Plantwide Control of Chemical Processes

The issue of control structure selection, where the control system designer must make decisions as to what variables need to be controlled and the corresponding manipulated variables, is usually treated in a very perfunctory manner in courses on control theory. In practical chemical process operation, it is this choice of the control structure that turns out to be crucial towards effective disturbance rejection and maximizing process profitability. Given the large number of control degrees-of-freedom even for the simplest of chemical processes with material/energy recycle, how does one systematically design an effective plant-wide control system? This course addresses the same using an engineering common sense approach. Essential process control theory fundamentals are very briefly covered followed by control structure design for common unit operations such as reactors, distillation columns, heat exchangers and miscellaneous operations (furnaces, refrigeration systems etc). Issues in plantwide control such as proper inventory management and effect of material/energy recycle are then highlighted followed by comprehensive plant-wide control system design case-studies on example processes. Control structure design considerations for maximizing plant profitability are explicitly covered. (from nptel.ac.in)