AIChE Journal, Vol.64, No.7, 2379-2389, 2018
Stochastic back-off algorithm for simultaneous design, control, and scheduling of multiproduct systems under uncertainty
An algorithm that employs the back-off method to provide optimal solutions for integration of design, control, and scheduling for multiproduct systems is presented, featuring a flexibility and feasibility analysis. The algorithm employs Monte Carlo (MC) sampling to generate a large number of random realizations, and simulate the system to determine feasibility. Back-off terms are determined and incorporated into a new flexibility analysis to approximate the effect of stochastic uncertainty and disturbances. Through successive iterations, the algorithm converges, terminating on a solution that is robust to a specified level of process variability due to stochastic realizations in the disturbances and uncertain parameters. The proposed algorithm has been successfully applied to a multiproduct continuous stirred tank reactor for which optimal design, control, and scheduling decisions are identified, subject to stochastic uncertainty and disturbance. The present approach has been compared to a critical-set (multiscenario) method showing the benefits and limitations of both approaches. (c) 2018 American Institute of Chemical Engineers AIChE J, 64: 2379-2389, 2018