| Traditionally, chemical process design is focused on the selection of technologies and optimization based on economic considerations. Increasingly, there is a need to broaden its scope by conducting environmentally conscious process design. To be successful, multiple objectives must be chosen to consider a variety of economic, environmental and safety attributes.; This dissertation reviews the current status in the field of environmentally conscious chemical process design and identifies several needs including a hierarchical design methodology, design tools, and design guidance or heuristics. Contributions in these three design aspects are presented. This dissertation describes the development of a hierarchical design procedure, from process creation to detailed design. It presents the implementation of an integrated assessment and design tool, "SCENE" (Simultaneous Comparison of Environmental and Non-Environmental Process Criteria). This tool contains several modules, including an economic assessment tool, an environmental assessment tool, a decision analysis tool and an optimization algorithm based on the Genetic Algorithm. Several case studies are analyzed following the hierarchical design procedure and using this design tool, including (1) selection of mass separation agent; (2) uncertainty analysis of toxicity assessment; (3) process optimization of VOC (Volatile Organic Chemical) recovery and recycling from a gaseous waste stream; and (4) comparisons of optimum designs of maleic anhydride production from benzene or n-butane feedstocks.; This dissertation provides design guidance for performing environmentally conscious chemical process design. These should help process design engineers to conduct environmental impact assessment, decision analysis and multi-objective global optimization of chemical processes. |
