Multicriteria Optimization Under Uncertainty
Systematic methods and tools for managing the complexity
Process Synthesis & Design - II (T4-1b)
Keywords: multicriteria optimization, uncertainty, direct methanol fuel cell,
Design with partially unknown information remains an important problem in process systems engineering. While extensive surveys of the problem formulation and solution strategies are available, there is less discussion of different sources of unknown information and their impact on the design problem. In this presentation I will discuss the issue of parameteric uncertainty and two types of unknown information encountered for the design problem. We consider unknown input parameters in some domain for the process and we distinguish the following types of these parameters in the problem formulation:
• Uncertain parameters are never known exactly. Although expected values and confidence regions may be known for these parameters, the value of these parameters is not well known for the design problem. Examples of these include model parameters determined from experimental studies, as well as unmeasured and unobservable disturbances in the process.
• Variable parameters are not known at the design stage but can be determined accurately during the operation of the process. Examples of these include feed flow rates, process conditions and product demands. For these we can assume that control variables in the process can be adjusted to compensate for process variability.
Next we will consider the impact of uncertainty in multicriteria optimization (MCO). MCO is an important problem in many engineering disciplines. In process engineering, very often, process performance cannot be adequately captured using a single criterion. Therefore it has been necessary to consider several possibly conflicting performance criteria. For example optimizing process economics while minimizing environmental impact is a very desirable goal, but can only be partially achieved by trade-off. MCO determines the optimal trade-off in this case. Unfortunately MCO has largely been considered while ignoring uncertainty. This has motivated our development of methodologies to address MCO under uncertainty. In the presentation, case studies will include applications to the operation of a Direct Methanol Fuel Cell.
See the full pdf manuscript of the abstract.
Presented Tuesday 18, 15:00 to 15:20, in session Process Synthesis & Design - II (T4-1b).
