Model-based integration of process design and control via process synthesis: Development of highly controllable and environmentally benign processes

Process integration techniques have been increasingly employed in the process and allied industries to reduce energy and material costs and, more recently, to minimize waste. Industrial practice has shown, however, that improper integration can cause various operational problems, and may make economic and environmental goals unachievable. Consequently, to ensure successful process integration, an integrated process must be structurally highly controllable. Naturally, the integration of process design and control is becoming one of the most promising, but most difficult area in the process systems engineering.; This dissertation is a fundamental study of the earliest integration of process design and control in the overall process engineering activities. The main focus is on the development of a novel and systematic model-based integration methodology for synthesizing cost-effective, highly structurally controllable, and environmentally benign process plants. The research interest is in the synthesis of complex network-structured processes where heavy interactions among units are the main obstacle to achieving economic and environmental goals. In this research, structural controllability will mainly address the ability of structural disturbance rejection, which ensures process operability and waste minimization capability. To achieve this target, various first principles-based, simplified system disturbance propagation (DP) models are developed to characterize DP through complex systems. By incorporating DP models, a comprehensive synthesis strategy is developed targeting cost-effective and maximum disturbance rejection. Process flow sheet is developed successfully by the integration procedure with little computational effort. The resultant processes are examined by the system model. The methodology features the earliest integration of process design and control, its generic nature, and the ability of incorporating fundamental and heuristic knowledge. With this methodology, major structural problems should be prevented during process synthesis. A highly controllable and environmentally benign process system should be identified in a systematic manner.; The significance of this research is demonstrated by solving practical industrial problems for maximized disturbance rejection, enhanced structural controllability, and minimized waste. The methodology should greatly advance current process integration techniques to achieve both economic and environmental goals in broad industrial applications.