A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering.
Johannesburg, 2016 / Traditional work in batch processes has focused mainly on the optimisation of batch reactors
and the scheduling of batch processes. Recent development in the application of attainable region
(AR) theory has allowed for its entry into this landscape. As time is a crucial consideration
in the study of these systems, furthering the application of AR theory to batch reactors required
the incorporation of time into the ARs. This was previously done in terms of residence time
for continuous systems. With its use in batch systems this work sought to investigate how the
time component differs within ARs between batch and continuous systems. It demonstrated that
while residence time could be undergo linear mixing, the time in batch systems could not due
to its nature. Therefore the ARs generated in concentration-residence time and concentrationtime
space would differ slightly. A way to circumnavigate this was proposed in that the AR
be plotted in terms of concentration and residence time following which the continuous reactor
structure is obtained. From this the batch structure can be determined by substituting the equivalent
reactor types. Production rates were also introduced as a method of interpreting an AR
plotted in concentration-residence time space. By minimising the time taken to reach a particular
point in the AR, one may effectively increase the rate at which the desired product can be
produced. The developed concepts were applied to two example systems with the aim of obtaining
the batch reactor structure for the most productive point that satisfied a given objective.
Success was achieved for 2D single reaction system as well as a more complex 3D two biological
reaction system. The more complex system led to the development of non-conventional
attainable regions in terms of another process variable; in this case pH was used to demonstrate
the concept although other variables such as temperature and pressure may be used in a similar
fashion. Such plots may be used to further optimise the reaction system or identify a particular
region in which to operate. Further development of AR theory to batch reactors has indeed allowed
its use in conjunction with optimisation and scheduling of batch processes. Most notably,
scheduling may utilise the obtained batch structure as part of the process to be scheduled or use
the indicated reaction time. / MT2016
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/21161 |
| Date | January 2016 |
| Creators | Mc Kelvey, Ryan Adam |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (108 leaves), application/pdf, application/pdf |
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