Combined Noncyclic Scheduling and Advanced Control for Continuous Chemical Processes

Keywords

scheduling, model predictive control, dynamic market, process disturbances, nonlinear

Abstract

A novel formulation for combined scheduling and control of multi-product, continuous chemical processes is introduced in which nonlinear model predictive control (NMPC) and noncyclic continuous-time scheduling are efficiently combined. A decomposition into nonlinear programming (NLP) dynamic optimization problems and mixed-integer linear programming (MILP) problems, without iterative alternation, allows for computationally light solution. An iterative method is introduced to determine the number of production slots for a noncyclic schedule during a prediction horizon. A filter method is introduced to reduce the number of MILP problems required. The formulation’s closed-loop performance with both process disturbances and updated market conditions is demonstrated through multiple scenarios on a benchmark continuously stirred tank reactor (CSTR) application with fluctuations in market demand and price for multiple products. Economic performance surpasses cyclic scheduling in all scenarios presented. Computational performance is sufficiently light to enable online operation in a dual-loop feedback structure.

Original Publication Citation

Petersen, D.; Beal, L.D.R.; Prestwich, D.; Warnick, S.; Hedengren, J.D. Combined Noncyclic Scheduling and Advanced Control for Continuous Chemical Processes. Processes 2017, 5, 83.

Document Type

Peer-Reviewed Article

Publication Date

2017-12-13

Permanent URL

http://hdl.lib.byu.edu/1877/4032

Publisher

MDPI

Language

English

College

Ira A. Fulton College of Engineering and Technology

Department

Chemical Engineering

University Standing at Time of Publication

Associate Professor

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