems in tuning
individual loops and the process characteristics. The problem for control of the
fed-batch process for the production of yeast is further complicated by the lack of
on-line sensors, lack ofadequate models as a result ofpoorly understood dynamics. The
lack of on-line sensors results in the impossibility oftuning the analogue controllers in
real time.
The process for propagation of yeast in aerobic conditions is considered in the
dissertation. The experiments are conducted at the University of Cape Town (DCT),
Department of Chemical Engineering with a bioreactor and bio-controller combined in
a Biostat ® C lab scale plant (H. Braun Biotech International, 1996).
The bio-controller has built in Pill controller loops for control variables, with the
ability to adjust the controller parameters i.e. P, D and I through the serial interface
(SeidIer, 1996).
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/1151 |
| Date | January 2005 |
| Creators | Chen, Haisong |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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