This thesis describes a process design procedure incorporating early consideration of extra design criteria. Traditionally cost is used as the main criterion to select a design alternative, but the design specification frequently has approximations and uncertainties associated with it. Further criteria for evaluating processes can be used to help the designer differentiate between alternatives. Synthesis is carried out on a cost basis selecting the <i>n </i>best processes based upon cost. The synthesis output is reassessed on the grounds of safety, environmental impact, flexibility etc. The methods are applicable to conceptual design and form the basis of further analysis. Where transparency and flexibility is required in the analysis, external packages are used. A post synthesis environment is described which stores the extra data required to perform the procedure and enables a collection of processes to be examined. Relationship assessments and value based assessments are applied to conflicting criteria so that a process ranking can be made. The procedure has been applied to two case studies in the manufacture of hydrogen cyanide and ethylene. The studies show how the method can be applied and demonstrates that the design selected upon a cost basis alone may not be the optimal design. The procedure demonstrates the requirement that the assessment package and synthesis package are linked to ensure consistency of the data set, and a record of all previous data sets are maintained. The cost of incorporating inherent features into a design can be evaluated and inferior designs can be removed from further consideration. By assessing the process alternatives early on in the design, development time can be reduced and the designers attention can focus upon the best process alternatives.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663818 |
| Date | January 2000 |
| Creators | Williams, Greville Wade |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14670 |
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