Advanced process control using DMCplus

Abstract

The purpose of advanced process control (APC) is to improve profitability by applying strategies which coordinate the regulatory control systems on the plant. APC benefits come from smoother operation of plants (reducing impacts of process disturbances) and providing consistent operation at optimal constraints. This has a clear economic impact on process operations and has motivated the successful growth of commercially available APC software and services. This paper gives two illustrations of the successful DMCplus approach to APC, using case studies of applications in the refining and chemicals industries. The case studies give a brief overview of the processes, describing process and optimisation strategies, the scope of the DMCplus controllers, how process non-linearities are accommodated and a discussion of the critical success factors in these projects. APC has been particularly successful and well accepted in the refining industry. Case study 1 discusses a typical refinery unit: the fluid catalytic cracking unit (FCCU). Case study 2 discusses an air separation unit (ASU) which is a much less well covered APC application. In discussing the applications, various features of DMCplus are introduced.