PLANTWIDE CONTROL DESIGN PROCEDURE

Plantwide control involves the systems and strategies required to cont rol an entire chemical plant consisting of many interconnected unit op erations. A general heuristic design procedure is presented that gener ates an effective plantwide control structure for an entire complex pr ocess flowsheet and not simply individual units. The nine steps of the proposed procedure center around the fundamental principles of plantw ide control: energy management; production rate; product quality; oper ational, environmental and safety constraints; liquid-level and gas-pr essure inventories; makeup of reactants; component balances; and econo mic or process optimization. Application of the procedure is illustrat ed with three industrial examples: the vinyl acetate monomer process, the Eastman plantwide-control process, and the HDA process.