Dynamic matrix control of a specialty chemical plant with different plantwide control structures

Abstract

Model predictive control technology has been successfully applied within the industry for more than 20 years. Most of the applications appear in the refining and petrochemicals industry, with few in specialty chemical plant. In this paper DMC+ commercial multivariable control software is evaluated for a specialty chemical process using offline simulation. The relative benefit that can be obtained from DMC+ above and beyond advanced regulatory plantwide control is carefully studied. In this study, DMC+ is built as a supervisory controller on the decentralized SISO plantwide control structure. DMC+ uses the setpoints of PI controllers as the manipulated variables. In this paper, different plantwide control structures are used and the performance of DMC+ on top of all these different plantwide control structures are compared. It will be shown that a well designed regulatory plantwide control structure is necessary to stabilize and linearize the process around some operating point. Good plantwide control design will give a better performance for DMC+.