CC-95-125 SELECTING THE PROPER LOCATION FOR ECONOMIC OPTIMIZATION: MULTIVARIABLE CONTROL OR RTO

Description:

Automation via process control has long been recognized as an effective manner for improving plant performance. More recently, optimization of plant operating conditions in response to short term disturbances has been acknowledged to provide the opportunity for higher profit while retaining consistently high product quality (e.g., Cutler and Perry, 1982). Modern advanced multivariable controllers can include a steady-state economic optimization as well as a minimization of deviation from set point during the transient response (e.g., Cutler and Ramaker, 1979; Yousfi and Toumier, 1991). Typically, a separate real-time operations optimization (RTO) involves more complex and less reliable computations than those needed in process control algorithms. Because of the reliability and relative simplicity of the multivariable controller technology, the preferred location for economic optimization would be the controller, provided it performed well.