Plant Design Report Series

Conceptual process design phase is of prime importance to the performance and the profitability of a new or retrofit process. It is also a highly complex task with a large number of process alternatives, a large variety of requirement specifications and large differences in temporal and spatial scales. Therefore, it is essential to continuously improve design methods. The research should not only be focused on modelling unit operations or processes but also to develop a framework to support design tasks during the lifecycle of the chemical process. Main target of this thesis is to study and present methods how to intensify the conceptual process design phase. The newly developed methods and tools are applied to process equipment selection and pre-design, separation process synthesis and process design support. First, the theory of case-based reasoning (CBR) was studied with focus in applicability in process engineering. CBR was utilised for general separation process synthesis. The main phases of general CBR-based separation process synthesis algorithm consist of selection of the methods of single separations, selection of separation sequences and selection of combined (hybrid) separations. Selection of single separation also includes selection of azeotropic separations. The applicability of CBR in separation process selection and design was studied by building few prototype CBR systems. The possibilities of CBR and object database techniques in chemical process engineering field have been illustrated by building applications for an inherently safer process design and for a heat exchanger selection. A web-service based approach in conceptual process design, parameterised constructors, which are able to construct process and initial data for control system configuration is also introduced in the thesis. The preliminary process design task can be first defined in a more general level and as the design process proceeds; more accurate models (e.g. PI and control system diagrams, simulation models) are composed and used.